Merge branch 'master' into feature/themes

29 files changed, 7000 insertions, 5733 deletions

diff --git a/crates/ra_hir_ty/Cargo.toml b/crates/ra_hir_ty/Cargo.toml
index 429242870..60793db44 100644
--- a/crates/ra_hir_ty/Cargo.toml
+++ b/crates/ra_hir_ty/Cargo.toml
@@ -21,10 +21,9 @@ ra_prof = { path = "../ra_prof" }
 ra_syntax = { path = "../ra_syntax" }
 test_utils = { path = "../test_utils" }
 
-# https://github.com/rust-lang/chalk/pull/294
-chalk-solve =   { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
-chalk-rust-ir = { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
-chalk-ir =      { git = "https://github.com/jackh726/chalk.git", rev = "095cd38a4f16337913bba487f2055b9ca0179f30" }
+chalk-solve =   { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
+chalk-rust-ir = { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
+chalk-ir =      { git = "https://github.com/rust-lang/chalk.git", rev = "ff65b5ac9860f3c36bd892c865ab23d5ff0bbae5" }
 
 lalrpop-intern = "0.15.1"
 
diff --git a/crates/ra_hir_ty/src/autoderef.rs b/crates/ra_hir_ty/src/autoderef.rs
index 9d1d4e48c..f32d5786a 100644
--- a/crates/ra_hir_ty/src/autoderef.rs
+++ b/crates/ra_hir_ty/src/autoderef.rs
@@ -6,14 +6,14 @@
 use std::iter::successors;
 
 use hir_def::lang_item::LangItemTarget;
-use hir_expand::name;
+use hir_expand::name::name;
 use log::{info, warn};
 use ra_db::CrateId;
 
-use crate::db::HirDatabase;
-
-use super::{
+use crate::{
+    db::HirDatabase,
     traits::{InEnvironment, Solution},
+    utils::generics,
     Canonical, Substs, Ty, TypeWalk,
 };
 
@@ -48,14 +48,14 @@ fn deref_by_trait(
     krate: CrateId,
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
-    let deref_trait = match db.lang_item(krate.into(), "deref".into())? {
+    let deref_trait = match db.lang_item(krate, "deref".into())? {
         LangItemTarget::TraitId(it) => it,
         _ => return None,
     };
-    let target = db.trait_data(deref_trait).associated_type_by_name(&name::TARGET_TYPE)?;
+    let target = db.trait_data(deref_trait).associated_type_by_name(&name![Target])?;
 
-    let generic_params = db.generic_params(target.into());
-    if generic_params.count_params_including_parent() != 1 {
+    let generic_params = generics(db, target.into());
+    if generic_params.len() != 1 {
         // the Target type + Deref trait should only have one generic parameter,
         // namely Deref's Self type
         return None;
@@ -78,7 +78,7 @@ fn deref_by_trait(
 
     let canonical = super::Canonical { num_vars: 1 + ty.value.num_vars, value: in_env };
 
-    let solution = db.trait_solve(krate.into(), canonical)?;
+    let solution = db.trait_solve(krate, canonical)?;
 
     match &solution {
         Solution::Unique(vars) => {
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 9ce154593..d52f65b83 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -10,8 +10,8 @@ use ra_db::{salsa, CrateId};
 
 use crate::{
     method_resolution::CrateImplBlocks,
-    traits::{AssocTyValue, Impl},
-    CallableDef, FnSig, GenericPredicate, ImplTy, InferenceResult, Substs, Ty, TyDefId, TypeCtor,
+    traits::{chalk, AssocTyValue, Impl},
+    CallableDef, FnSig, GenericPredicate, InferenceResult, Substs, TraitRef, Ty, TyDefId, TypeCtor,
     ValueTyDefId,
 };
 
@@ -22,13 +22,18 @@ pub trait HirDatabase: DefDatabase {
     fn infer(&self, def: DefWithBodyId) -> Arc<InferenceResult>;
 
     #[salsa::invoke(crate::lower::ty_query)]
+    #[salsa::cycle(crate::lower::ty_recover)]
     fn ty(&self, def: TyDefId) -> Ty;
 
     #[salsa::invoke(crate::lower::value_ty_query)]
     fn value_ty(&self, def: ValueTyDefId) -> Ty;
 
-    #[salsa::invoke(crate::lower::impl_ty_query)]
-    fn impl_ty(&self, def: ImplId) -> ImplTy;
+    #[salsa::invoke(crate::lower::impl_self_ty_query)]
+    #[salsa::cycle(crate::lower::impl_self_ty_recover)]
+    fn impl_self_ty(&self, def: ImplId) -> Ty;
+
+    #[salsa::invoke(crate::lower::impl_trait_query)]
+    fn impl_trait(&self, def: ImplId) -> Option<TraitRef>;
 
     #[salsa::invoke(crate::lower::field_types_query)]
     fn field_types(&self, var: VariantId) -> Arc<ArenaMap<LocalStructFieldId, Ty>>;
@@ -37,6 +42,7 @@ pub trait HirDatabase: DefDatabase {
     fn callable_item_signature(&self, def: CallableDef) -> FnSig;
 
     #[salsa::invoke(crate::lower::generic_predicates_for_param_query)]
+    #[salsa::cycle(crate::lower::generic_predicates_for_param_recover)]
     fn generic_predicates_for_param(
         &self,
         def: GenericDefId,
@@ -71,39 +77,24 @@ pub trait HirDatabase: DefDatabase {
     #[salsa::interned]
     fn intern_assoc_ty_value(&self, assoc_ty_value: AssocTyValue) -> crate::traits::AssocTyValueId;
 
-    #[salsa::invoke(crate::traits::chalk::associated_ty_data_query)]
-    fn associated_ty_data(
-        &self,
-        id: chalk_ir::TypeId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::associated_ty_data_query)]
+    fn associated_ty_data(&self, id: chalk::AssocTypeId) -> Arc<chalk::AssociatedTyDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::trait_datum_query)]
-    fn trait_datum(
-        &self,
-        krate: CrateId,
-        trait_id: chalk_ir::TraitId,
-    ) -> Arc<chalk_rust_ir::TraitDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::trait_datum_query)]
+    fn trait_datum(&self, krate: CrateId, trait_id: chalk::TraitId) -> Arc<chalk::TraitDatum>;
 
-    #[salsa::invoke(crate::traits::chalk::struct_datum_query)]
-    fn struct_datum(
-        &self,
-        krate: CrateId,
-        struct_id: chalk_ir::StructId,
-    ) -> Arc<chalk_rust_ir::StructDatum<chalk_ir::family::ChalkIr>>;
+    #[salsa::invoke(chalk::struct_datum_query)]
+    fn struct_datum(&self, krate: CrateId, struct_id: chalk::StructId) -> Arc<chalk::StructDatum>;
 
     #[salsa::invoke(crate::traits::chalk::impl_datum_query)]
-    fn impl_datum(
-        &self,
-        krate: CrateId,
-        impl_id: chalk_ir::ImplId,
-    ) -> Arc<chalk_rust_ir::ImplDatum<chalk_ir::family::ChalkIr>>;
+    fn impl_datum(&self, krate: CrateId, impl_id: chalk::ImplId) -> Arc<chalk::ImplDatum>;
 
     #[salsa::invoke(crate::traits::chalk::associated_ty_value_query)]
     fn associated_ty_value(
         &self,
         krate: CrateId,
-        id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> Arc<chalk_rust_ir::AssociatedTyValue<chalk_ir::family::ChalkIr>>;
+        id: chalk::AssociatedTyValueId,
+    ) -> Arc<chalk::AssociatedTyValue>;
 
     #[salsa::invoke(crate::traits::trait_solve_query)]
     fn trait_solve(
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 4a13fac23..5054189cc 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -2,7 +2,7 @@
 
 use std::any::Any;
 
-use hir_expand::{db::AstDatabase, name::Name, HirFileId, Source};
+use hir_expand::{db::AstDatabase, name::Name, HirFileId, InFile};
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNodePtr};
 
 pub use hir_def::diagnostics::UnresolvedModule;
@@ -19,8 +19,8 @@ impl Diagnostic for NoSuchField {
         "no such field".to_string()
     }
 
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.field.into() }
     }
 
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
@@ -44,8 +44,8 @@ impl Diagnostic for MissingFields {
         }
         message
     }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.field_list.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.field_list.into() }
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
@@ -72,8 +72,8 @@ impl Diagnostic for MissingOkInTailExpr {
     fn message(&self) -> String {
         "wrap return expression in Ok".to_string()
     }
-    fn source(&self) -> Source<SyntaxNodePtr> {
-        Source { file_id: self.file, value: self.expr.into() }
+    fn source(&self) -> InFile<SyntaxNodePtr> {
+        InFile { file_id: self.file, value: self.expr.into() }
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
diff --git a/crates/ra_hir_ty/src/display.rs b/crates/ra_hir_ty/src/display.rs
index 9bb3ece6c..dcca1bace 100644
--- a/crates/ra_hir_ty/src/display.rs
+++ b/crates/ra_hir_ty/src/display.rs
@@ -10,6 +10,7 @@ pub struct HirFormatter<'a, 'b, DB> {
     buf: String,
     curr_size: usize,
     max_size: Option<usize>,
+    should_display_default_types: bool,
 }
 
 pub trait HirDisplay {
@@ -19,7 +20,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, None)
+        HirDisplayWrapper(db, self, None, true)
     }
 
     fn display_truncated<'a, DB>(
@@ -30,7 +31,7 @@ pub trait HirDisplay {
     where
         Self: Sized,
     {
-        HirDisplayWrapper(db, self, max_size)
+        HirDisplayWrapper(db, self, max_size, false)
     }
 }
 
@@ -72,9 +73,13 @@ where
             false
         }
     }
+
+    pub fn should_display_default_types(&self) -> bool {
+        self.should_display_default_types
+    }
 }
 
-pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>);
+pub struct HirDisplayWrapper<'a, DB, T>(&'a DB, &'a T, Option<usize>, bool);
 
 impl<'a, DB, T> fmt::Display for HirDisplayWrapper<'a, DB, T>
 where
@@ -88,6 +93,7 @@ where
             buf: String::with_capacity(20),
             curr_size: 0,
             max_size: self.2,
+            should_display_default_types: self.3,
         })
     }
 }
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index 5c65f9370..f752a9f09 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -3,7 +3,7 @@
 use std::sync::Arc;
 
 use hir_def::{
-    path::{known, Path},
+    path::{path, Path},
     resolver::HasResolver,
     AdtId, FunctionId,
 };
@@ -97,7 +97,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
         let (_, source_map) = db.body_with_source_map(self.func.into());
 
         if let Some(source_ptr) = source_map.expr_syntax(id) {
-            if let Some(expr) = source_ptr.value.a() {
+            if let Some(expr) = source_ptr.value.left() {
                 let root = source_ptr.file_syntax(db);
                 if let ast::Expr::RecordLit(record_lit) = expr.to_node(&root) {
                     if let Some(field_list) = record_lit.record_field_list() {
@@ -124,7 +124,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             None => return,
         };
 
-        let std_result_path = known::std_result_result();
+        let std_result_path = path![std::result::Result];
 
         let resolver = self.func.resolver(db);
         let std_result_enum = match resolver.resolve_known_enum(db, &std_result_path) {
@@ -142,7 +142,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             let (_, source_map) = db.body_with_source_map(self.func.into());
 
             if let Some(source_ptr) = source_map.expr_syntax(id) {
-                if let Some(expr) = source_ptr.value.a() {
+                if let Some(expr) = source_ptr.value.left() {
                     self.sink.push(MissingOkInTailExpr { file: source_ptr.file_id, expr });
                 }
             }
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index 1e9f4b208..e97b81473 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -18,19 +18,18 @@ use std::mem;
 use std::ops::Index;
 use std::sync::Arc;
 
-use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
 use rustc_hash::FxHashMap;
 
 use hir_def::{
     body::Body,
     data::{ConstData, FunctionData},
     expr::{BindingAnnotation, ExprId, PatId},
-    path::{known, Path},
+    path::{path, Path},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{Mutability, TypeRef},
     AdtId, AssocItemId, DefWithBodyId, FunctionId, StructFieldId, TypeAliasId, VariantId,
 };
-use hir_expand::{diagnostics::DiagnosticSink, name};
+use hir_expand::{diagnostics::DiagnosticSink, name::name};
 use ra_arena::map::ArenaMap;
 use ra_prof::profile;
 use test_utils::tested_by;
@@ -43,6 +42,8 @@ use super::{
 };
 use crate::{db::HirDatabase, infer::diagnostics::InferenceDiagnostic};
 
+pub(crate) use unify::unify;
+
 macro_rules! ty_app {
     ($ctor:pat, $param:pat) => {
         crate::Ty::Apply(crate::ApplicationTy { ctor: $ctor, parameters: $param })
@@ -191,11 +192,16 @@ struct InferenceContext<'a, D: HirDatabase> {
     owner: DefWithBodyId,
     body: Arc<Body>,
     resolver: Resolver,
-    var_unification_table: InPlaceUnificationTable<TypeVarId>,
+    table: unify::InferenceTable,
     trait_env: Arc<TraitEnvironment>,
     obligations: Vec<Obligation>,
     result: InferenceResult,
-    /// The return type of the function being inferred.
+    /// The return type of the function being inferred, or the closure if we're
+    /// currently within one.
+    ///
+    /// We might consider using a nested inference context for checking
+    /// closures, but currently this is the only field that will change there,
+    /// so it doesn't make sense.
     return_ty: Ty,
 
     /// Impls of `CoerceUnsized` used in coercion.
@@ -209,7 +215,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn new(db: &'a D, owner: DefWithBodyId, resolver: Resolver) -> Self {
         InferenceContext {
             result: InferenceResult::default(),
-            var_unification_table: InPlaceUnificationTable::new(),
+            table: unify::InferenceTable::new(),
             obligations: Vec::default(),
             return_ty: Ty::Unknown, // set in collect_fn_signature
             trait_env: TraitEnvironment::lower(db, &resolver),
@@ -224,13 +230,12 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn resolve_all(mut self) -> InferenceResult {
         // FIXME resolve obligations as well (use Guidance if necessary)
         let mut result = mem::replace(&mut self.result, InferenceResult::default());
-        let mut tv_stack = Vec::new();
         for ty in result.type_of_expr.values_mut() {
-            let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
+            let resolved = self.table.resolve_ty_completely(mem::replace(ty, Ty::Unknown));
             *ty = resolved;
         }
         for ty in result.type_of_pat.values_mut() {
-            let resolved = self.resolve_ty_completely(&mut tv_stack, mem::replace(ty, Ty::Unknown));
+            let resolved = self.table.resolve_ty_completely(mem::replace(ty, Ty::Unknown));
             *ty = resolved;
         }
         result
@@ -275,96 +280,38 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         self.normalize_associated_types_in(ty)
     }
 
-    fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
-        substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
-    }
-
-    fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
-        self.unify_inner(ty1, ty2, 0)
-    }
-
-    fn unify_inner(&mut self, ty1: &Ty, ty2: &Ty, depth: usize) -> bool {
-        if depth > 1000 {
-            // prevent stackoverflows
-            panic!("infinite recursion in unification");
-        }
-        if ty1 == ty2 {
-            return true;
-        }
-        // try to resolve type vars first
-        let ty1 = self.resolve_ty_shallow(ty1);
-        let ty2 = self.resolve_ty_shallow(ty2);
-        match (&*ty1, &*ty2) {
-            (Ty::Apply(a_ty1), Ty::Apply(a_ty2)) if a_ty1.ctor == a_ty2.ctor => {
-                self.unify_substs(&a_ty1.parameters, &a_ty2.parameters, depth + 1)
-            }
-            _ => self.unify_inner_trivial(&ty1, &ty2),
-        }
-    }
-
-    fn unify_inner_trivial(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
-        match (ty1, ty2) {
-            (Ty::Unknown, _) | (_, Ty::Unknown) => true,
-
-            (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
-            | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
-            | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
-            | (
-                Ty::Infer(InferTy::MaybeNeverTypeVar(tv1)),
-                Ty::Infer(InferTy::MaybeNeverTypeVar(tv2)),
-            ) => {
-                // both type vars are unknown since we tried to resolve them
-                self.var_unification_table.union(*tv1, *tv2);
-                true
-            }
-
-            // The order of MaybeNeverTypeVar matters here.
-            // Unifying MaybeNeverTypeVar and TypeVar will let the latter become MaybeNeverTypeVar.
-            // Unifying MaybeNeverTypeVar and other concrete type will let the former become it.
-            (Ty::Infer(InferTy::TypeVar(tv)), other)
-            | (other, Ty::Infer(InferTy::TypeVar(tv)))
-            | (Ty::Infer(InferTy::MaybeNeverTypeVar(tv)), other)
-            | (other, Ty::Infer(InferTy::MaybeNeverTypeVar(tv)))
-            | (Ty::Infer(InferTy::IntVar(tv)), other @ ty_app!(TypeCtor::Int(_)))
-            | (other @ ty_app!(TypeCtor::Int(_)), Ty::Infer(InferTy::IntVar(tv)))
-            | (Ty::Infer(InferTy::FloatVar(tv)), other @ ty_app!(TypeCtor::Float(_)))
-            | (other @ ty_app!(TypeCtor::Float(_)), Ty::Infer(InferTy::FloatVar(tv))) => {
-                // the type var is unknown since we tried to resolve it
-                self.var_unification_table.union_value(*tv, TypeVarValue::Known(other.clone()));
-                true
+    /// Replaces `impl Trait` in `ty` by type variables and obligations for
+    /// those variables. This is done for function arguments when calling a
+    /// function, and for return types when inside the function body, i.e. in
+    /// the cases where the `impl Trait` is 'transparent'. In other cases, `impl
+    /// Trait` is represented by `Ty::Opaque`.
+    fn insert_vars_for_impl_trait(&mut self, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Opaque(preds) => {
+                tested_by!(insert_vars_for_impl_trait);
+                let var = self.table.new_type_var();
+                let var_subst = Substs::builder(1).push(var.clone()).build();
+                self.obligations.extend(
+                    preds
+                        .iter()
+                        .map(|pred| pred.clone().subst_bound_vars(&var_subst))
+                        .filter_map(Obligation::from_predicate),
+                );
+                var
             }
-
-            _ => false,
-        }
-    }
-
-    fn new_type_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_integer_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_float_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
-    }
-
-    fn new_maybe_never_type_var(&mut self) -> Ty {
-        Ty::Infer(InferTy::MaybeNeverTypeVar(
-            self.var_unification_table.new_key(TypeVarValue::Unknown),
-        ))
+            _ => ty,
+        })
     }
 
     /// Replaces Ty::Unknown by a new type var, so we can maybe still infer it.
     fn insert_type_vars_shallow(&mut self, ty: Ty) -> Ty {
         match ty {
-            Ty::Unknown => self.new_type_var(),
+            Ty::Unknown => self.table.new_type_var(),
             Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(Uncertain::Unknown), .. }) => {
-                self.new_integer_var()
+                self.table.new_integer_var()
             }
             Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(Uncertain::Unknown), .. }) => {
-                self.new_float_var()
+                self.table.new_float_var()
             }
             _ => ty,
         }
@@ -402,64 +349,52 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         }
     }
 
+    fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        self.table.unify(ty1, ty2)
+    }
+
     /// Resolves the type as far as currently possible, replacing type variables
     /// by their known types. All types returned by the infer_* functions should
     /// be resolved as far as possible, i.e. contain no type variables with
     /// known type.
-    fn resolve_ty_as_possible(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+    fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
         self.resolve_obligations_as_possible();
 
-        ty.fold(&mut |ty| match ty {
-            Ty::Infer(tv) => {
-                let inner = tv.to_inner();
-                if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_as_possible);
-                    // recursive type
-                    return tv.fallback_value();
-                }
-                if let Some(known_ty) =
-                    self.var_unification_table.inlined_probe_value(inner).known()
-                {
-                    // known_ty may contain other variables that are known by now
-                    tv_stack.push(inner);
-                    let result = self.resolve_ty_as_possible(tv_stack, known_ty.clone());
-                    tv_stack.pop();
-                    result
-                } else {
-                    ty
-                }
-            }
-            _ => ty,
-        })
+        self.table.resolve_ty_as_possible(ty)
     }
 
-    /// If `ty` is a type variable with known type, returns that type;
-    /// otherwise, return ty.
     fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
-        let mut ty = Cow::Borrowed(ty);
-        // The type variable could resolve to a int/float variable. Hence try
-        // resolving up to three times; each type of variable shouldn't occur
-        // more than once
-        for i in 0..3 {
-            if i > 0 {
-                tested_by!(type_var_resolves_to_int_var);
-            }
-            match &*ty {
-                Ty::Infer(tv) => {
-                    let inner = tv.to_inner();
-                    match self.var_unification_table.inlined_probe_value(inner).known() {
-                        Some(known_ty) => {
-                            // The known_ty can't be a type var itself
-                            ty = Cow::Owned(known_ty.clone());
-                        }
-                        _ => return ty,
-                    }
-                }
-                _ => return ty,
+        self.table.resolve_ty_shallow(ty)
+    }
+
+    fn resolve_associated_type(&mut self, inner_ty: Ty, assoc_ty: Option<TypeAliasId>) -> Ty {
+        self.resolve_associated_type_with_params(inner_ty, assoc_ty, &[])
+    }
+
+    fn resolve_associated_type_with_params(
+        &mut self,
+        inner_ty: Ty,
+        assoc_ty: Option<TypeAliasId>,
+        params: &[Ty],
+    ) -> Ty {
+        match assoc_ty {
+            Some(res_assoc_ty) => {
+                let ty = self.table.new_type_var();
+                let builder = Substs::build_for_def(self.db, res_assoc_ty)
+                    .push(inner_ty)
+                    .fill(params.iter().cloned());
+                let projection = ProjectionPredicate {
+                    ty: ty.clone(),
+                    projection_ty: ProjectionTy {
+                        associated_ty: res_assoc_ty,
+                        parameters: builder.build(),
+                    },
+                };
+                self.obligations.push(Obligation::Projection(projection));
+                self.resolve_ty_as_possible(ty)
             }
+            None => Ty::Unknown,
         }
-        log::error!("Inference variable still not resolved: {:?}", ty);
-        ty
     }
 
     /// Recurses through the given type, normalizing associated types mentioned
@@ -469,7 +404,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// call). `make_ty` handles this already, but e.g. for field types we need
     /// to do it as well.
     fn normalize_associated_types_in(&mut self, ty: Ty) -> Ty {
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(ty);
         ty.fold(&mut |ty| match ty {
             Ty::Projection(proj_ty) => self.normalize_projection_ty(proj_ty),
             _ => ty,
@@ -477,40 +412,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     }
 
     fn normalize_projection_ty(&mut self, proj_ty: ProjectionTy) -> Ty {
-        let var = self.new_type_var();
+        let var = self.table.new_type_var();
         let predicate = ProjectionPredicate { projection_ty: proj_ty, ty: var.clone() };
         let obligation = Obligation::Projection(predicate);
         self.obligations.push(obligation);
         var
     }
 
-    /// Resolves the type completely; type variables without known type are
-    /// replaced by Ty::Unknown.
-    fn resolve_ty_completely(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
-        ty.fold(&mut |ty| match ty {
-            Ty::Infer(tv) => {
-                let inner = tv.to_inner();
-                if tv_stack.contains(&inner) {
-                    tested_by!(type_var_cycles_resolve_completely);
-                    // recursive type
-                    return tv.fallback_value();
-                }
-                if let Some(known_ty) =
-                    self.var_unification_table.inlined_probe_value(inner).known()
-                {
-                    // known_ty may contain other variables that are known by now
-                    tv_stack.push(inner);
-                    let result = self.resolve_ty_completely(tv_stack, known_ty.clone());
-                    tv_stack.pop();
-                    result
-                } else {
-                    tv.fallback_value()
-                }
-            }
-            _ => ty,
-        })
-    }
-
     fn resolve_variant(&mut self, path: Option<&Path>) -> (Ty, Option<VariantId>) {
         let path = match path {
             Some(path) => path,
@@ -519,7 +427,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let resolver = &self.resolver;
         // FIXME: this should resolve assoc items as well, see this example:
         // https://play.rust-lang.org/?gist=087992e9e22495446c01c0d4e2d69521
-        match resolver.resolve_path_in_type_ns_fully(self.db, &path) {
+        match resolver.resolve_path_in_type_ns_fully(self.db, path.mod_path()) {
             Some(TypeNs::AdtId(AdtId::StructId(strukt))) => {
                 let substs = Ty::substs_from_path(self.db, resolver, path, strukt.into());
                 let ty = self.db.ty(strukt.into());
@@ -547,93 +455,90 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
             self.infer_pat(*pat, &ty, BindingMode::default());
         }
-        self.return_ty = self.make_ty(&data.ret_type);
+        let return_ty = self.make_ty(&data.ret_type);
+        self.return_ty = self.insert_vars_for_impl_trait(return_ty);
     }
 
     fn infer_body(&mut self) {
-        self.infer_expr(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
+        self.infer_expr_coerce(self.body.body_expr, &Expectation::has_type(self.return_ty.clone()));
     }
 
     fn resolve_into_iter_item(&self) -> Option<TypeAliasId> {
-        let path = known::std_iter_into_iterator();
+        let path = path![std::iter::IntoIterator];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::ITEM_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Item])
     }
 
     fn resolve_ops_try_ok(&self) -> Option<TypeAliasId> {
-        let path = known::std_ops_try();
+        let path = path![std::ops::Try];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Ok])
+    }
+
+    fn resolve_ops_neg_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Neg];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
+    }
+
+    fn resolve_ops_not_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Not];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::OK_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 
     fn resolve_future_future_output(&self) -> Option<TypeAliasId> {
-        let path = known::std_future_future();
+        let path = path![std::future::Future];
         let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
-        self.db.trait_data(trait_).associated_type_by_name(&name::OUTPUT_TYPE)
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 
     fn resolve_boxed_box(&self) -> Option<AdtId> {
-        let path = known::std_boxed_box();
+        let path = path![std::boxed::Box];
         let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
         Some(struct_.into())
     }
-}
-
-/// The ID of a type variable.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
-pub struct TypeVarId(pub(super) u32);
-
-impl UnifyKey for TypeVarId {
-    type Value = TypeVarValue;
 
-    fn index(&self) -> u32 {
-        self.0
+    fn resolve_range_full(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeFull];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
 
-    fn from_index(i: u32) -> Self {
-        TypeVarId(i)
+    fn resolve_range(&self) -> Option<AdtId> {
+        let path = path![std::ops::Range];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
 
-    fn tag() -> &'static str {
-        "TypeVarId"
+    fn resolve_range_inclusive(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeInclusive];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
-}
-
-/// The value of a type variable: either we already know the type, or we don't
-/// know it yet.
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum TypeVarValue {
-    Known(Ty),
-    Unknown,
-}
 
-impl TypeVarValue {
-    fn known(&self) -> Option<&Ty> {
-        match self {
-            TypeVarValue::Known(ty) => Some(ty),
-            TypeVarValue::Unknown => None,
-        }
+    fn resolve_range_from(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeFrom];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
     }
-}
 
-impl UnifyValue for TypeVarValue {
-    type Error = NoError;
-
-    fn unify_values(value1: &Self, value2: &Self) -> Result<Self, NoError> {
-        match (value1, value2) {
-            // We should never equate two type variables, both of which have
-            // known types. Instead, we recursively equate those types.
-            (TypeVarValue::Known(t1), TypeVarValue::Known(t2)) => panic!(
-                "equating two type variables, both of which have known types: {:?} and {:?}",
-                t1, t2
-            ),
+    fn resolve_range_to(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeTo];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
+    }
 
-            // If one side is known, prefer that one.
-            (TypeVarValue::Known(..), TypeVarValue::Unknown) => Ok(value1.clone()),
-            (TypeVarValue::Unknown, TypeVarValue::Known(..)) => Ok(value2.clone()),
+    fn resolve_range_to_inclusive(&self) -> Option<AdtId> {
+        let path = path![std::ops::RangeToInclusive];
+        let struct_ = self.resolver.resolve_known_struct(self.db, &path)?;
+        Some(struct_.into())
+    }
 
-            (TypeVarValue::Unknown, TypeVarValue::Unknown) => Ok(TypeVarValue::Unknown),
-        }
+    fn resolve_ops_index_output(&self) -> Option<TypeAliasId> {
+        let path = path![std::ops::Index];
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name![Output])
     }
 }
 
@@ -643,14 +548,14 @@ impl UnifyValue for TypeVarValue {
 /// several integer types).
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub enum InferTy {
-    TypeVar(TypeVarId),
-    IntVar(TypeVarId),
-    FloatVar(TypeVarId),
-    MaybeNeverTypeVar(TypeVarId),
+    TypeVar(unify::TypeVarId),
+    IntVar(unify::TypeVarId),
+    FloatVar(unify::TypeVarId),
+    MaybeNeverTypeVar(unify::TypeVarId),
 }
 
 impl InferTy {
-    fn to_inner(self) -> TypeVarId {
+    fn to_inner(self) -> unify::TypeVarId {
         match self {
             InferTy::TypeVar(ty)
             | InferTy::IntVar(ty)
@@ -693,7 +598,7 @@ impl Expectation {
 }
 
 mod diagnostics {
-    use hir_def::{expr::ExprId, FunctionId, HasSource, Lookup};
+    use hir_def::{expr::ExprId, src::HasSource, FunctionId, Lookup};
     use hir_expand::diagnostics::DiagnosticSink;
 
     use crate::{db::HirDatabase, diagnostics::NoSuchField};
diff --git a/crates/ra_hir_ty/src/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 719a0f395..83c0c2c3f 100644
--- a/crates/ra_hir_ty/src/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -8,9 +8,9 @@ use hir_def::{lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutabilit
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
-use crate::{autoderef, db::HirDatabase, ImplTy, Substs, Ty, TypeCtor, TypeWalk};
+use crate::{autoderef, db::HirDatabase, Substs, Ty, TypeCtor, TypeWalk};
 
-use super::{InEnvironment, InferTy, InferenceContext, TypeVarValue};
+use super::{unify::TypeVarValue, InEnvironment, InferTy, InferenceContext};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// Unify two types, but may coerce the first one to the second one
@@ -54,10 +54,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         impls
             .iter()
             .filter_map(|&impl_id| {
-                let trait_ref = match db.impl_ty(impl_id) {
-                    ImplTy::TraitRef(it) => it,
-                    ImplTy::Inherent(_) => return None,
-                };
+                let trait_ref = db.impl_trait(impl_id)?;
 
                 // `CoerseUnsized` has one generic parameter for the target type.
                 let cur_from_ty = trait_ref.substs.0.get(0)?;
@@ -88,8 +85,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         match (&from_ty, to_ty) {
             // Never type will make type variable to fallback to Never Type instead of Unknown.
             (ty_app!(TypeCtor::Never), Ty::Infer(InferTy::TypeVar(tv))) => {
-                let var = self.new_maybe_never_type_var();
-                self.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
+                let var = self.table.new_maybe_never_type_var();
+                self.table.var_unification_table.union_value(*tv, TypeVarValue::Known(var));
                 return true;
             }
             (ty_app!(TypeCtor::Never), _) => return true,
@@ -97,7 +94,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             // Trivial cases, this should go after `never` check to
             // avoid infer result type to be never
             _ => {
-                if self.unify_inner_trivial(&from_ty, &to_ty) {
+                if self.table.unify_inner_trivial(&from_ty, &to_ty) {
                     return true;
                 }
             }
@@ -137,6 +134,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
             }
 
+            (ty_app!(TypeCtor::Closure { .. }, params), ty_app!(TypeCtor::FnPtr { .. })) => {
+                from_ty = params[0].clone();
+            }
+
             _ => {}
         }
 
@@ -333,9 +334,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // Stop when constructor matches.
                 (ty_app!(from_ctor, st1), ty_app!(to_ctor, st2)) if from_ctor == to_ctor => {
                     // It will not recurse to `coerce`.
-                    return self.unify_substs(st1, st2, 0);
+                    return self.table.unify_substs(st1, st2, 0);
+                }
+                _ => {
+                    if self.table.unify_inner_trivial(&derefed_ty, &to_ty) {
+                        return true;
+                    }
                 }
-                _ => {}
             }
         }
 
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 2f9ca4bbb..3af05394c 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -6,17 +6,21 @@ use std::sync::Arc;
 use hir_def::{
     builtin_type::Signedness,
     expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp},
-    generics::GenericParams,
     path::{GenericArg, GenericArgs},
     resolver::resolver_for_expr,
-    AdtId, ContainerId, Lookup, StructFieldId,
+    AdtId, AssocContainerId, Lookup, StructFieldId,
 };
-use hir_expand::name::{self, Name};
+use hir_expand::name::{name, Name};
+use ra_syntax::ast::RangeOp;
 
 use crate::{
-    autoderef, db::HirDatabase, method_resolution, op, traits::InEnvironment, utils::variant_data,
-    CallableDef, InferTy, IntTy, Mutability, Obligation, ProjectionPredicate, ProjectionTy, Substs,
-    TraitRef, Ty, TypeCtor, TypeWalk, Uncertain,
+    autoderef,
+    db::HirDatabase,
+    method_resolution, op,
+    traits::InEnvironment,
+    utils::{generics, variant_data, Generics},
+    ApplicationTy, CallableDef, InferTy, IntTy, Mutability, Obligation, Substs, TraitRef, Ty,
+    TypeCtor, TypeWalk, Uncertain,
 };
 
 use super::{BindingMode, Expectation, InferenceContext, InferenceDiagnostic, TypeMismatch};
@@ -31,13 +35,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
             );
         }
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(ty);
         ty
     }
 
     /// Infer type of expression with possibly implicit coerce to the expected type.
     /// Return the type after possible coercion.
-    fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
+    pub(super) fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty {
         let ty = self.infer_expr_inner(expr, &expected);
         let ty = if !self.coerce(&ty, &expected.ty) {
             self.result
@@ -52,7 +56,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             expected.ty.clone()
         };
 
-        self.resolve_ty_as_possible(&mut vec![], ty)
+        self.resolve_ty_as_possible(ty)
     }
 
     fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
@@ -91,27 +95,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::For { iterable, body, pat } => {
                 let iterable_ty = self.infer_expr(*iterable, &Expectation::none());
 
-                let pat_ty = match self.resolve_into_iter_item() {
-                    Some(into_iter_item_alias) => {
-                        let pat_ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: pat_ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: into_iter_item_alias,
-                                parameters: Substs::single(iterable_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], pat_ty)
-                    }
-                    None => Ty::Unknown,
-                };
+                let pat_ty =
+                    self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item());
 
                 self.infer_pat(*pat, &pat_ty, BindingMode::default());
                 self.infer_expr(*body, &Expectation::has_type(Ty::unit()));
                 Ty::unit()
             }
-            Expr::Lambda { body, args, arg_types } => {
+            Expr::Lambda { body, args, ret_type, arg_types } => {
                 assert_eq!(args.len(), arg_types.len());
 
                 let mut sig_tys = Vec::new();
@@ -127,7 +118,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
 
                 // add return type
-                let ret_ty = self.new_type_var();
+                let ret_ty = match ret_type {
+                    Some(type_ref) => self.make_ty(type_ref),
+                    None => self.table.new_type_var(),
+                };
                 sig_tys.push(ret_ty.clone());
                 let sig_ty = Ty::apply(
                     TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1 },
@@ -143,7 +137,12 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // infer the body.
                 self.coerce(&closure_ty, &expected.ty);
 
-                self.infer_expr(*body, &Expectation::has_type(ret_ty));
+                let prev_ret_ty = std::mem::replace(&mut self.return_ty, ret_ty.clone());
+
+                self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty));
+
+                self.return_ty = prev_ret_ty;
+
                 closure_ty
             }
             Expr::Call { callee, args } => {
@@ -166,7 +165,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Expr::Match { expr, arms } => {
                 let input_ty = self.infer_expr(*expr, &Expectation::none());
 
-                let mut result_ty = self.new_maybe_never_type_var();
+                let mut result_ty = self.table.new_maybe_never_type_var();
 
                 for arm in arms {
                     for &pat in &arm.pats {
@@ -200,7 +199,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
             Expr::Return { expr } => {
                 if let Some(expr) = expr {
-                    self.infer_expr(*expr, &Expectation::has_type(self.return_ty.clone()));
+                    self.infer_expr_coerce(*expr, &Expectation::has_type(self.return_ty.clone()));
+                } else {
+                    let unit = Ty::unit();
+                    self.coerce(&unit, &self.return_ty.clone());
                 }
                 Ty::simple(TypeCtor::Never)
             }
@@ -244,7 +246,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 ty
             }
             Expr::Field { expr, name } => {
-                let receiver_ty = self.infer_expr(*expr, &Expectation::none());
+                let receiver_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 let canonicalized = self.canonicalizer().canonicalize_ty(receiver_ty);
                 let ty = autoderef::autoderef(
                     self.db,
@@ -279,45 +281,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 self.normalize_associated_types_in(ty)
             }
             Expr::Await { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                let ty = match self.resolve_future_future_output() {
-                    Some(future_future_output_alias) => {
-                        let ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: future_future_output_alias,
-                                parameters: Substs::single(inner_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], ty)
-                    }
-                    None => Ty::Unknown,
-                };
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
+                let ty =
+                    self.resolve_associated_type(inner_ty, self.resolve_future_future_output());
                 ty
             }
             Expr::Try { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
-                let ty = match self.resolve_ops_try_ok() {
-                    Some(ops_try_ok_alias) => {
-                        let ty = self.new_type_var();
-                        let projection = ProjectionPredicate {
-                            ty: ty.clone(),
-                            projection_ty: ProjectionTy {
-                                associated_ty: ops_try_ok_alias,
-                                parameters: Substs::single(inner_ty),
-                            },
-                        };
-                        self.obligations.push(Obligation::Projection(projection));
-                        self.resolve_ty_as_possible(&mut vec![], ty)
-                    }
-                    None => Ty::Unknown,
-                };
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
+                let ty = self.resolve_associated_type(inner_ty, self.resolve_ops_try_ok());
                 ty
             }
             Expr::Cast { expr, type_ref } => {
-                let _inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let _inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 let cast_ty = self.make_ty(type_ref);
                 // FIXME check the cast...
                 cast_ty
@@ -333,12 +308,11 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     } else {
                         Expectation::none()
                     };
-                // FIXME reference coercions etc.
-                let inner_ty = self.infer_expr(*expr, &expectation);
+                let inner_ty = self.infer_expr_inner(*expr, &expectation);
                 Ty::apply_one(TypeCtor::Ref(*mutability), inner_ty)
             }
             Expr::Box { expr } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 if let Some(box_) = self.resolve_boxed_box() {
                     Ty::apply_one(TypeCtor::Adt(box_), inner_ty)
                 } else {
@@ -346,7 +320,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
             }
             Expr::UnaryOp { expr, op } => {
-                let inner_ty = self.infer_expr(*expr, &Expectation::none());
+                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 match op {
                     UnaryOp::Deref => match self.resolver.krate() {
                         Some(krate) => {
@@ -369,31 +343,36 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     },
                     UnaryOp::Neg => {
                         match &inner_ty {
-                            Ty::Apply(a_ty) => match a_ty.ctor {
-                                TypeCtor::Int(Uncertain::Unknown)
-                                | TypeCtor::Int(Uncertain::Known(IntTy {
-                                    signedness: Signedness::Signed,
-                                    ..
-                                }))
-                                | TypeCtor::Float(..) => inner_ty,
-                                _ => Ty::Unknown,
-                            },
-                            Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => {
-                                inner_ty
-                            }
-                            // FIXME: resolve ops::Neg trait
-                            _ => Ty::Unknown,
+                            // Fast path for builtins
+                            Ty::Apply(ApplicationTy {
+                                ctor:
+                                    TypeCtor::Int(Uncertain::Known(IntTy {
+                                        signedness: Signedness::Signed,
+                                        ..
+                                    })),
+                                ..
+                            })
+                            | Ty::Apply(ApplicationTy {
+                                ctor: TypeCtor::Int(Uncertain::Unknown),
+                                ..
+                            })
+                            | Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(_), .. })
+                            | Ty::Infer(InferTy::IntVar(..))
+                            | Ty::Infer(InferTy::FloatVar(..)) => inner_ty,
+                            // Otherwise we resolve via the std::ops::Neg trait
+                            _ => self
+                                .resolve_associated_type(inner_ty, self.resolve_ops_neg_output()),
                         }
                     }
                     UnaryOp::Not => {
                         match &inner_ty {
-                            Ty::Apply(a_ty) => match a_ty.ctor {
-                                TypeCtor::Bool | TypeCtor::Int(_) => inner_ty,
-                                _ => Ty::Unknown,
-                            },
-                            Ty::Infer(InferTy::IntVar(..)) => inner_ty,
-                            // FIXME: resolve ops::Not trait for inner_ty
-                            _ => Ty::Unknown,
+                            // Fast path for builtins
+                            Ty::Apply(ApplicationTy { ctor: TypeCtor::Bool, .. })
+                            | Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(_), .. })
+                            | Ty::Infer(InferTy::IntVar(..)) => inner_ty,
+                            // Otherwise we resolve via the std::ops::Not trait
+                            _ => self
+                                .resolve_associated_type(inner_ty, self.resolve_ops_not_output()),
                         }
                     }
                 }
@@ -415,21 +394,63 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
                 _ => Ty::Unknown,
             },
+            Expr::Range { lhs, rhs, range_type } => {
+                let lhs_ty = lhs.map(|e| self.infer_expr_inner(e, &Expectation::none()));
+                let rhs_expect = lhs_ty
+                    .as_ref()
+                    .map_or_else(Expectation::none, |ty| Expectation::has_type(ty.clone()));
+                let rhs_ty = rhs.map(|e| self.infer_expr(e, &rhs_expect));
+                match (range_type, lhs_ty, rhs_ty) {
+                    (RangeOp::Exclusive, None, None) => match self.resolve_range_full() {
+                        Some(adt) => Ty::simple(TypeCtor::Adt(adt)),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Exclusive, None, Some(ty)) => match self.resolve_range_to() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, None, Some(ty)) => {
+                        match self.resolve_range_to_inclusive() {
+                            Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                            None => Ty::Unknown,
+                        }
+                    }
+                    (RangeOp::Exclusive, Some(_), Some(ty)) => match self.resolve_range() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, Some(_), Some(ty)) => {
+                        match self.resolve_range_inclusive() {
+                            Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                            None => Ty::Unknown,
+                        }
+                    }
+                    (RangeOp::Exclusive, Some(ty), None) => match self.resolve_range_from() {
+                        Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty),
+                        None => Ty::Unknown,
+                    },
+                    (RangeOp::Inclusive, _, None) => Ty::Unknown,
+                }
+            }
             Expr::Index { base, index } => {
-                let _base_ty = self.infer_expr(*base, &Expectation::none());
-                let _index_ty = self.infer_expr(*index, &Expectation::none());
-                // FIXME: use `std::ops::Index::Output` to figure out the real return type
-                Ty::Unknown
+                let base_ty = self.infer_expr_inner(*base, &Expectation::none());
+                let index_ty = self.infer_expr(*index, &Expectation::none());
+
+                self.resolve_associated_type_with_params(
+                    base_ty,
+                    self.resolve_ops_index_output(),
+                    &[index_ty],
+                )
             }
             Expr::Tuple { exprs } => {
                 let mut tys = match &expected.ty {
                     ty_app!(TypeCtor::Tuple { .. }, st) => st
                         .iter()
                         .cloned()
-                        .chain(repeat_with(|| self.new_type_var()))
+                        .chain(repeat_with(|| self.table.new_type_var()))
                         .take(exprs.len())
                         .collect::<Vec<_>>(),
-                    _ => (0..exprs.len()).map(|_| self.new_type_var()).collect(),
+                    _ => (0..exprs.len()).map(|_| self.table.new_type_var()).collect(),
                 };
 
                 for (expr, ty) in exprs.iter().zip(tys.iter_mut()) {
@@ -443,7 +464,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => {
                         st.as_single().clone()
                     }
-                    _ => self.new_type_var(),
+                    _ => self.table.new_type_var(),
                 };
 
                 match array {
@@ -485,7 +506,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         };
         // use a new type variable if we got Ty::Unknown here
         let ty = self.insert_type_vars_shallow(ty);
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(ty);
         self.write_expr_ty(tgt_expr, ty.clone());
         ty
     }
@@ -514,7 +535,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         }
                     }
 
-                    let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+                    let ty = self.resolve_ty_as_possible(ty);
                     self.infer_pat(*pat, &ty, BindingMode::default());
                 }
                 Statement::Expr(expr) => {
@@ -558,7 +579,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             Some((ty, func)) => {
                 let ty = canonicalized_receiver.decanonicalize_ty(ty);
                 self.write_method_resolution(tgt_expr, func);
-                (ty, self.db.value_ty(func.into()), Some(self.db.generic_params(func.into())))
+                (ty, self.db.value_ty(func.into()), Some(generics(self.db, func.into())))
             }
             None => (receiver_ty, Ty::Unknown, None),
         };
@@ -607,6 +628,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     continue;
                 }
 
+                let param_ty = self.insert_vars_for_impl_trait(param_ty);
                 let param_ty = self.normalize_associated_types_in(param_ty);
                 self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone()));
             }
@@ -615,17 +637,17 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
     fn substs_for_method_call(
         &mut self,
-        def_generics: Option<Arc<GenericParams>>,
+        def_generics: Option<Generics>,
         generic_args: Option<&GenericArgs>,
         receiver_ty: &Ty,
     ) -> Substs {
-        let (parent_param_count, param_count) =
-            def_generics.as_ref().map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
-        let mut substs = Vec::with_capacity(parent_param_count + param_count);
+        let (total_len, _parent_len, child_len) =
+            def_generics.as_ref().map_or((0, 0, 0), |g| g.len_split());
+        let mut substs = Vec::with_capacity(total_len);
         // Parent arguments are unknown, except for the receiver type
-        if let Some(parent_generics) = def_generics.and_then(|p| p.parent_params.clone()) {
-            for param in &parent_generics.params {
-                if param.name == name::SELF_TYPE {
+        if let Some(parent_generics) = def_generics.as_ref().map(|p| p.iter_parent()) {
+            for (_id, param) in parent_generics {
+                if param.name == name![Self] {
                     substs.push(receiver_ty.clone());
                 } else {
                     substs.push(Ty::Unknown);
@@ -635,7 +657,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         // handle provided type arguments
         if let Some(generic_args) = generic_args {
             // if args are provided, it should be all of them, but we can't rely on that
-            for arg in generic_args.args.iter().take(param_count) {
+            for arg in generic_args.args.iter().take(child_len) {
                 match arg {
                     GenericArg::Type(type_ref) => {
                         let ty = self.make_ty(type_ref);
@@ -645,10 +667,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
         };
         let supplied_params = substs.len();
-        for _ in supplied_params..parent_param_count + param_count {
+        for _ in supplied_params..total_len {
             substs.push(Ty::Unknown);
         }
-        assert_eq!(substs.len(), parent_param_count + param_count);
+        assert_eq!(substs.len(), total_len);
         Substs(substs.into())
     }
 
@@ -665,13 +687,10 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // add obligation for trait implementation, if this is a trait method
                 match def {
                     CallableDef::FunctionId(f) => {
-                        if let ContainerId::TraitId(trait_) = f.lookup(self.db).container {
+                        if let AssocContainerId::TraitId(trait_) = f.lookup(self.db).container {
                             // construct a TraitDef
-                            let substs = a_ty.parameters.prefix(
-                                self.db
-                                    .generic_params(trait_.into())
-                                    .count_params_including_parent(),
-                            );
+                            let substs =
+                                a_ty.parameters.prefix(generics(self.db, trait_.into()).len());
                             self.obligations.push(Obligation::Trait(TraitRef {
                                 trait_: trait_.into(),
                                 substs,
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 1ebb36239..a14662884 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -170,7 +170,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     }
                     BindingMode::Move => inner_ty.clone(),
                 };
-                let bound_ty = self.resolve_ty_as_possible(&mut vec![], bound_ty);
+                let bound_ty = self.resolve_ty_as_possible(bound_ty);
                 self.write_pat_ty(pat, bound_ty);
                 return inner_ty;
             }
@@ -179,7 +179,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         // use a new type variable if we got Ty::Unknown here
         let ty = self.insert_type_vars_shallow(ty);
         self.unify(&ty, expected);
-        let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+        let ty = self.resolve_ty_as_possible(ty);
         self.write_pat_ty(pat, ty.clone());
         ty
     }
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 14be66836..ffd358367 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -1,9 +1,11 @@
 //! Path expression resolution.
 
+use std::iter;
+
 use hir_def::{
-    path::{Path, PathKind, PathSegment},
+    path::{Path, PathSegment},
     resolver::{ResolveValueResult, Resolver, TypeNs, ValueNs},
-    AssocItemId, ContainerId, Lookup,
+    AssocContainerId, AssocItemId, Lookup,
 };
 use hir_expand::name::Name;
 
@@ -30,21 +32,21 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         path: &Path,
         id: ExprOrPatId,
     ) -> Option<Ty> {
-        let (value, self_subst) = if let PathKind::Type(type_ref) = &path.kind {
-            if path.segments.is_empty() {
+        let (value, self_subst) = if let Some(type_ref) = path.type_anchor() {
+            if path.segments().is_empty() {
                 // This can't actually happen syntax-wise
                 return None;
             }
             let ty = self.make_ty(type_ref);
-            let remaining_segments_for_ty = &path.segments[..path.segments.len() - 1];
+            let remaining_segments_for_ty = path.segments().take(path.segments().len() - 1);
             let ty = Ty::from_type_relative_path(self.db, resolver, ty, remaining_segments_for_ty);
             self.resolve_ty_assoc_item(
                 ty,
-                &path.segments.last().expect("path had at least one segment").name,
+                &path.segments().last().expect("path had at least one segment").name,
                 id,
             )?
         } else {
-            let value_or_partial = resolver.resolve_path_in_value_ns(self.db, &path)?;
+            let value_or_partial = resolver.resolve_path_in_value_ns(self.db, path.mod_path())?;
 
             match value_or_partial {
                 ResolveValueResult::ValueNs(it) => (it, None),
@@ -57,7 +59,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let typable: ValueTyDefId = match value {
             ValueNs::LocalBinding(pat) => {
                 let ty = self.result.type_of_pat.get(pat)?.clone();
-                let ty = self.resolve_ty_as_possible(&mut vec![], ty);
+                let ty = self.resolve_ty_as_possible(ty);
                 return Some(ty);
             }
             ValueNs::FunctionId(it) => it.into(),
@@ -83,13 +85,13 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         remaining_index: usize,
         id: ExprOrPatId,
     ) -> Option<(ValueNs, Option<Substs>)> {
-        assert!(remaining_index < path.segments.len());
+        assert!(remaining_index < path.segments().len());
         // there may be more intermediate segments between the resolved one and
         // the end. Only the last segment needs to be resolved to a value; from
         // the segments before that, we need to get either a type or a trait ref.
 
-        let resolved_segment = &path.segments[remaining_index - 1];
-        let remaining_segments = &path.segments[remaining_index..];
+        let resolved_segment = path.segments().get(remaining_index - 1).unwrap();
+        let remaining_segments = path.segments().skip(remaining_index);
         let is_before_last = remaining_segments.len() == 1;
 
         match (def, is_before_last) {
@@ -110,7 +112,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 // trait but it's not the last segment, so the next segment
                 // should resolve to an associated type of that trait (e.g. `<T
                 // as Iterator>::Item::default`)
-                let remaining_segments_for_ty = &remaining_segments[..remaining_segments.len() - 1];
+                let remaining_segments_for_ty =
+                    remaining_segments.take(remaining_segments.len() - 1);
                 let ty = Ty::from_partly_resolved_hir_path(
                     self.db,
                     &self.resolver,
@@ -136,7 +139,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     fn resolve_trait_assoc_item(
         &mut self,
         trait_ref: TraitRef,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         id: ExprOrPatId,
     ) -> Option<(ValueNs, Option<Substs>)> {
         let trait_ = trait_ref.trait_;
@@ -148,7 +151,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             .map(|(_name, id)| (*id).into())
             .find_map(|item| match item {
                 AssocItemId::FunctionId(func) => {
-                    if segment.name == self.db.function_data(func).name {
+                    if segment.name == &self.db.function_data(func).name {
                         Some(AssocItemId::FunctionId(func))
                     } else {
                         None
@@ -156,7 +159,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 }
 
                 AssocItemId::ConstId(konst) => {
-                    if self.db.const_data(konst).name.as_ref().map_or(false, |n| n == &segment.name)
+                    if self.db.const_data(konst).name.as_ref().map_or(false, |n| n == segment.name)
                     {
                         Some(AssocItemId::ConstId(konst))
                     } else {
@@ -206,12 +209,23 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                     AssocItemId::TypeAliasId(_) => unreachable!(),
                 };
                 let substs = match container {
-                    ContainerId::ImplId(_) => self.find_self_types(&def, ty.clone()),
-                    ContainerId::TraitId(trait_) => {
+                    AssocContainerId::ImplId(impl_id) => {
+                        let impl_substs = Substs::build_for_def(self.db, impl_id)
+                            .fill(iter::repeat_with(|| self.table.new_type_var()))
+                            .build();
+                        let impl_self_ty = self.db.impl_self_ty(impl_id).subst(&impl_substs);
+                        let substs = Substs::build_for_def(self.db, item)
+                            .use_parent_substs(&impl_substs)
+                            .fill_with_params()
+                            .build();
+                        self.unify(&impl_self_ty, &ty);
+                        Some(substs)
+                    }
+                    AssocContainerId::TraitId(trait_) => {
                         // we're picking this method
                         let trait_substs = Substs::build_for_def(self.db, trait_)
                             .push(ty.clone())
-                            .fill(std::iter::repeat_with(|| self.new_type_var()))
+                            .fill(std::iter::repeat_with(|| self.table.new_type_var()))
                             .build();
                         let substs = Substs::build_for_def(self.db, item)
                             .use_parent_substs(&trait_substs)
@@ -223,7 +237,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                         }));
                         Some(substs)
                     }
-                    ContainerId::ModuleId(_) => None,
+                    AssocContainerId::ContainerId(_) => None,
                 };
 
                 self.write_assoc_resolution(id, item.into());
@@ -231,38 +245,4 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             },
         )
     }
-
-    fn find_self_types(&self, def: &ValueNs, actual_def_ty: Ty) -> Option<Substs> {
-        if let ValueNs::FunctionId(func) = *def {
-            // We only do the infer if parent has generic params
-            let gen = self.db.generic_params(func.into());
-            if gen.count_parent_params() == 0 {
-                return None;
-            }
-
-            let impl_id = match func.lookup(self.db).container {
-                ContainerId::ImplId(it) => it,
-                _ => return None,
-            };
-            let self_ty = self.db.impl_ty(impl_id).self_type().clone();
-            let self_ty_substs = self_ty.substs()?;
-            let actual_substs = actual_def_ty.substs()?;
-
-            let mut new_substs = vec![Ty::Unknown; gen.count_parent_params()];
-
-            // The following code *link up* the function actual parma type
-            // and impl_block type param index
-            self_ty_substs.iter().zip(actual_substs.iter()).for_each(|(param, pty)| {
-                if let Ty::Param { idx, .. } = param {
-                    if let Some(s) = new_substs.get_mut(*idx as usize) {
-                        *s = pty.clone();
-                    }
-                }
-            });
-
-            Some(Substs(new_substs.into()))
-        } else {
-            None
-        }
-    }
 }
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index f3a875678..fe05642ae 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -1,9 +1,15 @@
 //! Unification and canonicalization logic.
 
+use std::borrow::Cow;
+
+use ena::unify::{InPlaceUnificationTable, NoError, UnifyKey, UnifyValue};
+
+use test_utils::tested_by;
+
 use super::{InferenceContext, Obligation};
 use crate::{
     db::HirDatabase, utils::make_mut_slice, Canonical, InEnvironment, InferTy, ProjectionPredicate,
-    ProjectionTy, Substs, TraitRef, Ty, TypeWalk,
+    ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
@@ -24,7 +30,7 @@ where
     /// A stack of type variables that is used to detect recursive types (which
     /// are an error, but we need to protect against them to avoid stack
     /// overflows).
-    var_stack: Vec<super::TypeVarId>,
+    var_stack: Vec<TypeVarId>,
 }
 
 pub(super) struct Canonicalized<T> {
@@ -53,14 +59,14 @@ where
                     return tv.fallback_value();
                 }
                 if let Some(known_ty) =
-                    self.ctx.var_unification_table.inlined_probe_value(inner).known()
+                    self.ctx.table.var_unification_table.inlined_probe_value(inner).known()
                 {
                     self.var_stack.push(inner);
                     let result = self.do_canonicalize_ty(known_ty.clone());
                     self.var_stack.pop();
                     result
                 } else {
-                    let root = self.ctx.var_unification_table.find(inner);
+                    let root = self.ctx.table.var_unification_table.find(inner);
                     let free_var = match tv {
                         InferTy::TypeVar(_) => InferTy::TypeVar(root),
                         InferTy::IntVar(_) => InferTy::IntVar(root),
@@ -153,10 +159,268 @@ impl<T> Canonicalized<T> {
         solution: Canonical<Vec<Ty>>,
     ) {
         // the solution may contain new variables, which we need to convert to new inference vars
-        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.new_type_var()).collect());
+        let new_vars = Substs((0..solution.num_vars).map(|_| ctx.table.new_type_var()).collect());
         for (i, ty) in solution.value.into_iter().enumerate() {
             let var = self.free_vars[i];
-            ctx.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
+            ctx.table.unify(&Ty::Infer(var), &ty.subst_bound_vars(&new_vars));
+        }
+    }
+}
+
+pub fn unify(ty1: &Canonical<Ty>, ty2: &Canonical<Ty>) -> Option<Substs> {
+    let mut table = InferenceTable::new();
+    let vars =
+        Substs::builder(ty1.num_vars).fill(std::iter::repeat_with(|| table.new_type_var())).build();
+    let ty_with_vars = ty1.value.clone().subst_bound_vars(&vars);
+    if !table.unify(&ty_with_vars, &ty2.value) {
+        return None;
+    }
+    Some(
+        Substs::builder(ty1.num_vars)
+            .fill(vars.iter().map(|v| table.resolve_ty_completely(v.clone())))
+            .build(),
+    )
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct InferenceTable {
+    pub(super) var_unification_table: InPlaceUnificationTable<TypeVarId>,
+}
+
+impl InferenceTable {
+    pub fn new() -> Self {
+        InferenceTable { var_unification_table: InPlaceUnificationTable::new() }
+    }
+
+    pub fn new_type_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_integer_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_float_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
+    }
+
+    pub fn new_maybe_never_type_var(&mut self) -> Ty {
+        Ty::Infer(InferTy::MaybeNeverTypeVar(
+            self.var_unification_table.new_key(TypeVarValue::Unknown),
+        ))
+    }
+
+    pub fn resolve_ty_completely(&mut self, ty: Ty) -> Ty {
+        self.resolve_ty_completely_inner(&mut Vec::new(), ty)
+    }
+
+    pub fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
+        self.resolve_ty_as_possible_inner(&mut Vec::new(), ty)
+    }
+
+    pub fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        self.unify_inner(ty1, ty2, 0)
+    }
+
+    pub fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
+        substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
+    }
+
+    fn unify_inner(&mut self, ty1: &Ty, ty2: &Ty, depth: usize) -> bool {
+        if depth > 1000 {
+            // prevent stackoverflows
+            panic!("infinite recursion in unification");
+        }
+        if ty1 == ty2 {
+            return true;
+        }
+        // try to resolve type vars first
+        let ty1 = self.resolve_ty_shallow(ty1);
+        let ty2 = self.resolve_ty_shallow(ty2);
+        match (&*ty1, &*ty2) {
+            (Ty::Apply(a_ty1), Ty::Apply(a_ty2)) if a_ty1.ctor == a_ty2.ctor => {
+                self.unify_substs(&a_ty1.parameters, &a_ty2.parameters, depth + 1)
+            }
+            _ => self.unify_inner_trivial(&ty1, &ty2),
+        }
+    }
+
+    pub(super) fn unify_inner_trivial(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        match (ty1, ty2) {
+            (Ty::Unknown, _) | (_, Ty::Unknown) => true,
+
+            (Ty::Infer(InferTy::TypeVar(tv1)), Ty::Infer(InferTy::TypeVar(tv2)))
+            | (Ty::Infer(InferTy::IntVar(tv1)), Ty::Infer(InferTy::IntVar(tv2)))
+            | (Ty::Infer(InferTy::FloatVar(tv1)), Ty::Infer(InferTy::FloatVar(tv2)))
+            | (
+                Ty::Infer(InferTy::MaybeNeverTypeVar(tv1)),
+                Ty::Infer(InferTy::MaybeNeverTypeVar(tv2)),
+            ) => {
+                // both type vars are unknown since we tried to resolve them
+                self.var_unification_table.union(*tv1, *tv2);
+                true
+            }
+
+            // The order of MaybeNeverTypeVar matters here.
+            // Unifying MaybeNeverTypeVar and TypeVar will let the latter become MaybeNeverTypeVar.
+            // Unifying MaybeNeverTypeVar and other concrete type will let the former become it.
+            (Ty::Infer(InferTy::TypeVar(tv)), other)
+            | (other, Ty::Infer(InferTy::TypeVar(tv)))
+            | (Ty::Infer(InferTy::MaybeNeverTypeVar(tv)), other)
+            | (other, Ty::Infer(InferTy::MaybeNeverTypeVar(tv)))
+            | (Ty::Infer(InferTy::IntVar(tv)), other @ ty_app!(TypeCtor::Int(_)))
+            | (other @ ty_app!(TypeCtor::Int(_)), Ty::Infer(InferTy::IntVar(tv)))
+            | (Ty::Infer(InferTy::FloatVar(tv)), other @ ty_app!(TypeCtor::Float(_)))
+            | (other @ ty_app!(TypeCtor::Float(_)), Ty::Infer(InferTy::FloatVar(tv))) => {
+                // the type var is unknown since we tried to resolve it
+                self.var_unification_table.union_value(*tv, TypeVarValue::Known(other.clone()));
+                true
+            }
+
+            _ => false,
+        }
+    }
+
+    /// If `ty` is a type variable with known type, returns that type;
+    /// otherwise, return ty.
+    pub fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
+        let mut ty = Cow::Borrowed(ty);
+        // The type variable could resolve to a int/float variable. Hence try
+        // resolving up to three times; each type of variable shouldn't occur
+        // more than once
+        for i in 0..3 {
+            if i > 0 {
+                tested_by!(type_var_resolves_to_int_var);
+            }
+            match &*ty {
+                Ty::Infer(tv) => {
+                    let inner = tv.to_inner();
+                    match self.var_unification_table.inlined_probe_value(inner).known() {
+                        Some(known_ty) => {
+                            // The known_ty can't be a type var itself
+                            ty = Cow::Owned(known_ty.clone());
+                        }
+                        _ => return ty,
+                    }
+                }
+                _ => return ty,
+            }
+        }
+        log::error!("Inference variable still not resolved: {:?}", ty);
+        ty
+    }
+
+    /// Resolves the type as far as currently possible, replacing type variables
+    /// by their known types. All types returned by the infer_* functions should
+    /// be resolved as far as possible, i.e. contain no type variables with
+    /// known type.
+    fn resolve_ty_as_possible_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Infer(tv) => {
+                let inner = tv.to_inner();
+                if tv_stack.contains(&inner) {
+                    tested_by!(type_var_cycles_resolve_as_possible);
+                    // recursive type
+                    return tv.fallback_value();
+                }
+                if let Some(known_ty) =
+                    self.var_unification_table.inlined_probe_value(inner).known()
+                {
+                    // known_ty may contain other variables that are known by now
+                    tv_stack.push(inner);
+                    let result = self.resolve_ty_as_possible_inner(tv_stack, known_ty.clone());
+                    tv_stack.pop();
+                    result
+                } else {
+                    ty
+                }
+            }
+            _ => ty,
+        })
+    }
+
+    /// Resolves the type completely; type variables without known type are
+    /// replaced by Ty::Unknown.
+    fn resolve_ty_completely_inner(&mut self, tv_stack: &mut Vec<TypeVarId>, ty: Ty) -> Ty {
+        ty.fold(&mut |ty| match ty {
+            Ty::Infer(tv) => {
+                let inner = tv.to_inner();
+                if tv_stack.contains(&inner) {
+                    tested_by!(type_var_cycles_resolve_completely);
+                    // recursive type
+                    return tv.fallback_value();
+                }
+                if let Some(known_ty) =
+                    self.var_unification_table.inlined_probe_value(inner).known()
+                {
+                    // known_ty may contain other variables that are known by now
+                    tv_stack.push(inner);
+                    let result = self.resolve_ty_completely_inner(tv_stack, known_ty.clone());
+                    tv_stack.pop();
+                    result
+                } else {
+                    tv.fallback_value()
+                }
+            }
+            _ => ty,
+        })
+    }
+}
+
+/// The ID of a type variable.
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub struct TypeVarId(pub(super) u32);
+
+impl UnifyKey for TypeVarId {
+    type Value = TypeVarValue;
+
+    fn index(&self) -> u32 {
+        self.0
+    }
+
+    fn from_index(i: u32) -> Self {
+        TypeVarId(i)
+    }
+
+    fn tag() -> &'static str {
+        "TypeVarId"
+    }
+}
+
+/// The value of a type variable: either we already know the type, or we don't
+/// know it yet.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum TypeVarValue {
+    Known(Ty),
+    Unknown,
+}
+
+impl TypeVarValue {
+    fn known(&self) -> Option<&Ty> {
+        match self {
+            TypeVarValue::Known(ty) => Some(ty),
+            TypeVarValue::Unknown => None,
+        }
+    }
+}
+
+impl UnifyValue for TypeVarValue {
+    type Error = NoError;
+
+    fn unify_values(value1: &Self, value2: &Self) -> Result<Self, NoError> {
+        match (value1, value2) {
+            // We should never equate two type variables, both of which have
+            // known types. Instead, we recursively equate those types.
+            (TypeVarValue::Known(t1), TypeVarValue::Known(t2)) => panic!(
+                "equating two type variables, both of which have known types: {:?} and {:?}",
+                t1, t2
+            ),
+
+            // If one side is known, prefer that one.
+            (TypeVarValue::Known(..), TypeVarValue::Unknown) => Ok(value1.clone()),
+            (TypeVarValue::Unknown, TypeVarValue::Known(..)) => Ok(value2.clone()),
+
+            (TypeVarValue::Unknown, TypeVarValue::Unknown) => Ok(TypeVarValue::Unknown),
         }
     }
 }
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index b45c8f82f..48abf97c9 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -44,8 +44,8 @@ use std::sync::Arc;
 use std::{fmt, iter, mem};
 
 use hir_def::{
-    expr::ExprId, generics::GenericParams, type_ref::Mutability, AdtId, ContainerId, DefWithBodyId,
-    GenericDefId, HasModule, Lookup, TraitId, TypeAliasId,
+    expr::ExprId, type_ref::Mutability, AdtId, AssocContainerId, DefWithBodyId, GenericDefId,
+    HasModule, Lookup, TraitId, TypeAliasId,
 };
 use hir_expand::name::Name;
 use ra_db::{impl_intern_key, salsa, CrateId};
@@ -53,7 +53,7 @@ use ra_db::{impl_intern_key, salsa, CrateId};
 use crate::{
     db::HirDatabase,
     primitive::{FloatTy, IntTy, Uncertain},
-    utils::make_mut_slice,
+    utils::{generics, make_mut_slice, Generics},
 };
 use display::{HirDisplay, HirFormatter};
 
@@ -166,16 +166,16 @@ impl TypeCtor {
             | TypeCtor::Closure { .. } // 1 param representing the signature of the closure
             => 1,
             TypeCtor::Adt(adt) => {
-                let generic_params = db.generic_params(AdtId::from(adt).into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, AdtId::from(adt).into());
+                generic_params.len()
             }
             TypeCtor::FnDef(callable) => {
-                let generic_params = db.generic_params(callable.into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, callable.into());
+                generic_params.len()
             }
             TypeCtor::AssociatedType(type_alias) => {
-                let generic_params = db.generic_params(type_alias.into());
-                generic_params.count_params_including_parent()
+                let generic_params = generics(db, type_alias.into());
+                generic_params.len()
             }
             TypeCtor::FnPtr { num_args } => num_args as usize + 1,
             TypeCtor::Tuple { cardinality } => cardinality as usize,
@@ -251,7 +251,7 @@ impl ProjectionTy {
 
     fn trait_(&self, db: &impl HirDatabase) -> TraitId {
         match self.associated_ty.lookup(db).container {
-            ContainerId::TraitId(it) => it,
+            AssocContainerId::TraitId(it) => it,
             _ => panic!("projection ty without parent trait"),
         }
     }
@@ -364,36 +364,26 @@ impl Substs {
     }
 
     /// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
-    pub fn identity(generic_params: &GenericParams) -> Substs {
+    pub(crate) fn identity(generic_params: &Generics) -> Substs {
         Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Param { idx: p.idx, name: p.name.clone() })
-                .collect(),
+            generic_params.iter().map(|(idx, p)| Ty::Param { idx, name: p.name.clone() }).collect(),
         )
     }
 
     /// Return Substs that replace each parameter by a bound variable.
-    pub fn bound_vars(generic_params: &GenericParams) -> Substs {
-        Substs(
-            generic_params
-                .params_including_parent()
-                .into_iter()
-                .map(|p| Ty::Bound(p.idx))
-                .collect(),
-        )
+    pub(crate) fn bound_vars(generic_params: &Generics) -> Substs {
+        Substs(generic_params.iter().map(|(idx, _p)| Ty::Bound(idx)).collect())
     }
 
     pub fn build_for_def(db: &impl HirDatabase, def: impl Into<GenericDefId>) -> SubstsBuilder {
         let def = def.into();
-        let params = db.generic_params(def);
-        let param_count = params.count_params_including_parent();
+        let params = generics(db, def);
+        let param_count = params.len();
         Substs::builder(param_count)
     }
 
-    pub fn build_for_generics(generic_params: &GenericParams) -> SubstsBuilder {
-        Substs::builder(generic_params.count_params_including_parent())
+    pub(crate) fn build_for_generics(generic_params: &Generics) -> SubstsBuilder {
+        Substs::builder(generic_params.len())
     }
 
     pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
@@ -486,21 +476,6 @@ impl TypeWalk for TraitRef {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum ImplTy {
-    Inherent(Ty),
-    TraitRef(TraitRef),
-}
-
-impl ImplTy {
-    pub(crate) fn self_type(&self) -> &Ty {
-        match self {
-            ImplTy::Inherent(it) => it,
-            ImplTy::TraitRef(tr) => &tr.substs[0],
-        }
-    }
-}
-
 /// Like `generics::WherePredicate`, but with resolved types: A condition on the
 /// parameters of a generic item.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
@@ -931,13 +906,44 @@ impl HirDisplay for ApplicationTy {
                 write!(f, "{}", name)?;
                 if self.parameters.len() > 0 {
                     write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
+
+                    let mut non_default_parameters = Vec::with_capacity(self.parameters.len());
+                    let parameters_to_write = if f.should_display_default_types() {
+                        self.parameters.0.as_ref()
+                    } else {
+                        match self
+                            .ctor
+                            .as_generic_def()
+                            .map(|generic_def_id| f.db.generic_defaults(generic_def_id))
+                            .filter(|defaults| !defaults.is_empty())
+                        {
+                            Option::None => self.parameters.0.as_ref(),
+                            Option::Some(default_parameters) => {
+                                for (i, parameter) in self.parameters.iter().enumerate() {
+                                    match (parameter, default_parameters.get(i)) {
+                                        (&Ty::Unknown, _) | (_, None) => {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        (_, Some(default_parameter))
+                                            if parameter != default_parameter =>
+                                        {
+                                            non_default_parameters.push(parameter.clone())
+                                        }
+                                        _ => (),
+                                    }
+                                }
+                                &non_default_parameters
+                            }
+                        }
+                    };
+
+                    f.write_joined(parameters_to_write, ", ")?;
                     write!(f, ">")?;
                 }
             }
             TypeCtor::AssociatedType(type_alias) => {
                 let trait_ = match type_alias.lookup(f.db).container {
-                    ContainerId::TraitId(it) => it,
+                    AssocContainerId::TraitId(it) => it,
                     _ => panic!("not an associated type"),
                 };
                 let trait_name = f.db.trait_data(trait_).name.clone();
diff --git a/crates/ra_hir_ty/src/lower.rs b/crates/ra_hir_ty/src/lower.rs
index 091c60f4f..af3db2e1d 100644
--- a/crates/ra_hir_ty/src/lower.rs
+++ b/crates/ra_hir_ty/src/lower.rs
@@ -11,10 +11,10 @@ use std::sync::Arc;
 use hir_def::{
     builtin_type::BuiltinType,
     generics::WherePredicate,
-    path::{GenericArg, Path, PathKind, PathSegment},
+    path::{GenericArg, Path, PathSegment, PathSegments},
     resolver::{HasResolver, Resolver, TypeNs},
     type_ref::{TypeBound, TypeRef},
-    AdtId, AstItemDef, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
+    AdtId, ConstId, EnumId, EnumVariantId, FunctionId, GenericDefId, HasModule, ImplId,
     LocalStructFieldId, Lookup, StaticId, StructId, TraitId, TypeAliasId, UnionId, VariantId,
 };
 use ra_arena::map::ArenaMap;
@@ -24,11 +24,11 @@ use crate::{
     db::HirDatabase,
     primitive::{FloatTy, IntTy},
     utils::{
-        all_super_traits, associated_type_by_name_including_super_traits, make_mut_slice,
+        all_super_traits, associated_type_by_name_including_super_traits, generics, make_mut_slice,
         variant_data,
     },
-    FnSig, GenericPredicate, ImplTy, ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment,
-    TraitRef, Ty, TypeCtor, TypeWalk,
+    FnSig, GenericPredicate, ProjectionPredicate, ProjectionTy, Substs, TraitEnvironment, TraitRef,
+    Ty, TypeCtor, TypeWalk,
 };
 
 impl Ty {
@@ -101,17 +101,19 @@ impl Ty {
             TypeRef::Path(path) => path,
             _ => return None,
         };
-        if let PathKind::Type(_) = &path.kind {
+        if path.type_anchor().is_some() {
             return None;
         }
-        if path.segments.len() > 1 {
+        if path.segments().len() > 1 {
             return None;
         }
-        let resolution = match resolver.resolve_path_in_type_ns(db, path) {
+        let resolution = match resolver.resolve_path_in_type_ns(db, path.mod_path()) {
             Some((it, None)) => it,
             _ => return None,
         };
-        if let TypeNs::GenericParam(idx) = resolution {
+        if let TypeNs::GenericParam(param_id) = resolution {
+            let generics = generics(db, resolver.generic_def().expect("generics in scope"));
+            let idx = generics.param_idx(param_id);
             Some(idx)
         } else {
             None
@@ -122,11 +124,11 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         ty: Ty,
-        remaining_segments: &[PathSegment],
+        remaining_segments: PathSegments<'_>,
     ) -> Ty {
         if remaining_segments.len() == 1 {
             // resolve unselected assoc types
-            let segment = &remaining_segments[0];
+            let segment = remaining_segments.first().unwrap();
             Ty::select_associated_type(db, resolver, ty, segment)
         } else if remaining_segments.len() > 1 {
             // FIXME report error (ambiguous associated type)
@@ -140,15 +142,15 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         resolution: TypeNs,
-        resolved_segment: &PathSegment,
-        remaining_segments: &[PathSegment],
+        resolved_segment: PathSegment<'_>,
+        remaining_segments: PathSegments<'_>,
     ) -> Ty {
         let ty = match resolution {
             TypeNs::TraitId(trait_) => {
                 let trait_ref =
                     TraitRef::from_resolved_path(db, resolver, trait_, resolved_segment, None);
                 return if remaining_segments.len() == 1 {
-                    let segment = &remaining_segments[0];
+                    let segment = remaining_segments.first().unwrap();
                     let associated_ty = associated_type_by_name_including_super_traits(
                         db,
                         trait_ref.trait_,
@@ -174,12 +176,14 @@ impl Ty {
                     Ty::Dyn(Arc::new([GenericPredicate::Implemented(trait_ref)]))
                 };
             }
-            TypeNs::GenericParam(idx) => {
+            TypeNs::GenericParam(param_id) => {
+                let generics = generics(db, resolver.generic_def().expect("generics in scope"));
+                let idx = generics.param_idx(param_id);
                 // FIXME: maybe return name in resolution?
-                let name = resolved_segment.name.clone();
+                let name = generics.param_name(param_id);
                 Ty::Param { idx, name }
             }
-            TypeNs::SelfType(impl_id) => db.impl_ty(impl_id).self_type().clone(),
+            TypeNs::SelfType(impl_id) => db.impl_self_ty(impl_id).clone(),
             TypeNs::AdtSelfType(adt) => db.ty(adt.into()),
 
             TypeNs::AdtId(it) => Ty::from_hir_path_inner(db, resolver, resolved_segment, it.into()),
@@ -198,21 +202,21 @@ impl Ty {
 
     pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Ty {
         // Resolve the path (in type namespace)
-        if let PathKind::Type(type_ref) = &path.kind {
+        if let Some(type_ref) = path.type_anchor() {
             let ty = Ty::from_hir(db, resolver, &type_ref);
-            let remaining_segments = &path.segments[..];
-            return Ty::from_type_relative_path(db, resolver, ty, remaining_segments);
+            return Ty::from_type_relative_path(db, resolver, ty, path.segments());
         }
-        let (resolution, remaining_index) = match resolver.resolve_path_in_type_ns(db, path) {
-            Some(it) => it,
-            None => return Ty::Unknown,
-        };
+        let (resolution, remaining_index) =
+            match resolver.resolve_path_in_type_ns(db, path.mod_path()) {
+                Some(it) => it,
+                None => return Ty::Unknown,
+            };
         let (resolved_segment, remaining_segments) = match remaining_index {
             None => (
-                path.segments.last().expect("resolved path has at least one element"),
-                &[] as &[PathSegment],
+                path.segments().last().expect("resolved path has at least one element"),
+                PathSegments::EMPTY,
             ),
-            Some(i) => (&path.segments[i - 1], &path.segments[i..]),
+            Some(i) => (path.segments().get(i - 1).unwrap(), path.segments().skip(i)),
         };
         Ty::from_partly_resolved_hir_path(
             db,
@@ -227,7 +231,7 @@ impl Ty {
         db: &impl HirDatabase,
         resolver: &Resolver,
         self_ty: Ty,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
     ) -> Ty {
         let param_idx = match self_ty {
             Ty::Param { idx, .. } => idx,
@@ -257,7 +261,7 @@ impl Ty {
     fn from_hir_path_inner(
         db: &impl HirDatabase,
         resolver: &Resolver,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         typable: TyDefId,
     ) -> Ty {
         let generic_def = match typable {
@@ -280,7 +284,7 @@ impl Ty {
         // special-case enum variants
         resolved: ValueTyDefId,
     ) -> Substs {
-        let last = path.segments.last().expect("path should have at least one segment");
+        let last = path.segments().last().expect("path should have at least one segment");
         let (segment, generic_def) = match resolved {
             ValueTyDefId::FunctionId(it) => (last, Some(it.into())),
             ValueTyDefId::StructId(it) => (last, Some(it.into())),
@@ -292,13 +296,11 @@ impl Ty {
                 // referring to the variant. So `Option::<T>::None` and
                 // `Option::None::<T>` are both allowed (though the former is
                 // preferred). See also `def_ids_for_path_segments` in rustc.
-                let len = path.segments.len();
-                let segment = if len >= 2 && path.segments[len - 2].args_and_bindings.is_some() {
-                    // Option::<T>::None
-                    &path.segments[len - 2]
-                } else {
-                    // Option::None::<T>
-                    last
+                let len = path.segments().len();
+                let penultimate = if len >= 2 { path.segments().get(len - 2) } else { None };
+                let segment = match penultimate {
+                    Some(segment) if segment.args_and_bindings.is_some() => segment,
+                    _ => last,
                 };
                 (segment, Some(var.parent.into()))
             }
@@ -310,16 +312,15 @@ impl Ty {
 pub(super) fn substs_from_path_segment(
     db: &impl HirDatabase,
     resolver: &Resolver,
-    segment: &PathSegment,
+    segment: PathSegment<'_>,
     def_generic: Option<GenericDefId>,
     add_self_param: bool,
 ) -> Substs {
     let mut substs = Vec::new();
-    let def_generics = def_generic.map(|def| db.generic_params(def.into()));
+    let def_generics = def_generic.map(|def| generics(db, def.into()));
 
-    let (parent_param_count, param_count) =
-        def_generics.map_or((0, 0), |g| (g.count_parent_params(), g.params.len()));
-    substs.extend(iter::repeat(Ty::Unknown).take(parent_param_count));
+    let (total_len, parent_len, child_len) = def_generics.map_or((0, 0, 0), |g| g.len_split());
+    substs.extend(iter::repeat(Ty::Unknown).take(parent_len));
     if add_self_param {
         // FIXME this add_self_param argument is kind of a hack: Traits have the
         // Self type as an implicit first type parameter, but it can't be
@@ -330,8 +331,8 @@ pub(super) fn substs_from_path_segment(
     if let Some(generic_args) = &segment.args_and_bindings {
         // if args are provided, it should be all of them, but we can't rely on that
         let self_param_correction = if add_self_param { 1 } else { 0 };
-        let param_count = param_count - self_param_correction;
-        for arg in generic_args.args.iter().take(param_count) {
+        let child_len = child_len + self_param_correction;
+        for arg in generic_args.args.iter().take(child_len) {
             match arg {
                 GenericArg::Type(type_ref) => {
                     let ty = Ty::from_hir(db, resolver, type_ref);
@@ -342,10 +343,10 @@ pub(super) fn substs_from_path_segment(
     }
     // add placeholders for args that were not provided
     let supplied_params = substs.len();
-    for _ in supplied_params..parent_param_count + param_count {
+    for _ in supplied_params..total_len {
         substs.push(Ty::Unknown);
     }
-    assert_eq!(substs.len(), parent_param_count + param_count);
+    assert_eq!(substs.len(), total_len);
 
     // handle defaults
     if let Some(def_generic) = def_generic {
@@ -369,11 +370,11 @@ impl TraitRef {
         path: &Path,
         explicit_self_ty: Option<Ty>,
     ) -> Option<Self> {
-        let resolved = match resolver.resolve_path_in_type_ns_fully(db, &path)? {
+        let resolved = match resolver.resolve_path_in_type_ns_fully(db, path.mod_path())? {
             TypeNs::TraitId(tr) => tr,
             _ => return None,
         };
-        let segment = path.segments.last().expect("path should have at least one segment");
+        let segment = path.segments().last().expect("path should have at least one segment");
         Some(TraitRef::from_resolved_path(db, resolver, resolved.into(), segment, explicit_self_ty))
     }
 
@@ -381,7 +382,7 @@ impl TraitRef {
         db: &impl HirDatabase,
         resolver: &Resolver,
         resolved: TraitId,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         explicit_self_ty: Option<Ty>,
     ) -> Self {
         let mut substs = TraitRef::substs_from_path(db, resolver, segment, resolved);
@@ -407,7 +408,7 @@ impl TraitRef {
     fn substs_from_path(
         db: &impl HirDatabase,
         resolver: &Resolver,
-        segment: &PathSegment,
+        segment: PathSegment<'_>,
         resolved: TraitId,
     ) -> Substs {
         let has_self_param =
@@ -461,12 +462,12 @@ fn assoc_type_bindings_from_type_bound<'a>(
     trait_ref: TraitRef,
 ) -> impl Iterator<Item = GenericPredicate> + 'a {
     let last_segment = match bound {
-        TypeBound::Path(path) => path.segments.last(),
+        TypeBound::Path(path) => path.segments().last(),
         TypeBound::Error => None,
     };
     last_segment
         .into_iter()
-        .flat_map(|segment| segment.args_and_bindings.iter())
+        .flat_map(|segment| segment.args_and_bindings.into_iter())
         .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
         .map(move |(name, type_ref)| {
             let associated_ty =
@@ -532,6 +533,15 @@ pub(crate) fn generic_predicates_for_param_query(
         .collect()
 }
 
+pub(crate) fn generic_predicates_for_param_recover(
+    _db: &impl HirDatabase,
+    _cycle: &[String],
+    _def: &GenericDefId,
+    _param_idx: &u32,
+) -> Arc<[GenericPredicate]> {
+    Arc::new([])
+}
+
 impl TraitEnvironment {
     pub fn lower(db: &impl HirDatabase, resolver: &Resolver) -> Arc<TraitEnvironment> {
         let predicates = resolver
@@ -558,12 +568,11 @@ pub(crate) fn generic_predicates_query(
 /// Resolve the default type params from generics
 pub(crate) fn generic_defaults_query(db: &impl HirDatabase, def: GenericDefId) -> Substs {
     let resolver = def.resolver(db);
-    let generic_params = db.generic_params(def.into());
+    let generic_params = generics(db, def.into());
 
     let defaults = generic_params
-        .params_including_parent()
-        .into_iter()
-        .map(|p| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(db, &resolver, t)))
+        .iter()
+        .map(|(_idx, p)| p.default.as_ref().map_or(Ty::Unknown, |t| Ty::from_hir(db, &resolver, t)))
         .collect();
 
     Substs(defaults)
@@ -580,7 +589,7 @@ fn fn_sig_for_fn(db: &impl HirDatabase, def: FunctionId) -> FnSig {
 /// Build the declared type of a function. This should not need to look at the
 /// function body.
 fn type_for_fn(db: &impl HirDatabase, def: FunctionId) -> Ty {
-    let generics = db.generic_params(def.into());
+    let generics = generics(db, def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
@@ -630,7 +639,7 @@ fn type_for_struct_constructor(db: &impl HirDatabase, def: StructId) -> Ty {
     if struct_data.variant_data.is_unit() {
         return type_for_adt(db, def.into()); // Unit struct
     }
-    let generics = db.generic_params(def.into());
+    let generics = generics(db, def.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(def.into()), substs)
 }
@@ -644,7 +653,7 @@ fn fn_sig_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId
         .iter()
         .map(|(_, field)| Ty::from_hir(db, &resolver, &field.type_ref))
         .collect::<Vec<_>>();
-    let generics = db.generic_params(def.parent.into());
+    let generics = generics(db, def.parent.into());
     let substs = Substs::identity(&generics);
     let ret = type_for_adt(db, def.parent.into()).subst(&substs);
     FnSig::from_params_and_return(params, ret)
@@ -657,18 +666,18 @@ fn type_for_enum_variant_constructor(db: &impl HirDatabase, def: EnumVariantId)
     if var_data.is_unit() {
         return type_for_adt(db, def.parent.into()); // Unit variant
     }
-    let generics = db.generic_params(def.parent.into());
+    let generics = generics(db, def.parent.into());
     let substs = Substs::identity(&generics);
     Ty::apply(TypeCtor::FnDef(EnumVariantId::from(def).into()), substs)
 }
 
 fn type_for_adt(db: &impl HirDatabase, adt: AdtId) -> Ty {
-    let generics = db.generic_params(adt.into());
+    let generics = generics(db, adt.into());
     Ty::apply(TypeCtor::Adt(adt), Substs::identity(&generics))
 }
 
 fn type_for_type_alias(db: &impl HirDatabase, t: TypeAliasId) -> Ty {
-    let generics = db.generic_params(t.into());
+    let generics = generics(db, t.into());
     let resolver = t.resolver(db);
     let type_ref = &db.type_alias_data(t).type_ref;
     let substs = Substs::identity(&generics);
@@ -687,10 +696,11 @@ impl_froms!(CallableDef: FunctionId, StructId, EnumVariantId);
 impl CallableDef {
     pub fn krate(self, db: &impl HirDatabase) -> CrateId {
         match self {
-            CallableDef::FunctionId(f) => f.lookup(db).module(db).krate,
-            CallableDef::StructId(s) => s.module(db).krate,
-            CallableDef::EnumVariantId(e) => e.parent.module(db).krate,
+            CallableDef::FunctionId(f) => f.lookup(db).module(db),
+            CallableDef::StructId(s) => s.lookup(db).container.module(db),
+            CallableDef::EnumVariantId(e) => e.parent.lookup(db).container.module(db),
         }
+        .krate
     }
 }
 
@@ -733,6 +743,11 @@ pub(crate) fn ty_query(db: &impl HirDatabase, def: TyDefId) -> Ty {
         TyDefId::TypeAliasId(it) => type_for_type_alias(db, it),
     }
 }
+
+pub(crate) fn ty_recover(_db: &impl HirDatabase, _cycle: &[String], _def: &TyDefId) -> Ty {
+    Ty::Unknown
+}
+
 pub(crate) fn value_ty_query(db: &impl HirDatabase, def: ValueTyDefId) -> Ty {
     match def {
         ValueTyDefId::FunctionId(it) => type_for_fn(db, it),
@@ -743,17 +758,24 @@ pub(crate) fn value_ty_query(db: &impl HirDatabase, def: ValueTyDefId) -> Ty {
     }
 }
 
-pub(crate) fn impl_ty_query(db: &impl HirDatabase, impl_id: ImplId) -> ImplTy {
+pub(crate) fn impl_self_ty_query(db: &impl HirDatabase, impl_id: ImplId) -> Ty {
     let impl_data = db.impl_data(impl_id);
     let resolver = impl_id.resolver(db);
-    let self_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
-    match impl_data.target_trait.as_ref() {
-        Some(trait_ref) => {
-            match TraitRef::from_hir(db, &resolver, trait_ref, Some(self_ty.clone())) {
-                Some(it) => ImplTy::TraitRef(it),
-                None => ImplTy::Inherent(self_ty),
-            }
-        }
-        None => ImplTy::Inherent(self_ty),
-    }
+    Ty::from_hir(db, &resolver, &impl_data.target_type)
+}
+
+pub(crate) fn impl_self_ty_recover(
+    _db: &impl HirDatabase,
+    _cycle: &[String],
+    _impl_id: &ImplId,
+) -> Ty {
+    Ty::Unknown
+}
+
+pub(crate) fn impl_trait_query(db: &impl HirDatabase, impl_id: ImplId) -> Option<TraitRef> {
+    let impl_data = db.impl_data(impl_id);
+    let resolver = impl_id.resolver(db);
+    let self_ty = db.impl_self_ty(impl_id);
+    let target_trait = impl_data.target_trait.as_ref()?;
+    TraitRef::from_hir(db, &resolver, target_trait, Some(self_ty.clone()))
 }
diff --git a/crates/ra_hir_ty/src/marks.rs b/crates/ra_hir_ty/src/marks.rs
index 0f754eb9c..fe74acf11 100644
--- a/crates/ra_hir_ty/src/marks.rs
+++ b/crates/ra_hir_ty/src/marks.rs
@@ -6,4 +6,5 @@ test_utils::marks!(
     type_var_resolves_to_int_var
     match_ergonomics_ref
     coerce_merge_fail_fallback
+    insert_vars_for_impl_trait
 );
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index ee1936b0e..888dc3116 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -6,20 +6,21 @@ use std::sync::Arc;
 
 use arrayvec::ArrayVec;
 use hir_def::{
-    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocItemId, AstItemDef,
-    FunctionId, HasModule, ImplId, TraitId,
+    lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutability, AssocContainerId,
+    AssocItemId, FunctionId, HasModule, ImplId, Lookup, TraitId,
 };
 use hir_expand::name::Name;
 use ra_db::CrateId;
 use ra_prof::profile;
 use rustc_hash::FxHashMap;
 
+use super::Substs;
 use crate::{
     autoderef,
     db::HirDatabase,
     primitive::{FloatBitness, Uncertain},
     utils::all_super_traits,
-    Canonical, ImplTy, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor,
+    Canonical, InEnvironment, TraitEnvironment, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
 /// This is used as a key for indexing impls.
@@ -57,12 +58,13 @@ impl CrateImplBlocks {
 
         let crate_def_map = db.crate_def_map(krate);
         for (_module_id, module_data) in crate_def_map.modules.iter() {
-            for &impl_id in module_data.impls.iter() {
-                match db.impl_ty(impl_id) {
-                    ImplTy::TraitRef(tr) => {
+            for impl_id in module_data.scope.impls() {
+                match db.impl_trait(impl_id) {
+                    Some(tr) => {
                         res.impls_by_trait.entry(tr.trait_).or_default().push(impl_id);
                     }
-                    ImplTy::Inherent(self_ty) => {
+                    None => {
+                        let self_ty = db.impl_self_ty(impl_id);
                         if let Some(self_ty_fp) = TyFingerprint::for_impl(&self_ty) {
                             res.impls.entry(self_ty_fp).or_default().push(impl_id);
                         }
@@ -132,7 +134,7 @@ impl Ty {
                 LangItemTarget::ImplBlockId(it) => Some(it),
                 _ => None,
             })
-            .map(|it| it.module(db).krate)
+            .map(|it| it.lookup(db).container.module(db).krate)
             .collect();
         Some(res)
     }
@@ -175,7 +177,6 @@ pub fn iterate_method_candidates<T>(
     mode: LookupMode,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    let krate = resolver.krate()?;
     match mode {
         LookupMode::MethodCall => {
             // For method calls, rust first does any number of autoderef, and then one
@@ -188,57 +189,159 @@ pub fn iterate_method_candidates<T>(
             // rustc does an autoderef and then autoref again).
             let environment = TraitEnvironment::lower(db, resolver);
             let ty = InEnvironment { value: ty.clone(), environment };
-            for derefed_ty in autoderef::autoderef(db, resolver.krate(), ty) {
-                if let Some(result) =
-                    iterate_inherent_methods(&derefed_ty, db, name, mode, krate, &mut callback)
-                {
-                    return Some(result);
-                }
-                if let Some(result) = iterate_trait_method_candidates(
-                    &derefed_ty,
+            let krate = resolver.krate()?;
+
+            // We have to be careful about the order we're looking at candidates
+            // in here. Consider the case where we're resolving `x.clone()`
+            // where `x: &Vec<_>`. This resolves to the clone method with self
+            // type `Vec<_>`, *not* `&_`. I.e. we need to consider methods where
+            // the receiver type exactly matches before cases where we have to
+            // do autoref. But in the autoderef steps, the `&_` self type comes
+            // up *before* the `Vec<_>` self type.
+            //
+            // On the other hand, we don't want to just pick any by-value method
+            // before any by-autoref method; it's just that we need to consider
+            // the methods by autoderef order of *receiver types*, not *self
+            // types*.
+
+            let deref_chain: Vec<_> = autoderef::autoderef(db, Some(krate), ty.clone()).collect();
+            for i in 0..deref_chain.len() {
+                if let Some(result) = iterate_method_candidates_with_autoref(
+                    &deref_chain[i..],
                     db,
                     resolver,
                     name,
-                    mode,
                     &mut callback,
                 ) {
                     return Some(result);
                 }
             }
+            None
         }
         LookupMode::Path => {
             // No autoderef for path lookups
-            if let Some(result) =
-                iterate_inherent_methods(&ty, db, name, mode, krate.into(), &mut callback)
-            {
-                return Some(result);
-            }
-            if let Some(result) =
-                iterate_trait_method_candidates(&ty, db, resolver, name, mode, &mut callback)
-            {
-                return Some(result);
-            }
+            iterate_method_candidates_for_self_ty(&ty, db, resolver, name, &mut callback)
+        }
+    }
+}
+
+fn iterate_method_candidates_with_autoref<T>(
+    deref_chain: &[Canonical<Ty>],
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &deref_chain[0],
+        &deref_chain[1..],
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    let refed = Canonical {
+        num_vars: deref_chain[0].num_vars,
+        value: Ty::apply_one(TypeCtor::Ref(Mutability::Shared), deref_chain[0].value.clone()),
+    };
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &refed,
+        deref_chain,
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    let ref_muted = Canonical {
+        num_vars: deref_chain[0].num_vars,
+        value: Ty::apply_one(TypeCtor::Ref(Mutability::Mut), deref_chain[0].value.clone()),
+    };
+    if let Some(result) = iterate_method_candidates_by_receiver(
+        &ref_muted,
+        deref_chain,
+        db,
+        resolver,
+        name,
+        &mut callback,
+    ) {
+        return Some(result);
+    }
+    None
+}
+
+fn iterate_method_candidates_by_receiver<T>(
+    receiver_ty: &Canonical<Ty>,
+    rest_of_deref_chain: &[Canonical<Ty>],
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    // We're looking for methods with *receiver* type receiver_ty. These could
+    // be found in any of the derefs of receiver_ty, so we have to go through
+    // that.
+    let krate = resolver.krate()?;
+    for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
+        if let Some(result) =
+            iterate_inherent_methods(self_ty, db, name, Some(receiver_ty), krate, &mut callback)
+        {
+            return Some(result);
+        }
+    }
+    for self_ty in std::iter::once(receiver_ty).chain(rest_of_deref_chain) {
+        if let Some(result) = iterate_trait_method_candidates(
+            self_ty,
+            db,
+            resolver,
+            name,
+            Some(receiver_ty),
+            &mut callback,
+        ) {
+            return Some(result);
         }
     }
     None
 }
 
+fn iterate_method_candidates_for_self_ty<T>(
+    self_ty: &Canonical<Ty>,
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    name: Option<&Name>,
+    mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
+) -> Option<T> {
+    let krate = resolver.krate()?;
+    if let Some(result) = iterate_inherent_methods(self_ty, db, name, None, krate, &mut callback) {
+        return Some(result);
+    }
+    if let Some(result) =
+        iterate_trait_method_candidates(self_ty, db, resolver, name, None, &mut callback)
+    {
+        return Some(result);
+    }
+    None
+}
+
 fn iterate_trait_method_candidates<T>(
-    ty: &Canonical<Ty>,
+    self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     resolver: &Resolver,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
     let krate = resolver.krate()?;
     // FIXME: maybe put the trait_env behind a query (need to figure out good input parameters for that)
     let env = TraitEnvironment::lower(db, resolver);
     // if ty is `impl Trait` or `dyn Trait`, the trait doesn't need to be in scope
-    let inherent_trait = ty.value.inherent_trait().into_iter();
+    let inherent_trait = self_ty.value.inherent_trait().into_iter();
     // if we have `T: Trait` in the param env, the trait doesn't need to be in scope
     let traits_from_env = env
-        .trait_predicates_for_self_ty(&ty.value)
+        .trait_predicates_for_self_ty(&self_ty.value)
         .map(|tr| tr.trait_)
         .flat_map(|t| all_super_traits(db, t));
     let traits =
@@ -251,17 +354,17 @@ fn iterate_trait_method_candidates<T>(
         // iteration
         let mut known_implemented = false;
         for (_name, item) in data.items.iter() {
-            if !is_valid_candidate(db, name, mode, (*item).into()) {
+            if !is_valid_candidate(db, name, receiver_ty, (*item).into(), self_ty) {
                 continue;
             }
             if !known_implemented {
-                let goal = generic_implements_goal(db, env.clone(), t, ty.clone());
+                let goal = generic_implements_goal(db, env.clone(), t, self_ty.clone());
                 if db.trait_solve(krate.into(), goal).is_none() {
                     continue 'traits;
                 }
             }
             known_implemented = true;
-            if let Some(result) = callback(&ty.value, (*item).into()) {
+            if let Some(result) = callback(&self_ty.value, (*item).into()) {
                 return Some(result);
             }
         }
@@ -270,22 +373,22 @@ fn iterate_trait_method_candidates<T>(
 }
 
 fn iterate_inherent_methods<T>(
-    ty: &Canonical<Ty>,
+    self_ty: &Canonical<Ty>,
     db: &impl HirDatabase,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     krate: CrateId,
     mut callback: impl FnMut(&Ty, AssocItemId) -> Option<T>,
 ) -> Option<T> {
-    for krate in ty.value.def_crates(db, krate)? {
+    for krate in self_ty.value.def_crates(db, krate)? {
         let impls = db.impls_in_crate(krate);
 
-        for impl_block in impls.lookup_impl_blocks(&ty.value) {
+        for impl_block in impls.lookup_impl_blocks(&self_ty.value) {
             for &item in db.impl_data(impl_block).items.iter() {
-                if !is_valid_candidate(db, name, mode, item) {
+                if !is_valid_candidate(db, name, receiver_ty, item, self_ty) {
                     continue;
                 }
-                if let Some(result) = callback(&ty.value, item.into()) {
+                if let Some(result) = callback(&self_ty.value, item) {
                     return Some(result);
                 }
             }
@@ -297,23 +400,68 @@ fn iterate_inherent_methods<T>(
 fn is_valid_candidate(
     db: &impl HirDatabase,
     name: Option<&Name>,
-    mode: LookupMode,
+    receiver_ty: Option<&Canonical<Ty>>,
     item: AssocItemId,
+    self_ty: &Canonical<Ty>,
 ) -> bool {
     match item {
         AssocItemId::FunctionId(m) => {
             let data = db.function_data(m);
-            name.map_or(true, |name| &data.name == name)
-                && (data.has_self_param || mode == LookupMode::Path)
+            if let Some(name) = name {
+                if &data.name != name {
+                    return false;
+                }
+            }
+            if let Some(receiver_ty) = receiver_ty {
+                if !data.has_self_param {
+                    return false;
+                }
+                let transformed_receiver_ty = match transform_receiver_ty(db, m, self_ty) {
+                    Some(ty) => ty,
+                    None => return false,
+                };
+                if transformed_receiver_ty != receiver_ty.value {
+                    return false;
+                }
+            }
+            true
         }
         AssocItemId::ConstId(c) => {
             let data = db.const_data(c);
-            name.map_or(true, |name| data.name.as_ref() == Some(name)) && (mode == LookupMode::Path)
+            name.map_or(true, |name| data.name.as_ref() == Some(name)) && receiver_ty.is_none()
         }
         _ => false,
     }
 }
 
+pub(crate) fn inherent_impl_substs(
+    db: &impl HirDatabase,
+    impl_id: ImplId,
+    self_ty: &Canonical<Ty>,
+) -> Option<Substs> {
+    let vars = Substs::build_for_def(db, impl_id).fill_with_bound_vars(0).build();
+    let self_ty_with_vars = db.impl_self_ty(impl_id).subst(&vars);
+    let self_ty_with_vars = Canonical { num_vars: vars.len(), value: self_ty_with_vars };
+    super::infer::unify(&self_ty_with_vars, self_ty)
+}
+
+fn transform_receiver_ty(
+    db: &impl HirDatabase,
+    function_id: FunctionId,
+    self_ty: &Canonical<Ty>,
+) -> Option<Ty> {
+    let substs = match function_id.lookup(db).container {
+        AssocContainerId::TraitId(_) => Substs::build_for_def(db, function_id)
+            .push(self_ty.value.clone())
+            .fill_with_unknown()
+            .build(),
+        AssocContainerId::ImplId(impl_id) => inherent_impl_substs(db, impl_id, &self_ty)?,
+        AssocContainerId::ContainerId(_) => unreachable!(),
+    };
+    let sig = db.callable_item_signature(function_id.into());
+    Some(sig.params()[0].clone().subst(&substs))
+}
+
 pub fn implements_trait(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 1dc9793f9..1a31b587b 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -74,7 +74,7 @@ impl TestDB {
         for &krate in self.relevant_crates(file_id).iter() {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules.iter() {
-                if data.definition == Some(file_id) {
+                if data.origin.file_id() == Some(file_id) {
                     return ModuleId { krate, local_id };
                 }
             }
@@ -98,7 +98,7 @@ impl TestDB {
                     }
                 }
 
-                for &impl_id in crate_def_map[module_id].impls.iter() {
+                for impl_id in crate_def_map[module_id].scope.impls() {
                     let impl_data = self.impl_data(impl_id);
                     for item in impl_data.items.iter() {
                         if let AssocItemId::FunctionId(f) = item {
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index c8461b447..d447b4571 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -1,21 +1,26 @@
 mod never_type;
 mod coercion;
+mod regression;
+mod simple;
+mod patterns;
+mod traits;
+mod method_resolution;
+mod macros;
 
 use std::fmt::Write;
 use std::sync::Arc;
 
 use hir_def::{
-    body::BodySourceMap, db::DefDatabase, nameres::CrateDefMap, AssocItemId, DefWithBodyId,
-    LocalModuleId, Lookup, ModuleDefId,
+    body::BodySourceMap, child_by_source::ChildBySource, db::DefDatabase, keys,
+    nameres::CrateDefMap, AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
-use hir_expand::Source;
+use hir_expand::InFile;
 use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
 };
-use test_utils::covers;
 
 use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResult};
 
@@ -23,4669 +28,20 @@ use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResu
 // against snapshots of the expected results using insta. Use cargo-insta to
 // update the snapshots.
 
-#[test]
-fn cfg_impl_block() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:foo cfg:test
-use foo::S as T;
-struct S;
-
-#[cfg(test)]
-impl S {
-    fn foo1(&self) -> i32 { 0 }
-}
-
-#[cfg(not(test))]
-impl S {
-    fn foo2(&self) -> i32 { 0 }
-}
-
-fn test() {
-    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
-    t<|>;
-}
-
-//- /foo.rs crate:foo
-struct S;
-
-#[cfg(not(test))]
-impl S {
-    fn foo3(&self) -> i32 { 0 }
-}
-
-#[cfg(test)]
-impl S {
-    fn foo4(&self) -> i32 { 0 }
-}
-"#,
-    );
-    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_await() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-struct IntFuture;
-
-impl Future for IntFuture {
-    type Output = u64;
-}
-
-fn test() {
-    let r = IntFuture;
-    let v = r.await;
-    v<|>;
-}
-
-//- /std.rs crate:std
-#[prelude_import] use future::*;
-mod future {
-    trait Future {
-        type Output;
-    }
-}
-
-"#,
-    );
-    assert_eq!("u64", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_box() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-fn test() {
-    let x = box 1;
-    let t = (x, box x, box &1, box [1]);
-    t<|>;
-}
-
-//- /std.rs crate:std
-#[prelude_import] use prelude::*;
-mod prelude {}
-
-mod boxed {
-    pub struct Box<T: ?Sized> {
-        inner: *mut T,
-    }
-}
-
-"#,
-    );
-    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_adt_self() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs
-enum Nat { Succ(Self), Demo(Nat), Zero }
-
-fn test() {
-    let foo: Nat = Nat::Zero;
-    if let Nat::Succ(x) = foo {
-        x<|>
-    }
-}
-
-"#,
-    );
-    assert_eq!("Nat", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_try() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-fn test() {
-    let r: Result<i32, u64> = Result::Ok(1);
-    let v = r?;
-    v<|>;
-}
-
-//- /std.rs crate:std
-
-#[prelude_import] use ops::*;
-mod ops {
-    trait Try {
-        type Ok;
-        type Error;
-    }
-}
-
-#[prelude_import] use result::*;
-mod result {
-    enum Result<O, E> {
-        Ok(O),
-        Err(E)
-    }
-
-    impl<O, E> crate::ops::Try for Result<O, E> {
-        type Ok = O;
-        type Error = E;
-    }
-}
-
-"#,
-    );
-    assert_eq!("i32", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_for_loop() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-
-use std::collections::Vec;
-
-fn test() {
-    let v = Vec::new();
-    v.push("foo");
-    for x in v {
-        x<|>;
-    }
-}
-
-//- /std.rs crate:std
-
-#[prelude_import] use iter::*;
-mod iter {
-    trait IntoIterator {
-        type Item;
-    }
-}
-
-mod collections {
-    struct Vec<T> {}
-    impl<T> Vec<T> {
-        fn new() -> Self { Vec {} }
-        fn push(&mut self, t: T) { }
-    }
-
-    impl<T> crate::iter::IntoIterator for Vec<T> {
-        type Item=T;
-    }
-}
-"#,
-    );
-    assert_eq!("&str", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_while_let() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs
-enum Option<T> { Some(T), None }
-
-fn test() {
-    let foo: Option<f32> = None;
-    while let Option::Some(x) = foo {
-        <|>x
-    }
-}
-
-"#,
-    );
-    assert_eq!("f32", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_basics() {
-    assert_snapshot!(
-        infer(r#"
-fn test(a: u32, b: isize, c: !, d: &str) {
-    a;
-    b;
-    c;
-    d;
-    1usize;
-    1isize;
-    "test";
-    1.0f32;
-}"#),
-        @r###"
-    [9; 10) 'a': u32
-    [17; 18) 'b': isize
-    [27; 28) 'c': !
-    [33; 34) 'd': &str
-    [42; 121) '{     ...f32; }': !
-    [48; 49) 'a': u32
-    [55; 56) 'b': isize
-    [62; 63) 'c': !
-    [69; 70) 'd': &str
-    [76; 82) '1usize': usize
-    [88; 94) '1isize': isize
-    [100; 106) '"test"': &str
-    [112; 118) '1.0f32': f32
-    "###
-    );
-}
-
-#[test]
-fn infer_let() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let a = 1isize;
-    let b: usize = 1;
-    let c = b;
-    let d: u32;
-    let e;
-    let f: i32 = e;
-}
-"#),
-        @r###"
-    [11; 118) '{     ...= e; }': ()
-    [21; 22) 'a': isize
-    [25; 31) '1isize': isize
-    [41; 42) 'b': usize
-    [52; 53) '1': usize
-    [63; 64) 'c': usize
-    [67; 68) 'b': usize
-    [78; 79) 'd': u32
-    [94; 95) 'e': i32
-    [105; 106) 'f': i32
-    [114; 115) 'e': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_paths() {
-    assert_snapshot!(
-        infer(r#"
-fn a() -> u32 { 1 }
-
-mod b {
-    fn c() -> u32 { 1 }
-}
-
-fn test() {
-    a();
-    b::c();
-}
-"#),
-        @r###"
-    [15; 20) '{ 1 }': u32
-    [17; 18) '1': u32
-    [48; 53) '{ 1 }': u32
-    [50; 51) '1': u32
-    [67; 91) '{     ...c(); }': ()
-    [73; 74) 'a': fn a() -> u32
-    [73; 76) 'a()': u32
-    [82; 86) 'b::c': fn c() -> u32
-    [82; 88) 'b::c()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_path_type() {
-    assert_snapshot!(
-        infer(r#"
-struct S;
-
-impl S {
-    fn foo() -> i32 { 1 }
-}
-
-fn test() {
-    S::foo();
-    <S>::foo();
-}
-"#),
-        @r###"
-    [41; 46) '{ 1 }': i32
-    [43; 44) '1': i32
-    [60; 93) '{     ...o(); }': ()
-    [66; 72) 'S::foo': fn foo() -> i32
-    [66; 74) 'S::foo()': i32
-    [80; 88) '<S>::foo': fn foo() -> i32
-    [80; 90) '<S>::foo()': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_slice_method() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "slice"]
-impl<T> [T] {
-    fn foo(&self) -> T {
-        loop {}
-    }
-}
-
-#[lang = "slice_alloc"]
-impl<T> [T] {}
-
-fn test() {
-    <[_]>::foo(b"foo");
-}
-"#),
-        @r###"
-    [45; 49) 'self': &[T]
-    [56; 79) '{     ...     }': T
-    [66; 73) 'loop {}': !
-    [71; 73) '{}': ()
-    [133; 160) '{     ...o"); }': ()
-    [139; 149) '<[_]>::foo': fn foo<u8>(&[T]) -> T
-    [139; 157) '<[_]>:..."foo")': u8
-    [150; 156) 'b"foo"': &[u8]
-    "###
-    );
-}
-
-#[test]
-fn infer_struct() {
-    assert_snapshot!(
-        infer(r#"
-struct A {
-    b: B,
-    c: C,
-}
-struct B;
-struct C(usize);
-
-fn test() {
-    let c = C(1);
-    B;
-    let a: A = A { b: B, c: C(1) };
-    a.b;
-    a.c;
-}
-"#),
-        @r###"
-    [72; 154) '{     ...a.c; }': ()
-    [82; 83) 'c': C
-    [86; 87) 'C': C(usize) -> C
-    [86; 90) 'C(1)': C
-    [88; 89) '1': usize
-    [96; 97) 'B': B
-    [107; 108) 'a': A
-    [114; 133) 'A { b:...C(1) }': A
-    [121; 122) 'B': B
-    [127; 128) 'C': C(usize) -> C
-    [127; 131) 'C(1)': C
-    [129; 130) '1': usize
-    [139; 140) 'a': A
-    [139; 142) 'a.b': B
-    [148; 149) 'a': A
-    [148; 151) 'a.c': C
-    "###
-    );
-}
-
-#[test]
-fn infer_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum E {
-  V1 { field: u32 },
-  V2
-}
-fn test() {
-  E::V1 { field: 1 };
-  E::V2;
-}"#),
-        @r###"
-    [48; 82) '{   E:...:V2; }': ()
-    [52; 70) 'E::V1 ...d: 1 }': E
-    [67; 68) '1': u32
-    [74; 79) 'E::V2': E
-    "###
-    );
-}
-
-#[test]
-fn infer_refs() {
-    assert_snapshot!(
-        infer(r#"
-fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
-    a;
-    *a;
-    &a;
-    &mut a;
-    b;
-    *b;
-    &b;
-    c;
-    *c;
-    d;
-    *d;
-}
-"#),
-        @r###"
-    [9; 10) 'a': &u32
-    [18; 19) 'b': &mut u32
-    [31; 32) 'c': *const u32
-    [46; 47) 'd': *mut u32
-    [59; 150) '{     ... *d; }': ()
-    [65; 66) 'a': &u32
-    [72; 74) '*a': u32
-    [73; 74) 'a': &u32
-    [80; 82) '&a': &&u32
-    [81; 82) 'a': &u32
-    [88; 94) '&mut a': &mut &u32
-    [93; 94) 'a': &u32
-    [100; 101) 'b': &mut u32
-    [107; 109) '*b': u32
-    [108; 109) 'b': &mut u32
-    [115; 117) '&b': &&mut u32
-    [116; 117) 'b': &mut u32
-    [123; 124) 'c': *const u32
-    [130; 132) '*c': u32
-    [131; 132) 'c': *const u32
-    [138; 139) 'd': *mut u32
-    [145; 147) '*d': u32
-    [146; 147) 'd': *mut u32
-    "###
-    );
-}
-
-#[test]
-fn infer_literals() {
-    assert_snapshot!(
-        infer(r##"
-fn test() {
-    5i32;
-    5f32;
-    5f64;
-    "hello";
-    b"bytes";
-    'c';
-    b'b';
-    3.14;
-    5000;
-    false;
-    true;
-    r#"
-        //! doc
-        // non-doc
-        mod foo {}
-        "#;
-    br#"yolo"#;
-}
-"##),
-        @r###"
-    [11; 221) '{     ...o"#; }': ()
-    [17; 21) '5i32': i32
-    [27; 31) '5f32': f32
-    [37; 41) '5f64': f64
-    [47; 54) '"hello"': &str
-    [60; 68) 'b"bytes"': &[u8]
-    [74; 77) ''c'': char
-    [83; 87) 'b'b'': u8
-    [93; 97) '3.14': f64
-    [103; 107) '5000': i32
-    [113; 118) 'false': bool
-    [124; 128) 'true': bool
-    [134; 202) 'r#"   ...    "#': &str
-    [208; 218) 'br#"yolo"#': &[u8]
-    "###
-    );
-}
-
-#[test]
-fn infer_unary_op() {
-    assert_snapshot!(
-        infer(r#"
-enum SomeType {}
-
-fn test(x: SomeType) {
-    let b = false;
-    let c = !b;
-    let a = 100;
-    let d: i128 = -a;
-    let e = -100;
-    let f = !!!true;
-    let g = !42;
-    let h = !10u32;
-    let j = !a;
-    -3.14;
-    !3;
-    -x;
-    !x;
-    -"hello";
-    !"hello";
-}
-"#),
-        @r###"
-    [27; 28) 'x': SomeType
-    [40; 272) '{     ...lo"; }': ()
-    [50; 51) 'b': bool
-    [54; 59) 'false': bool
-    [69; 70) 'c': bool
-    [73; 75) '!b': bool
-    [74; 75) 'b': bool
-    [85; 86) 'a': i128
-    [89; 92) '100': i128
-    [102; 103) 'd': i128
-    [112; 114) '-a': i128
-    [113; 114) 'a': i128
-    [124; 125) 'e': i32
-    [128; 132) '-100': i32
-    [129; 132) '100': i32
-    [142; 143) 'f': bool
-    [146; 153) '!!!true': bool
-    [147; 153) '!!true': bool
-    [148; 153) '!true': bool
-    [149; 153) 'true': bool
-    [163; 164) 'g': i32
-    [167; 170) '!42': i32
-    [168; 170) '42': i32
-    [180; 181) 'h': u32
-    [184; 190) '!10u32': u32
-    [185; 190) '10u32': u32
-    [200; 201) 'j': i128
-    [204; 206) '!a': i128
-    [205; 206) 'a': i128
-    [212; 217) '-3.14': f64
-    [213; 217) '3.14': f64
-    [223; 225) '!3': i32
-    [224; 225) '3': i32
-    [231; 233) '-x': {unknown}
-    [232; 233) 'x': SomeType
-    [239; 241) '!x': {unknown}
-    [240; 241) 'x': SomeType
-    [247; 255) '-"hello"': {unknown}
-    [248; 255) '"hello"': &str
-    [261; 269) '!"hello"': {unknown}
-    [262; 269) '"hello"': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_backwards() {
-    assert_snapshot!(
-        infer(r#"
-fn takes_u32(x: u32) {}
-
-struct S { i32_field: i32 }
-
-fn test() -> &mut &f64 {
-    let a = unknown_function();
-    takes_u32(a);
-    let b = unknown_function();
-    S { i32_field: b };
-    let c = unknown_function();
-    &mut &c
-}
-"#),
-        @r###"
-    [14; 15) 'x': u32
-    [22; 24) '{}': ()
-    [78; 231) '{     ...t &c }': &mut &f64
-    [88; 89) 'a': u32
-    [92; 108) 'unknow...nction': {unknown}
-    [92; 110) 'unknow...tion()': u32
-    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
-    [116; 128) 'takes_u32(a)': ()
-    [126; 127) 'a': u32
-    [138; 139) 'b': i32
-    [142; 158) 'unknow...nction': {unknown}
-    [142; 160) 'unknow...tion()': i32
-    [166; 184) 'S { i3...d: b }': S
-    [181; 182) 'b': i32
-    [194; 195) 'c': f64
-    [198; 214) 'unknow...nction': {unknown}
-    [198; 216) 'unknow...tion()': f64
-    [222; 229) '&mut &c': &mut &f64
-    [227; 229) '&c': &f64
-    [228; 229) 'c': f64
-    "###
-    );
-}
-
-#[test]
-fn infer_self() {
-    assert_snapshot!(
-        infer(r#"
-struct S;
-
-impl S {
-    fn test(&self) {
-        self;
-    }
-    fn test2(self: &Self) {
-        self;
-    }
-    fn test3() -> Self {
-        S {}
-    }
-    fn test4() -> Self {
-        Self {}
-    }
-}
-"#),
-        @r###"
-    [34; 38) 'self': &S
-    [40; 61) '{     ...     }': ()
-    [50; 54) 'self': &S
-    [75; 79) 'self': &S
-    [88; 109) '{     ...     }': ()
-    [98; 102) 'self': &S
-    [133; 153) '{     ...     }': S
-    [143; 147) 'S {}': S
-    [177; 200) '{     ...     }': S
-    [187; 194) 'Self {}': S
-    "###
-    );
-}
-
-#[test]
-fn infer_binary_op() {
-    assert_snapshot!(
-        infer(r#"
-fn f(x: bool) -> i32 {
-    0i32
-}
-
-fn test() -> bool {
-    let x = a && b;
-    let y = true || false;
-    let z = x == y;
-    let t = x != y;
-    let minus_forty: isize = -40isize;
-    let h = minus_forty <= CONST_2;
-    let c = f(z || y) + 5;
-    let d = b;
-    let g = minus_forty ^= i;
-    let ten: usize = 10;
-    let ten_is_eleven = ten == some_num;
-
-    ten < 3
-}
-"#),
-        @r###"
-    [6; 7) 'x': bool
-    [22; 34) '{     0i32 }': i32
-    [28; 32) '0i32': i32
-    [54; 370) '{     ... < 3 }': bool
-    [64; 65) 'x': bool
-    [68; 69) 'a': bool
-    [68; 74) 'a && b': bool
-    [73; 74) 'b': bool
-    [84; 85) 'y': bool
-    [88; 92) 'true': bool
-    [88; 101) 'true || false': bool
-    [96; 101) 'false': bool
-    [111; 112) 'z': bool
-    [115; 116) 'x': bool
-    [115; 121) 'x == y': bool
-    [120; 121) 'y': bool
-    [131; 132) 't': bool
-    [135; 136) 'x': bool
-    [135; 141) 'x != y': bool
-    [140; 141) 'y': bool
-    [151; 162) 'minus_forty': isize
-    [172; 180) '-40isize': isize
-    [173; 180) '40isize': isize
-    [190; 191) 'h': bool
-    [194; 205) 'minus_forty': isize
-    [194; 216) 'minus_...ONST_2': bool
-    [209; 216) 'CONST_2': isize
-    [226; 227) 'c': i32
-    [230; 231) 'f': fn f(bool) -> i32
-    [230; 239) 'f(z || y)': i32
-    [230; 243) 'f(z || y) + 5': i32
-    [232; 233) 'z': bool
-    [232; 238) 'z || y': bool
-    [237; 238) 'y': bool
-    [242; 243) '5': i32
-    [253; 254) 'd': {unknown}
-    [257; 258) 'b': {unknown}
-    [268; 269) 'g': ()
-    [272; 283) 'minus_forty': isize
-    [272; 288) 'minus_...y ^= i': ()
-    [287; 288) 'i': isize
-    [298; 301) 'ten': usize
-    [311; 313) '10': usize
-    [323; 336) 'ten_is_eleven': bool
-    [339; 342) 'ten': usize
-    [339; 354) 'ten == some_num': bool
-    [346; 354) 'some_num': usize
-    [361; 364) 'ten': usize
-    [361; 368) 'ten < 3': bool
-    [367; 368) '3': usize
-    "###
-    );
-}
-
-#[test]
-fn infer_field_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-struct A {
-    b: B,
-}
-struct B;
-
-fn test1(a: A) {
-    let a1 = a;
-    a1.b;
-    let a2 = &a;
-    a2.b;
-    let a3 = &mut a;
-    a3.b;
-    let a4 = &&&&&&&a;
-    a4.b;
-    let a5 = &mut &&mut &&mut a;
-    a5.b;
-}
-
-fn test2(a1: *const A, a2: *mut A) {
-    a1.b;
-    a2.b;
-}
-"#),
-        @r###"
-    [44; 45) 'a': A
-    [50; 213) '{     ...5.b; }': ()
-    [60; 62) 'a1': A
-    [65; 66) 'a': A
-    [72; 74) 'a1': A
-    [72; 76) 'a1.b': B
-    [86; 88) 'a2': &A
-    [91; 93) '&a': &A
-    [92; 93) 'a': A
-    [99; 101) 'a2': &A
-    [99; 103) 'a2.b': B
-    [113; 115) 'a3': &mut A
-    [118; 124) '&mut a': &mut A
-    [123; 124) 'a': A
-    [130; 132) 'a3': &mut A
-    [130; 134) 'a3.b': B
-    [144; 146) 'a4': &&&&&&&A
-    [149; 157) '&&&&&&&a': &&&&&&&A
-    [150; 157) '&&&&&&a': &&&&&&A
-    [151; 157) '&&&&&a': &&&&&A
-    [152; 157) '&&&&a': &&&&A
-    [153; 157) '&&&a': &&&A
-    [154; 157) '&&a': &&A
-    [155; 157) '&a': &A
-    [156; 157) 'a': A
-    [163; 165) 'a4': &&&&&&&A
-    [163; 167) 'a4.b': B
-    [177; 179) 'a5': &mut &&mut &&mut A
-    [182; 200) '&mut &...&mut a': &mut &&mut &&mut A
-    [187; 200) '&&mut &&mut a': &&mut &&mut A
-    [188; 200) '&mut &&mut a': &mut &&mut A
-    [193; 200) '&&mut a': &&mut A
-    [194; 200) '&mut a': &mut A
-    [199; 200) 'a': A
-    [206; 208) 'a5': &mut &&mut &&mut A
-    [206; 210) 'a5.b': B
-    [224; 226) 'a1': *const A
-    [238; 240) 'a2': *mut A
-    [250; 273) '{     ...2.b; }': ()
-    [256; 258) 'a1': *const A
-    [256; 260) 'a1.b': B
-    [266; 268) 'a2': *mut A
-    [266; 270) 'a2.b': B
-    "###
-    );
-}
-
-#[test]
-fn infer_argument_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct A<T>(T);
-
-impl<T> A<T> {
-    fn foo(&self) -> &T {
-        &self.0
-    }
-}
-
-struct B<T>(T);
-
-impl<T> Deref for B<T> {
-    type Target = T;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-fn test() {
-    let t = A::foo(&&B(B(A(42))));
-}
-"#),
-        @r###"
-    [68; 72) 'self': &Self
-    [139; 143) 'self': &A<T>
-    [151; 174) '{     ...     }': &T
-    [161; 168) '&self.0': &T
-    [162; 166) 'self': &A<T>
-    [162; 168) 'self.0': T
-    [255; 259) 'self': &B<T>
-    [278; 301) '{     ...     }': &T
-    [288; 295) '&self.0': &T
-    [289; 293) 'self': &B<T>
-    [289; 295) 'self.0': T
-    [315; 353) '{     ...))); }': ()
-    [325; 326) 't': &i32
-    [329; 335) 'A::foo': fn foo<i32>(&A<T>) -> &T
-    [329; 350) 'A::foo...42))))': &i32
-    [336; 349) '&&B(B(A(42)))': &&B<B<A<i32>>>
-    [337; 349) '&B(B(A(42)))': &B<B<A<i32>>>
-    [338; 339) 'B': B<B<A<i32>>>(T) -> B<T>
-    [338; 349) 'B(B(A(42)))': B<B<A<i32>>>
-    [340; 341) 'B': B<A<i32>>(T) -> B<T>
-    [340; 348) 'B(A(42))': B<A<i32>>
-    [342; 343) 'A': A<i32>(T) -> A<T>
-    [342; 347) 'A(42)': A<i32>
-    [344; 346) '42': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_method_argument_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "deref"]
-pub trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct A<T>(*mut T);
-
-impl<T> A<T> {
-    fn foo(&self, x: &A<T>) -> &T {
-        &*x.0
-    }
-}
-
-struct B<T>(T);
-
-impl<T> Deref for B<T> {
-    type Target = T;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-fn test(a: A<i32>) {
-    let t = A(0 as *mut _).foo(&&B(B(a)));
-}
-"#),
-        @r###"
-    [68; 72) 'self': &Self
-    [144; 148) 'self': &A<T>
-    [150; 151) 'x': &A<T>
-    [166; 187) '{     ...     }': &T
-    [176; 181) '&*x.0': &T
-    [177; 181) '*x.0': T
-    [178; 179) 'x': &A<T>
-    [178; 181) 'x.0': *mut T
-    [268; 272) 'self': &B<T>
-    [291; 314) '{     ...     }': &T
-    [301; 308) '&self.0': &T
-    [302; 306) 'self': &B<T>
-    [302; 308) 'self.0': T
-    [326; 327) 'a': A<i32>
-    [337; 383) '{     ...))); }': ()
-    [347; 348) 't': &i32
-    [351; 352) 'A': A<i32>(*mut T) -> A<T>
-    [351; 365) 'A(0 as *mut _)': A<i32>
-    [351; 380) 'A(0 as...B(a)))': &i32
-    [353; 354) '0': i32
-    [353; 364) '0 as *mut _': *mut i32
-    [370; 379) '&&B(B(a))': &&B<B<A<i32>>>
-    [371; 379) '&B(B(a))': &B<B<A<i32>>>
-    [372; 373) 'B': B<B<A<i32>>>(T) -> B<T>
-    [372; 379) 'B(B(a))': B<B<A<i32>>>
-    [374; 375) 'B': B<A<i32>>(T) -> B<T>
-    [374; 378) 'B(a)': B<A<i32>>
-    [376; 377) 'a': A<i32>
-    "###
-    );
-}
-
-#[test]
-fn bug_484() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-   let x = if true {};
-}
-"#),
-        @r###"
-    [11; 37) '{    l... {}; }': ()
-    [20; 21) 'x': ()
-    [24; 34) 'if true {}': ()
-    [27; 31) 'true': bool
-    [32; 34) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_in_elseif() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo { field: i32 }
-fn main(foo: Foo) {
-    if true {
-
-    } else if false {
-        foo.field
-    }
-}
-"#),
-        @r###"
-    [35; 38) 'foo': Foo
-    [45; 109) '{     ...   } }': ()
-    [51; 107) 'if tru...     }': ()
-    [54; 58) 'true': bool
-    [59; 67) '{      }': ()
-    [73; 107) 'if fal...     }': ()
-    [76; 81) 'false': bool
-    [82; 107) '{     ...     }': i32
-    [92; 95) 'foo': Foo
-    [92; 101) 'foo.field': i32
-    "###
-    )
-}
-
-#[test]
-fn infer_if_match_with_return() {
-    assert_snapshot!(
-        infer(r#"
-fn foo() {
-    let _x1 = if true {
-        1
-    } else {
-        return;
-    };
-    let _x2 = if true {
-        2
-    } else {
-        return
-    };
-    let _x3 = match true {
-        true => 3,
-        _ => {
-            return;
-        }
-    };
-    let _x4 = match true {
-        true => 4,
-        _ => return
-    };
-}"#),
-        @r###"
-    [10; 323) '{     ...  }; }': ()
-    [20; 23) '_x1': i32
-    [26; 80) 'if tru...     }': i32
-    [29; 33) 'true': bool
-    [34; 51) '{     ...     }': i32
-    [44; 45) '1': i32
-    [57; 80) '{     ...     }': !
-    [67; 73) 'return': !
-    [90; 93) '_x2': i32
-    [96; 149) 'if tru...     }': i32
-    [99; 103) 'true': bool
-    [104; 121) '{     ...     }': i32
-    [114; 115) '2': i32
-    [127; 149) '{     ...     }': !
-    [137; 143) 'return': !
-    [159; 162) '_x3': i32
-    [165; 247) 'match ...     }': i32
-    [171; 175) 'true': bool
-    [186; 190) 'true': bool
-    [194; 195) '3': i32
-    [205; 206) '_': bool
-    [210; 241) '{     ...     }': !
-    [224; 230) 'return': !
-    [257; 260) '_x4': i32
-    [263; 320) 'match ...     }': i32
-    [269; 273) 'true': bool
-    [284; 288) 'true': bool
-    [292; 293) '4': i32
-    [303; 304) '_': bool
-    [308; 314) 'return': !
-    "###
-    )
-}
-
-#[test]
-fn infer_inherent_method() {
-    assert_snapshot!(
-        infer(r#"
-struct A;
-
-impl A {
-    fn foo(self, x: u32) -> i32 {}
-}
-
-mod b {
-    impl super::A {
-        fn bar(&self, x: u64) -> i64 {}
-    }
-}
-
-fn test(a: A) {
-    a.foo(1);
-    (&a).bar(1);
-    a.bar(1);
-}
-"#),
-        @r###"
-    [32; 36) 'self': A
-    [38; 39) 'x': u32
-    [53; 55) '{}': ()
-    [103; 107) 'self': &A
-    [109; 110) 'x': u64
-    [124; 126) '{}': ()
-    [144; 145) 'a': A
-    [150; 198) '{     ...(1); }': ()
-    [156; 157) 'a': A
-    [156; 164) 'a.foo(1)': i32
-    [162; 163) '1': u32
-    [170; 181) '(&a).bar(1)': i64
-    [171; 173) '&a': &A
-    [172; 173) 'a': A
-    [179; 180) '1': u64
-    [187; 188) 'a': A
-    [187; 195) 'a.bar(1)': i64
-    [193; 194) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_inherent_method_str() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "str"]
-impl str {
-    fn foo(&self) -> i32 {}
-}
-
-fn test() {
-    "foo".foo();
-}
-"#),
-        @r###"
-    [40; 44) 'self': &str
-    [53; 55) '{}': ()
-    [69; 89) '{     ...o(); }': ()
-    [75; 80) '"foo"': &str
-    [75; 86) '"foo".foo()': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_tuple() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &str, y: isize) {
-    let a: (u32, &str) = (1, "a");
-    let b = (a, x);
-    let c = (y, x);
-    let d = (c, x);
-    let e = (1, "e");
-    let f = (e, "d");
-}
-"#),
-        @r###"
-    [9; 10) 'x': &str
-    [18; 19) 'y': isize
-    [28; 170) '{     ...d"); }': ()
-    [38; 39) 'a': (u32, &str)
-    [55; 63) '(1, "a")': (u32, &str)
-    [56; 57) '1': u32
-    [59; 62) '"a"': &str
-    [73; 74) 'b': ((u32, &str), &str)
-    [77; 83) '(a, x)': ((u32, &str), &str)
-    [78; 79) 'a': (u32, &str)
-    [81; 82) 'x': &str
-    [93; 94) 'c': (isize, &str)
-    [97; 103) '(y, x)': (isize, &str)
-    [98; 99) 'y': isize
-    [101; 102) 'x': &str
-    [113; 114) 'd': ((isize, &str), &str)
-    [117; 123) '(c, x)': ((isize, &str), &str)
-    [118; 119) 'c': (isize, &str)
-    [121; 122) 'x': &str
-    [133; 134) 'e': (i32, &str)
-    [137; 145) '(1, "e")': (i32, &str)
-    [138; 139) '1': i32
-    [141; 144) '"e"': &str
-    [155; 156) 'f': ((i32, &str), &str)
-    [159; 167) '(e, "d")': ((i32, &str), &str)
-    [160; 161) 'e': (i32, &str)
-    [163; 166) '"d"': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_array() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &str, y: isize) {
-    let a = [x];
-    let b = [a, a];
-    let c = [b, b];
-
-    let d = [y, 1, 2, 3];
-    let d = [1, y, 2, 3];
-    let e = [y];
-    let f = [d, d];
-    let g = [e, e];
-
-    let h = [1, 2];
-    let i = ["a", "b"];
-
-    let b = [a, ["b"]];
-    let x: [u8; 0] = [];
-}
-"#),
-        @r###"
-    [9; 10) 'x': &str
-    [18; 19) 'y': isize
-    [28; 293) '{     ... []; }': ()
-    [38; 39) 'a': [&str;_]
-    [42; 45) '[x]': [&str;_]
-    [43; 44) 'x': &str
-    [55; 56) 'b': [[&str;_];_]
-    [59; 65) '[a, a]': [[&str;_];_]
-    [60; 61) 'a': [&str;_]
-    [63; 64) 'a': [&str;_]
-    [75; 76) 'c': [[[&str;_];_];_]
-    [79; 85) '[b, b]': [[[&str;_];_];_]
-    [80; 81) 'b': [[&str;_];_]
-    [83; 84) 'b': [[&str;_];_]
-    [96; 97) 'd': [isize;_]
-    [100; 112) '[y, 1, 2, 3]': [isize;_]
-    [101; 102) 'y': isize
-    [104; 105) '1': isize
-    [107; 108) '2': isize
-    [110; 111) '3': isize
-    [122; 123) 'd': [isize;_]
-    [126; 138) '[1, y, 2, 3]': [isize;_]
-    [127; 128) '1': isize
-    [130; 131) 'y': isize
-    [133; 134) '2': isize
-    [136; 137) '3': isize
-    [148; 149) 'e': [isize;_]
-    [152; 155) '[y]': [isize;_]
-    [153; 154) 'y': isize
-    [165; 166) 'f': [[isize;_];_]
-    [169; 175) '[d, d]': [[isize;_];_]
-    [170; 171) 'd': [isize;_]
-    [173; 174) 'd': [isize;_]
-    [185; 186) 'g': [[isize;_];_]
-    [189; 195) '[e, e]': [[isize;_];_]
-    [190; 191) 'e': [isize;_]
-    [193; 194) 'e': [isize;_]
-    [206; 207) 'h': [i32;_]
-    [210; 216) '[1, 2]': [i32;_]
-    [211; 212) '1': i32
-    [214; 215) '2': i32
-    [226; 227) 'i': [&str;_]
-    [230; 240) '["a", "b"]': [&str;_]
-    [231; 234) '"a"': &str
-    [236; 239) '"b"': &str
-    [251; 252) 'b': [[&str;_];_]
-    [255; 265) '[a, ["b"]]': [[&str;_];_]
-    [256; 257) 'a': [&str;_]
-    [259; 264) '["b"]': [&str;_]
-    [260; 263) '"b"': &str
-    [275; 276) 'x': [u8;_]
-    [288; 290) '[]': [u8;_]
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern() {
-    assert_snapshot!(
-        infer(r#"
-fn test(x: &i32) {
-    let y = x;
-    let &z = x;
-    let a = z;
-    let (c, d) = (1, "hello");
-
-    for (e, f) in some_iter {
-        let g = e;
-    }
-
-    if let [val] = opt {
-        let h = val;
-    }
-
-    let lambda = |a: u64, b, c: i32| { a + b; c };
-
-    let ref ref_to_x = x;
-    let mut mut_x = x;
-    let ref mut mut_ref_to_x = x;
-    let k = mut_ref_to_x;
-}
-"#),
-        @r###"
-    [9; 10) 'x': &i32
-    [18; 369) '{     ...o_x; }': ()
-    [28; 29) 'y': &i32
-    [32; 33) 'x': &i32
-    [43; 45) '&z': &i32
-    [44; 45) 'z': i32
-    [48; 49) 'x': &i32
-    [59; 60) 'a': i32
-    [63; 64) 'z': i32
-    [74; 80) '(c, d)': (i32, &str)
-    [75; 76) 'c': i32
-    [78; 79) 'd': &str
-    [83; 95) '(1, "hello")': (i32, &str)
-    [84; 85) '1': i32
-    [87; 94) '"hello"': &str
-    [102; 152) 'for (e...     }': ()
-    [106; 112) '(e, f)': ({unknown}, {unknown})
-    [107; 108) 'e': {unknown}
-    [110; 111) 'f': {unknown}
-    [116; 125) 'some_iter': {unknown}
-    [126; 152) '{     ...     }': ()
-    [140; 141) 'g': {unknown}
-    [144; 145) 'e': {unknown}
-    [158; 205) 'if let...     }': ()
-    [165; 170) '[val]': {unknown}
-    [173; 176) 'opt': {unknown}
-    [177; 205) '{     ...     }': ()
-    [191; 192) 'h': {unknown}
-    [195; 198) 'val': {unknown}
-    [215; 221) 'lambda': |u64, u64, i32| -> i32
-    [224; 256) '|a: u6...b; c }': |u64, u64, i32| -> i32
-    [225; 226) 'a': u64
-    [233; 234) 'b': u64
-    [236; 237) 'c': i32
-    [244; 256) '{ a + b; c }': i32
-    [246; 247) 'a': u64
-    [246; 251) 'a + b': u64
-    [250; 251) 'b': u64
-    [253; 254) 'c': i32
-    [267; 279) 'ref ref_to_x': &&i32
-    [282; 283) 'x': &i32
-    [293; 302) 'mut mut_x': &i32
-    [305; 306) 'x': &i32
-    [316; 336) 'ref mu...f_to_x': &mut &i32
-    [339; 340) 'x': &i32
-    [350; 351) 'k': &mut &i32
-    [354; 366) 'mut_ref_to_x': &mut &i32
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern_match_ergonomics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T>(T);
-
-fn test() {
-    let A(n) = &A(1);
-    let A(n) = &mut A(1);
-}
-"#),
-    @r###"
-    [28; 79) '{     ...(1); }': ()
-    [38; 42) 'A(n)': A<i32>
-    [40; 41) 'n': &i32
-    [45; 50) '&A(1)': &A<i32>
-    [46; 47) 'A': A<i32>(T) -> A<T>
-    [46; 50) 'A(1)': A<i32>
-    [48; 49) '1': i32
-    [60; 64) 'A(n)': A<i32>
-    [62; 63) 'n': &mut i32
-    [67; 76) '&mut A(1)': &mut A<i32>
-    [72; 73) 'A': A<i32>(T) -> A<T>
-    [72; 76) 'A(1)': A<i32>
-    [74; 75) '1': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_pattern_match_ergonomics_ref() {
-    covers!(match_ergonomics_ref);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let v = &(1, &2);
-    let (_, &w) = v;
-}
-"#),
-    @r###"
-    [11; 57) '{     ...= v; }': ()
-    [21; 22) 'v': &(i32, &i32)
-    [25; 33) '&(1, &2)': &(i32, &i32)
-    [26; 33) '(1, &2)': (i32, &i32)
-    [27; 28) '1': i32
-    [30; 32) '&2': &i32
-    [31; 32) '2': i32
-    [43; 50) '(_, &w)': (i32, &i32)
-    [44; 45) '_': i32
-    [47; 49) '&w': &i32
-    [48; 49) 'w': i32
-    [53; 54) 'v': &(i32, &i32)
-    "###
-    );
-}
-
-#[test]
-fn infer_adt_pattern() {
-    assert_snapshot!(
-        infer(r#"
-enum E {
-    A { x: usize },
-    B
-}
-
-struct S(u32, E);
-
-fn test() {
-    let e = E::A { x: 3 };
-
-    let S(y, z) = foo;
-    let E::A { x: new_var } = e;
-
-    match e {
-        E::A { x } => x,
-        E::B if foo => 1,
-        E::B => 10,
-    };
-
-    let ref d @ E::A { .. } = e;
-    d;
-}
-"#),
-        @r###"
-    [68; 289) '{     ...  d; }': ()
-    [78; 79) 'e': E
-    [82; 95) 'E::A { x: 3 }': E
-    [92; 93) '3': usize
-    [106; 113) 'S(y, z)': S
-    [108; 109) 'y': u32
-    [111; 112) 'z': E
-    [116; 119) 'foo': S
-    [129; 148) 'E::A {..._var }': E
-    [139; 146) 'new_var': usize
-    [151; 152) 'e': E
-    [159; 245) 'match ...     }': usize
-    [165; 166) 'e': E
-    [177; 187) 'E::A { x }': E
-    [184; 185) 'x': usize
-    [191; 192) 'x': usize
-    [202; 206) 'E::B': E
-    [210; 213) 'foo': bool
-    [217; 218) '1': usize
-    [228; 232) 'E::B': E
-    [236; 238) '10': usize
-    [256; 275) 'ref d ...{ .. }': &E
-    [264; 275) 'E::A { .. }': E
-    [278; 279) 'e': E
-    [285; 286) 'd': &E
-    "###
-    );
-}
-
-#[test]
-fn infer_struct_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-
-fn test(a1: A<u32>, i: i32) {
-    a1.x;
-    let a2 = A { x: i };
-    a2.x;
-    let a3 = A::<i128> { x: 1 };
-    a3.x;
-}
-"#),
-        @r###"
-    [36; 38) 'a1': A<u32>
-    [48; 49) 'i': i32
-    [56; 147) '{     ...3.x; }': ()
-    [62; 64) 'a1': A<u32>
-    [62; 66) 'a1.x': u32
-    [76; 78) 'a2': A<i32>
-    [81; 91) 'A { x: i }': A<i32>
-    [88; 89) 'i': i32
-    [97; 99) 'a2': A<i32>
-    [97; 101) 'a2.x': i32
-    [111; 113) 'a3': A<i128>
-    [116; 134) 'A::<i1...x: 1 }': A<i128>
-    [131; 132) '1': i128
-    [140; 142) 'a3': A<i128>
-    [140; 144) 'a3.x': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_tuple_struct_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T>(T);
-enum Option<T> { Some(T), None }
-use Option::*;
-
-fn test() {
-    A(42);
-    A(42u128);
-    Some("x");
-    Option::Some("x");
-    None;
-    let x: Option<i64> = None;
-}
-"#),
-        @r###"
-    [76; 184) '{     ...one; }': ()
-    [82; 83) 'A': A<i32>(T) -> A<T>
-    [82; 87) 'A(42)': A<i32>
-    [84; 86) '42': i32
-    [93; 94) 'A': A<u128>(T) -> A<T>
-    [93; 102) 'A(42u128)': A<u128>
-    [95; 101) '42u128': u128
-    [108; 112) 'Some': Some<&str>(T) -> Option<T>
-    [108; 117) 'Some("x")': Option<&str>
-    [113; 116) '"x"': &str
-    [123; 135) 'Option::Some': Some<&str>(T) -> Option<T>
-    [123; 140) 'Option...e("x")': Option<&str>
-    [136; 139) '"x"': &str
-    [146; 150) 'None': Option<{unknown}>
-    [160; 161) 'x': Option<i64>
-    [177; 181) 'None': Option<i64>
-    "###
-    );
-}
-
-#[test]
-fn infer_generics_in_patterns() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-
-enum Option<T> {
-    Some(T),
-    None,
-}
-
-fn test(a1: A<u32>, o: Option<u64>) {
-    let A { x: x2 } = a1;
-    let A::<i64> { x: x3 } = A { x: 1 };
-    match o {
-        Option::Some(t) => t,
-        _ => 1,
-    };
-}
-"#),
-        @r###"
-    [79; 81) 'a1': A<u32>
-    [91; 92) 'o': Option<u64>
-    [107; 244) '{     ...  }; }': ()
-    [117; 128) 'A { x: x2 }': A<u32>
-    [124; 126) 'x2': u32
-    [131; 133) 'a1': A<u32>
-    [143; 161) 'A::<i6...: x3 }': A<i64>
-    [157; 159) 'x3': i64
-    [164; 174) 'A { x: 1 }': A<i64>
-    [171; 172) '1': i64
-    [180; 241) 'match ...     }': u64
-    [186; 187) 'o': Option<u64>
-    [198; 213) 'Option::Some(t)': Option<u64>
-    [211; 212) 't': u64
-    [217; 218) 't': u64
-    [228; 229) '_': Option<u64>
-    [233; 234) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_function_generics() {
-    assert_snapshot!(
-        infer(r#"
-fn id<T>(t: T) -> T { t }
-
-fn test() {
-    id(1u32);
-    id::<i128>(1);
-    let x: u64 = id(1);
-}
-"#),
-        @r###"
-    [10; 11) 't': T
-    [21; 26) '{ t }': T
-    [23; 24) 't': T
-    [38; 98) '{     ...(1); }': ()
-    [44; 46) 'id': fn id<u32>(T) -> T
-    [44; 52) 'id(1u32)': u32
-    [47; 51) '1u32': u32
-    [58; 68) 'id::<i128>': fn id<i128>(T) -> T
-    [58; 71) 'id::<i128>(1)': i128
-    [69; 70) '1': i128
-    [81; 82) 'x': u64
-    [90; 92) 'id': fn id<u64>(T) -> T
-    [90; 95) 'id(1)': u64
-    [93; 94) '1': u64
-    "###
-    );
-}
-
-#[test]
-fn infer_impl_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T1, T2> {
-    x: T1,
-    y: T2,
-}
-impl<Y, X> A<X, Y> {
-    fn x(self) -> X {
-        self.x
-    }
-    fn y(self) -> Y {
-        self.y
-    }
-    fn z<T>(self, t: T) -> (X, Y, T) {
-        (self.x, self.y, t)
-    }
-}
-
-fn test() -> i128 {
-    let a = A { x: 1u64, y: 1i64 };
-    a.x();
-    a.y();
-    a.z(1i128);
-    a.z::<u128>(1);
-}
-"#),
-        @r###"
-    [74; 78) 'self': A<X, Y>
-    [85; 107) '{     ...     }': X
-    [95; 99) 'self': A<X, Y>
-    [95; 101) 'self.x': X
-    [117; 121) 'self': A<X, Y>
-    [128; 150) '{     ...     }': Y
-    [138; 142) 'self': A<X, Y>
-    [138; 144) 'self.y': Y
-    [163; 167) 'self': A<X, Y>
-    [169; 170) 't': T
-    [188; 223) '{     ...     }': (X, Y, T)
-    [198; 217) '(self.....y, t)': (X, Y, T)
-    [199; 203) 'self': A<X, Y>
-    [199; 205) 'self.x': X
-    [207; 211) 'self': A<X, Y>
-    [207; 213) 'self.y': Y
-    [215; 216) 't': T
-    [245; 342) '{     ...(1); }': ()
-    [255; 256) 'a': A<u64, i64>
-    [259; 281) 'A { x:...1i64 }': A<u64, i64>
-    [266; 270) '1u64': u64
-    [275; 279) '1i64': i64
-    [287; 288) 'a': A<u64, i64>
-    [287; 292) 'a.x()': u64
-    [298; 299) 'a': A<u64, i64>
-    [298; 303) 'a.y()': i64
-    [309; 310) 'a': A<u64, i64>
-    [309; 319) 'a.z(1i128)': (u64, i64, i128)
-    [313; 318) '1i128': i128
-    [325; 326) 'a': A<u64, i64>
-    [325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
-    [337; 338) '1': u128
-    "###
-    );
-}
-
-#[test]
-fn infer_impl_generics_with_autoderef() {
-    assert_snapshot!(
-        infer(r#"
-enum Option<T> {
-    Some(T),
-    None,
-}
-impl<T> Option<T> {
-    fn as_ref(&self) -> Option<&T> {}
-}
-fn test(o: Option<u32>) {
-    (&o).as_ref();
-    o.as_ref();
-}
-"#),
-        @r###"
-    [78; 82) 'self': &Option<T>
-    [98; 100) '{}': ()
-    [111; 112) 'o': Option<u32>
-    [127; 165) '{     ...f(); }': ()
-    [133; 146) '(&o).as_ref()': Option<&u32>
-    [134; 136) '&o': &Option<u32>
-    [135; 136) 'o': Option<u32>
-    [152; 153) 'o': Option<u32>
-    [152; 162) 'o.as_ref()': Option<&u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_generic_chain() {
-    assert_snapshot!(
-        infer(r#"
-struct A<T> {
-    x: T,
-}
-impl<T2> A<T2> {
-    fn x(self) -> T2 {
-        self.x
-    }
-}
-fn id<T>(t: T) -> T { t }
-
-fn test() -> i128 {
-     let x = 1;
-     let y = id(x);
-     let a = A { x: id(y) };
-     let z = id(a.x);
-     let b = A { x: z };
-     b.x()
-}
-"#),
-        @r###"
-    [53; 57) 'self': A<T2>
-    [65; 87) '{     ...     }': T2
-    [75; 79) 'self': A<T2>
-    [75; 81) 'self.x': T2
-    [99; 100) 't': T
-    [110; 115) '{ t }': T
-    [112; 113) 't': T
-    [135; 261) '{     ....x() }': i128
-    [146; 147) 'x': i128
-    [150; 151) '1': i128
-    [162; 163) 'y': i128
-    [166; 168) 'id': fn id<i128>(T) -> T
-    [166; 171) 'id(x)': i128
-    [169; 170) 'x': i128
-    [182; 183) 'a': A<i128>
-    [186; 200) 'A { x: id(y) }': A<i128>
-    [193; 195) 'id': fn id<i128>(T) -> T
-    [193; 198) 'id(y)': i128
-    [196; 197) 'y': i128
-    [211; 212) 'z': i128
-    [215; 217) 'id': fn id<i128>(T) -> T
-    [215; 222) 'id(a.x)': i128
-    [218; 219) 'a': A<i128>
-    [218; 221) 'a.x': i128
-    [233; 234) 'b': A<i128>
-    [237; 247) 'A { x: z }': A<i128>
-    [244; 245) 'z': i128
-    [254; 255) 'b': A<i128>
-    [254; 259) 'b.x()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_const() {
-    assert_snapshot!(
-        infer(r#"
-struct Struct;
-
-impl Struct {
-    const FOO: u32 = 1;
-}
-
-enum Enum {}
-
-impl Enum {
-    const BAR: u32 = 2;
-}
-
-trait Trait {
-    const ID: u32;
-}
-
-struct TraitTest;
-
-impl Trait for TraitTest {
-    const ID: u32 = 5;
-}
-
-fn test() {
-    let x = Struct::FOO;
-    let y = Enum::BAR;
-    let z = TraitTest::ID;
-}
-"#),
-        @r###"
-    [52; 53) '1': u32
-    [105; 106) '2': u32
-    [213; 214) '5': u32
-    [229; 307) '{     ...:ID; }': ()
-    [239; 240) 'x': u32
-    [243; 254) 'Struct::FOO': u32
-    [264; 265) 'y': u32
-    [268; 277) 'Enum::BAR': u32
-    [287; 288) 'z': u32
-    [291; 304) 'TraitTest::ID': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_struct() {
-    assert_snapshot!(
-        infer(r#"
-struct A { x: u32 }
-
-impl A {
-    fn new() -> A {
-        A { x: 0 }
-    }
-}
-fn test() {
-    let a = A::new();
-    a.x;
-}
-"#),
-        @r###"
-    [49; 75) '{     ...     }': A
-    [59; 69) 'A { x: 0 }': A
-    [66; 67) '0': u32
-    [88; 122) '{     ...a.x; }': ()
-    [98; 99) 'a': A
-    [102; 108) 'A::new': fn new() -> A
-    [102; 110) 'A::new()': A
-    [116; 117) 'a': A
-    [116; 119) 'a.x': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum A { B, C }
-
-impl A {
-    pub fn b() -> A {
-        A::B
-    }
-    pub fn c() -> A {
-        A::C
-    }
-}
-fn test() {
-    let a = A::b();
-    a;
-    let c = A::c();
-    c;
-}
-"#),
-        @r###"
-    [47; 67) '{     ...     }': A
-    [57; 61) 'A::B': A
-    [88; 108) '{     ...     }': A
-    [98; 102) 'A::C': A
-    [121; 178) '{     ...  c; }': ()
-    [131; 132) 'a': A
-    [135; 139) 'A::b': fn b() -> A
-    [135; 141) 'A::b()': A
-    [147; 148) 'a': A
-    [158; 159) 'c': A
-    [162; 166) 'A::c': fn c() -> A
-    [162; 168) 'A::c()': A
-    [174; 175) 'c': A
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_with_modules() {
-    assert_snapshot!(
-        infer(r#"
-mod a {
-    struct A;
-    impl A { pub fn thing() -> A { A {} }}
-}
-
-mod b {
-    struct B;
-    impl B { pub fn thing() -> u32 { 99 }}
-
-    mod c {
-        struct C;
-        impl C { pub fn thing() -> C { C {} }}
-    }
-}
-use b::c;
-
-fn test() {
-    let x = a::A::thing();
-    let y = b::B::thing();
-    let z = c::C::thing();
-}
-"#),
-        @r###"
-    [56; 64) '{ A {} }': A
-    [58; 62) 'A {}': A
-    [126; 132) '{ 99 }': u32
-    [128; 130) '99': u32
-    [202; 210) '{ C {} }': C
-    [204; 208) 'C {}': C
-    [241; 325) '{     ...g(); }': ()
-    [251; 252) 'x': A
-    [255; 266) 'a::A::thing': fn thing() -> A
-    [255; 268) 'a::A::thing()': A
-    [278; 279) 'y': u32
-    [282; 293) 'b::B::thing': fn thing() -> u32
-    [282; 295) 'b::B::thing()': u32
-    [305; 306) 'z': C
-    [309; 320) 'c::C::thing': fn thing() -> C
-    [309; 322) 'c::C::thing()': C
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make(val: T) -> Gen<T> {
-        Gen { val }
-    }
-}
-
-fn test() {
-    let a = Gen::make(0u32);
-}
-"#),
-        @r###"
-    [64; 67) 'val': T
-    [82; 109) '{     ...     }': Gen<T>
-    [92; 103) 'Gen { val }': Gen<T>
-    [98; 101) 'val': T
-    [123; 155) '{     ...32); }': ()
-    [133; 134) 'a': Gen<u32>
-    [137; 146) 'Gen::make': fn make<u32>(T) -> Gen<T>
-    [137; 152) 'Gen::make(0u32)': Gen<u32>
-    [147; 151) '0u32': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_param() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T=u32> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-}
-"#),
-        @r###"
-    [80; 104) '{     ...     }': Gen<T>
-    [90; 98) 'loop { }': !
-    [95; 98) '{ }': ()
-    [118; 146) '{     ...e(); }': ()
-    [128; 129) 'a': Gen<u32>
-    [132; 141) 'Gen::make': fn make<u32>() -> Gen<T>
-    [132; 143) 'Gen::make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_with_default_tuple_param() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct Gen<T=()> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::make();
-    a.val<|>;
-}
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
-fn infer_associated_method_generics_without_args() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T> {
-    val: T
-}
-
-impl<T> Gen<T> {
-    pub fn make() -> Gen<T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::<u32>::make();
-}
-"#),
-        @r###"
-    [76; 100) '{     ...     }': Gen<T>
-    [86; 94) 'loop { }': !
-    [91; 94) '{ }': ()
-    [114; 149) '{     ...e(); }': ()
-    [124; 125) 'a': Gen<u32>
-    [128; 144) 'Gen::<...::make': fn make<u32>() -> Gen<T>
-    [128; 146) 'Gen::<...make()': Gen<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_method_generics_2_type_params_without_args() {
-    assert_snapshot!(
-        infer(r#"
-struct Gen<T, U> {
-    val: T,
-    val2: U,
-}
-
-impl<T> Gen<u32, T> {
-    pub fn make() -> Gen<u32,T> {
-        loop { }
-    }
-}
-
-fn test() {
-    let a = Gen::<u32, u64>::make();
-}
-"#),
-        @r###"
-    [102; 126) '{     ...     }': Gen<u32, T>
-    [112; 120) 'loop { }': !
-    [117; 120) '{ }': ()
-    [140; 180) '{     ...e(); }': ()
-    [150; 151) 'a': Gen<u32, u64>
-    [154; 175) 'Gen::<...::make': fn make<u64>() -> Gen<u32, T>
-    [154; 177) 'Gen::<...make()': Gen<u32, u64>
-    "###
-    );
-}
-
-#[test]
-fn infer_type_alias() {
-    assert_snapshot!(
-        infer(r#"
-struct A<X, Y> { x: X, y: Y }
-type Foo = A<u32, i128>;
-type Bar<T> = A<T, u128>;
-type Baz<U, V> = A<V, U>;
-fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
-    x.x;
-    x.y;
-    y.x;
-    y.y;
-    z.x;
-    z.y;
-}
-"#),
-        @r###"
-    [116; 117) 'x': A<u32, i128>
-    [124; 125) 'y': A<&str, u128>
-    [138; 139) 'z': A<u8, i8>
-    [154; 211) '{     ...z.y; }': ()
-    [160; 161) 'x': A<u32, i128>
-    [160; 163) 'x.x': u32
-    [169; 170) 'x': A<u32, i128>
-    [169; 172) 'x.y': i128
-    [178; 179) 'y': A<&str, u128>
-    [178; 181) 'y.x': &str
-    [187; 188) 'y': A<&str, u128>
-    [187; 190) 'y.y': u128
-    [196; 197) 'z': A<u8, i8>
-    [196; 199) 'z.x': u8
-    [205; 206) 'z': A<u8, i8>
-    [205; 208) 'z.y': i8
-    "###
-    )
-}
-
-#[test]
-#[should_panic] // we currently can't handle this
-fn recursive_type_alias() {
-    assert_snapshot!(
-        infer(r#"
-struct A<X> {}
-type Foo = Foo;
-type Bar = A<Bar>;
-fn test(x: Foo) {}
-"#),
-        @""
-    )
-}
-
-#[test]
-fn no_panic_on_field_of_enum() {
-    assert_snapshot!(
-        infer(r#"
-enum X {}
-
-fn test(x: X) {
-    x.some_field;
-}
-"#),
-        @r###"
-    [20; 21) 'x': X
-    [26; 47) '{     ...eld; }': ()
-    [32; 33) 'x': X
-    [32; 44) 'x.some_field': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn bug_585() {
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    X {};
-    match x {
-        A::B {} => (),
-        A::Y() => (),
-    }
-}
-"#),
-        @r###"
-    [11; 89) '{     ...   } }': ()
-    [17; 21) 'X {}': {unknown}
-    [27; 87) 'match ...     }': ()
-    [33; 34) 'x': {unknown}
-    [45; 52) 'A::B {}': {unknown}
-    [56; 58) '()': ()
-    [68; 74) 'A::Y()': {unknown}
-    [78; 80) '()': ()
-    "###
-    );
-}
-
-#[test]
-fn bug_651() {
-    assert_snapshot!(
-        infer(r#"
-fn quux() {
-    let y = 92;
-    1 + y;
-}
-"#),
-        @r###"
-    [11; 41) '{     ...+ y; }': ()
-    [21; 22) 'y': i32
-    [25; 27) '92': i32
-    [33; 34) '1': i32
-    [33; 38) '1 + y': i32
-    [37; 38) 'y': i32
-    "###
-    );
-}
-
-#[test]
-fn recursive_vars() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let y = unknown;
-    [y, &y];
-}
-"#),
-        @r###"
-    [11; 48) '{     ...&y]; }': ()
-    [21; 22) 'y': &{unknown}
-    [25; 32) 'unknown': &{unknown}
-    [38; 45) '[y, &y]': [&&{unknown};_]
-    [39; 40) 'y': &{unknown}
-    [42; 44) '&y': &&{unknown}
-    [43; 44) 'y': &{unknown}
-    "###
-    );
-}
-
-#[test]
-fn recursive_vars_2() {
-    covers!(type_var_cycles_resolve_completely);
-    covers!(type_var_cycles_resolve_as_possible);
-    assert_snapshot!(
-        infer(r#"
-fn test() {
-    let x = unknown;
-    let y = unknown;
-    [(x, y), (&y, &x)];
-}
-"#),
-        @r###"
-    [11; 80) '{     ...x)]; }': ()
-    [21; 22) 'x': &&{unknown}
-    [25; 32) 'unknown': &&{unknown}
-    [42; 43) 'y': &&{unknown}
-    [46; 53) 'unknown': &&{unknown}
-    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
-    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
-    [61; 62) 'x': &&{unknown}
-    [64; 65) 'y': &&{unknown}
-    [68; 76) '(&y, &x)': (&&&{unknown}, &&&{unknown})
-    [69; 71) '&y': &&&{unknown}
-    [70; 71) 'y': &&{unknown}
-    [73; 75) '&x': &&&{unknown}
-    [74; 75) 'x': &&{unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_type_param() {
-    assert_snapshot!(
-        infer(r#"
-fn id<T>(x: T) -> T {
-    x
-}
-
-fn clone<T>(x: &T) -> T {
-    *x
-}
-
-fn test() {
-    let y = 10u32;
-    id(y);
-    let x: bool = clone(z);
-    id::<i128>(1);
-}
-"#),
-        @r###"
-    [10; 11) 'x': T
-    [21; 30) '{     x }': T
-    [27; 28) 'x': T
-    [44; 45) 'x': &T
-    [56; 66) '{     *x }': T
-    [62; 64) '*x': T
-    [63; 64) 'x': &T
-    [78; 158) '{     ...(1); }': ()
-    [88; 89) 'y': u32
-    [92; 97) '10u32': u32
-    [103; 105) 'id': fn id<u32>(T) -> T
-    [103; 108) 'id(y)': u32
-    [106; 107) 'y': u32
-    [118; 119) 'x': bool
-    [128; 133) 'clone': fn clone<bool>(&T) -> T
-    [128; 136) 'clone(z)': bool
-    [134; 135) 'z': &bool
-    [142; 152) 'id::<i128>': fn id<i128>(T) -> T
-    [142; 155) 'id::<i128>(1)': i128
-    [153; 154) '1': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_1() {
-    // caused stack overflow, taken from std
-    assert_snapshot!(
-        infer(r#"
-enum Maybe<T> {
-    Real(T),
-    Fake,
-}
-
-fn write() {
-    match something_unknown {
-        Maybe::Real(ref mut something) => (),
-    }
-}
-"#),
-        @r###"
-    [54; 139) '{     ...   } }': ()
-    [60; 137) 'match ...     }': ()
-    [66; 83) 'someth...nknown': Maybe<{unknown}>
-    [94; 124) 'Maybe:...thing)': Maybe<{unknown}>
-    [106; 123) 'ref mu...ething': &mut {unknown}
-    [128; 130) '()': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_2() {
-    covers!(type_var_resolves_to_int_var);
-    // caused "equating two type variables, ...", taken from std
-    assert_snapshot!(
-        infer(r#"
-fn test_line_buffer() {
-    &[0, b'\n', 1, b'\n'];
-}
-"#),
-        @r###"
-    [23; 53) '{     ...n']; }': ()
-    [29; 50) '&[0, b...b'\n']': &[u8;_]
-    [30; 50) '[0, b'...b'\n']': [u8;_]
-    [31; 32) '0': u8
-    [34; 39) 'b'\n'': u8
-    [41; 42) '1': u8
-    [44; 49) 'b'\n'': u8
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_3() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-pub fn compute() {
-    match nope!() {
-        SizeSkeleton::Pointer { non_zero: true, tail } => {}
-    }
-}
-"#),
-        @r###"
-    [18; 108) '{     ...   } }': ()
-    [24; 106) 'match ...     }': ()
-    [30; 37) 'nope!()': {unknown}
-    [48; 94) 'SizeSk...tail }': {unknown}
-    [82; 86) 'true': {unknown}
-    [88; 92) 'tail': {unknown}
-    [98; 100) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_4() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-pub fn primitive_type() {
-    match *self {
-        BorrowedRef { type_: Primitive(p), ..} => {},
-    }
-}
-"#),
-        @r###"
-    [25; 106) '{     ...   } }': ()
-    [31; 104) 'match ...     }': ()
-    [37; 42) '*self': {unknown}
-    [38; 42) 'self': {unknown}
-    [53; 91) 'Borrow...), ..}': {unknown}
-    [74; 86) 'Primitive(p)': {unknown}
-    [84; 85) 'p': {unknown}
-    [95; 97) '{}': ()
-    "###
-    );
-}
-
-#[test]
-fn infer_std_crash_5() {
-    // taken from rustc
-    assert_snapshot!(
-        infer(r#"
-fn extra_compiler_flags() {
-    for content in doesnt_matter {
-        let name = if doesnt_matter {
-            first
-        } else {
-            &content
-        };
-
-        let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
-            name
-        } else {
-            content
-        };
-    }
-}
-"#),
-        @r###"
-    [27; 323) '{     ...   } }': ()
-    [33; 321) 'for co...     }': ()
-    [37; 44) 'content': &{unknown}
-    [48; 61) 'doesnt_matter': {unknown}
-    [62; 321) '{     ...     }': ()
-    [76; 80) 'name': &&{unknown}
-    [83; 167) 'if doe...     }': &&{unknown}
-    [86; 99) 'doesnt_matter': bool
-    [100; 129) '{     ...     }': &&{unknown}
-    [114; 119) 'first': &&{unknown}
-    [135; 167) '{     ...     }': &&{unknown}
-    [149; 157) '&content': &&{unknown}
-    [150; 157) 'content': &{unknown}
-    [182; 189) 'content': &{unknown}
-    [192; 314) 'if ICE...     }': &{unknown}
-    [195; 232) 'ICE_RE..._VALUE': {unknown}
-    [195; 248) 'ICE_RE...&name)': bool
-    [242; 247) '&name': &&&{unknown}
-    [243; 247) 'name': &&{unknown}
-    [249; 277) '{     ...     }': &&{unknown}
-    [263; 267) 'name': &&{unknown}
-    [283; 314) '{     ...     }': &{unknown}
-    [297; 304) 'content': &{unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_nested_generics_crash() {
-    // another crash found typechecking rustc
-    assert_snapshot!(
-        infer(r#"
-struct Canonical<V> {
-    value: V,
-}
-struct QueryResponse<V> {
-    value: V,
-}
-fn test<R>(query_response: Canonical<QueryResponse<R>>) {
-    &query_response.value;
-}
-"#),
-        @r###"
-    [92; 106) 'query_response': Canonical<QueryResponse<R>>
-    [137; 167) '{     ...lue; }': ()
-    [143; 164) '&query....value': &QueryResponse<R>
-    [144; 158) 'query_response': Canonical<QueryResponse<R>>
-    [144; 164) 'query_....value': QueryResponse<R>
-    "###
-    );
-}
-
-#[test]
-fn bug_1030() {
-    assert_snapshot!(infer(r#"
-struct HashSet<T, H>;
-struct FxHasher;
-type FxHashSet<T> = HashSet<T, FxHasher>;
-
-impl<T, H> HashSet<T, H> {
-    fn default() -> HashSet<T, H> {}
-}
-
-pub fn main_loop() {
-    FxHashSet::default();
-}
-"#),
-    @r###"
-    [144; 146) '{}': ()
-    [169; 198) '{     ...t(); }': ()
-    [175; 193) 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<T, H>
-    [175; 195) 'FxHash...ault()': HashSet<{unknown}, FxHasher>
-    "###
-    );
-}
-
-#[test]
-fn cross_crate_associated_method_call() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:other_crate
-fn test() {
-    let x = other_crate::foo::S::thing();
-    x<|>;
-}
-
-//- /lib.rs crate:other_crate
-mod foo {
-    struct S;
-    impl S {
-        fn thing() -> i128 {}
-    }
-}
-"#,
-    );
-    assert_eq!("i128", type_at_pos(&db, pos));
-}
-
-#[test]
-fn infer_const() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo;
-impl Foo { const ASSOC_CONST: u32 = 0; }
-const GLOBAL_CONST: u32 = 101;
-fn test() {
-    const LOCAL_CONST: u32 = 99;
-    let x = LOCAL_CONST;
-    let z = GLOBAL_CONST;
-    let id = Foo::ASSOC_CONST;
-}
-"#),
-        @r###"
-    [49; 50) '0': u32
-    [80; 83) '101': u32
-    [95; 213) '{     ...NST; }': ()
-    [138; 139) 'x': {unknown}
-    [142; 153) 'LOCAL_CONST': {unknown}
-    [163; 164) 'z': u32
-    [167; 179) 'GLOBAL_CONST': u32
-    [189; 191) 'id': u32
-    [194; 210) 'Foo::A..._CONST': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_static() {
-    assert_snapshot!(
-        infer(r#"
-static GLOBAL_STATIC: u32 = 101;
-static mut GLOBAL_STATIC_MUT: u32 = 101;
-fn test() {
-    static LOCAL_STATIC: u32 = 99;
-    static mut LOCAL_STATIC_MUT: u32 = 99;
-    let x = LOCAL_STATIC;
-    let y = LOCAL_STATIC_MUT;
-    let z = GLOBAL_STATIC;
-    let w = GLOBAL_STATIC_MUT;
-}
-"#),
-        @r###"
-    [29; 32) '101': u32
-    [70; 73) '101': u32
-    [85; 280) '{     ...MUT; }': ()
-    [173; 174) 'x': {unknown}
-    [177; 189) 'LOCAL_STATIC': {unknown}
-    [199; 200) 'y': {unknown}
-    [203; 219) 'LOCAL_...IC_MUT': {unknown}
-    [229; 230) 'z': u32
-    [233; 246) 'GLOBAL_STATIC': u32
-    [256; 257) 'w': u32
-    [260; 277) 'GLOBAL...IC_MUT': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_simple() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait1 {
-    fn method(&self) -> u32;
-}
-struct S1;
-impl Trait1 for S1 {}
-trait Trait2 {
-    fn method(&self) -> i128;
-}
-struct S2;
-impl Trait2 for S2 {}
-fn test() {
-    S1.method(); // -> u32
-    S2.method(); // -> i128
-}
-"#),
-        @r###"
-    [31; 35) 'self': &Self
-    [110; 114) 'self': &Self
-    [170; 228) '{     ...i128 }': ()
-    [176; 178) 'S1': S1
-    [176; 187) 'S1.method()': u32
-    [203; 205) 'S2': S2
-    [203; 214) 'S2.method()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_scoped() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-struct S;
-mod foo {
-    pub trait Trait1 {
-        fn method(&self) -> u32;
-    }
-    impl Trait1 for super::S {}
-}
-mod bar {
-    pub trait Trait2 {
-        fn method(&self) -> i128;
-    }
-    impl Trait2 for super::S {}
-}
-
-mod foo_test {
-    use super::S;
-    use super::foo::Trait1;
-    fn test() {
-        S.method(); // -> u32
-    }
-}
-
-mod bar_test {
-    use super::S;
-    use super::bar::Trait2;
-    fn test() {
-        S.method(); // -> i128
-    }
-}
-"#),
-        @r###"
-    [63; 67) 'self': &Self
-    [169; 173) 'self': &Self
-    [300; 337) '{     ...     }': ()
-    [310; 311) 'S': S
-    [310; 320) 'S.method()': u32
-    [416; 454) '{     ...     }': ()
-    [426; 427) 'S': S
-    [426; 436) 'S.method()': i128
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_1() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-struct S;
-impl Trait<u32> for S {}
-fn test() {
-    S.method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [92; 111) '{     ...d(); }': ()
-    [98; 99) 'S': S
-    [98; 108) 'S.method()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_more_params() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T1, T2, T3> {
-    fn method1(&self) -> (T1, T2, T3);
-    fn method2(&self) -> (T3, T2, T1);
-}
-struct S1;
-impl Trait<u8, u16, u32> for S1 {}
-struct S2;
-impl<T> Trait<i8, i16, T> for S2 {}
-fn test() {
-    S1.method1(); // u8, u16, u32
-    S1.method2(); // u32, u16, u8
-    S2.method1(); // i8, i16, {unknown}
-    S2.method2(); // {unknown}, i16, i8
-}
-"#),
-        @r###"
-    [43; 47) 'self': &Self
-    [82; 86) 'self': &Self
-    [210; 361) '{     ..., i8 }': ()
-    [216; 218) 'S1': S1
-    [216; 228) 'S1.method1()': (u8, u16, u32)
-    [250; 252) 'S1': S1
-    [250; 262) 'S1.method2()': (u32, u16, u8)
-    [284; 286) 'S2': S2
-    [284; 296) 'S2.method1()': (i8, i16, {unknown})
-    [324; 326) 'S2': S2
-    [324; 336) 'S2.method2()': ({unknown}, i16, i8)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_method_generic_2() {
-    // the trait implementation is intentionally incomplete -- it shouldn't matter
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn test() {
-    S(1u32).method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [102; 127) '{     ...d(); }': ()
-    [108; 109) 'S': S<u32>(T) -> S<T>
-    [108; 115) 'S(1u32)': S<u32>
-    [108; 124) 'S(1u32...thod()': u32
-    [110; 114) '1u32': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method() {
-    assert_snapshot!(
-        infer(r#"
-trait Default {
-    fn default() -> Self;
-}
-struct S;
-impl Default for S {}
-fn test() {
-    let s1: S = Default::default();
-    let s2 = S::default();
-    let s3 = <S as Default>::default();
-}
-"#),
-        @r###"
-    [87; 193) '{     ...t(); }': ()
-    [97; 99) 's1': S
-    [105; 121) 'Defaul...efault': fn default<S>() -> Self
-    [105; 123) 'Defaul...ault()': S
-    [133; 135) 's2': S
-    [138; 148) 'S::default': fn default<S>() -> Self
-    [138; 150) 'S::default()': S
-    [160; 162) 's3': S
-    [165; 188) '<S as ...efault': fn default<S>() -> Self
-    [165; 190) '<S as ...ault()': S
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> T;
-}
-struct S;
-impl Trait<u32> for S {}
-struct G<T>;
-impl<T> Trait<T> for G<T> {}
-fn test() {
-    let a = S::make();
-    let b = G::<u64>::make();
-    let c: f64 = G::make();
-}
-"#),
-        @r###"
-    [127; 211) '{     ...e(); }': ()
-    [137; 138) 'a': u32
-    [141; 148) 'S::make': fn make<S, u32>() -> T
-    [141; 150) 'S::make()': u32
-    [160; 161) 'b': u64
-    [164; 178) 'G::<u64>::make': fn make<G<u64>, u64>() -> T
-    [164; 180) 'G::<u6...make()': u64
-    [190; 191) 'c': f64
-    [199; 206) 'G::make': fn make<G<f64>, f64>() -> T
-    [199; 208) 'G::make()': f64
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make<U>() -> (T, U);
-}
-struct S;
-impl Trait<u32> for S {}
-struct G<T>;
-impl<T> Trait<T> for G<T> {}
-fn test() {
-    let a = S::make::<i64>();
-    let b: (_, i64) = S::make();
-    let c = G::<u32>::make::<i64>();
-    let d: (u32, _) = G::make::<i64>();
-    let e: (u32, i64) = G::make();
-}
-"#),
-        @r###"
-    [135; 313) '{     ...e(); }': ()
-    [145; 146) 'a': (u32, i64)
-    [149; 163) 'S::make::<i64>': fn make<S, u32, i64>() -> (T, U)
-    [149; 165) 'S::mak...i64>()': (u32, i64)
-    [175; 176) 'b': (u32, i64)
-    [189; 196) 'S::make': fn make<S, u32, i64>() -> (T, U)
-    [189; 198) 'S::make()': (u32, i64)
-    [208; 209) 'c': (u32, i64)
-    [212; 233) 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
-    [212; 235) 'G::<u3...i64>()': (u32, i64)
-    [245; 246) 'd': (u32, i64)
-    [259; 273) 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
-    [259; 275) 'G::mak...i64>()': (u32, i64)
-    [285; 286) 'e': (u32, i64)
-    [301; 308) 'G::make': fn make<G<u32>, u32, i64>() -> (T, U)
-    [301; 310) 'G::make()': (u32, i64)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_3() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> (Self, T);
-}
-struct S<T>;
-impl Trait<i64> for S<i32> {}
-fn test() {
-    let a = S::make();
-}
-"#),
-        @r###"
-    [101; 127) '{     ...e(); }': ()
-    [111; 112) 'a': (S<i32>, i64)
-    [115; 122) 'S::make': fn make<S<i32>, i64>() -> (Self, T)
-    [115; 124) 'S::make()': (S<i32>, i64)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_4() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make() -> (Self, T);
-}
-struct S<T>;
-impl Trait<i64> for S<u64> {}
-impl Trait<i32> for S<u32> {}
-fn test() {
-    let a: (S<u64>, _) = S::make();
-    let b: (_, i32) = S::make();
-}
-"#),
-        @r###"
-    [131; 203) '{     ...e(); }': ()
-    [141; 142) 'a': (S<u64>, i64)
-    [158; 165) 'S::make': fn make<S<u64>, i64>() -> (Self, T)
-    [158; 167) 'S::make()': (S<u64>, i64)
-    [177; 178) 'b': (S<u32>, i32)
-    [191; 198) 'S::make': fn make<S<u32>, i32>() -> (Self, T)
-    [191; 200) 'S::make()': (S<u32>, i32)
-    "###
-    );
-}
-
-#[test]
-fn infer_trait_assoc_method_generics_5() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn make<U>() -> (Self, T, U);
-}
-struct S<T>;
-impl Trait<i64> for S<u64> {}
-fn test() {
-    let a = <S as Trait<i64>>::make::<u8>();
-    let b: (S<u64>, _, _) = Trait::<i64>::make::<u8>();
-}
-"#),
-        @r###"
-    [107; 211) '{     ...>(); }': ()
-    [117; 118) 'a': (S<u64>, i64, u8)
-    [121; 150) '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
-    [121; 152) '<S as ...<u8>()': (S<u64>, i64, u8)
-    [162; 163) 'b': (S<u64>, i64, u8)
-    [182; 206) 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
-    [182; 208) 'Trait:...<u8>()': (S<u64>, i64, u8)
-    "###
-    );
-}
-
-#[test]
-fn infer_from_bound_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn foo<T: Trait<u32>>(t: T) {}
-fn test() {
-    let s = S(unknown);
-    foo(s);
-}
-"#),
-        @r###"
-    [86; 87) 't': T
-    [92; 94) '{}': ()
-    [105; 144) '{     ...(s); }': ()
-    [115; 116) 's': S<u32>
-    [119; 120) 'S': S<u32>(T) -> S<T>
-    [119; 129) 'S(unknown)': S<u32>
-    [121; 128) 'unknown': u32
-    [135; 138) 'foo': fn foo<S<u32>>(T) -> ()
-    [135; 141) 'foo(s)': ()
-    [139; 140) 's': S<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_from_bound_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {}
-struct S<T>(T);
-impl<U> Trait<U> for S<U> {}
-fn foo<U, T: Trait<U>>(t: T) -> U {}
-fn test() {
-    let s = S(unknown);
-    let x: u32 = foo(s);
-}
-"#),
-        @r###"
-    [87; 88) 't': T
-    [98; 100) '{}': ()
-    [111; 163) '{     ...(s); }': ()
-    [121; 122) 's': S<u32>
-    [125; 126) 'S': S<u32>(T) -> S<T>
-    [125; 135) 'S(unknown)': S<u32>
-    [127; 134) 'unknown': u32
-    [145; 146) 'x': u32
-    [154; 157) 'foo': fn foo<u32, S<u32>>(T) -> U
-    [154; 160) 'foo(s)': u32
-    [158; 159) 's': S<u32>
-    "###
-    );
-}
-
-#[test]
-fn infer_call_trait_method_on_generic_param_1() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    fn method(&self) -> u32;
-}
-fn test<T: Trait>(t: T) {
-    t.method();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [64; 65) 't': T
-    [70; 89) '{     ...d(); }': ()
-    [76; 77) 't': T
-    [76; 86) 't.method()': u32
-    "###
-    );
-}
-
-#[test]
-fn infer_call_trait_method_on_generic_param_2() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn method(&self) -> T;
-}
-fn test<U, T: Trait<U>>(t: T) {
-    t.method();
-}
-"#),
-        @r###"
-    [33; 37) 'self': &Self
-    [71; 72) 't': T
-    [77; 96) '{     ...d(); }': ()
-    [83; 84) 't': T
-    [83; 93) 't.method()': [missing name]
-    "###
-    );
-}
-
-#[test]
-fn infer_with_multiple_trait_impls() {
-    assert_snapshot!(
-        infer(r#"
-trait Into<T> {
-    fn into(self) -> T;
-}
-struct S;
-impl Into<u32> for S {}
-impl Into<u64> for S {}
-fn test() {
-    let x: u32 = S.into();
-    let y: u64 = S.into();
-    let z = Into::<u64>::into(S);
-}
-"#),
-        @r###"
-    [29; 33) 'self': Self
-    [111; 202) '{     ...(S); }': ()
-    [121; 122) 'x': u32
-    [130; 131) 'S': S
-    [130; 138) 'S.into()': u32
-    [148; 149) 'y': u64
-    [157; 158) 'S': S
-    [157; 165) 'S.into()': u64
-    [175; 176) 'z': u64
-    [179; 196) 'Into::...::into': fn into<S, u64>(Self) -> T
-    [179; 199) 'Into::...nto(S)': u64
-    [197; 198) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn infer_project_associated_type() {
-    // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-struct S;
-impl Iterable for S { type Item = u32; }
-fn test<T: Iterable>() {
-    let x: <S as Iterable>::Item = 1;
-    let y: <T as Iterable>::Item = no_matter;
-    let z: T::Item = no_matter;
-    let a: <T>::Item = no_matter;
-}
-"#),
-        @r###"
-    [108; 261) '{     ...ter; }': ()
-    [118; 119) 'x': u32
-    [145; 146) '1': u32
-    [156; 157) 'y': {unknown}
-    [183; 192) 'no_matter': {unknown}
-    [202; 203) 'z': {unknown}
-    [215; 224) 'no_matter': {unknown}
-    [234; 235) 'a': {unknown}
-    [249; 258) 'no_matter': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_return_associated_type() {
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-struct S;
-impl Iterable for S { type Item = u32; }
-fn foo1<T: Iterable>(t: T) -> T::Item {}
-fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
-fn foo3<T: Iterable>(t: T) -> <T>::Item {}
-fn test() {
-    let x = foo1(S);
-    let y = foo2(S);
-    let z = foo3(S);
-}
-"#),
-        @r###"
-    [106; 107) 't': T
-    [123; 125) '{}': ()
-    [147; 148) 't': T
-    [178; 180) '{}': ()
-    [202; 203) 't': T
-    [221; 223) '{}': ()
-    [234; 300) '{     ...(S); }': ()
-    [244; 245) 'x': u32
-    [248; 252) 'foo1': fn foo1<S>(T) -> <T as Iterable>::Item
-    [248; 255) 'foo1(S)': u32
-    [253; 254) 'S': S
-    [265; 266) 'y': u32
-    [269; 273) 'foo2': fn foo2<S>(T) -> <T as Iterable>::Item
-    [269; 276) 'foo2(S)': u32
-    [274; 275) 'S': S
-    [286; 287) 'z': u32
-    [290; 294) 'foo3': fn foo3<S>(T) -> <T as Iterable>::Item
-    [290; 297) 'foo3(S)': u32
-    [295; 296) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn infer_associated_type_bound() {
-    assert_snapshot!(
-        infer(r#"
-trait Iterable {
-   type Item;
-}
-fn test<T: Iterable<Item=u32>>() {
-    let y: T::Item = unknown;
-}
-"#),
-        @r###"
-    [67; 100) '{     ...own; }': ()
-    [77; 78) 'y': {unknown}
-    [90; 97) 'unknown': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_const_body() {
-    assert_snapshot!(
-        infer(r#"
-const A: u32 = 1 + 1;
-static B: u64 = { let x = 1; x };
-"#),
-        @r###"
-    [16; 17) '1': u32
-    [16; 21) '1 + 1': u32
-    [20; 21) '1': u32
-    [39; 55) '{ let ...1; x }': u64
-    [45; 46) 'x': u64
-    [49; 50) '1': u64
-    [52; 53) 'x': u64
-    "###
-    );
-}
-
-#[test]
-fn tuple_struct_fields() {
-    assert_snapshot!(
-        infer(r#"
-struct S(i32, u64);
-fn test() -> u64 {
-    let a = S(4, 6);
-    let b = a.0;
-    a.1
-}
-"#),
-        @r###"
-    [38; 87) '{     ... a.1 }': u64
-    [48; 49) 'a': S
-    [52; 53) 'S': S(i32, u64) -> S
-    [52; 59) 'S(4, 6)': S
-    [54; 55) '4': i32
-    [57; 58) '6': u64
-    [69; 70) 'b': i32
-    [73; 74) 'a': S
-    [73; 76) 'a.0': i32
-    [82; 83) 'a': S
-    [82; 85) 'a.1': u64
-    "###
-    );
-}
-
-#[test]
-fn tuple_struct_with_fn() {
-    assert_snapshot!(
-        infer(r#"
-struct S(fn(u32) -> u64);
-fn test() -> u64 {
-    let a = S(|i| 2*i);
-    let b = a.0(4);
-    a.0(2)
-}
-"#),
-        @r###"
-    [44; 102) '{     ...0(2) }': u64
-    [54; 55) 'a': S
-    [58; 59) 'S': S(fn(u32) -> u64) -> S
-    [58; 68) 'S(|i| 2*i)': S
-    [60; 67) '|i| 2*i': |i32| -> i32
-    [61; 62) 'i': i32
-    [64; 65) '2': i32
-    [64; 67) '2*i': i32
-    [66; 67) 'i': i32
-    [78; 79) 'b': u64
-    [82; 83) 'a': S
-    [82; 85) 'a.0': fn(u32) -> u64
-    [82; 88) 'a.0(4)': u64
-    [86; 87) '4': u32
-    [94; 95) 'a': S
-    [94; 97) 'a.0': fn(u32) -> u64
-    [94; 100) 'a.0(2)': u64
-    [98; 99) '2': u32
-    "###
-    );
-}
-
-#[test]
-fn indexing_arrays() {
-    assert_snapshot!(
-        infer("fn main() { &mut [9][2]; }"),
-        @r###"
-    [10; 26) '{ &mut...[2]; }': ()
-    [12; 23) '&mut [9][2]': &mut {unknown}
-    [17; 20) '[9]': [i32;_]
-    [17; 23) '[9][2]': {unknown}
-    [18; 19) '9': i32
-    [21; 22) '2': i32
-    "###
-    )
-}
-
-#[test]
-fn infer_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo(Vec<i32>);
-
-macro_rules! foo {
-    ($($item:expr),*) => {
-            {
-                Foo(vec![$($item,)*])
-            }
-    };
-}
-
-fn main() {
-    let x = foo!(1,2);
-}
-"#),
-        @r###"
-    ![0; 17) '{Foo(v...,2,])}': Foo
-    ![1; 4) 'Foo': Foo({unknown}) -> Foo
-    ![1; 16) 'Foo(vec![1,2,])': Foo
-    ![5; 15) 'vec![1,2,]': {unknown}
-    [156; 182) '{     ...,2); }': ()
-    [166; 167) 'x': Foo
-    "###
-    );
-}
-
-#[test]
-fn infer_legacy_textual_scoped_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-struct Foo(Vec<i32>);
-
-#[macro_use]
-mod m {
-    macro_rules! foo {
-        ($($item:expr),*) => {
-            {
-                Foo(vec![$($item,)*])
-            }
-        };
-    }
-}
-
-fn main() {
-    let x = foo!(1,2);
-    let y = crate::foo!(1,2);
-}
-"#),
-        @r###"
-    ![0; 17) '{Foo(v...,2,])}': Foo
-    ![1; 4) 'Foo': Foo({unknown}) -> Foo
-    ![1; 16) 'Foo(vec![1,2,])': Foo
-    ![5; 15) 'vec![1,2,]': {unknown}
-    [195; 251) '{     ...,2); }': ()
-    [205; 206) 'x': Foo
-    [228; 229) 'y': {unknown}
-    [232; 248) 'crate:...!(1,2)': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn infer_path_qualified_macros_expanded() {
-    assert_snapshot!(
-        infer(r#"
-#[macro_export]
-macro_rules! foo {
-    () => { 42i32 }
-}
-
-mod m {
-    pub use super::foo as bar;
-}
-
-fn main() {
-    let x = crate::foo!();
-    let y = m::bar!();
-}
-"#),
-        @r###"
-    ![0; 5) '42i32': i32
-    ![0; 5) '42i32': i32
-    [111; 164) '{     ...!(); }': ()
-    [121; 122) 'x': i32
-    [148; 149) 'y': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_type_value_macro_having_same_name() {
-    assert_snapshot!(
-        infer(r#"
-#[macro_export]
-macro_rules! foo {
-    () => {
-        mod foo {
-            pub use super::foo;
-        }
-    };
-    ($x:tt) => {
-        $x
-    };
-}
-
-foo!();
-
-fn foo() {
-    let foo = foo::foo!(42i32);
-}
-"#),
-        @r###"
-    ![0; 5) '42i32': i32
-    [171; 206) '{     ...32); }': ()
-    [181; 184) 'foo': i32
-    "###
-    );
-}
-
-#[test]
-fn processes_impls_generated_by_macros() {
-    let t = type_at(
-        r#"
-//- /main.rs
-macro_rules! m {
-    ($ident:ident) => (impl Trait for $ident {})
-}
-trait Trait { fn foo(self) -> u128 {} }
-struct S;
-m!(S);
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn infer_macro_with_dollar_crate_is_correct_in_expr() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:foo
-fn test() {
-    let x = (foo::foo!(1), foo::foo!(2));
-    x<|>;
-}
-
-//- /lib.rs crate:foo
-#[macro_export]
-macro_rules! foo {
-    (1) => { $crate::bar!() };
-    (2) => { 1 + $crate::baz() };
-}
-
-#[macro_export]
-macro_rules! bar {
-    () => { 42 }
-}
-
-pub fn baz() -> usize { 31usize }
-"#,
-    );
-    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
-}
-
-#[ignore]
-#[test]
-fn method_resolution_trait_before_autoref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(&self) -> i8 { 0 } }
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[ignore]
-#[test]
-fn method_resolution_by_value_before_autoref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone { fn clone(&self) -> Self; }
-struct S;
-impl Clone for S {}
-impl Clone for &S {}
-fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
-"#,
-    );
-    assert_eq!(t, "(S, S, &S)");
-}
-
-#[test]
-fn method_resolution_trait_before_autoderef() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(self) -> i8 { 0 } }
-impl Trait for &S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_impl_before_trait() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl S { fn foo(self) -> i8 { 0 } }
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "i8");
-}
-
-#[test]
-fn method_resolution_trait_autoderef() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S { fn foo(self) -> u128 { 0 } }
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_trait_from_prelude() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:other_crate
-struct S;
-impl Clone for S {}
-
-fn test() {
-    S.clone()<|>;
-}
-
-//- /lib.rs crate:other_crate
-#[prelude_import] use foo::*;
-
-mod foo {
-    trait Clone {
-        fn clone(&self) -> Self;
-    }
-}
-"#,
-    );
-    assert_eq!("S", type_at_pos(&db, pos));
-}
-
-#[test]
-fn method_resolution_where_clause_for_unknown_trait() {
-    // The blanket impl shouldn't apply because we can't even resolve UnknownTrait
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T> Trait for T where T: UnknownTrait {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_not_met() {
-    // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T> Trait for T where T: Clone {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    // This is also to make sure that we don't resolve to the foo method just
-    // because that's the only method named foo we can find, which would make
-    // the below tests not work
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_inline_not_met() {
-    // The blanket impl shouldn't apply because we can't prove S: Clone
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl<T: Clone> Trait for T {}
-fn test() { (&S).foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test() { S.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn method_resolution_where_clause_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Into<T> { fn into(self) -> T; }
-trait From<T> { fn from(other: T) -> Self; }
-struct S1;
-struct S2;
-impl From<S2> for S1 {}
-impl<T, U> Into<U> for T where U: From<T> {}
-fn test() { S2.into()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_where_clause_inline() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Into<T> { fn into(self) -> T; }
-trait From<T> { fn from(other: T) -> Self; }
-struct S1;
-struct S2;
-impl From<S2> for S1 {}
-impl<T, U: From<T>> Into<U> for T {}
-fn test() { S2.into()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn method_resolution_encountering_fn_type() {
-    type_at(
-        r#"
-//- /main.rs
-fn foo() {}
-trait FnOnce { fn call(self); }
-fn test() { foo.call()<|>; }
-"#,
-    );
-}
-
-#[test]
-fn method_resolution_slow() {
-    // this can get quite slow if we set the solver size limit too high
-    let t = type_at(
-        r#"
-//- /main.rs
-trait SendX {}
-
-struct S1; impl SendX for S1 {}
-struct S2; impl SendX for S2 {}
-struct U1;
-
-trait Trait { fn method(self); }
-
-struct X1<A, B> {}
-impl<A, B> SendX for X1<A, B> where A: SendX, B: SendX {}
-
-struct S<B, C> {}
-
-trait FnX {}
-
-impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
-
-fn test() { (S {}).method()<|>; }
-"#,
-    );
-    assert_eq!(t, "()");
-}
-
-#[test]
-fn shadowing_primitive() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct i32;
-struct Foo;
-
-impl i32 { fn foo(&self) -> Foo { Foo } }
-
-fn main() {
-    let x: i32 = i32;
-    x.foo()<|>;
-}"#,
-    );
-    assert_eq!(t, "Foo");
-}
-
-#[test]
-fn deref_trait() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-impl S {
-    fn foo(&self) -> u128 {}
-}
-
-fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
-"#,
-    );
-    assert_eq!(t, "(S, u128)");
-}
-
-#[test]
-fn deref_trait_with_inference_var() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-fn new_arc<T>() -> Arc<T> {}
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-fn foo(a: Arc<S>) {}
-
-fn test() {
-    let a = new_arc();
-    let b = (*a)<|>;
-    foo(a);
-}
-"#,
-    );
-    assert_eq!(t, "S");
-}
-
-#[test]
-fn deref_trait_infinite_recursion() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct S;
-
-impl Deref for S {
-    type Target = S;
-}
-
-fn test(s: S) {
-    s.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn deref_trait_with_question_mark_size() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-    fn deref(&self) -> &Self::Target;
-}
-
-struct Arc<T>;
-impl<T> Deref for Arc<T> {
-    type Target = T;
-}
-
-struct S;
-impl S {
-    fn foo(&self) -> u128 {}
-}
-
-fn test(s: Arc<S>) {
-    (*s, s.foo())<|>;
-}
-"#,
-    );
-    assert_eq!(t, "(S, u128)");
-}
-
-#[test]
-fn obligation_from_function_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<u32> for S {}
-
-fn foo<T: Trait<U>, U>(t: T) -> U {}
-
-fn test(s: S) {
-    foo(s)<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn obligation_from_method_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<isize> for S {}
-
-struct O;
-impl O {
-    fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
-}
-
-fn test() {
-    O.foo(S)<|>;
-}
-"#,
-    );
-    assert_eq!(t, "isize");
-}
-
-#[test]
-fn obligation_from_self_method_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<i64> for S {}
-
-impl S {
-    fn foo<U>(&self) -> U where Self: Trait<U> {}
-}
-
-fn test() {
-    S.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "i64");
-}
-
-#[test]
-fn obligation_from_impl_clause() {
-    let t = type_at(
-        r#"
-//- /main.rs
-struct S;
-
-trait Trait<T> {}
-impl Trait<&str> for S {}
-
-struct O<T>;
-impl<U, T: Trait<U>> O<T> {
-    fn foo(&self) -> U {}
-}
-
-fn test(o: O<S>) {
-    o.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "&str");
-}
-
-#[test]
-fn generic_param_env_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test<T: Clone>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn generic_param_env_1_not_met() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Clone {}
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Clone for S {}
-impl<T> Trait for T where T: Clone {}
-fn test<T>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn generic_param_env_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S {}
-fn test<T: Trait>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "u128");
-}
-
-#[test]
-fn generic_param_env_2_not_met() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait { fn foo(self) -> u128; }
-struct S;
-impl Trait for S {}
-fn test<T>(t: T) { t.foo()<|>; }
-"#,
-    );
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn generic_param_env_deref() {
-    let t = type_at(
-        r#"
-//- /main.rs
-#[lang = "deref"]
-trait Deref {
-    type Target;
-}
-trait Trait {}
-impl<T> Deref for T where T: Trait {
-    type Target = i128;
-}
-fn test<T: Trait>(t: T) { (*t)<|>; }
-"#,
-    );
-    assert_eq!(t, "i128");
-}
-
-#[test]
-fn associated_type_placeholder() {
-    let t = type_at(
-        r#"
-//- /main.rs
-pub trait ApplyL {
-    type Out;
-}
-
-pub struct RefMutL<T>;
-
-impl<T> ApplyL for RefMutL<T> {
-    type Out = <T as ApplyL>::Out;
-}
-
-fn test<T: ApplyL>() {
-    let y: <RefMutL<T> as ApplyL>::Out = no_matter;
-    y<|>;
-}
-"#,
-    );
-    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
-    // FIXME: fix type parameter names going missing when going through Chalk
-    assert_eq!(t, "ApplyL::Out<[missing name]>");
-}
-
-#[test]
-fn associated_type_placeholder_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-pub trait ApplyL {
-    type Out;
-}
-fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
-
-fn test<T: ApplyL>(t: T) {
-    let y = foo(t);
-    y<|>;
-}
-"#,
-    );
-    // FIXME here Chalk doesn't normalize the type to a placeholder. I think we
-    // need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
-    // to the trait env ourselves here; probably Chalk can't do this by itself.
-    // assert_eq!(t, "ApplyL::Out<[missing name]>");
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-fn impl_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn foo(&self) -> T;
-    fn foo2(&self) -> i64;
-}
-fn bar() -> impl Trait<u64> {}
-
-fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-    x.foo2();
-    y.foo2();
-    z.foo2();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [55; 59) 'self': &Self
-    [99; 101) '{}': ()
-    [111; 112) 'x': impl Trait<u64>
-    [131; 132) 'y': &impl Trait<u64>
-    [152; 269) '{     ...2(); }': ()
-    [158; 159) 'x': impl Trait<u64>
-    [165; 166) 'y': &impl Trait<u64>
-    [176; 177) 'z': impl Trait<u64>
-    [180; 183) 'bar': fn bar() -> impl Trait<u64>
-    [180; 185) 'bar()': impl Trait<u64>
-    [191; 192) 'x': impl Trait<u64>
-    [191; 198) 'x.foo()': u64
-    [204; 205) 'y': &impl Trait<u64>
-    [204; 211) 'y.foo()': u64
-    [217; 218) 'z': impl Trait<u64>
-    [217; 224) 'z.foo()': u64
-    [230; 231) 'x': impl Trait<u64>
-    [230; 238) 'x.foo2()': i64
-    [244; 245) 'y': &impl Trait<u64>
-    [244; 252) 'y.foo2()': i64
-    [258; 259) 'z': impl Trait<u64>
-    [258; 266) 'z.foo2()': i64
-    "###
-    );
-}
-
-#[test]
-fn dyn_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait<T> {
-    fn foo(&self) -> T;
-    fn foo2(&self) -> i64;
-}
-fn bar() -> dyn Trait<u64> {}
-
-fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-    x.foo2();
-    y.foo2();
-    z.foo2();
-}
-"#),
-        @r###"
-    [30; 34) 'self': &Self
-    [55; 59) 'self': &Self
-    [98; 100) '{}': ()
-    [110; 111) 'x': dyn Trait<u64>
-    [129; 130) 'y': &dyn Trait<u64>
-    [149; 266) '{     ...2(); }': ()
-    [155; 156) 'x': dyn Trait<u64>
-    [162; 163) 'y': &dyn Trait<u64>
-    [173; 174) 'z': dyn Trait<u64>
-    [177; 180) 'bar': fn bar() -> dyn Trait<u64>
-    [177; 182) 'bar()': dyn Trait<u64>
-    [188; 189) 'x': dyn Trait<u64>
-    [188; 195) 'x.foo()': u64
-    [201; 202) 'y': &dyn Trait<u64>
-    [201; 208) 'y.foo()': u64
-    [214; 215) 'z': dyn Trait<u64>
-    [214; 221) 'z.foo()': u64
-    [227; 228) 'x': dyn Trait<u64>
-    [227; 235) 'x.foo2()': i64
-    [241; 242) 'y': &dyn Trait<u64>
-    [241; 249) 'y.foo2()': i64
-    [255; 256) 'z': dyn Trait<u64>
-    [255; 263) 'z.foo2()': i64
-    "###
-    );
-}
-
-#[test]
-fn dyn_trait_bare() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    fn foo(&self) -> u64;
-}
-fn bar() -> Trait {}
-
-fn test(x: Trait, y: &Trait) -> u64 {
-    x;
-    y;
-    let z = bar();
-    x.foo();
-    y.foo();
-    z.foo();
-}
-"#),
-        @r###"
-    [27; 31) 'self': &Self
-    [61; 63) '{}': ()
-    [73; 74) 'x': dyn Trait
-    [83; 84) 'y': &dyn Trait
-    [101; 176) '{     ...o(); }': ()
-    [107; 108) 'x': dyn Trait
-    [114; 115) 'y': &dyn Trait
-    [125; 126) 'z': dyn Trait
-    [129; 132) 'bar': fn bar() -> dyn Trait
-    [129; 134) 'bar()': dyn Trait
-    [140; 141) 'x': dyn Trait
-    [140; 147) 'x.foo()': u64
-    [153; 154) 'y': &dyn Trait
-    [153; 160) 'y.foo()': u64
-    [166; 167) 'z': dyn Trait
-    [166; 173) 'z.foo()': u64
-    "###
-    );
-}
-
-#[test]
-fn weird_bounds() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {}
-fn test() {
-    let a: impl Trait + 'lifetime = foo;
-    let b: impl 'lifetime = foo;
-    let b: impl (Trait) = foo;
-    let b: impl ('lifetime) = foo;
-    let d: impl ?Sized = foo;
-    let e: impl Trait + ?Sized = foo;
-}
-"#),
-        @r###"
-    [26; 237) '{     ...foo; }': ()
-    [36; 37) 'a': impl Trait + {error}
-    [64; 67) 'foo': impl Trait + {error}
-    [77; 78) 'b': impl {error}
-    [97; 100) 'foo': impl {error}
-    [110; 111) 'b': impl Trait
-    [128; 131) 'foo': impl Trait
-    [141; 142) 'b': impl {error}
-    [163; 166) 'foo': impl {error}
-    [176; 177) 'd': impl {error}
-    [193; 196) 'foo': impl {error}
-    [206; 207) 'e': impl Trait + {error}
-    [231; 234) 'foo': impl Trait + {error}
-    "###
-    );
-}
-
-#[test]
-fn assoc_type_bindings() {
-    assert_snapshot!(
-        infer(r#"
-trait Trait {
-    type Type;
-}
-
-fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
-fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
-fn set<T: Trait<Type = u64>>(t: T) -> T {t}
-
-struct S<T>;
-impl<T> Trait for S<T> { type Type = T; }
-
-fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
-    get(x);
-    get2(x);
-    get(y);
-    get2(y);
-    get(set(S));
-    get2(set(S));
-    get2(S::<str>);
-}
-"#),
-        @r###"
-    [50; 51) 't': T
-    [78; 80) '{}': ()
-    [112; 113) 't': T
-    [123; 125) '{}': ()
-    [155; 156) 't': T
-    [166; 169) '{t}': T
-    [167; 168) 't': T
-    [257; 258) 'x': T
-    [263; 264) 'y': impl Trait<Type = i64>
-    [290; 398) '{     ...r>); }': ()
-    [296; 299) 'get': fn get<T>(T) -> <T as Trait>::Type
-    [296; 302) 'get(x)': {unknown}
-    [300; 301) 'x': T
-    [308; 312) 'get2': fn get2<{unknown}, T>(T) -> U
-    [308; 315) 'get2(x)': {unknown}
-    [313; 314) 'x': T
-    [321; 324) 'get': fn get<impl Trait<Type = i64>>(T) -> <T as Trait>::Type
-    [321; 327) 'get(y)': {unknown}
-    [325; 326) 'y': impl Trait<Type = i64>
-    [333; 337) 'get2': fn get2<{unknown}, impl Trait<Type = i64>>(T) -> U
-    [333; 340) 'get2(y)': {unknown}
-    [338; 339) 'y': impl Trait<Type = i64>
-    [346; 349) 'get': fn get<S<u64>>(T) -> <T as Trait>::Type
-    [346; 357) 'get(set(S))': u64
-    [350; 353) 'set': fn set<S<u64>>(T) -> T
-    [350; 356) 'set(S)': S<u64>
-    [354; 355) 'S': S<u64>
-    [363; 367) 'get2': fn get2<u64, S<u64>>(T) -> U
-    [363; 375) 'get2(set(S))': u64
-    [368; 371) 'set': fn set<S<u64>>(T) -> T
-    [368; 374) 'set(S)': S<u64>
-    [372; 373) 'S': S<u64>
-    [381; 385) 'get2': fn get2<str, S<str>>(T) -> U
-    [381; 395) 'get2(S::<str>)': str
-    [386; 394) 'S::<str>': S<str>
-    "###
-    );
-}
-
-#[test]
-fn impl_trait_assoc_binding_projection_bug() {
-    let (db, pos) = TestDB::with_position(
-        r#"
-//- /main.rs crate:main deps:std
-pub trait Language {
-    type Kind;
-}
-pub enum RustLanguage {}
-impl Language for RustLanguage {
-    type Kind = SyntaxKind;
-}
-struct SyntaxNode<L> {}
-fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
-
-trait Clone {
-    fn clone(&self) -> Self;
-}
-
-fn api_walkthrough() {
-    for node in foo() {
-        node.clone()<|>;
-    }
-}
-
-//- /std.rs crate:std
-#[prelude_import] use iter::*;
-mod iter {
-    trait IntoIterator {
-        type Item;
-    }
-    trait Iterator {
-        type Item;
-    }
-    impl<T: Iterator> IntoIterator for T {
-        type Item = <T as Iterator>::Item;
-    }
-}
-"#,
-    );
-    assert_eq!("{unknown}", type_at_pos(&db, pos));
-}
-
-#[test]
-fn projection_eq_within_chalk() {
-    // std::env::set_var("CHALK_DEBUG", "1");
-    assert_snapshot!(
-        infer(r#"
-trait Trait1 {
-    type Type;
-}
-trait Trait2<T> {
-    fn foo(self) -> T;
-}
-impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
-
-fn test<T: Trait1<Type = u32>>(x: T) {
-    x.foo();
-}
-"#),
-        @r###"
-    [62; 66) 'self': Self
-    [164; 165) 'x': T
-    [170; 186) '{     ...o(); }': ()
-    [176; 177) 'x': T
-    [176; 183) 'x.foo()': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn where_clause_trait_in_scope_for_method_resolution() {
-    let t = type_at(
-        r#"
-//- /main.rs
-mod foo {
-    trait Trait {
-        fn foo(&self) -> u32 {}
-    }
-}
-
-fn test<T: foo::Trait>(x: T) {
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn super_trait_method_resolution() {
-    assert_snapshot!(
-        infer(r#"
-mod foo {
-    trait SuperTrait {
-        fn foo(&self) -> u32 {}
-    }
-}
-trait Trait1: foo::SuperTrait {}
-trait Trait2 where Self: foo::SuperTrait {}
-
-fn test<T: Trait1, U: Trait2>(x: T, y: U) {
-    x.foo();
-    y.foo();
-}
-"#),
-        @r###"
-    [50; 54) 'self': &Self
-    [63; 65) '{}': ()
-    [182; 183) 'x': T
-    [188; 189) 'y': U
-    [194; 223) '{     ...o(); }': ()
-    [200; 201) 'x': T
-    [200; 207) 'x.foo()': u32
-    [213; 214) 'y': U
-    [213; 220) 'y.foo()': u32
-    "###
-    );
-}
-
-#[test]
-fn super_trait_cycle() {
-    // This just needs to not crash
-    assert_snapshot!(
-        infer(r#"
-trait A: B {}
-trait B: A {}
-
-fn test<T: A>(x: T) {
-    x.foo();
-}
-"#),
-        @r###"
-    [44; 45) 'x': T
-    [50; 66) '{     ...o(); }': ()
-    [56; 57) 'x': T
-    [56; 63) 'x.foo()': {unknown}
-    "###
-    );
-}
-
-#[test]
-fn super_trait_assoc_type_bounds() {
-    assert_snapshot!(
-        infer(r#"
-trait SuperTrait { type Type; }
-trait Trait where Self: SuperTrait {}
-
-fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
-fn set<T: Trait<Type = u64>>(t: T) -> T {t}
-
-struct S<T>;
-impl<T> SuperTrait for S<T> { type Type = T; }
-impl<T> Trait for S<T> {}
-
-fn test() {
-    get2(set(S));
-}
-"#),
-        @r###"
-    [103; 104) 't': T
-    [114; 116) '{}': ()
-    [146; 147) 't': T
-    [157; 160) '{t}': T
-    [158; 159) 't': T
-    [259; 280) '{     ...S)); }': ()
-    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
-    [265; 277) 'get2(set(S))': u64
-    [270; 273) 'set': fn set<S<u64>>(T) -> T
-    [270; 276) 'set(S)': S<u64>
-    [274; 275) 'S': S<u64>
-    "###
-    );
-}
-
-#[test]
-fn fn_trait() {
-    assert_snapshot!(
-        infer(r#"
-trait FnOnce<Args> {
-    type Output;
-
-    fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
-}
-
-fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
-    f.call_once((1, 2));
-}
-"#),
-        @r###"
-    [57; 61) 'self': Self
-    [63; 67) 'args': Args
-    [150; 151) 'f': F
-    [156; 184) '{     ...2)); }': ()
-    [162; 163) 'f': F
-    [162; 181) 'f.call...1, 2))': {unknown}
-    [174; 180) '(1, 2)': (u32, u64)
-    [175; 176) '1': u32
-    [178; 179) '2': u64
-    "###
-    );
-}
-
-#[test]
-fn closure_1() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "fn_once"]
-trait FnOnce<Args> {
-    type Output;
-}
-
-enum Option<T> { Some(T), None }
-impl<T> Option<T> {
-    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
-}
-
-fn test() {
-    let x = Option::Some(1u32);
-    x.map(|v| v + 1);
-    x.map(|_v| 1u64);
-    let y: Option<i64> = x.map(|_v| 1);
-}
-"#),
-        @r###"
-    [148; 152) 'self': Option<T>
-    [154; 155) 'f': F
-    [173; 175) '{}': ()
-    [189; 308) '{     ... 1); }': ()
-    [199; 200) 'x': Option<u32>
-    [203; 215) 'Option::Some': Some<u32>(T) -> Option<T>
-    [203; 221) 'Option...(1u32)': Option<u32>
-    [216; 220) '1u32': u32
-    [227; 228) 'x': Option<u32>
-    [227; 243) 'x.map(...v + 1)': Option<u32>
-    [233; 242) '|v| v + 1': |u32| -> u32
-    [234; 235) 'v': u32
-    [237; 238) 'v': u32
-    [237; 242) 'v + 1': u32
-    [241; 242) '1': u32
-    [249; 250) 'x': Option<u32>
-    [249; 265) 'x.map(... 1u64)': Option<u64>
-    [255; 264) '|_v| 1u64': |u32| -> u64
-    [256; 258) '_v': u32
-    [260; 264) '1u64': u64
-    [275; 276) 'y': Option<i64>
-    [292; 293) 'x': Option<u32>
-    [292; 305) 'x.map(|_v| 1)': Option<i64>
-    [298; 304) '|_v| 1': |u32| -> i64
-    [299; 301) '_v': u32
-    [303; 304) '1': i64
-    "###
-    );
-}
-
-#[test]
-fn closure_2() {
-    assert_snapshot!(
-        infer(r#"
-trait FnOnce<Args> {
-    type Output;
-}
-
-fn test<F: FnOnce(u32) -> u64>(f: F) {
-    f(1);
-    let g = |v| v + 1;
-    g(1u64);
-    let h = |v| 1u128 + v;
-}
-"#),
-        @r###"
-    [73; 74) 'f': F
-    [79; 155) '{     ...+ v; }': ()
-    [85; 86) 'f': F
-    [85; 89) 'f(1)': {unknown}
-    [87; 88) '1': i32
-    [99; 100) 'g': |u64| -> i32
-    [103; 112) '|v| v + 1': |u64| -> i32
-    [104; 105) 'v': u64
-    [107; 108) 'v': u64
-    [107; 112) 'v + 1': i32
-    [111; 112) '1': i32
-    [118; 119) 'g': |u64| -> i32
-    [118; 125) 'g(1u64)': i32
-    [120; 124) '1u64': u64
-    [135; 136) 'h': |u128| -> u128
-    [139; 152) '|v| 1u128 + v': |u128| -> u128
-    [140; 141) 'v': u128
-    [143; 148) '1u128': u128
-    [143; 152) '1u128 + v': u128
-    [151; 152) 'v': u128
-    "###
-    );
-}
-
-#[test]
-fn closure_as_argument_inference_order() {
-    assert_snapshot!(
-        infer(r#"
-#[lang = "fn_once"]
-trait FnOnce<Args> {
-    type Output;
-}
-
-fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
-fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
-
-struct S;
-impl S {
-    fn method(self) -> u64;
-
-    fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
-    fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
-}
-
-fn test() {
-    let x1 = foo1(S, |s| s.method());
-    let x2 = foo2(|s| s.method(), S);
-    let x3 = S.foo1(S, |s| s.method());
-    let x4 = S.foo2(|s| s.method(), S);
-}
-"#),
-        @r###"
-    [95; 96) 'x': T
-    [101; 102) 'f': F
-    [112; 114) '{}': ()
-    [148; 149) 'f': F
-    [154; 155) 'x': T
-    [165; 167) '{}': ()
-    [202; 206) 'self': S
-    [254; 258) 'self': S
-    [260; 261) 'x': T
-    [266; 267) 'f': F
-    [277; 279) '{}': ()
-    [317; 321) 'self': S
-    [323; 324) 'f': F
-    [329; 330) 'x': T
-    [340; 342) '{}': ()
-    [356; 515) '{     ... S); }': ()
-    [366; 368) 'x1': u64
-    [371; 375) 'foo1': fn foo1<S, u64, |S| -> u64>(T, F) -> U
-    [371; 394) 'foo1(S...hod())': u64
-    [376; 377) 'S': S
-    [379; 393) '|s| s.method()': |S| -> u64
-    [380; 381) 's': S
-    [383; 384) 's': S
-    [383; 393) 's.method()': u64
-    [404; 406) 'x2': u64
-    [409; 413) 'foo2': fn foo2<S, u64, |S| -> u64>(F, T) -> U
-    [409; 432) 'foo2(|...(), S)': u64
-    [414; 428) '|s| s.method()': |S| -> u64
-    [415; 416) 's': S
-    [418; 419) 's': S
-    [418; 428) 's.method()': u64
-    [430; 431) 'S': S
-    [442; 444) 'x3': u64
-    [447; 448) 'S': S
-    [447; 472) 'S.foo1...hod())': u64
-    [454; 455) 'S': S
-    [457; 471) '|s| s.method()': |S| -> u64
-    [458; 459) 's': S
-    [461; 462) 's': S
-    [461; 471) 's.method()': u64
-    [482; 484) 'x4': u64
-    [487; 488) 'S': S
-    [487; 512) 'S.foo2...(), S)': u64
-    [494; 508) '|s| s.method()': |S| -> u64
-    [495; 496) 's': S
-    [498; 499) 's': S
-    [498; 508) 's.method()': u64
-    [510; 511) 'S': S
-    "###
-    );
-}
-
-#[test]
-fn unselected_projection_in_trait_env_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait {
-    type Item;
-}
-
-trait Trait2 {
-    fn foo(&self) -> u32;
-}
-
-fn test<T: Trait>() where T::Item: Trait2 {
-    let x: T::Item = no_matter;
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-fn unselected_projection_in_trait_env_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait<T> {
-    type Item;
-}
-
-trait Trait2 {
-    fn foo(&self) -> u32;
-}
-
-fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
-    let x: T::Item = no_matter;
-    x.foo()<|>;
-}
-"#,
-    );
-    assert_eq!(t, "u32");
-}
-
-#[test]
-// FIXME this is currently a Salsa panic; it would be nicer if it just returned
-// in Unknown, and we should be able to do that once Salsa allows us to handle
-// the cycle. But at least it doesn't overflow for now.
-#[should_panic]
-fn unselected_projection_in_trait_env_cycle_1() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait {
-    type Item;
-}
-
-trait Trait2<T> {}
-
-fn test<T: Trait>() where T: Trait2<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
-"#,
-    );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
-}
-
-#[test]
-// FIXME this is currently a Salsa panic; it would be nicer if it just returned
-// in Unknown, and we should be able to do that once Salsa allows us to handle
-// the cycle. But at least it doesn't overflow for now.
-#[should_panic]
-fn unselected_projection_in_trait_env_cycle_2() {
-    let t = type_at(
-        r#"
-//- /main.rs
-trait Trait<T> {
-    type Item;
-}
-
-fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
-    let x: T::Item = no_matter<|>;
-}
-"#,
-    );
-    // this is a legitimate cycle
-    assert_eq!(t, "{unknown}");
-}
-
 fn type_at_pos(db: &TestDB, pos: FilePosition) -> String {
     let file = db.parse(pos.file_id).ok().unwrap();
     let expr = algo::find_node_at_offset::<ast::Expr>(file.syntax(), pos.offset).unwrap();
-
+    let fn_def = expr.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
     let module = db.module_for_file(pos.file_id);
-    let crate_def_map = db.crate_def_map(module.krate);
-    for decl in crate_def_map[module.local_id].scope.declarations() {
-        if let ModuleDefId::FunctionId(func) = decl {
-            let (_body, source_map) = db.body_with_source_map(func.into());
-            if let Some(expr_id) = source_map.node_expr(Source::new(pos.file_id.into(), &expr)) {
-                let infer = db.infer(func.into());
-                let ty = &infer[expr_id];
-                return ty.display(db).to_string();
-            }
-        }
+    let func = *module.child_by_source(db)[keys::FUNCTION]
+        .get(&InFile::new(pos.file_id.into(), fn_def))
+        .unwrap();
+
+    let (_body, source_map) = db.body_with_source_map(func.into());
+    if let Some(expr_id) = source_map.node_expr(InFile::new(pos.file_id.into(), &expr)) {
+        let infer = db.infer(func.into());
+        let ty = &infer[expr_id];
+        return ty.display(db).to_string();
     }
     panic!("Can't find expression")
 }
@@ -4696,6 +52,10 @@ fn type_at(content: &str) -> String {
 }
 
 fn infer(content: &str) -> String {
+    infer_with_mismatches(content, false)
+}
+
+fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
     let (db, file_id) = TestDB::with_single_file(content);
 
     let mut acc = String::new();
@@ -4703,6 +63,7 @@ fn infer(content: &str) -> String {
     let mut infer_def = |inference_result: Arc<InferenceResult>,
                          body_source_map: Arc<BodySourceMap>| {
         let mut types = Vec::new();
+        let mut mismatches = Vec::new();
 
         for (pat, ty) in inference_result.type_of_pat.iter() {
             let syntax_ptr = match body_source_map.pat_syntax(pat) {
@@ -4722,6 +83,9 @@ fn infer(content: &str) -> String {
                 None => continue,
             };
             types.push((syntax_ptr, ty));
+            if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr) {
+                mismatches.push((syntax_ptr, mismatch));
+            }
         }
 
         // sort ranges for consistency
@@ -4747,6 +111,24 @@ fn infer(content: &str) -> String {
             )
             .unwrap();
         }
+        if include_mismatches {
+            mismatches.sort_by_key(|(src_ptr, _)| {
+                (src_ptr.value.range().start(), src_ptr.value.range().end())
+            });
+            for (src_ptr, mismatch) in &mismatches {
+                let range = src_ptr.value.range();
+                let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
+                write!(
+                    acc,
+                    "{}{}: expected {}, got {}\n",
+                    macro_prefix,
+                    range,
+                    mismatch.expected.display(&db),
+                    mismatch.actual.display(&db),
+                )
+                .unwrap();
+            }
+        }
     };
 
     let module = db.module_for_file(file_id);
@@ -4800,7 +182,7 @@ fn visit_module(
             _ => (),
         }
     }
-    for &impl_id in crate_def_map[module_id].impls.iter() {
+    for impl_id in crate_def_map[module_id].scope.impls() {
         let impl_data = db.impl_data(impl_id);
         for &item in impl_data.items.iter() {
             match item {
@@ -4899,60 +281,3 @@ fn no_such_field_diagnostics() {
     "###
     );
 }
-
-#[test]
-fn infer_builtin_macros_line() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! line {() => {}}
-
-fn main() {
-    let x = line!();
-}
-"#),
-        @r###"
-    ![0; 1) '6': i32
-    [64; 88) '{     ...!(); }': ()
-    [74; 75) 'x': i32
-    "###
-    );
-}
-
-#[test]
-fn infer_builtin_macros_file() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! file {() => {}}
-
-fn main() {
-    let x = file!();
-}
-"#),
-        @r###"
-    ![0; 2) '""': &str
-    [64; 88) '{     ...!(); }': ()
-    [74; 75) 'x': &str
-    "###
-    );
-}
-
-#[test]
-fn infer_builtin_macros_column() {
-    assert_snapshot!(
-        infer(r#"
-#[rustc_builtin_macro]
-macro_rules! column {() => {}}
-
-fn main() {
-    let x = column!();
-}
-"#),
-        @r###"
-    ![0; 2) '13': i32
-    [66; 92) '{     ...!(); }': ()
-    [76; 77) 'x': i32
-    "###
-    );
-}
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 1530fcc63..7e99a42ed 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -1,3 +1,4 @@
+use super::infer_with_mismatches;
 use insta::assert_snapshot;
 use test_utils::covers;
 
@@ -367,3 +368,161 @@ fn test() {
     "###
     );
 }
+
+#[test]
+fn return_coerce_unknown() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo() -> u32 {
+    return unknown;
+}
+"#, true),
+        @r###"
+    [17; 40) '{     ...own; }': !
+    [23; 37) 'return unknown': !
+    [30; 37) 'unknown': u32
+    "###
+    );
+}
+
+#[test]
+fn coerce_autoderef() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+struct Foo;
+fn takes_ref_foo(x: &Foo) {}
+fn test() {
+    takes_ref_foo(&Foo);
+    takes_ref_foo(&&Foo);
+    takes_ref_foo(&&&Foo);
+}
+"#, true),
+        @r###"
+    [30; 31) 'x': &Foo
+    [39; 41) '{}': ()
+    [52; 133) '{     ...oo); }': ()
+    [58; 71) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [58; 77) 'takes_...(&Foo)': ()
+    [72; 76) '&Foo': &Foo
+    [73; 76) 'Foo': Foo
+    [83; 96) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [83; 103) 'takes_...&&Foo)': ()
+    [97; 102) '&&Foo': &&Foo
+    [98; 102) '&Foo': &Foo
+    [99; 102) 'Foo': Foo
+    [109; 122) 'takes_ref_foo': fn takes_ref_foo(&Foo) -> ()
+    [109; 130) 'takes_...&&Foo)': ()
+    [123; 129) '&&&Foo': &&&Foo
+    [124; 129) '&&Foo': &&Foo
+    [125; 129) '&Foo': &Foo
+    [126; 129) 'Foo': Foo
+    "###
+    );
+}
+
+#[test]
+fn coerce_autoderef_generic() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+struct Foo;
+fn takes_ref<T>(x: &T) -> T { *x }
+fn test() {
+    takes_ref(&Foo);
+    takes_ref(&&Foo);
+    takes_ref(&&&Foo);
+}
+"#, true),
+        @r###"
+    [29; 30) 'x': &T
+    [41; 47) '{ *x }': T
+    [43; 45) '*x': T
+    [44; 45) 'x': &T
+    [58; 127) '{     ...oo); }': ()
+    [64; 73) 'takes_ref': fn takes_ref<Foo>(&T) -> T
+    [64; 79) 'takes_ref(&Foo)': Foo
+    [74; 78) '&Foo': &Foo
+    [75; 78) 'Foo': Foo
+    [85; 94) 'takes_ref': fn takes_ref<&Foo>(&T) -> T
+    [85; 101) 'takes_...&&Foo)': &Foo
+    [95; 100) '&&Foo': &&Foo
+    [96; 100) '&Foo': &Foo
+    [97; 100) 'Foo': Foo
+    [107; 116) 'takes_ref': fn takes_ref<&&Foo>(&T) -> T
+    [107; 124) 'takes_...&&Foo)': &&Foo
+    [117; 123) '&&&Foo': &&&Foo
+    [118; 123) '&&Foo': &&Foo
+    [119; 123) '&Foo': &Foo
+    [120; 123) 'Foo': Foo
+    "###
+    );
+}
+
+#[test]
+fn closure_return_coerce() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo() {
+    let x = || {
+        if true {
+            return &1u32;
+        }
+        &&1u32
+    };
+}
+"#, true),
+        @r###"
+    [10; 106) '{     ...  }; }': ()
+    [20; 21) 'x': || -> &u32
+    [24; 103) '|| {  ...     }': || -> &u32
+    [27; 103) '{     ...     }': &u32
+    [37; 82) 'if tru...     }': ()
+    [40; 44) 'true': bool
+    [45; 82) '{     ...     }': !
+    [59; 71) 'return &1u32': !
+    [66; 71) '&1u32': &u32
+    [67; 71) '1u32': u32
+    [91; 97) '&&1u32': &&u32
+    [92; 97) '&1u32': &u32
+    [93; 97) '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn coerce_fn_item_to_fn_ptr() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn foo(x: u32) -> isize { 1 }
+fn test() {
+    let f: fn(u32) -> isize = foo;
+}
+"#, true),
+        @r###"
+    [8; 9) 'x': u32
+    [25; 30) '{ 1 }': isize
+    [27; 28) '1': isize
+    [41; 79) '{     ...foo; }': ()
+    [51; 52) 'f': fn(u32) -> isize
+    [73; 76) 'foo': fn foo(u32) -> isize
+    "###
+    );
+}
+
+#[test]
+fn coerce_closure_to_fn_ptr() {
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+fn test() {
+    let f: fn(u32) -> isize = |x| { 1 };
+}
+"#, true),
+        @r###"
+    [11; 55) '{     ...1 }; }': ()
+    [21; 22) 'f': fn(u32) -> isize
+    [43; 52) '|x| { 1 }': |u32| -> isize
+    [44; 45) 'x': u32
+    [47; 52) '{ 1 }': isize
+    [49; 50) '1': isize
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/macros.rs b/crates/ra_hir_ty/src/tests/macros.rs
new file mode 100644
index 000000000..69c695cc8
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/macros.rs
@@ -0,0 +1,390 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn cfg_impl_block() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo cfg:test
+use foo::S as T;
+struct S;
+
+#[cfg(test)]
+impl S {
+    fn foo1(&self) -> i32 { 0 }
+}
+
+#[cfg(not(test))]
+impl S {
+    fn foo2(&self) -> i32 { 0 }
+}
+
+fn test() {
+    let t = (S.foo1(), S.foo2(), T.foo3(), T.foo4());
+    t<|>;
+}
+
+//- /foo.rs crate:foo
+struct S;
+
+#[cfg(not(test))]
+impl S {
+    fn foo3(&self) -> i32 { 0 }
+}
+
+#[cfg(test)]
+impl S {
+    fn foo4(&self) -> i32 { 0 }
+}
+"#,
+    );
+    assert_eq!("(i32, {unknown}, i32, {unknown})", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+macro_rules! foo {
+    ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+    };
+}
+
+fn main() {
+    let x = foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [156; 182) '{     ...,2); }': ()
+    [166; 167) 'x': Foo
+    "###
+    );
+}
+
+#[test]
+fn infer_legacy_textual_scoped_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+#[macro_use]
+mod m {
+    macro_rules! foo {
+        ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+        };
+    }
+}
+
+fn main() {
+    let x = foo!(1,2);
+    let y = crate::foo!(1,2);
+}
+"#),
+        @r###"
+    ![0; 17) '{Foo(v...,2,])}': Foo
+    ![1; 4) 'Foo': Foo({unknown}) -> Foo
+    ![1; 16) 'Foo(vec![1,2,])': Foo
+    ![5; 15) 'vec![1,2,]': {unknown}
+    [195; 251) '{     ...,2); }': ()
+    [205; 206) 'x': Foo
+    [228; 229) 'y': {unknown}
+    [232; 248) 'crate:...!(1,2)': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_path_qualified_macros_expanded() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => { 42i32 }
+}
+
+mod m {
+    pub use super::foo as bar;
+}
+
+fn main() {
+    let x = crate::foo!();
+    let y = m::bar!();
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    ![0; 5) '42i32': i32
+    [111; 164) '{     ...!(); }': ()
+    [121; 122) 'x': i32
+    [148; 149) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_value_macro_having_same_name() {
+    assert_snapshot!(
+        infer(r#"
+#[macro_export]
+macro_rules! foo {
+    () => {
+        mod foo {
+            pub use super::foo;
+        }
+    };
+    ($x:tt) => {
+        $x
+    };
+}
+
+foo!();
+
+fn foo() {
+    let foo = foo::foo!(42i32);
+}
+"#),
+        @r###"
+    ![0; 5) '42i32': i32
+    [171; 206) '{     ...32); }': ()
+    [181; 184) 'foo': i32
+    "###
+    );
+}
+
+#[test]
+fn processes_impls_generated_by_macros() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m {
+    ($ident:ident) => (impl Trait for $ident {})
+}
+trait Trait { fn foo(self) -> u128 {} }
+struct S;
+m!(S);
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_impl_items_generated_by_macros() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m {
+    () => (fn foo(&self) -> u128 {0})
+}
+struct S;
+impl S {
+    m!();
+}
+
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_impl_items_generated_by_macros_chain() {
+    let t = type_at(
+        r#"
+//- /main.rs
+macro_rules! m_inner {
+    () => {fn foo(&self) -> u128 {0}}
+}
+macro_rules! m {
+    () => {m_inner!();}
+}
+
+struct S;
+impl S {
+    m!();
+}
+
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn infer_macro_with_dollar_crate_is_correct_in_expr() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo
+fn test() {
+    let x = (foo::foo!(1), foo::foo!(2));
+    x<|>;
+}
+
+//- /lib.rs crate:foo
+#[macro_export]
+macro_rules! foo {
+    (1) => { $crate::bar!() };
+    (2) => { 1 + $crate::baz() };
+}
+
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+
+pub fn baz() -> usize { 31usize }
+"#,
+    );
+    assert_eq!("(i32, usize)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_type_value_non_legacy_macro_use_as() {
+    assert_snapshot!(
+        infer(r#"
+mod m {
+    macro_rules! _foo {
+        ($x:ident) => { type $x = u64; }
+    }
+    pub(crate) use _foo as foo;
+}
+
+m::foo!(foo);
+use foo as bar;
+fn f() -> bar { 0 }
+fn main() {  
+    let _a  = f();
+}
+"#),
+        @r###"
+        [159; 164) '{ 0 }': u64
+        [161; 162) '0': u64
+        [175; 199) '{     ...f(); }': ()
+        [187; 189) '_a': u64
+        [193; 194) 'f': fn f() -> u64
+        [193; 196) 'f()': u64        
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_line() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! line {() => {}}
+
+fn main() {
+    let x = line!();
+}
+"#),
+        @r###"
+    ![0; 1) '6': i32
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_file() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! file {() => {}}
+
+fn main() {
+    let x = file!();
+}
+"#),
+        @r###"
+    ![0; 2) '""': &str
+    [64; 88) '{     ...!(); }': ()
+    [74; 75) 'x': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_builtin_macros_column() {
+    assert_snapshot!(
+        infer(r#"
+#[rustc_builtin_macro]
+macro_rules! column {() => {}}
+
+fn main() {
+    let x = column!();
+}
+"#),
+        @r###"
+    ![0; 2) '13': i32
+    [66; 92) '{     ...!(); }': ()
+    [76; 77) 'x': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_derive_clone_simple() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+#[derive(Clone)]
+struct S;
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:std
+#[prelude_import]
+use clone::*;
+mod clone {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_derive_clone_with_params() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+#[derive(Clone)]
+struct S;
+#[derive(Clone)]
+struct Wrapper<T>(T);
+struct NonClone;
+fn test() {
+    (Wrapper(S).clone(), Wrapper(NonClone).clone())<|>;
+}
+
+//- /lib.rs crate:std
+#[prelude_import]
+use clone::*;
+mod clone {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("(Wrapper<S>, {unknown})", type_at_pos(&db, pos));
+}
diff --git a/crates/ra_hir_ty/src/tests/method_resolution.rs b/crates/ra_hir_ty/src/tests/method_resolution.rs
new file mode 100644
index 000000000..ce9a06fde
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/method_resolution.rs
@@ -0,0 +1,1005 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_slice_method() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "slice"]
+impl<T> [T] {
+    fn foo(&self) -> T {
+        loop {}
+    }
+}
+
+#[lang = "slice_alloc"]
+impl<T> [T] {}
+
+fn test() {
+    <[_]>::foo(b"foo");
+}
+"#),
+        @r###"
+    [45; 49) 'self': &[T]
+    [56; 79) '{     ...     }': T
+    [66; 73) 'loop {}': !
+    [71; 73) '{}': ()
+    [133; 160) '{     ...o"); }': ()
+    [139; 149) '<[_]>::foo': fn foo<u8>(&[T]) -> T
+    [139; 157) '<[_]>:..."foo")': u8
+    [150; 156) 'b"foo"': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A { x: u32 }
+
+impl A {
+    fn new() -> A {
+        A { x: 0 }
+    }
+}
+fn test() {
+    let a = A::new();
+    a.x;
+}
+"#),
+        @r###"
+    [49; 75) '{     ...     }': A
+    [59; 69) 'A { x: 0 }': A
+    [66; 67) '0': u32
+    [88; 122) '{     ...a.x; }': ()
+    [98; 99) 'a': A
+    [102; 108) 'A::new': fn new() -> A
+    [102; 110) 'A::new()': A
+    [116; 117) 'a': A
+    [116; 119) 'a.x': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum A { B, C }
+
+impl A {
+    pub fn b() -> A {
+        A::B
+    }
+    pub fn c() -> A {
+        A::C
+    }
+}
+fn test() {
+    let a = A::b();
+    a;
+    let c = A::c();
+    c;
+}
+"#),
+        @r###"
+    [47; 67) '{     ...     }': A
+    [57; 61) 'A::B': A
+    [88; 108) '{     ...     }': A
+    [98; 102) 'A::C': A
+    [121; 178) '{     ...  c; }': ()
+    [131; 132) 'a': A
+    [135; 139) 'A::b': fn b() -> A
+    [135; 141) 'A::b()': A
+    [147; 148) 'a': A
+    [158; 159) 'c': A
+    [162; 166) 'A::c': fn c() -> A
+    [162; 168) 'A::c()': A
+    [174; 175) 'c': A
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_with_modules() {
+    assert_snapshot!(
+        infer(r#"
+mod a {
+    struct A;
+    impl A { pub fn thing() -> A { A {} }}
+}
+
+mod b {
+    struct B;
+    impl B { pub fn thing() -> u32 { 99 }}
+
+    mod c {
+        struct C;
+        impl C { pub fn thing() -> C { C {} }}
+    }
+}
+use b::c;
+
+fn test() {
+    let x = a::A::thing();
+    let y = b::B::thing();
+    let z = c::C::thing();
+}
+"#),
+        @r###"
+    [56; 64) '{ A {} }': A
+    [58; 62) 'A {}': A
+    [126; 132) '{ 99 }': u32
+    [128; 130) '99': u32
+    [202; 210) '{ C {} }': C
+    [204; 208) 'C {}': C
+    [241; 325) '{     ...g(); }': ()
+    [251; 252) 'x': A
+    [255; 266) 'a::A::thing': fn thing() -> A
+    [255; 268) 'a::A::thing()': A
+    [278; 279) 'y': u32
+    [282; 293) 'b::B::thing': fn thing() -> u32
+    [282; 295) 'b::B::thing()': u32
+    [305; 306) 'z': C
+    [309; 320) 'c::C::thing': fn thing() -> C
+    [309; 322) 'c::C::thing()': C
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make(val: T) -> Gen<T> {
+        Gen { val }
+    }
+}
+
+fn test() {
+    let a = Gen::make(0u32);
+}
+"#),
+        @r###"
+    [64; 67) 'val': T
+    [82; 109) '{     ...     }': Gen<T>
+    [92; 103) 'Gen { val }': Gen<T>
+    [98; 101) 'val': T
+    [123; 155) '{     ...32); }': ()
+    [133; 134) 'a': Gen<u32>
+    [137; 146) 'Gen::make': fn make<u32>(T) -> Gen<T>
+    [137; 152) 'Gen::make(0u32)': Gen<u32>
+    [147; 151) '0u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_param() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T=u32> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+}
+"#),
+        @r###"
+    [80; 104) '{     ...     }': Gen<T>
+    [90; 98) 'loop { }': !
+    [95; 98) '{ }': ()
+    [118; 146) '{     ...e(); }': ()
+    [128; 129) 'a': Gen<u32>
+    [132; 141) 'Gen::make': fn make<u32>() -> Gen<T>
+    [132; 143) 'Gen::make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_with_default_tuple_param() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct Gen<T=()> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::make();
+    a.val<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn infer_associated_method_generics_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T> {
+    val: T
+}
+
+impl<T> Gen<T> {
+    pub fn make() -> Gen<T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32>::make();
+}
+"#),
+        @r###"
+    [76; 100) '{     ...     }': Gen<T>
+    [86; 94) 'loop { }': !
+    [91; 94) '{ }': ()
+    [114; 149) '{     ...e(); }': ()
+    [124; 125) 'a': Gen<u32>
+    [128; 144) 'Gen::<...::make': fn make<u32>() -> Gen<T>
+    [128; 146) 'Gen::<...make()': Gen<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_method_generics_2_type_params_without_args() {
+    assert_snapshot!(
+        infer(r#"
+struct Gen<T, U> {
+    val: T,
+    val2: U,
+}
+
+impl<T> Gen<u32, T> {
+    pub fn make() -> Gen<u32,T> {
+        loop { }
+    }
+}
+
+fn test() {
+    let a = Gen::<u32, u64>::make();
+}
+"#),
+        @r###"
+    [102; 126) '{     ...     }': Gen<u32, T>
+    [112; 120) 'loop { }': !
+    [117; 120) '{ }': ()
+    [140; 180) '{     ...e(); }': ()
+    [150; 151) 'a': Gen<u32, u64>
+    [154; 175) 'Gen::<...::make': fn make<u64>() -> Gen<u32, T>
+    [154; 177) 'Gen::<...make()': Gen<u32, u64>
+    "###
+    );
+}
+
+#[test]
+fn cross_crate_associated_method_call() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+fn test() {
+    let x = other_crate::foo::S::thing();
+    x<|>;
+}
+
+//- /lib.rs crate:other_crate
+mod foo {
+    struct S;
+    impl S {
+        fn thing() -> i128 {}
+    }
+}
+"#,
+    );
+    assert_eq!("i128", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_trait_method_simple() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    fn method(&self) -> u32;
+}
+struct S1;
+impl Trait1 for S1 {}
+trait Trait2 {
+    fn method(&self) -> i128;
+}
+struct S2;
+impl Trait2 for S2 {}
+fn test() {
+    S1.method(); // -> u32
+    S2.method(); // -> i128
+}
+"#),
+        @r###"
+    [31; 35) 'self': &Self
+    [110; 114) 'self': &Self
+    [170; 228) '{     ...i128 }': ()
+    [176; 178) 'S1': S1
+    [176; 187) 'S1.method()': u32
+    [203; 205) 'S2': S2
+    [203; 214) 'S2.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_scoped() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+struct S;
+mod foo {
+    pub trait Trait1 {
+        fn method(&self) -> u32;
+    }
+    impl Trait1 for super::S {}
+}
+mod bar {
+    pub trait Trait2 {
+        fn method(&self) -> i128;
+    }
+    impl Trait2 for super::S {}
+}
+
+mod foo_test {
+    use super::S;
+    use super::foo::Trait1;
+    fn test() {
+        S.method(); // -> u32
+    }
+}
+
+mod bar_test {
+    use super::S;
+    use super::bar::Trait2;
+    fn test() {
+        S.method(); // -> i128
+    }
+}
+"#),
+        @r###"
+    [63; 67) 'self': &Self
+    [169; 173) 'self': &Self
+    [300; 337) '{     ...     }': ()
+    [310; 311) 'S': S
+    [310; 320) 'S.method()': u32
+    [416; 454) '{     ...     }': ()
+    [426; 427) 'S': S
+    [426; 436) 'S.method()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_1() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+fn test() {
+    S.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [92; 111) '{     ...d(); }': ()
+    [98; 99) 'S': S
+    [98; 108) 'S.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_more_params() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T1, T2, T3> {
+    fn method1(&self) -> (T1, T2, T3);
+    fn method2(&self) -> (T3, T2, T1);
+}
+struct S1;
+impl Trait<u8, u16, u32> for S1 {}
+struct S2;
+impl<T> Trait<i8, i16, T> for S2 {}
+fn test() {
+    S1.method1(); // u8, u16, u32
+    S1.method2(); // u32, u16, u8
+    S2.method1(); // i8, i16, {unknown}
+    S2.method2(); // {unknown}, i16, i8
+}
+"#),
+        @r###"
+    [43; 47) 'self': &Self
+    [82; 86) 'self': &Self
+    [210; 361) '{     ..., i8 }': ()
+    [216; 218) 'S1': S1
+    [216; 228) 'S1.method1()': (u8, u16, u32)
+    [250; 252) 'S1': S1
+    [250; 262) 'S1.method2()': (u32, u16, u8)
+    [284; 286) 'S2': S2
+    [284; 296) 'S2.method1()': (i8, i16, {unknown})
+    [324; 326) 'S2': S2
+    [324; 336) 'S2.method2()': ({unknown}, i16, i8)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_method_generic_2() {
+    // the trait implementation is intentionally incomplete -- it shouldn't matter
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn test() {
+    S(1u32).method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [102; 127) '{     ...d(); }': ()
+    [108; 109) 'S': S<u32>(T) -> S<T>
+    [108; 115) 'S(1u32)': S<u32>
+    [108; 124) 'S(1u32...thod()': u32
+    [110; 114) '1u32': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method() {
+    assert_snapshot!(
+        infer(r#"
+trait Default {
+    fn default() -> Self;
+}
+struct S;
+impl Default for S {}
+fn test() {
+    let s1: S = Default::default();
+    let s2 = S::default();
+    let s3 = <S as Default>::default();
+}
+"#),
+        @r###"
+    [87; 193) '{     ...t(); }': ()
+    [97; 99) 's1': S
+    [105; 121) 'Defaul...efault': fn default<S>() -> Self
+    [105; 123) 'Defaul...ault()': S
+    [133; 135) 's2': S
+    [138; 148) 'S::default': fn default<S>() -> Self
+    [138; 150) 'S::default()': S
+    [160; 162) 's3': S
+    [165; 188) '<S as ...efault': fn default<S>() -> Self
+    [165; 190) '<S as ...ault()': S
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> T;
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make();
+    let b = G::<u64>::make();
+    let c: f64 = G::make();
+}
+"#),
+        @r###"
+    [127; 211) '{     ...e(); }': ()
+    [137; 138) 'a': u32
+    [141; 148) 'S::make': fn make<S, u32>() -> T
+    [141; 150) 'S::make()': u32
+    [160; 161) 'b': u64
+    [164; 178) 'G::<u64>::make': fn make<G<u64>, u64>() -> T
+    [164; 180) 'G::<u6...make()': u64
+    [190; 191) 'c': f64
+    [199; 206) 'G::make': fn make<G<f64>, f64>() -> T
+    [199; 208) 'G::make()': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (T, U);
+}
+struct S;
+impl Trait<u32> for S {}
+struct G<T>;
+impl<T> Trait<T> for G<T> {}
+fn test() {
+    let a = S::make::<i64>();
+    let b: (_, i64) = S::make();
+    let c = G::<u32>::make::<i64>();
+    let d: (u32, _) = G::make::<i64>();
+    let e: (u32, i64) = G::make();
+}
+"#),
+        @r###"
+    [135; 313) '{     ...e(); }': ()
+    [145; 146) 'a': (u32, i64)
+    [149; 163) 'S::make::<i64>': fn make<S, u32, i64>() -> (T, U)
+    [149; 165) 'S::mak...i64>()': (u32, i64)
+    [175; 176) 'b': (u32, i64)
+    [189; 196) 'S::make': fn make<S, u32, i64>() -> (T, U)
+    [189; 198) 'S::make()': (u32, i64)
+    [208; 209) 'c': (u32, i64)
+    [212; 233) 'G::<u3...:<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [212; 235) 'G::<u3...i64>()': (u32, i64)
+    [245; 246) 'd': (u32, i64)
+    [259; 273) 'G::make::<i64>': fn make<G<u32>, u32, i64>() -> (T, U)
+    [259; 275) 'G::mak...i64>()': (u32, i64)
+    [285; 286) 'e': (u32, i64)
+    [301; 308) 'G::make': fn make<G<u32>, u32, i64>() -> (T, U)
+    [301; 310) 'G::make()': (u32, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_3() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<i32> {}
+fn test() {
+    let a = S::make();
+}
+"#),
+        @r###"
+    [101; 127) '{     ...e(); }': ()
+    [111; 112) 'a': (S<i32>, i64)
+    [115; 122) 'S::make': fn make<S<i32>, i64>() -> (Self, T)
+    [115; 124) 'S::make()': (S<i32>, i64)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_4() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make() -> (Self, T);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+impl Trait<i32> for S<u32> {}
+fn test() {
+    let a: (S<u64>, _) = S::make();
+    let b: (_, i32) = S::make();
+}
+"#),
+        @r###"
+    [131; 203) '{     ...e(); }': ()
+    [141; 142) 'a': (S<u64>, i64)
+    [158; 165) 'S::make': fn make<S<u64>, i64>() -> (Self, T)
+    [158; 167) 'S::make()': (S<u64>, i64)
+    [177; 178) 'b': (S<u32>, i32)
+    [191; 198) 'S::make': fn make<S<u32>, i32>() -> (Self, T)
+    [191; 200) 'S::make()': (S<u32>, i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_trait_assoc_method_generics_5() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn make<U>() -> (Self, T, U);
+}
+struct S<T>;
+impl Trait<i64> for S<u64> {}
+fn test() {
+    let a = <S as Trait<i64>>::make::<u8>();
+    let b: (S<u64>, _, _) = Trait::<i64>::make::<u8>();
+}
+"#),
+        @r###"
+    [107; 211) '{     ...>(); }': ()
+    [117; 118) 'a': (S<u64>, i64, u8)
+    [121; 150) '<S as ...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [121; 152) '<S as ...<u8>()': (S<u64>, i64, u8)
+    [162; 163) 'b': (S<u64>, i64, u8)
+    [182; 206) 'Trait:...::<u8>': fn make<S<u64>, i64, u8>() -> (Self, T, U)
+    [182; 208) 'Trait:...<u8>()': (S<u64>, i64, u8)
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn method(&self) -> u32;
+}
+fn test<T: Trait>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [64; 65) 't': T
+    [70; 89) '{     ...d(); }': ()
+    [76; 77) 't': T
+    [76; 86) 't.method()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_call_trait_method_on_generic_param_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn method(&self) -> T;
+}
+fn test<U, T: Trait<U>>(t: T) {
+    t.method();
+}
+"#),
+        @r###"
+    [33; 37) 'self': &Self
+    [71; 72) 't': T
+    [77; 96) '{     ...d(); }': ()
+    [83; 84) 't': T
+    [83; 93) 't.method()': [missing name]
+    "###
+    );
+}
+
+#[test]
+fn infer_with_multiple_trait_impls() {
+    assert_snapshot!(
+        infer(r#"
+trait Into<T> {
+    fn into(self) -> T;
+}
+struct S;
+impl Into<u32> for S {}
+impl Into<u64> for S {}
+fn test() {
+    let x: u32 = S.into();
+    let y: u64 = S.into();
+    let z = Into::<u64>::into(S);
+}
+"#),
+        @r###"
+    [29; 33) 'self': Self
+    [111; 202) '{     ...(S); }': ()
+    [121; 122) 'x': u32
+    [130; 131) 'S': S
+    [130; 138) 'S.into()': u32
+    [148; 149) 'y': u64
+    [157; 158) 'S': S
+    [157; 165) 'S.into()': u64
+    [175; 176) 'z': u64
+    [179; 196) 'Into::...::into': fn into<S, u64>(Self) -> T
+    [179; 199) 'Into::...nto(S)': u64
+    [197; 198) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn method_resolution_unify_impl_self_type() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S<T>;
+impl S<u32> { fn foo(&self) -> u8 {} }
+impl S<i32> { fn foo(&self) -> i8 {} }
+fn test() { (S::<u32>.foo(), S::<i32>.foo())<|>; }
+"#,
+    );
+    assert_eq!(t, "(u8, i8)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_by_value_before_autoref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone { fn clone(&self) -> Self; }
+struct S;
+impl Clone for S {}
+impl Clone for &S {}
+fn test() { (S.clone(), (&S).clone(), (&&S).clone())<|>; }
+"#,
+    );
+    assert_eq!(t, "(S, S, &S)");
+}
+
+#[test]
+fn method_resolution_trait_before_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_impl_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(self) -> i8 { 0 } }
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_impl_ref_before_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl S { fn foo(&self) -> i8 { 0 } }
+impl Trait for &S { fn foo(self) -> u128 { 0 } }
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "i8");
+}
+
+#[test]
+fn method_resolution_trait_autoderef() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S { fn foo(self) -> u128 { 0 } }
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_trait_from_prelude() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:other_crate
+struct S;
+impl Clone for S {}
+
+fn test() {
+    S.clone()<|>;
+}
+
+//- /lib.rs crate:other_crate
+#[prelude_import] use foo::*;
+
+mod foo {
+    trait Clone {
+        fn clone(&self) -> Self;
+    }
+}
+"#,
+    );
+    assert_eq!("S", type_at_pos(&db, pos));
+}
+
+#[test]
+fn method_resolution_where_clause_for_unknown_trait() {
+    // The blanket impl currently applies because we ignore the unresolved where clause
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: UnknownTrait {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_where_clause_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T> Trait for T where T: Clone {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    // This is also to make sure that we don't resolve to the foo method just
+    // because that's the only method named foo we can find, which would make
+    // the below tests not work
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline_not_met() {
+    // The blanket impl shouldn't apply because we can't prove S: Clone
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl<T: Clone> Trait for T {}
+fn test() { (&S).foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test() { S.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn method_resolution_where_clause_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U> Into<U> for T where U: From<T> {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_where_clause_inline() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Into<T> { fn into(self) -> T; }
+trait From<T> { fn from(other: T) -> Self; }
+struct S1;
+struct S2;
+impl From<S2> for S1 {}
+impl<T, U: From<T>> Into<U> for T {}
+fn test() { S2.into()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn method_resolution_encountering_fn_type() {
+    type_at(
+        r#"
+//- /main.rs
+fn foo() {}
+trait FnOnce { fn call(self); }
+fn test() { foo.call()<|>; }
+"#,
+    );
+}
+
+#[test]
+fn method_resolution_slow() {
+    // this can get quite slow if we set the solver size limit too high
+    let t = type_at(
+        r#"
+//- /main.rs
+trait SendX {}
+
+struct S1; impl SendX for S1 {}
+struct S2; impl SendX for S2 {}
+struct U1;
+
+trait Trait { fn method(self); }
+
+struct X1<A, B> {}
+impl<A, B> SendX for X1<A, B> where A: SendX, B: SendX {}
+
+struct S<B, C> {}
+
+trait FnX {}
+
+impl<B, C> Trait for S<B, C> where C: FnX, B: SendX {}
+
+fn test() { (S {}).method()<|>; }
+"#,
+    );
+    assert_eq!(t, "()");
+}
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
new file mode 100644
index 000000000..cb3890b42
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -0,0 +1,238 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn infer_pattern() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &i32) {
+    let y = x;
+    let &z = x;
+    let a = z;
+    let (c, d) = (1, "hello");
+
+    for (e, f) in some_iter {
+        let g = e;
+    }
+
+    if let [val] = opt {
+        let h = val;
+    }
+
+    let lambda = |a: u64, b, c: i32| { a + b; c };
+
+    let ref ref_to_x = x;
+    let mut mut_x = x;
+    let ref mut mut_ref_to_x = x;
+    let k = mut_ref_to_x;
+}
+"#),
+        @r###"
+    [9; 10) 'x': &i32
+    [18; 369) '{     ...o_x; }': ()
+    [28; 29) 'y': &i32
+    [32; 33) 'x': &i32
+    [43; 45) '&z': &i32
+    [44; 45) 'z': i32
+    [48; 49) 'x': &i32
+    [59; 60) 'a': i32
+    [63; 64) 'z': i32
+    [74; 80) '(c, d)': (i32, &str)
+    [75; 76) 'c': i32
+    [78; 79) 'd': &str
+    [83; 95) '(1, "hello")': (i32, &str)
+    [84; 85) '1': i32
+    [87; 94) '"hello"': &str
+    [102; 152) 'for (e...     }': ()
+    [106; 112) '(e, f)': ({unknown}, {unknown})
+    [107; 108) 'e': {unknown}
+    [110; 111) 'f': {unknown}
+    [116; 125) 'some_iter': {unknown}
+    [126; 152) '{     ...     }': ()
+    [140; 141) 'g': {unknown}
+    [144; 145) 'e': {unknown}
+    [158; 205) 'if let...     }': ()
+    [165; 170) '[val]': {unknown}
+    [173; 176) 'opt': {unknown}
+    [177; 205) '{     ...     }': ()
+    [191; 192) 'h': {unknown}
+    [195; 198) 'val': {unknown}
+    [215; 221) 'lambda': |u64, u64, i32| -> i32
+    [224; 256) '|a: u6...b; c }': |u64, u64, i32| -> i32
+    [225; 226) 'a': u64
+    [233; 234) 'b': u64
+    [236; 237) 'c': i32
+    [244; 256) '{ a + b; c }': i32
+    [246; 247) 'a': u64
+    [246; 251) 'a + b': u64
+    [250; 251) 'b': u64
+    [253; 254) 'c': i32
+    [267; 279) 'ref ref_to_x': &&i32
+    [282; 283) 'x': &i32
+    [293; 302) 'mut mut_x': &i32
+    [305; 306) 'x': &i32
+    [316; 336) 'ref mu...f_to_x': &mut &i32
+    [339; 340) 'x': &i32
+    [350; 351) 'k': &mut &i32
+    [354; 366) 'mut_ref_to_x': &mut &i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+
+fn test() {
+    let A(n) = &A(1);
+    let A(n) = &mut A(1);
+}
+"#),
+    @r###"
+    [28; 79) '{     ...(1); }': ()
+    [38; 42) 'A(n)': A<i32>
+    [40; 41) 'n': &i32
+    [45; 50) '&A(1)': &A<i32>
+    [46; 47) 'A': A<i32>(T) -> A<T>
+    [46; 50) 'A(1)': A<i32>
+    [48; 49) '1': i32
+    [60; 64) 'A(n)': A<i32>
+    [62; 63) 'n': &mut i32
+    [67; 76) '&mut A(1)': &mut A<i32>
+    [72; 73) 'A': A<i32>(T) -> A<T>
+    [72; 76) 'A(1)': A<i32>
+    [74; 75) '1': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_pattern_match_ergonomics_ref() {
+    covers!(match_ergonomics_ref);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let v = &(1, &2);
+    let (_, &w) = v;
+}
+"#),
+    @r###"
+    [11; 57) '{     ...= v; }': ()
+    [21; 22) 'v': &(i32, &i32)
+    [25; 33) '&(1, &2)': &(i32, &i32)
+    [26; 33) '(1, &2)': (i32, &i32)
+    [27; 28) '1': i32
+    [30; 32) '&2': &i32
+    [31; 32) '2': i32
+    [43; 50) '(_, &w)': (i32, &i32)
+    [44; 45) '_': i32
+    [47; 49) '&w': &i32
+    [48; 49) 'w': i32
+    [53; 54) 'v': &(i32, &i32)
+    "###
+    );
+}
+
+#[test]
+fn infer_adt_pattern() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+    A { x: usize },
+    B
+}
+
+struct S(u32, E);
+
+fn test() {
+    let e = E::A { x: 3 };
+
+    let S(y, z) = foo;
+    let E::A { x: new_var } = e;
+
+    match e {
+        E::A { x } => x,
+        E::B if foo => 1,
+        E::B => 10,
+    };
+
+    let ref d @ E::A { .. } = e;
+    d;
+}
+"#),
+        @r###"
+    [68; 289) '{     ...  d; }': ()
+    [78; 79) 'e': E
+    [82; 95) 'E::A { x: 3 }': E
+    [92; 93) '3': usize
+    [106; 113) 'S(y, z)': S
+    [108; 109) 'y': u32
+    [111; 112) 'z': E
+    [116; 119) 'foo': S
+    [129; 148) 'E::A {..._var }': E
+    [139; 146) 'new_var': usize
+    [151; 152) 'e': E
+    [159; 245) 'match ...     }': usize
+    [165; 166) 'e': E
+    [177; 187) 'E::A { x }': E
+    [184; 185) 'x': usize
+    [191; 192) 'x': usize
+    [202; 206) 'E::B': E
+    [210; 213) 'foo': bool
+    [217; 218) '1': usize
+    [228; 232) 'E::B': E
+    [236; 238) '10': usize
+    [256; 275) 'ref d ...{ .. }': &E
+    [264; 275) 'E::A { .. }': E
+    [278; 279) 'e': E
+    [285; 286) 'd': &E
+    "###
+    );
+}
+
+#[test]
+fn infer_generics_in_patterns() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+enum Option<T> {
+    Some(T),
+    None,
+}
+
+fn test(a1: A<u32>, o: Option<u64>) {
+    let A { x: x2 } = a1;
+    let A::<i64> { x: x3 } = A { x: 1 };
+    match o {
+        Option::Some(t) => t,
+        _ => 1,
+    };
+}
+"#),
+        @r###"
+    [79; 81) 'a1': A<u32>
+    [91; 92) 'o': Option<u64>
+    [107; 244) '{     ...  }; }': ()
+    [117; 128) 'A { x: x2 }': A<u32>
+    [124; 126) 'x2': u32
+    [131; 133) 'a1': A<u32>
+    [143; 161) 'A::<i6...: x3 }': A<i64>
+    [157; 159) 'x3': i64
+    [164; 174) 'A { x: 1 }': A<i64>
+    [171; 172) '1': i64
+    [180; 241) 'match ...     }': u64
+    [186; 187) 'o': Option<u64>
+    [198; 213) 'Option::Some(t)': Option<u64>
+    [211; 212) 't': u64
+    [217; 218) 't': u64
+    [228; 229) '_': Option<u64>
+    [233; 234) '1': u64
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
new file mode 100644
index 000000000..09d684ac2
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -0,0 +1,333 @@
+use super::infer;
+use insta::assert_snapshot;
+use test_utils::covers;
+
+#[test]
+fn bug_484() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+   let x = if true {};
+}
+"#),
+        @r###"
+    [11; 37) '{    l... {}; }': ()
+    [20; 21) 'x': ()
+    [24; 34) 'if true {}': ()
+    [27; 31) 'true': bool
+    [32; 34) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn no_panic_on_field_of_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum X {}
+
+fn test(x: X) {
+    x.some_field;
+}
+"#),
+        @r###"
+    [20; 21) 'x': X
+    [26; 47) '{     ...eld; }': ()
+    [32; 33) 'x': X
+    [32; 44) 'x.some_field': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn bug_585() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    X {};
+    match x {
+        A::B {} => (),
+        A::Y() => (),
+    }
+}
+"#),
+        @r###"
+    [11; 89) '{     ...   } }': ()
+    [17; 21) 'X {}': {unknown}
+    [27; 87) 'match ...     }': ()
+    [33; 34) 'x': {unknown}
+    [45; 52) 'A::B {}': {unknown}
+    [56; 58) '()': ()
+    [68; 74) 'A::Y()': {unknown}
+    [78; 80) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn bug_651() {
+    assert_snapshot!(
+        infer(r#"
+fn quux() {
+    let y = 92;
+    1 + y;
+}
+"#),
+        @r###"
+    [11; 41) '{     ...+ y; }': ()
+    [21; 22) 'y': i32
+    [25; 27) '92': i32
+    [33; 34) '1': i32
+    [33; 38) '1 + y': i32
+    [37; 38) 'y': i32
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let y = unknown;
+    [y, &y];
+}
+"#),
+        @r###"
+    [11; 48) '{     ...&y]; }': ()
+    [21; 22) 'y': &{unknown}
+    [25; 32) 'unknown': &{unknown}
+    [38; 45) '[y, &y]': [&&{unknown};_]
+    [39; 40) 'y': &{unknown}
+    [42; 44) '&y': &&{unknown}
+    [43; 44) 'y': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn recursive_vars_2() {
+    covers!(type_var_cycles_resolve_completely);
+    covers!(type_var_cycles_resolve_as_possible);
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let x = unknown;
+    let y = unknown;
+    [(x, y), (&y, &x)];
+}
+"#),
+        @r###"
+    [11; 80) '{     ...x)]; }': ()
+    [21; 22) 'x': &&{unknown}
+    [25; 32) 'unknown': &&{unknown}
+    [42; 43) 'y': &&{unknown}
+    [46; 53) 'unknown': &&{unknown}
+    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
+    [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
+    [61; 62) 'x': &&{unknown}
+    [64; 65) 'y': &&{unknown}
+    [68; 76) '(&y, &x)': (&&&{unknown}, &&&{unknown})
+    [69; 71) '&y': &&&{unknown}
+    [70; 71) 'y': &&{unknown}
+    [73; 75) '&x': &&&{unknown}
+    [74; 75) 'x': &&{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_1() {
+    // caused stack overflow, taken from std
+    assert_snapshot!(
+        infer(r#"
+enum Maybe<T> {
+    Real(T),
+    Fake,
+}
+
+fn write() {
+    match something_unknown {
+        Maybe::Real(ref mut something) => (),
+    }
+}
+"#),
+        @r###"
+    [54; 139) '{     ...   } }': ()
+    [60; 137) 'match ...     }': ()
+    [66; 83) 'someth...nknown': Maybe<{unknown}>
+    [94; 124) 'Maybe:...thing)': Maybe<{unknown}>
+    [106; 123) 'ref mu...ething': &mut {unknown}
+    [128; 130) '()': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_2() {
+    covers!(type_var_resolves_to_int_var);
+    // caused "equating two type variables, ...", taken from std
+    assert_snapshot!(
+        infer(r#"
+fn test_line_buffer() {
+    &[0, b'\n', 1, b'\n'];
+}
+"#),
+        @r###"
+    [23; 53) '{     ...n']; }': ()
+    [29; 50) '&[0, b...b'\n']': &[u8;_]
+    [30; 50) '[0, b'...b'\n']': [u8;_]
+    [31; 32) '0': u8
+    [34; 39) 'b'\n'': u8
+    [41; 42) '1': u8
+    [44; 49) 'b'\n'': u8
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_3() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn compute() {
+    match nope!() {
+        SizeSkeleton::Pointer { non_zero: true, tail } => {}
+    }
+}
+"#),
+        @r###"
+    [18; 108) '{     ...   } }': ()
+    [24; 106) 'match ...     }': ()
+    [30; 37) 'nope!()': {unknown}
+    [48; 94) 'SizeSk...tail }': {unknown}
+    [82; 86) 'true': {unknown}
+    [88; 92) 'tail': {unknown}
+    [98; 100) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_4() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+pub fn primitive_type() {
+    match *self {
+        BorrowedRef { type_: Primitive(p), ..} => {},
+    }
+}
+"#),
+        @r###"
+    [25; 106) '{     ...   } }': ()
+    [31; 104) 'match ...     }': ()
+    [37; 42) '*self': {unknown}
+    [38; 42) 'self': {unknown}
+    [53; 91) 'Borrow...), ..}': {unknown}
+    [74; 86) 'Primitive(p)': {unknown}
+    [84; 85) 'p': {unknown}
+    [95; 97) '{}': ()
+    "###
+    );
+}
+
+#[test]
+fn infer_std_crash_5() {
+    // taken from rustc
+    assert_snapshot!(
+        infer(r#"
+fn extra_compiler_flags() {
+    for content in doesnt_matter {
+        let name = if doesnt_matter {
+            first
+        } else {
+            &content
+        };
+
+        let content = if ICE_REPORT_COMPILER_FLAGS_STRIP_VALUE.contains(&name) {
+            name
+        } else {
+            content
+        };
+    }
+}
+"#),
+        @r###"
+    [27; 323) '{     ...   } }': ()
+    [33; 321) 'for co...     }': ()
+    [37; 44) 'content': &{unknown}
+    [48; 61) 'doesnt_matter': {unknown}
+    [62; 321) '{     ...     }': ()
+    [76; 80) 'name': &&{unknown}
+    [83; 167) 'if doe...     }': &&{unknown}
+    [86; 99) 'doesnt_matter': bool
+    [100; 129) '{     ...     }': &&{unknown}
+    [114; 119) 'first': &&{unknown}
+    [135; 167) '{     ...     }': &&{unknown}
+    [149; 157) '&content': &&{unknown}
+    [150; 157) 'content': &{unknown}
+    [182; 189) 'content': &{unknown}
+    [192; 314) 'if ICE...     }': &{unknown}
+    [195; 232) 'ICE_RE..._VALUE': {unknown}
+    [195; 248) 'ICE_RE...&name)': bool
+    [242; 247) '&name': &&&{unknown}
+    [243; 247) 'name': &&{unknown}
+    [249; 277) '{     ...     }': &&{unknown}
+    [263; 267) 'name': &&{unknown}
+    [283; 314) '{     ...     }': &{unknown}
+    [297; 304) 'content': &{unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_nested_generics_crash() {
+    // another crash found typechecking rustc
+    assert_snapshot!(
+        infer(r#"
+struct Canonical<V> {
+    value: V,
+}
+struct QueryResponse<V> {
+    value: V,
+}
+fn test<R>(query_response: Canonical<QueryResponse<R>>) {
+    &query_response.value;
+}
+"#),
+        @r###"
+    [92; 106) 'query_response': Canonical<QueryResponse<R>>
+    [137; 167) '{     ...lue; }': ()
+    [143; 164) '&query....value': &QueryResponse<R>
+    [144; 158) 'query_response': Canonical<QueryResponse<R>>
+    [144; 164) 'query_....value': QueryResponse<R>
+    "###
+    );
+}
+
+#[test]
+fn bug_1030() {
+    assert_snapshot!(infer(r#"
+struct HashSet<T, H>;
+struct FxHasher;
+type FxHashSet<T> = HashSet<T, FxHasher>;
+
+impl<T, H> HashSet<T, H> {
+    fn default() -> HashSet<T, H> {}
+}
+
+pub fn main_loop() {
+    FxHashSet::default();
+}
+"#),
+    @r###"
+    [144; 146) '{}': ()
+    [169; 198) '{     ...t(); }': ()
+    [175; 193) 'FxHash...efault': fn default<{unknown}, FxHasher>() -> HashSet<T, H>
+    [175; 195) 'FxHash...ault()': HashSet<{unknown}, FxHasher>
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
new file mode 100644
index 000000000..3e5e163e3
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -0,0 +1,1663 @@
+use super::{infer, type_at, type_at_pos};
+use crate::test_db::TestDB;
+use insta::assert_snapshot;
+use ra_db::fixture::WithFixture;
+
+#[test]
+fn infer_box() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let x = box 1;
+    let t = (x, box x, box &1, box [1]);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+mod boxed {
+    pub struct Box<T: ?Sized> {
+        inner: *mut T,
+    }
+}
+
+"#,
+    );
+    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_adt_self() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+enum Nat { Succ(Self), Demo(Nat), Zero }
+
+fn test() {
+    let foo: Nat = Nat::Zero;
+    if let Nat::Succ(x) = foo {
+        x<|>
+    }
+}
+
+"#,
+    );
+    assert_eq!("Nat", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ranges() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+fn test() {
+    let a = ..;
+    let b = 1..;
+    let c = ..2u32;
+    let d = 1..2usize;
+    let e = ..=10;
+    let f = 'a'..='z';
+
+    let t = (a, b, c, d, e, f);
+    t<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use prelude::*;
+mod prelude {}
+
+pub mod ops {
+    pub struct Range<Idx> {
+        pub start: Idx,
+        pub end: Idx,
+    }
+    pub struct RangeFrom<Idx> {
+        pub start: Idx,
+    }
+    struct RangeFull;
+    pub struct RangeInclusive<Idx> {
+        start: Idx,
+        end: Idx,
+        is_empty: u8,
+    }
+    pub struct RangeTo<Idx> {
+        pub end: Idx,
+    }
+    pub struct RangeToInclusive<Idx> {
+        pub end: Idx,
+    }
+}
+"#,
+    );
+    assert_eq!(
+        "(RangeFull, RangeFrom<i32>, RangeTo<u32>, Range<usize>, RangeToInclusive<i32>, RangeInclusive<char>)",
+        type_at_pos(&db, pos),
+    );
+}
+
+#[test]
+fn infer_while_let() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs
+enum Option<T> { Some(T), None }
+
+fn test() {
+    let foo: Option<f32> = None;
+    while let Option::Some(x) = foo {
+        <|>x
+    }
+}
+
+"#,
+    );
+    assert_eq!("f32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_basics() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: u32, b: isize, c: !, d: &str) {
+    a;
+    b;
+    c;
+    d;
+    1usize;
+    1isize;
+    "test";
+    1.0f32;
+}"#),
+        @r###"
+    [9; 10) 'a': u32
+    [17; 18) 'b': isize
+    [27; 28) 'c': !
+    [33; 34) 'd': &str
+    [42; 121) '{     ...f32; }': !
+    [48; 49) 'a': u32
+    [55; 56) 'b': isize
+    [62; 63) 'c': !
+    [69; 70) 'd': &str
+    [76; 82) '1usize': usize
+    [88; 94) '1isize': isize
+    [100; 106) '"test"': &str
+    [112; 118) '1.0f32': f32
+    "###
+    );
+}
+
+#[test]
+fn infer_let() {
+    assert_snapshot!(
+        infer(r#"
+fn test() {
+    let a = 1isize;
+    let b: usize = 1;
+    let c = b;
+    let d: u32;
+    let e;
+    let f: i32 = e;
+}
+"#),
+        @r###"
+    [11; 118) '{     ...= e; }': ()
+    [21; 22) 'a': isize
+    [25; 31) '1isize': isize
+    [41; 42) 'b': usize
+    [52; 53) '1': usize
+    [63; 64) 'c': usize
+    [67; 68) 'b': usize
+    [78; 79) 'd': u32
+    [94; 95) 'e': i32
+    [105; 106) 'f': i32
+    [114; 115) 'e': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_paths() {
+    assert_snapshot!(
+        infer(r#"
+fn a() -> u32 { 1 }
+
+mod b {
+    fn c() -> u32 { 1 }
+}
+
+fn test() {
+    a();
+    b::c();
+}
+"#),
+        @r###"
+    [15; 20) '{ 1 }': u32
+    [17; 18) '1': u32
+    [48; 53) '{ 1 }': u32
+    [50; 51) '1': u32
+    [67; 91) '{     ...c(); }': ()
+    [73; 74) 'a': fn a() -> u32
+    [73; 76) 'a()': u32
+    [82; 86) 'b::c': fn c() -> u32
+    [82; 88) 'b::c()': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_path_type() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn foo() -> i32 { 1 }
+}
+
+fn test() {
+    S::foo();
+    <S>::foo();
+}
+"#),
+        @r###"
+    [41; 46) '{ 1 }': i32
+    [43; 44) '1': i32
+    [60; 93) '{     ...o(); }': ()
+    [66; 72) 'S::foo': fn foo() -> i32
+    [66; 74) 'S::foo()': i32
+    [80; 88) '<S>::foo': fn foo() -> i32
+    [80; 90) '<S>::foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_struct() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+    c: C,
+}
+struct B;
+struct C(usize);
+
+fn test() {
+    let c = C(1);
+    B;
+    let a: A = A { b: B, c: C(1) };
+    a.b;
+    a.c;
+}
+"#),
+        @r###"
+    [72; 154) '{     ...a.c; }': ()
+    [82; 83) 'c': C
+    [86; 87) 'C': C(usize) -> C
+    [86; 90) 'C(1)': C
+    [88; 89) '1': usize
+    [96; 97) 'B': B
+    [107; 108) 'a': A
+    [114; 133) 'A { b:...C(1) }': A
+    [121; 122) 'B': B
+    [127; 128) 'C': C(usize) -> C
+    [127; 131) 'C(1)': C
+    [129; 130) '1': usize
+    [139; 140) 'a': A
+    [139; 142) 'a.b': B
+    [148; 149) 'a': A
+    [148; 151) 'a.c': C
+    "###
+    );
+}
+
+#[test]
+fn infer_enum() {
+    assert_snapshot!(
+        infer(r#"
+enum E {
+  V1 { field: u32 },
+  V2
+}
+fn test() {
+  E::V1 { field: 1 };
+  E::V2;
+}"#),
+        @r###"
+    [48; 82) '{   E:...:V2; }': ()
+    [52; 70) 'E::V1 ...d: 1 }': E
+    [67; 68) '1': u32
+    [74; 79) 'E::V2': E
+    "###
+    );
+}
+
+#[test]
+fn infer_refs() {
+    assert_snapshot!(
+        infer(r#"
+fn test(a: &u32, b: &mut u32, c: *const u32, d: *mut u32) {
+    a;
+    *a;
+    &a;
+    &mut a;
+    b;
+    *b;
+    &b;
+    c;
+    *c;
+    d;
+    *d;
+}
+"#),
+        @r###"
+    [9; 10) 'a': &u32
+    [18; 19) 'b': &mut u32
+    [31; 32) 'c': *const u32
+    [46; 47) 'd': *mut u32
+    [59; 150) '{     ... *d; }': ()
+    [65; 66) 'a': &u32
+    [72; 74) '*a': u32
+    [73; 74) 'a': &u32
+    [80; 82) '&a': &&u32
+    [81; 82) 'a': &u32
+    [88; 94) '&mut a': &mut &u32
+    [93; 94) 'a': &u32
+    [100; 101) 'b': &mut u32
+    [107; 109) '*b': u32
+    [108; 109) 'b': &mut u32
+    [115; 117) '&b': &&mut u32
+    [116; 117) 'b': &mut u32
+    [123; 124) 'c': *const u32
+    [130; 132) '*c': u32
+    [131; 132) 'c': *const u32
+    [138; 139) 'd': *mut u32
+    [145; 147) '*d': u32
+    [146; 147) 'd': *mut u32
+    "###
+    );
+}
+
+#[test]
+fn infer_literals() {
+    assert_snapshot!(
+        infer(r##"
+fn test() {
+    5i32;
+    5f32;
+    5f64;
+    "hello";
+    b"bytes";
+    'c';
+    b'b';
+    3.14;
+    5000;
+    false;
+    true;
+    r#"
+        //! doc
+        // non-doc
+        mod foo {}
+        "#;
+    br#"yolo"#;
+}
+"##),
+        @r###"
+    [11; 221) '{     ...o"#; }': ()
+    [17; 21) '5i32': i32
+    [27; 31) '5f32': f32
+    [37; 41) '5f64': f64
+    [47; 54) '"hello"': &str
+    [60; 68) 'b"bytes"': &[u8]
+    [74; 77) ''c'': char
+    [83; 87) 'b'b'': u8
+    [93; 97) '3.14': f64
+    [103; 107) '5000': i32
+    [113; 118) 'false': bool
+    [124; 128) 'true': bool
+    [134; 202) 'r#"   ...    "#': &str
+    [208; 218) 'br#"yolo"#': &[u8]
+    "###
+    );
+}
+
+#[test]
+fn infer_unary_op() {
+    assert_snapshot!(
+        infer(r#"
+enum SomeType {}
+
+fn test(x: SomeType) {
+    let b = false;
+    let c = !b;
+    let a = 100;
+    let d: i128 = -a;
+    let e = -100;
+    let f = !!!true;
+    let g = !42;
+    let h = !10u32;
+    let j = !a;
+    -3.14;
+    !3;
+    -x;
+    !x;
+    -"hello";
+    !"hello";
+}
+"#),
+        @r###"
+    [27; 28) 'x': SomeType
+    [40; 272) '{     ...lo"; }': ()
+    [50; 51) 'b': bool
+    [54; 59) 'false': bool
+    [69; 70) 'c': bool
+    [73; 75) '!b': bool
+    [74; 75) 'b': bool
+    [85; 86) 'a': i128
+    [89; 92) '100': i128
+    [102; 103) 'd': i128
+    [112; 114) '-a': i128
+    [113; 114) 'a': i128
+    [124; 125) 'e': i32
+    [128; 132) '-100': i32
+    [129; 132) '100': i32
+    [142; 143) 'f': bool
+    [146; 153) '!!!true': bool
+    [147; 153) '!!true': bool
+    [148; 153) '!true': bool
+    [149; 153) 'true': bool
+    [163; 164) 'g': i32
+    [167; 170) '!42': i32
+    [168; 170) '42': i32
+    [180; 181) 'h': u32
+    [184; 190) '!10u32': u32
+    [185; 190) '10u32': u32
+    [200; 201) 'j': i128
+    [204; 206) '!a': i128
+    [205; 206) 'a': i128
+    [212; 217) '-3.14': f64
+    [213; 217) '3.14': f64
+    [223; 225) '!3': i32
+    [224; 225) '3': i32
+    [231; 233) '-x': {unknown}
+    [232; 233) 'x': SomeType
+    [239; 241) '!x': {unknown}
+    [240; 241) 'x': SomeType
+    [247; 255) '-"hello"': {unknown}
+    [248; 255) '"hello"': &str
+    [261; 269) '!"hello"': {unknown}
+    [262; 269) '"hello"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_backwards() {
+    assert_snapshot!(
+        infer(r#"
+fn takes_u32(x: u32) {}
+
+struct S { i32_field: i32 }
+
+fn test() -> &mut &f64 {
+    let a = unknown_function();
+    takes_u32(a);
+    let b = unknown_function();
+    S { i32_field: b };
+    let c = unknown_function();
+    &mut &c
+}
+"#),
+        @r###"
+    [14; 15) 'x': u32
+    [22; 24) '{}': ()
+    [78; 231) '{     ...t &c }': &mut &f64
+    [88; 89) 'a': u32
+    [92; 108) 'unknow...nction': {unknown}
+    [92; 110) 'unknow...tion()': u32
+    [116; 125) 'takes_u32': fn takes_u32(u32) -> ()
+    [116; 128) 'takes_u32(a)': ()
+    [126; 127) 'a': u32
+    [138; 139) 'b': i32
+    [142; 158) 'unknow...nction': {unknown}
+    [142; 160) 'unknow...tion()': i32
+    [166; 184) 'S { i3...d: b }': S
+    [181; 182) 'b': i32
+    [194; 195) 'c': f64
+    [198; 214) 'unknow...nction': {unknown}
+    [198; 216) 'unknow...tion()': f64
+    [222; 229) '&mut &c': &mut &f64
+    [227; 229) '&c': &f64
+    [228; 229) 'c': f64
+    "###
+    );
+}
+
+#[test]
+fn infer_self() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+
+impl S {
+    fn test(&self) {
+        self;
+    }
+    fn test2(self: &Self) {
+        self;
+    }
+    fn test3() -> Self {
+        S {}
+    }
+    fn test4() -> Self {
+        Self {}
+    }
+}
+"#),
+        @r###"
+    [34; 38) 'self': &S
+    [40; 61) '{     ...     }': ()
+    [50; 54) 'self': &S
+    [75; 79) 'self': &S
+    [88; 109) '{     ...     }': ()
+    [98; 102) 'self': &S
+    [133; 153) '{     ...     }': S
+    [143; 147) 'S {}': S
+    [177; 200) '{     ...     }': S
+    [187; 194) 'Self {}': S
+    "###
+    );
+}
+
+#[test]
+fn infer_binary_op() {
+    assert_snapshot!(
+        infer(r#"
+fn f(x: bool) -> i32 {
+    0i32
+}
+
+fn test() -> bool {
+    let x = a && b;
+    let y = true || false;
+    let z = x == y;
+    let t = x != y;
+    let minus_forty: isize = -40isize;
+    let h = minus_forty <= CONST_2;
+    let c = f(z || y) + 5;
+    let d = b;
+    let g = minus_forty ^= i;
+    let ten: usize = 10;
+    let ten_is_eleven = ten == some_num;
+
+    ten < 3
+}
+"#),
+        @r###"
+    [6; 7) 'x': bool
+    [22; 34) '{     0i32 }': i32
+    [28; 32) '0i32': i32
+    [54; 370) '{     ... < 3 }': bool
+    [64; 65) 'x': bool
+    [68; 69) 'a': bool
+    [68; 74) 'a && b': bool
+    [73; 74) 'b': bool
+    [84; 85) 'y': bool
+    [88; 92) 'true': bool
+    [88; 101) 'true || false': bool
+    [96; 101) 'false': bool
+    [111; 112) 'z': bool
+    [115; 116) 'x': bool
+    [115; 121) 'x == y': bool
+    [120; 121) 'y': bool
+    [131; 132) 't': bool
+    [135; 136) 'x': bool
+    [135; 141) 'x != y': bool
+    [140; 141) 'y': bool
+    [151; 162) 'minus_forty': isize
+    [172; 180) '-40isize': isize
+    [173; 180) '40isize': isize
+    [190; 191) 'h': bool
+    [194; 205) 'minus_forty': isize
+    [194; 216) 'minus_...ONST_2': bool
+    [209; 216) 'CONST_2': isize
+    [226; 227) 'c': i32
+    [230; 231) 'f': fn f(bool) -> i32
+    [230; 239) 'f(z || y)': i32
+    [230; 243) 'f(z || y) + 5': i32
+    [232; 233) 'z': bool
+    [232; 238) 'z || y': bool
+    [237; 238) 'y': bool
+    [242; 243) '5': i32
+    [253; 254) 'd': {unknown}
+    [257; 258) 'b': {unknown}
+    [268; 269) 'g': ()
+    [272; 283) 'minus_forty': isize
+    [272; 288) 'minus_...y ^= i': ()
+    [287; 288) 'i': isize
+    [298; 301) 'ten': usize
+    [311; 313) '10': usize
+    [323; 336) 'ten_is_eleven': bool
+    [339; 342) 'ten': usize
+    [339; 354) 'ten == some_num': bool
+    [346; 354) 'some_num': usize
+    [361; 364) 'ten': usize
+    [361; 368) 'ten < 3': bool
+    [367; 368) '3': usize
+    "###
+    );
+}
+
+#[test]
+fn infer_field_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+struct A {
+    b: B,
+}
+struct B;
+
+fn test1(a: A) {
+    let a1 = a;
+    a1.b;
+    let a2 = &a;
+    a2.b;
+    let a3 = &mut a;
+    a3.b;
+    let a4 = &&&&&&&a;
+    a4.b;
+    let a5 = &mut &&mut &&mut a;
+    a5.b;
+}
+
+fn test2(a1: *const A, a2: *mut A) {
+    a1.b;
+    a2.b;
+}
+"#),
+        @r###"
+    [44; 45) 'a': A
+    [50; 213) '{     ...5.b; }': ()
+    [60; 62) 'a1': A
+    [65; 66) 'a': A
+    [72; 74) 'a1': A
+    [72; 76) 'a1.b': B
+    [86; 88) 'a2': &A
+    [91; 93) '&a': &A
+    [92; 93) 'a': A
+    [99; 101) 'a2': &A
+    [99; 103) 'a2.b': B
+    [113; 115) 'a3': &mut A
+    [118; 124) '&mut a': &mut A
+    [123; 124) 'a': A
+    [130; 132) 'a3': &mut A
+    [130; 134) 'a3.b': B
+    [144; 146) 'a4': &&&&&&&A
+    [149; 157) '&&&&&&&a': &&&&&&&A
+    [150; 157) '&&&&&&a': &&&&&&A
+    [151; 157) '&&&&&a': &&&&&A
+    [152; 157) '&&&&a': &&&&A
+    [153; 157) '&&&a': &&&A
+    [154; 157) '&&a': &&A
+    [155; 157) '&a': &A
+    [156; 157) 'a': A
+    [163; 165) 'a4': &&&&&&&A
+    [163; 167) 'a4.b': B
+    [177; 179) 'a5': &mut &&mut &&mut A
+    [182; 200) '&mut &...&mut a': &mut &&mut &&mut A
+    [187; 200) '&&mut &&mut a': &&mut &&mut A
+    [188; 200) '&mut &&mut a': &mut &&mut A
+    [193; 200) '&&mut a': &&mut A
+    [194; 200) '&mut a': &mut A
+    [199; 200) 'a': A
+    [206; 208) 'a5': &mut &&mut &&mut A
+    [206; 210) 'a5.b': B
+    [224; 226) 'a1': *const A
+    [238; 240) 'a2': *mut A
+    [250; 273) '{     ...2.b; }': ()
+    [256; 258) 'a1': *const A
+    [256; 260) 'a1.b': B
+    [266; 268) 'a2': *mut A
+    [266; 270) 'a2.b': B
+    "###
+    );
+}
+
+#[test]
+fn infer_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(T);
+
+impl<T> A<T> {
+    fn foo(&self) -> &T {
+        &self.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test() {
+    let t = A::foo(&&B(B(A(42))));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [139; 143) 'self': &A<T>
+    [151; 174) '{     ...     }': &T
+    [161; 168) '&self.0': &T
+    [162; 166) 'self': &A<T>
+    [162; 168) 'self.0': T
+    [255; 259) 'self': &B<T>
+    [278; 301) '{     ...     }': &T
+    [288; 295) '&self.0': &T
+    [289; 293) 'self': &B<T>
+    [289; 295) 'self.0': T
+    [315; 353) '{     ...))); }': ()
+    [325; 326) 't': &i32
+    [329; 335) 'A::foo': fn foo<i32>(&A<T>) -> &T
+    [329; 350) 'A::foo...42))))': &i32
+    [336; 349) '&&B(B(A(42)))': &&B<B<A<i32>>>
+    [337; 349) '&B(B(A(42)))': &B<B<A<i32>>>
+    [338; 339) 'B': B<B<A<i32>>>(T) -> B<T>
+    [338; 349) 'B(B(A(42)))': B<B<A<i32>>>
+    [340; 341) 'B': B<A<i32>>(T) -> B<T>
+    [340; 348) 'B(A(42))': B<A<i32>>
+    [342; 343) 'A': A<i32>(T) -> A<T>
+    [342; 347) 'A(42)': A<i32>
+    [344; 346) '42': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_method_argument_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "deref"]
+pub trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct A<T>(*mut T);
+
+impl<T> A<T> {
+    fn foo(&self, x: &A<T>) -> &T {
+        &*x.0
+    }
+}
+
+struct B<T>(T);
+
+impl<T> Deref for B<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+fn test(a: A<i32>) {
+    let t = A(0 as *mut _).foo(&&B(B(a)));
+}
+"#),
+        @r###"
+    [68; 72) 'self': &Self
+    [144; 148) 'self': &A<T>
+    [150; 151) 'x': &A<T>
+    [166; 187) '{     ...     }': &T
+    [176; 181) '&*x.0': &T
+    [177; 181) '*x.0': T
+    [178; 179) 'x': &A<T>
+    [178; 181) 'x.0': *mut T
+    [268; 272) 'self': &B<T>
+    [291; 314) '{     ...     }': &T
+    [301; 308) '&self.0': &T
+    [302; 306) 'self': &B<T>
+    [302; 308) 'self.0': T
+    [326; 327) 'a': A<i32>
+    [337; 383) '{     ...))); }': ()
+    [347; 348) 't': &i32
+    [351; 352) 'A': A<i32>(*mut T) -> A<T>
+    [351; 365) 'A(0 as *mut _)': A<i32>
+    [351; 380) 'A(0 as...B(a)))': &i32
+    [353; 354) '0': i32
+    [353; 364) '0 as *mut _': *mut i32
+    [370; 379) '&&B(B(a))': &&B<B<A<i32>>>
+    [371; 379) '&B(B(a))': &B<B<A<i32>>>
+    [372; 373) 'B': B<B<A<i32>>>(T) -> B<T>
+    [372; 379) 'B(B(a))': B<B<A<i32>>>
+    [374; 375) 'B': B<A<i32>>(T) -> B<T>
+    [374; 378) 'B(a)': B<A<i32>>
+    [376; 377) 'a': A<i32>
+    "###
+    );
+}
+
+#[test]
+fn infer_in_elseif() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo { field: i32 }
+fn main(foo: Foo) {
+    if true {
+
+    } else if false {
+        foo.field
+    }
+}
+"#),
+        @r###"
+    [35; 38) 'foo': Foo
+    [45; 109) '{     ...   } }': ()
+    [51; 107) 'if tru...     }': ()
+    [54; 58) 'true': bool
+    [59; 67) '{      }': ()
+    [73; 107) 'if fal...     }': ()
+    [76; 81) 'false': bool
+    [82; 107) '{     ...     }': i32
+    [92; 95) 'foo': Foo
+    [92; 101) 'foo.field': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_if_match_with_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() {
+    let _x1 = if true {
+        1
+    } else {
+        return;
+    };
+    let _x2 = if true {
+        2
+    } else {
+        return
+    };
+    let _x3 = match true {
+        true => 3,
+        _ => {
+            return;
+        }
+    };
+    let _x4 = match true {
+        true => 4,
+        _ => return
+    };
+}"#),
+        @r###"
+    [10; 323) '{     ...  }; }': ()
+    [20; 23) '_x1': i32
+    [26; 80) 'if tru...     }': i32
+    [29; 33) 'true': bool
+    [34; 51) '{     ...     }': i32
+    [44; 45) '1': i32
+    [57; 80) '{     ...     }': !
+    [67; 73) 'return': !
+    [90; 93) '_x2': i32
+    [96; 149) 'if tru...     }': i32
+    [99; 103) 'true': bool
+    [104; 121) '{     ...     }': i32
+    [114; 115) '2': i32
+    [127; 149) '{     ...     }': !
+    [137; 143) 'return': !
+    [159; 162) '_x3': i32
+    [165; 247) 'match ...     }': i32
+    [171; 175) 'true': bool
+    [186; 190) 'true': bool
+    [194; 195) '3': i32
+    [205; 206) '_': bool
+    [210; 241) '{     ...     }': !
+    [224; 230) 'return': !
+    [257; 260) '_x4': i32
+    [263; 320) 'match ...     }': i32
+    [269; 273) 'true': bool
+    [284; 288) 'true': bool
+    [292; 293) '4': i32
+    [303; 304) '_': bool
+    [308; 314) 'return': !
+    "###
+    )
+}
+
+#[test]
+fn infer_inherent_method() {
+    assert_snapshot!(
+        infer(r#"
+struct A;
+
+impl A {
+    fn foo(self, x: u32) -> i32 {}
+}
+
+mod b {
+    impl super::A {
+        fn bar(&self, x: u64) -> i64 {}
+    }
+}
+
+fn test(a: A) {
+    a.foo(1);
+    (&a).bar(1);
+    a.bar(1);
+}
+"#),
+        @r###"
+    [32; 36) 'self': A
+    [38; 39) 'x': u32
+    [53; 55) '{}': ()
+    [103; 107) 'self': &A
+    [109; 110) 'x': u64
+    [124; 126) '{}': ()
+    [144; 145) 'a': A
+    [150; 198) '{     ...(1); }': ()
+    [156; 157) 'a': A
+    [156; 164) 'a.foo(1)': i32
+    [162; 163) '1': u32
+    [170; 181) '(&a).bar(1)': i64
+    [171; 173) '&a': &A
+    [172; 173) 'a': A
+    [179; 180) '1': u64
+    [187; 188) 'a': A
+    [187; 195) 'a.bar(1)': i64
+    [193; 194) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_inherent_method_str() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "str"]
+impl str {
+    fn foo(&self) -> i32 {}
+}
+
+fn test() {
+    "foo".foo();
+}
+"#),
+        @r###"
+    [40; 44) 'self': &str
+    [53; 55) '{}': ()
+    [69; 89) '{     ...o(); }': ()
+    [75; 80) '"foo"': &str
+    [75; 86) '"foo".foo()': i32
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a: (u32, &str) = (1, "a");
+    let b = (a, x);
+    let c = (y, x);
+    let d = (c, x);
+    let e = (1, "e");
+    let f = (e, "d");
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 170) '{     ...d"); }': ()
+    [38; 39) 'a': (u32, &str)
+    [55; 63) '(1, "a")': (u32, &str)
+    [56; 57) '1': u32
+    [59; 62) '"a"': &str
+    [73; 74) 'b': ((u32, &str), &str)
+    [77; 83) '(a, x)': ((u32, &str), &str)
+    [78; 79) 'a': (u32, &str)
+    [81; 82) 'x': &str
+    [93; 94) 'c': (isize, &str)
+    [97; 103) '(y, x)': (isize, &str)
+    [98; 99) 'y': isize
+    [101; 102) 'x': &str
+    [113; 114) 'd': ((isize, &str), &str)
+    [117; 123) '(c, x)': ((isize, &str), &str)
+    [118; 119) 'c': (isize, &str)
+    [121; 122) 'x': &str
+    [133; 134) 'e': (i32, &str)
+    [137; 145) '(1, "e")': (i32, &str)
+    [138; 139) '1': i32
+    [141; 144) '"e"': &str
+    [155; 156) 'f': ((i32, &str), &str)
+    [159; 167) '(e, "d")': ((i32, &str), &str)
+    [160; 161) 'e': (i32, &str)
+    [163; 166) '"d"': &str
+    "###
+    );
+}
+
+#[test]
+fn infer_array() {
+    assert_snapshot!(
+        infer(r#"
+fn test(x: &str, y: isize) {
+    let a = [x];
+    let b = [a, a];
+    let c = [b, b];
+
+    let d = [y, 1, 2, 3];
+    let d = [1, y, 2, 3];
+    let e = [y];
+    let f = [d, d];
+    let g = [e, e];
+
+    let h = [1, 2];
+    let i = ["a", "b"];
+
+    let b = [a, ["b"]];
+    let x: [u8; 0] = [];
+}
+"#),
+        @r###"
+    [9; 10) 'x': &str
+    [18; 19) 'y': isize
+    [28; 293) '{     ... []; }': ()
+    [38; 39) 'a': [&str;_]
+    [42; 45) '[x]': [&str;_]
+    [43; 44) 'x': &str
+    [55; 56) 'b': [[&str;_];_]
+    [59; 65) '[a, a]': [[&str;_];_]
+    [60; 61) 'a': [&str;_]
+    [63; 64) 'a': [&str;_]
+    [75; 76) 'c': [[[&str;_];_];_]
+    [79; 85) '[b, b]': [[[&str;_];_];_]
+    [80; 81) 'b': [[&str;_];_]
+    [83; 84) 'b': [[&str;_];_]
+    [96; 97) 'd': [isize;_]
+    [100; 112) '[y, 1, 2, 3]': [isize;_]
+    [101; 102) 'y': isize
+    [104; 105) '1': isize
+    [107; 108) '2': isize
+    [110; 111) '3': isize
+    [122; 123) 'd': [isize;_]
+    [126; 138) '[1, y, 2, 3]': [isize;_]
+    [127; 128) '1': isize
+    [130; 131) 'y': isize
+    [133; 134) '2': isize
+    [136; 137) '3': isize
+    [148; 149) 'e': [isize;_]
+    [152; 155) '[y]': [isize;_]
+    [153; 154) 'y': isize
+    [165; 166) 'f': [[isize;_];_]
+    [169; 175) '[d, d]': [[isize;_];_]
+    [170; 171) 'd': [isize;_]
+    [173; 174) 'd': [isize;_]
+    [185; 186) 'g': [[isize;_];_]
+    [189; 195) '[e, e]': [[isize;_];_]
+    [190; 191) 'e': [isize;_]
+    [193; 194) 'e': [isize;_]
+    [206; 207) 'h': [i32;_]
+    [210; 216) '[1, 2]': [i32;_]
+    [211; 212) '1': i32
+    [214; 215) '2': i32
+    [226; 227) 'i': [&str;_]
+    [230; 240) '["a", "b"]': [&str;_]
+    [231; 234) '"a"': &str
+    [236; 239) '"b"': &str
+    [251; 252) 'b': [[&str;_];_]
+    [255; 265) '[a, ["b"]]': [[&str;_];_]
+    [256; 257) 'a': [&str;_]
+    [259; 264) '["b"]': [&str;_]
+    [260; 263) '"b"': &str
+    [275; 276) 'x': [u8;_]
+    [288; 290) '[]': [u8;_]
+    "###
+    );
+}
+
+#[test]
+fn infer_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+
+fn test(a1: A<u32>, i: i32) {
+    a1.x;
+    let a2 = A { x: i };
+    a2.x;
+    let a3 = A::<i128> { x: 1 };
+    a3.x;
+}
+"#),
+        @r###"
+    [36; 38) 'a1': A<u32>
+    [48; 49) 'i': i32
+    [56; 147) '{     ...3.x; }': ()
+    [62; 64) 'a1': A<u32>
+    [62; 66) 'a1.x': u32
+    [76; 78) 'a2': A<i32>
+    [81; 91) 'A { x: i }': A<i32>
+    [88; 89) 'i': i32
+    [97; 99) 'a2': A<i32>
+    [97; 101) 'a2.x': i32
+    [111; 113) 'a3': A<i128>
+    [116; 134) 'A::<i1...x: 1 }': A<i128>
+    [131; 132) '1': i128
+    [140; 142) 'a3': A<i128>
+    [140; 144) 'a3.x': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_tuple_struct_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T>(T);
+enum Option<T> { Some(T), None }
+use Option::*;
+
+fn test() {
+    A(42);
+    A(42u128);
+    Some("x");
+    Option::Some("x");
+    None;
+    let x: Option<i64> = None;
+}
+"#),
+        @r###"
+    [76; 184) '{     ...one; }': ()
+    [82; 83) 'A': A<i32>(T) -> A<T>
+    [82; 87) 'A(42)': A<i32>
+    [84; 86) '42': i32
+    [93; 94) 'A': A<u128>(T) -> A<T>
+    [93; 102) 'A(42u128)': A<u128>
+    [95; 101) '42u128': u128
+    [108; 112) 'Some': Some<&str>(T) -> Option<T>
+    [108; 117) 'Some("x")': Option<&str>
+    [113; 116) '"x"': &str
+    [123; 135) 'Option::Some': Some<&str>(T) -> Option<T>
+    [123; 140) 'Option...e("x")': Option<&str>
+    [136; 139) '"x"': &str
+    [146; 150) 'None': Option<{unknown}>
+    [160; 161) 'x': Option<i64>
+    [177; 181) 'None': Option<i64>
+    "###
+    );
+}
+
+#[test]
+fn infer_function_generics() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(t: T) -> T { t }
+
+fn test() {
+    id(1u32);
+    id::<i128>(1);
+    let x: u64 = id(1);
+}
+"#),
+        @r###"
+    [10; 11) 't': T
+    [21; 26) '{ t }': T
+    [23; 24) 't': T
+    [38; 98) '{     ...(1); }': ()
+    [44; 46) 'id': fn id<u32>(T) -> T
+    [44; 52) 'id(1u32)': u32
+    [47; 51) '1u32': u32
+    [58; 68) 'id::<i128>': fn id<i128>(T) -> T
+    [58; 71) 'id::<i128>(1)': i128
+    [69; 70) '1': i128
+    [81; 82) 'x': u64
+    [90; 92) 'id': fn id<u64>(T) -> T
+    [90; 95) 'id(1)': u64
+    [93; 94) '1': u64
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T1, T2> {
+    x: T1,
+    y: T2,
+}
+impl<Y, X> A<X, Y> {
+    fn x(self) -> X {
+        self.x
+    }
+    fn y(self) -> Y {
+        self.y
+    }
+    fn z<T>(self, t: T) -> (X, Y, T) {
+        (self.x, self.y, t)
+    }
+}
+
+fn test() -> i128 {
+    let a = A { x: 1u64, y: 1i64 };
+    a.x();
+    a.y();
+    a.z(1i128);
+    a.z::<u128>(1);
+}
+"#),
+        @r###"
+    [74; 78) 'self': A<X, Y>
+    [85; 107) '{     ...     }': X
+    [95; 99) 'self': A<X, Y>
+    [95; 101) 'self.x': X
+    [117; 121) 'self': A<X, Y>
+    [128; 150) '{     ...     }': Y
+    [138; 142) 'self': A<X, Y>
+    [138; 144) 'self.y': Y
+    [163; 167) 'self': A<X, Y>
+    [169; 170) 't': T
+    [188; 223) '{     ...     }': (X, Y, T)
+    [198; 217) '(self.....y, t)': (X, Y, T)
+    [199; 203) 'self': A<X, Y>
+    [199; 205) 'self.x': X
+    [207; 211) 'self': A<X, Y>
+    [207; 213) 'self.y': Y
+    [215; 216) 't': T
+    [245; 342) '{     ...(1); }': ()
+    [255; 256) 'a': A<u64, i64>
+    [259; 281) 'A { x:...1i64 }': A<u64, i64>
+    [266; 270) '1u64': u64
+    [275; 279) '1i64': i64
+    [287; 288) 'a': A<u64, i64>
+    [287; 292) 'a.x()': u64
+    [298; 299) 'a': A<u64, i64>
+    [298; 303) 'a.y()': i64
+    [309; 310) 'a': A<u64, i64>
+    [309; 319) 'a.z(1i128)': (u64, i64, i128)
+    [313; 318) '1i128': i128
+    [325; 326) 'a': A<u64, i64>
+    [325; 339) 'a.z::<u128>(1)': (u64, i64, u128)
+    [337; 338) '1': u128
+    "###
+    );
+}
+
+#[test]
+fn infer_impl_generics_with_autoderef() {
+    assert_snapshot!(
+        infer(r#"
+enum Option<T> {
+    Some(T),
+    None,
+}
+impl<T> Option<T> {
+    fn as_ref(&self) -> Option<&T> {}
+}
+fn test(o: Option<u32>) {
+    (&o).as_ref();
+    o.as_ref();
+}
+"#),
+        @r###"
+    [78; 82) 'self': &Option<T>
+    [98; 100) '{}': ()
+    [111; 112) 'o': Option<u32>
+    [127; 165) '{     ...f(); }': ()
+    [133; 146) '(&o).as_ref()': Option<&u32>
+    [134; 136) '&o': &Option<u32>
+    [135; 136) 'o': Option<u32>
+    [152; 153) 'o': Option<u32>
+    [152; 162) 'o.as_ref()': Option<&u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_generic_chain() {
+    assert_snapshot!(
+        infer(r#"
+struct A<T> {
+    x: T,
+}
+impl<T2> A<T2> {
+    fn x(self) -> T2 {
+        self.x
+    }
+}
+fn id<T>(t: T) -> T { t }
+
+fn test() -> i128 {
+     let x = 1;
+     let y = id(x);
+     let a = A { x: id(y) };
+     let z = id(a.x);
+     let b = A { x: z };
+     b.x()
+}
+"#),
+        @r###"
+    [53; 57) 'self': A<T2>
+    [65; 87) '{     ...     }': T2
+    [75; 79) 'self': A<T2>
+    [75; 81) 'self.x': T2
+    [99; 100) 't': T
+    [110; 115) '{ t }': T
+    [112; 113) 't': T
+    [135; 261) '{     ....x() }': i128
+    [146; 147) 'x': i128
+    [150; 151) '1': i128
+    [162; 163) 'y': i128
+    [166; 168) 'id': fn id<i128>(T) -> T
+    [166; 171) 'id(x)': i128
+    [169; 170) 'x': i128
+    [182; 183) 'a': A<i128>
+    [186; 200) 'A { x: id(y) }': A<i128>
+    [193; 195) 'id': fn id<i128>(T) -> T
+    [193; 198) 'id(y)': i128
+    [196; 197) 'y': i128
+    [211; 212) 'z': i128
+    [215; 217) 'id': fn id<i128>(T) -> T
+    [215; 222) 'id(a.x)': i128
+    [218; 219) 'a': A<i128>
+    [218; 221) 'a.x': i128
+    [233; 234) 'b': A<i128>
+    [237; 247) 'A { x: z }': A<i128>
+    [244; 245) 'z': i128
+    [254; 255) 'b': A<i128>
+    [254; 259) 'b.x()': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Struct;
+
+impl Struct {
+    const FOO: u32 = 1;
+}
+
+enum Enum {}
+
+impl Enum {
+    const BAR: u32 = 2;
+}
+
+trait Trait {
+    const ID: u32;
+}
+
+struct TraitTest;
+
+impl Trait for TraitTest {
+    const ID: u32 = 5;
+}
+
+fn test() {
+    let x = Struct::FOO;
+    let y = Enum::BAR;
+    let z = TraitTest::ID;
+}
+"#),
+        @r###"
+    [52; 53) '1': u32
+    [105; 106) '2': u32
+    [213; 214) '5': u32
+    [229; 307) '{     ...:ID; }': ()
+    [239; 240) 'x': u32
+    [243; 254) 'Struct::FOO': u32
+    [264; 265) 'y': u32
+    [268; 277) 'Enum::BAR': u32
+    [287; 288) 'z': u32
+    [291; 304) 'TraitTest::ID': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X, Y> { x: X, y: Y }
+type Foo = A<u32, i128>;
+type Bar<T> = A<T, u128>;
+type Baz<U, V> = A<V, U>;
+fn test(x: Foo, y: Bar<&str>, z: Baz<i8, u8>) {
+    x.x;
+    x.y;
+    y.x;
+    y.y;
+    z.x;
+    z.y;
+}
+"#),
+        @r###"
+    [116; 117) 'x': A<u32, i128>
+    [124; 125) 'y': A<&str, u128>
+    [138; 139) 'z': A<u8, i8>
+    [154; 211) '{     ...z.y; }': ()
+    [160; 161) 'x': A<u32, i128>
+    [160; 163) 'x.x': u32
+    [169; 170) 'x': A<u32, i128>
+    [169; 172) 'x.y': i128
+    [178; 179) 'y': A<&str, u128>
+    [178; 181) 'y.x': &str
+    [187; 188) 'y': A<&str, u128>
+    [187; 190) 'y.y': u128
+    [196; 197) 'z': A<u8, i8>
+    [196; 199) 'z.x': u8
+    [205; 206) 'z': A<u8, i8>
+    [205; 208) 'z.y': i8
+    "###
+    )
+}
+
+#[test]
+fn recursive_type_alias() {
+    assert_snapshot!(
+        infer(r#"
+struct A<X> {}
+type Foo = Foo;
+type Bar = A<Bar>;
+fn test(x: Foo) {}
+"#),
+        @r###"
+    [59; 60) 'x': {unknown}
+    [67; 69) '{}': ()
+    "###
+    )
+}
+
+#[test]
+fn infer_type_param() {
+    assert_snapshot!(
+        infer(r#"
+fn id<T>(x: T) -> T {
+    x
+}
+
+fn clone<T>(x: &T) -> T {
+    *x
+}
+
+fn test() {
+    let y = 10u32;
+    id(y);
+    let x: bool = clone(z);
+    id::<i128>(1);
+}
+"#),
+        @r###"
+    [10; 11) 'x': T
+    [21; 30) '{     x }': T
+    [27; 28) 'x': T
+    [44; 45) 'x': &T
+    [56; 66) '{     *x }': T
+    [62; 64) '*x': T
+    [63; 64) 'x': &T
+    [78; 158) '{     ...(1); }': ()
+    [88; 89) 'y': u32
+    [92; 97) '10u32': u32
+    [103; 105) 'id': fn id<u32>(T) -> T
+    [103; 108) 'id(y)': u32
+    [106; 107) 'y': u32
+    [118; 119) 'x': bool
+    [128; 133) 'clone': fn clone<bool>(&T) -> T
+    [128; 136) 'clone(z)': bool
+    [134; 135) 'z': &bool
+    [142; 152) 'id::<i128>': fn id<i128>(T) -> T
+    [142; 155) 'id::<i128>(1)': i128
+    [153; 154) '1': i128
+    "###
+    );
+}
+
+#[test]
+fn infer_const() {
+    assert_snapshot!(
+        infer(r#"
+struct Foo;
+impl Foo { const ASSOC_CONST: u32 = 0; }
+const GLOBAL_CONST: u32 = 101;
+fn test() {
+    const LOCAL_CONST: u32 = 99;
+    let x = LOCAL_CONST;
+    let z = GLOBAL_CONST;
+    let id = Foo::ASSOC_CONST;
+}
+"#),
+        @r###"
+    [49; 50) '0': u32
+    [80; 83) '101': u32
+    [95; 213) '{     ...NST; }': ()
+    [138; 139) 'x': u32
+    [142; 153) 'LOCAL_CONST': u32
+    [163; 164) 'z': u32
+    [167; 179) 'GLOBAL_CONST': u32
+    [189; 191) 'id': u32
+    [194; 210) 'Foo::A..._CONST': u32
+    "###
+    );
+}
+
+#[test]
+fn infer_static() {
+    assert_snapshot!(
+        infer(r#"
+static GLOBAL_STATIC: u32 = 101;
+static mut GLOBAL_STATIC_MUT: u32 = 101;
+fn test() {
+    static LOCAL_STATIC: u32 = 99;
+    static mut LOCAL_STATIC_MUT: u32 = 99;
+    let x = LOCAL_STATIC;
+    let y = LOCAL_STATIC_MUT;
+    let z = GLOBAL_STATIC;
+    let w = GLOBAL_STATIC_MUT;
+}
+"#),
+        @r###"
+    [29; 32) '101': u32
+    [70; 73) '101': u32
+    [85; 280) '{     ...MUT; }': ()
+    [173; 174) 'x': u32
+    [177; 189) 'LOCAL_STATIC': u32
+    [199; 200) 'y': u32
+    [203; 219) 'LOCAL_...IC_MUT': u32
+    [229; 230) 'z': u32
+    [233; 246) 'GLOBAL_STATIC': u32
+    [256; 257) 'w': u32
+    [260; 277) 'GLOBAL...IC_MUT': u32
+    "###
+    );
+}
+
+#[test]
+fn shadowing_primitive() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct i32;
+struct Foo;
+
+impl i32 { fn foo(&self) -> Foo { Foo } }
+
+fn main() {
+    let x: i32 = i32;
+    x.foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "Foo");
+}
+
+#[test]
+fn not_shadowing_primitive_by_module() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() {}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn not_shadowing_module_by_primitive() {
+    let t = type_at(
+        r#"
+//- /str.rs
+fn foo() -> u32 {0}
+
+//- /main.rs
+mod str;
+fn foo() -> &'static str { "" }
+
+fn main() {
+    str::foo()<|>;
+}"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn closure_return() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || -> usize { return 1; };
+}
+"#),
+        @r###"
+    [17; 59) '{     ...; }; }': ()
+    [27; 28) 'x': || -> usize
+    [31; 56) '|| -> ...n 1; }': || -> usize
+    [43; 56) '{ return 1; }': !
+    [45; 53) 'return 1': !
+    [52; 53) '1': usize
+    "###
+    );
+}
+
+#[test]
+fn closure_return_unit() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || { return; };
+}
+"#),
+        @r###"
+    [17; 48) '{     ...; }; }': ()
+    [27; 28) 'x': || -> ()
+    [31; 45) '|| { return; }': || -> ()
+    [34; 45) '{ return; }': !
+    [36; 42) 'return': !
+    "###
+    );
+}
+
+#[test]
+fn closure_return_inferred() {
+    assert_snapshot!(
+        infer(r#"
+fn foo() -> u32 {
+    let x = || { "test" };
+}
+"#),
+        @r###"
+    [17; 47) '{     ..." }; }': ()
+    [27; 28) 'x': || -> &str
+    [31; 44) '|| { "test" }': || -> &str
+    [34; 44) '{ "test" }': &str
+    [36; 42) '"test"': &str
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
new file mode 100644
index 000000000..ae316922b
--- /dev/null
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -0,0 +1,1598 @@
+use insta::assert_snapshot;
+
+use ra_db::fixture::WithFixture;
+use test_utils::covers;
+
+use super::{infer, infer_with_mismatches, type_at, type_at_pos};
+use crate::test_db::TestDB;
+
+#[test]
+fn infer_await() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct IntFuture;
+
+impl Future for IntFuture {
+    type Output = u64;
+}
+
+fn test() {
+    let r = IntFuture;
+    let v = r.await;
+    v<|>;
+}
+
+//- /std.rs crate:std
+#[prelude_import] use future::*;
+mod future {
+    trait Future {
+        type Output;
+    }
+}
+
+"#,
+    );
+    assert_eq!("u64", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_try() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+fn test() {
+    let r: Result<i32, u64> = Result::Ok(1);
+    let v = r?;
+    v<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    trait Try {
+        type Ok;
+        type Error;
+    }
+}
+
+#[prelude_import] use result::*;
+mod result {
+    enum Result<O, E> {
+        Ok(O),
+        Err(E)
+    }
+
+    impl<O, E> crate::ops::Try for Result<O, E> {
+        type Ok = O;
+        type Error = E;
+    }
+}
+
+"#,
+    );
+    assert_eq!("i32", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_for_loop() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+use std::collections::Vec;
+
+fn test() {
+    let v = Vec::new();
+    v.push("foo");
+    for x in v {
+        x<|>;
+    }
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+}
+
+mod collections {
+    struct Vec<T> {}
+    impl<T> Vec<T> {
+        fn new() -> Self { Vec {} }
+        fn push(&mut self, t: T) { }
+    }
+
+    impl<T> crate::iter::IntoIterator for Vec<T> {
+        type Item=T;
+    }
+}
+"#,
+    );
+    assert_eq!("&str", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ops_neg() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Neg for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = -a;
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Neg {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_ops_not() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Not for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = !a;
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Not {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn infer_from_bound_1() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<T: Trait<u32>>(t: T) {}
+fn test() {
+    let s = S(unknown);
+    foo(s);
+}
+"#),
+        @r###"
+    [86; 87) 't': T
+    [92; 94) '{}': ()
+    [105; 144) '{     ...(s); }': ()
+    [115; 116) 's': S<u32>
+    [119; 120) 'S': S<u32>(T) -> S<T>
+    [119; 129) 'S(unknown)': S<u32>
+    [121; 128) 'unknown': u32
+    [135; 138) 'foo': fn foo<S<u32>>(T) -> ()
+    [135; 141) 'foo(s)': ()
+    [139; 140) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_from_bound_2() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {}
+struct S<T>(T);
+impl<U> Trait<U> for S<U> {}
+fn foo<U, T: Trait<U>>(t: T) -> U {}
+fn test() {
+    let s = S(unknown);
+    let x: u32 = foo(s);
+}
+"#),
+        @r###"
+    [87; 88) 't': T
+    [98; 100) '{}': ()
+    [111; 163) '{     ...(s); }': ()
+    [121; 122) 's': S<u32>
+    [125; 126) 'S': S<u32>(T) -> S<T>
+    [125; 135) 'S(unknown)': S<u32>
+    [127; 134) 'unknown': u32
+    [145; 146) 'x': u32
+    [154; 157) 'foo': fn foo<u32, S<u32>>(T) -> U
+    [154; 160) 'foo(s)': u32
+    [158; 159) 's': S<u32>
+    "###
+    );
+}
+
+#[test]
+fn infer_project_associated_type() {
+    // y, z, a don't yet work because of https://github.com/rust-lang/chalk/issues/234
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn test<T: Iterable>() {
+    let x: <S as Iterable>::Item = 1;
+    let y: <T as Iterable>::Item = no_matter;
+    let z: T::Item = no_matter;
+    let a: <T>::Item = no_matter;
+}
+"#),
+        @r###"
+    [108; 261) '{     ...ter; }': ()
+    [118; 119) 'x': u32
+    [145; 146) '1': u32
+    [156; 157) 'y': {unknown}
+    [183; 192) 'no_matter': {unknown}
+    [202; 203) 'z': {unknown}
+    [215; 224) 'no_matter': {unknown}
+    [234; 235) 'a': {unknown}
+    [249; 258) 'no_matter': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_return_associated_type() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+struct S;
+impl Iterable for S { type Item = u32; }
+fn foo1<T: Iterable>(t: T) -> T::Item {}
+fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
+fn foo3<T: Iterable>(t: T) -> <T>::Item {}
+fn test() {
+    let x = foo1(S);
+    let y = foo2(S);
+    let z = foo3(S);
+}
+"#),
+        @r###"
+    [106; 107) 't': T
+    [123; 125) '{}': ()
+    [147; 148) 't': T
+    [178; 180) '{}': ()
+    [202; 203) 't': T
+    [221; 223) '{}': ()
+    [234; 300) '{     ...(S); }': ()
+    [244; 245) 'x': u32
+    [248; 252) 'foo1': fn foo1<S>(T) -> <T as Iterable>::Item
+    [248; 255) 'foo1(S)': u32
+    [253; 254) 'S': S
+    [265; 266) 'y': u32
+    [269; 273) 'foo2': fn foo2<S>(T) -> <T as Iterable>::Item
+    [269; 276) 'foo2(S)': u32
+    [274; 275) 'S': S
+    [286; 287) 'z': u32
+    [290; 294) 'foo3': fn foo3<S>(T) -> <T as Iterable>::Item
+    [290; 297) 'foo3(S)': u32
+    [295; 296) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn infer_associated_type_bound() {
+    assert_snapshot!(
+        infer(r#"
+trait Iterable {
+   type Item;
+}
+fn test<T: Iterable<Item=u32>>() {
+    let y: T::Item = unknown;
+}
+"#),
+        @r###"
+    [67; 100) '{     ...own; }': ()
+    [77; 78) 'y': {unknown}
+    [90; 97) 'unknown': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn infer_const_body() {
+    assert_snapshot!(
+        infer(r#"
+const A: u32 = 1 + 1;
+static B: u64 = { let x = 1; x };
+"#),
+        @r###"
+    [16; 17) '1': u32
+    [16; 21) '1 + 1': u32
+    [20; 21) '1': u32
+    [39; 55) '{ let ...1; x }': u64
+    [45; 46) 'x': u64
+    [49; 50) '1': u64
+    [52; 53) 'x': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_fields() {
+    assert_snapshot!(
+        infer(r#"
+struct S(i32, u64);
+fn test() -> u64 {
+    let a = S(4, 6);
+    let b = a.0;
+    a.1
+}
+"#),
+        @r###"
+    [38; 87) '{     ... a.1 }': u64
+    [48; 49) 'a': S
+    [52; 53) 'S': S(i32, u64) -> S
+    [52; 59) 'S(4, 6)': S
+    [54; 55) '4': i32
+    [57; 58) '6': u64
+    [69; 70) 'b': i32
+    [73; 74) 'a': S
+    [73; 76) 'a.0': i32
+    [82; 83) 'a': S
+    [82; 85) 'a.1': u64
+    "###
+    );
+}
+
+#[test]
+fn tuple_struct_with_fn() {
+    assert_snapshot!(
+        infer(r#"
+struct S(fn(u32) -> u64);
+fn test() -> u64 {
+    let a = S(|i| 2*i);
+    let b = a.0(4);
+    a.0(2)
+}
+"#),
+        @r###"
+    [44; 102) '{     ...0(2) }': u64
+    [54; 55) 'a': S
+    [58; 59) 'S': S(fn(u32) -> u64) -> S
+    [58; 68) 'S(|i| 2*i)': S
+    [60; 67) '|i| 2*i': |u32| -> u64
+    [61; 62) 'i': u32
+    [64; 65) '2': u32
+    [64; 67) '2*i': u32
+    [66; 67) 'i': u32
+    [78; 79) 'b': u64
+    [82; 83) 'a': S
+    [82; 85) 'a.0': fn(u32) -> u64
+    [82; 88) 'a.0(4)': u64
+    [86; 87) '4': u32
+    [94; 95) 'a': S
+    [94; 97) 'a.0': fn(u32) -> u64
+    [94; 100) 'a.0(2)': u64
+    [98; 99) '2': u32
+    "###
+    );
+}
+
+#[test]
+fn indexing_arrays() {
+    assert_snapshot!(
+        infer("fn main() { &mut [9][2]; }"),
+        @r###"
+    [10; 26) '{ &mut...[2]; }': ()
+    [12; 23) '&mut [9][2]': &mut {unknown}
+    [17; 20) '[9]': [i32;_]
+    [17; 23) '[9][2]': {unknown}
+    [18; 19) '9': i32
+    [21; 22) '2': i32
+    "###
+    )
+}
+
+#[test]
+fn infer_ops_index() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+
+struct Bar;
+struct Foo;
+
+impl std::ops::Index<u32> for Bar {
+    type Output = Foo;
+}
+
+fn test() {
+    let a = Bar;
+    let b = a[1];
+    b<|>;
+}
+
+//- /std.rs crate:std
+
+#[prelude_import] use ops::*;
+mod ops {
+    pub trait Index<Idx> {
+        type Output;
+    }
+}
+"#,
+    );
+    assert_eq!("Foo", type_at_pos(&db, pos));
+}
+
+#[test]
+fn deref_trait() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn deref_trait_with_inference_var() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+fn new_arc<T>() -> Arc<T> {}
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+fn foo(a: Arc<S>) {}
+
+fn test() {
+    let a = new_arc();
+    let b = (*a)<|>;
+    foo(a);
+}
+"#,
+    );
+    assert_eq!(t, "S");
+}
+
+#[test]
+fn deref_trait_infinite_recursion() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct S;
+
+impl Deref for S {
+    type Target = S;
+}
+
+fn test(s: S) {
+    s.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn deref_trait_with_question_mark_size() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+    fn deref(&self) -> &Self::Target;
+}
+
+struct Arc<T>;
+impl<T> Deref for Arc<T> {
+    type Target = T;
+}
+
+struct S;
+impl S {
+    fn foo(&self) -> u128 {}
+}
+
+fn test(s: Arc<S>) {
+    (*s, s.foo())<|>;
+}
+"#,
+    );
+    assert_eq!(t, "(S, u128)");
+}
+
+#[test]
+fn obligation_from_function_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<u32> for S {}
+
+fn foo<T: Trait<U>, U>(t: T) -> U {}
+
+fn test(s: S) {
+    foo(s)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn obligation_from_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<isize> for S {}
+
+struct O;
+impl O {
+    fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
+}
+
+fn test() {
+    O.foo(S)<|>;
+}
+"#,
+    );
+    assert_eq!(t, "isize");
+}
+
+#[test]
+fn obligation_from_self_method_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<i64> for S {}
+
+impl S {
+    fn foo<U>(&self) -> U where Self: Trait<U> {}
+}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "i64");
+}
+
+#[test]
+fn obligation_from_impl_clause() {
+    let t = type_at(
+        r#"
+//- /main.rs
+struct S;
+
+trait Trait<T> {}
+impl Trait<&str> for S {}
+
+struct O<T>;
+impl<U, T: Trait<U>> O<T> {
+    fn foo(&self) -> U {}
+}
+
+fn test(o: O<S>) {
+    o.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "&str");
+}
+
+#[test]
+fn generic_param_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T: Clone>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_1_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Clone {}
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Clone for S {}
+impl<T> Trait for T where T: Clone {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T: Trait>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "u128");
+}
+
+#[test]
+fn generic_param_env_2_not_met() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait { fn foo(self) -> u128; }
+struct S;
+impl Trait for S {}
+fn test<T>(t: T) { t.foo()<|>; }
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn generic_param_env_deref() {
+    let t = type_at(
+        r#"
+//- /main.rs
+#[lang = "deref"]
+trait Deref {
+    type Target;
+}
+trait Trait {}
+impl<T> Deref for T where T: Trait {
+    type Target = i128;
+}
+fn test<T: Trait>(t: T) { (*t)<|>; }
+"#,
+    );
+    assert_eq!(t, "i128");
+}
+
+#[test]
+fn associated_type_placeholder() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+
+pub struct RefMutL<T>;
+
+impl<T> ApplyL for RefMutL<T> {
+    type Out = <T as ApplyL>::Out;
+}
+
+fn test<T: ApplyL>() {
+    let y: <RefMutL<T> as ApplyL>::Out = no_matter;
+    y<|>;
+}
+"#,
+    );
+    // inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
+    // FIXME: fix type parameter names going missing when going through Chalk
+    assert_eq!(t, "ApplyL::Out<[missing name]>");
+}
+
+#[test]
+fn associated_type_placeholder_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+pub trait ApplyL {
+    type Out;
+}
+fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
+
+fn test<T: ApplyL>(t: T) {
+    let y = foo(t);
+    y<|>;
+}
+"#,
+    );
+    // FIXME here Chalk doesn't normalize the type to a placeholder. I think we
+    // need to add a rule like Normalize(<T as ApplyL>::Out -> ApplyL::Out<T>)
+    // to the trait env ourselves here; probably Chalk can't do this by itself.
+    // assert_eq!(t, "ApplyL::Out<[missing name]>");
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn impl_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> impl Trait<u64> {}
+
+fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [99; 101) '{}': ()
+    [111; 112) 'x': impl Trait<u64>
+    [131; 132) 'y': &impl Trait<u64>
+    [152; 269) '{     ...2(); }': ()
+    [158; 159) 'x': impl Trait<u64>
+    [165; 166) 'y': &impl Trait<u64>
+    [176; 177) 'z': impl Trait<u64>
+    [180; 183) 'bar': fn bar() -> impl Trait<u64>
+    [180; 185) 'bar()': impl Trait<u64>
+    [191; 192) 'x': impl Trait<u64>
+    [191; 198) 'x.foo()': u64
+    [204; 205) 'y': &impl Trait<u64>
+    [204; 211) 'y.foo()': u64
+    [217; 218) 'z': impl Trait<u64>
+    [217; 224) 'z.foo()': u64
+    [230; 231) 'x': impl Trait<u64>
+    [230; 238) 'x.foo2()': i64
+    [244; 245) 'y': &impl Trait<u64>
+    [244; 252) 'y.foo2()': i64
+    [258; 259) 'z': impl Trait<u64>
+    [258; 266) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait<T> {
+    fn foo(&self) -> T;
+    fn foo2(&self) -> i64;
+}
+fn bar() -> dyn Trait<u64> {}
+
+fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+    x.foo2();
+    y.foo2();
+    z.foo2();
+}
+"#),
+        @r###"
+    [30; 34) 'self': &Self
+    [55; 59) 'self': &Self
+    [98; 100) '{}': ()
+    [110; 111) 'x': dyn Trait<u64>
+    [129; 130) 'y': &dyn Trait<u64>
+    [149; 266) '{     ...2(); }': ()
+    [155; 156) 'x': dyn Trait<u64>
+    [162; 163) 'y': &dyn Trait<u64>
+    [173; 174) 'z': dyn Trait<u64>
+    [177; 180) 'bar': fn bar() -> dyn Trait<u64>
+    [177; 182) 'bar()': dyn Trait<u64>
+    [188; 189) 'x': dyn Trait<u64>
+    [188; 195) 'x.foo()': u64
+    [201; 202) 'y': &dyn Trait<u64>
+    [201; 208) 'y.foo()': u64
+    [214; 215) 'z': dyn Trait<u64>
+    [214; 221) 'z.foo()': u64
+    [227; 228) 'x': dyn Trait<u64>
+    [227; 235) 'x.foo2()': i64
+    [241; 242) 'y': &dyn Trait<u64>
+    [241; 249) 'y.foo2()': i64
+    [255; 256) 'z': dyn Trait<u64>
+    [255; 263) 'z.foo2()': i64
+    "###
+    );
+}
+
+#[test]
+fn dyn_trait_bare() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    fn foo(&self) -> u64;
+}
+fn bar() -> Trait {}
+
+fn test(x: Trait, y: &Trait) -> u64 {
+    x;
+    y;
+    let z = bar();
+    x.foo();
+    y.foo();
+    z.foo();
+}
+"#),
+        @r###"
+    [27; 31) 'self': &Self
+    [61; 63) '{}': ()
+    [73; 74) 'x': dyn Trait
+    [83; 84) 'y': &dyn Trait
+    [101; 176) '{     ...o(); }': ()
+    [107; 108) 'x': dyn Trait
+    [114; 115) 'y': &dyn Trait
+    [125; 126) 'z': dyn Trait
+    [129; 132) 'bar': fn bar() -> dyn Trait
+    [129; 134) 'bar()': dyn Trait
+    [140; 141) 'x': dyn Trait
+    [140; 147) 'x.foo()': u64
+    [153; 154) 'y': &dyn Trait
+    [153; 160) 'y.foo()': u64
+    [166; 167) 'z': dyn Trait
+    [166; 173) 'z.foo()': u64
+    "###
+    );
+}
+
+#[test]
+fn weird_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {}
+fn test() {
+    let a: impl Trait + 'lifetime = foo;
+    let b: impl 'lifetime = foo;
+    let b: impl (Trait) = foo;
+    let b: impl ('lifetime) = foo;
+    let d: impl ?Sized = foo;
+    let e: impl Trait + ?Sized = foo;
+}
+"#),
+        @r###"
+    [26; 237) '{     ...foo; }': ()
+    [36; 37) 'a': impl Trait + {error}
+    [64; 67) 'foo': impl Trait + {error}
+    [77; 78) 'b': impl {error}
+    [97; 100) 'foo': impl {error}
+    [110; 111) 'b': impl Trait
+    [128; 131) 'foo': impl Trait
+    [141; 142) 'b': impl {error}
+    [163; 166) 'foo': impl {error}
+    [176; 177) 'd': impl {error}
+    [193; 196) 'foo': impl {error}
+    [206; 207) 'e': impl Trait + {error}
+    [231; 234) 'foo': impl Trait + {error}
+    "###
+    );
+}
+
+#[test]
+fn error_bound_chalk() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    fn foo(&self) -> u32 {}
+}
+
+fn test(x: (impl Trait + UnknownTrait)) {
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn assoc_type_bindings() {
+    assert_snapshot!(
+        infer(r#"
+trait Trait {
+    type Type;
+}
+
+fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> Trait for S<T> { type Type = T; }
+
+fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
+    get(x);
+    get2(x);
+    get(y);
+    get2(y);
+    get(set(S));
+    get2(set(S));
+    get2(S::<str>);
+}
+"#),
+        @r###"
+    [50; 51) 't': T
+    [78; 80) '{}': ()
+    [112; 113) 't': T
+    [123; 125) '{}': ()
+    [155; 156) 't': T
+    [166; 169) '{t}': T
+    [167; 168) 't': T
+    [257; 258) 'x': T
+    [263; 264) 'y': impl Trait<Type = i64>
+    [290; 398) '{     ...r>); }': ()
+    [296; 299) 'get': fn get<T>(T) -> <T as Trait>::Type
+    [296; 302) 'get(x)': {unknown}
+    [300; 301) 'x': T
+    [308; 312) 'get2': fn get2<{unknown}, T>(T) -> U
+    [308; 315) 'get2(x)': {unknown}
+    [313; 314) 'x': T
+    [321; 324) 'get': fn get<impl Trait<Type = i64>>(T) -> <T as Trait>::Type
+    [321; 327) 'get(y)': {unknown}
+    [325; 326) 'y': impl Trait<Type = i64>
+    [333; 337) 'get2': fn get2<{unknown}, impl Trait<Type = i64>>(T) -> U
+    [333; 340) 'get2(y)': {unknown}
+    [338; 339) 'y': impl Trait<Type = i64>
+    [346; 349) 'get': fn get<S<u64>>(T) -> <T as Trait>::Type
+    [346; 357) 'get(set(S))': u64
+    [350; 353) 'set': fn set<S<u64>>(T) -> T
+    [350; 356) 'set(S)': S<u64>
+    [354; 355) 'S': S<u64>
+    [363; 367) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [363; 375) 'get2(set(S))': u64
+    [368; 371) 'set': fn set<S<u64>>(T) -> T
+    [368; 374) 'set(S)': S<u64>
+    [372; 373) 'S': S<u64>
+    [381; 385) 'get2': fn get2<str, S<str>>(T) -> U
+    [381; 395) 'get2(S::<str>)': str
+    [386; 394) 'S::<str>': S<str>
+    "###
+    );
+}
+
+#[test]
+fn impl_trait_assoc_binding_projection_bug() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:std
+pub trait Language {
+    type Kind;
+}
+pub enum RustLanguage {}
+impl Language for RustLanguage {
+    type Kind = SyntaxKind;
+}
+struct SyntaxNode<L> {}
+fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
+
+trait Clone {
+    fn clone(&self) -> Self;
+}
+
+fn api_walkthrough() {
+    for node in foo() {
+        node.clone()<|>;
+    }
+}
+
+//- /std.rs crate:std
+#[prelude_import] use iter::*;
+mod iter {
+    trait IntoIterator {
+        type Item;
+    }
+    trait Iterator {
+        type Item;
+    }
+    impl<T: Iterator> IntoIterator for T {
+        type Item = <T as Iterator>::Item;
+    }
+}
+"#,
+    );
+    assert_eq!("{unknown}", type_at_pos(&db, pos));
+}
+
+#[test]
+fn projection_eq_within_chalk() {
+    // std::env::set_var("CHALK_DEBUG", "1");
+    assert_snapshot!(
+        infer(r#"
+trait Trait1 {
+    type Type;
+}
+trait Trait2<T> {
+    fn foo(self) -> T;
+}
+impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
+
+fn test<T: Trait1<Type = u32>>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [62; 66) 'self': Self
+    [164; 165) 'x': T
+    [170; 186) '{     ...o(); }': ()
+    [176; 177) 'x': T
+    [176; 183) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn where_clause_trait_in_scope_for_method_resolution() {
+    let t = type_at(
+        r#"
+//- /main.rs
+mod foo {
+    trait Trait {
+        fn foo(&self) -> u32 {}
+    }
+}
+
+fn test<T: foo::Trait>(x: T) {
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn super_trait_method_resolution() {
+    assert_snapshot!(
+        infer(r#"
+mod foo {
+    trait SuperTrait {
+        fn foo(&self) -> u32 {}
+    }
+}
+trait Trait1: foo::SuperTrait {}
+trait Trait2 where Self: foo::SuperTrait {}
+
+fn test<T: Trait1, U: Trait2>(x: T, y: U) {
+    x.foo();
+    y.foo();
+}
+"#),
+        @r###"
+    [50; 54) 'self': &Self
+    [63; 65) '{}': ()
+    [182; 183) 'x': T
+    [188; 189) 'y': U
+    [194; 223) '{     ...o(); }': ()
+    [200; 201) 'x': T
+    [200; 207) 'x.foo()': u32
+    [213; 214) 'y': U
+    [213; 220) 'y.foo()': u32
+    "###
+    );
+}
+
+#[test]
+fn super_trait_cycle() {
+    // This just needs to not crash
+    assert_snapshot!(
+        infer(r#"
+trait A: B {}
+trait B: A {}
+
+fn test<T: A>(x: T) {
+    x.foo();
+}
+"#),
+        @r###"
+    [44; 45) 'x': T
+    [50; 66) '{     ...o(); }': ()
+    [56; 57) 'x': T
+    [56; 63) 'x.foo()': {unknown}
+    "###
+    );
+}
+
+#[test]
+fn super_trait_assoc_type_bounds() {
+    assert_snapshot!(
+        infer(r#"
+trait SuperTrait { type Type; }
+trait Trait where Self: SuperTrait {}
+
+fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
+fn set<T: Trait<Type = u64>>(t: T) -> T {t}
+
+struct S<T>;
+impl<T> SuperTrait for S<T> { type Type = T; }
+impl<T> Trait for S<T> {}
+
+fn test() {
+    get2(set(S));
+}
+"#),
+        @r###"
+    [103; 104) 't': T
+    [114; 116) '{}': ()
+    [146; 147) 't': T
+    [157; 160) '{t}': T
+    [158; 159) 't': T
+    [259; 280) '{     ...S)); }': ()
+    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [265; 277) 'get2(set(S))': u64
+    [270; 273) 'set': fn set<S<u64>>(T) -> T
+    [270; 276) 'set(S)': S<u64>
+    [274; 275) 'S': S<u64>
+    "###
+    );
+}
+
+#[test]
+fn fn_trait() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+
+    fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
+}
+
+fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
+    f.call_once((1, 2));
+}
+"#),
+        @r###"
+    [57; 61) 'self': Self
+    [63; 67) 'args': Args
+    [150; 151) 'f': F
+    [156; 184) '{     ...2)); }': ()
+    [162; 163) 'f': F
+    [162; 181) 'f.call...1, 2))': {unknown}
+    [174; 180) '(1, 2)': (u32, u64)
+    [175; 176) '1': u32
+    [178; 179) '2': u64
+    "###
+    );
+}
+
+#[test]
+fn closure_1() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+enum Option<T> { Some(T), None }
+impl<T> Option<T> {
+    fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
+}
+
+fn test() {
+    let x = Option::Some(1u32);
+    x.map(|v| v + 1);
+    x.map(|_v| 1u64);
+    let y: Option<i64> = x.map(|_v| 1);
+}
+"#),
+        @r###"
+    [148; 152) 'self': Option<T>
+    [154; 155) 'f': F
+    [173; 175) '{}': ()
+    [189; 308) '{     ... 1); }': ()
+    [199; 200) 'x': Option<u32>
+    [203; 215) 'Option::Some': Some<u32>(T) -> Option<T>
+    [203; 221) 'Option...(1u32)': Option<u32>
+    [216; 220) '1u32': u32
+    [227; 228) 'x': Option<u32>
+    [227; 243) 'x.map(...v + 1)': Option<u32>
+    [233; 242) '|v| v + 1': |u32| -> u32
+    [234; 235) 'v': u32
+    [237; 238) 'v': u32
+    [237; 242) 'v + 1': u32
+    [241; 242) '1': u32
+    [249; 250) 'x': Option<u32>
+    [249; 265) 'x.map(... 1u64)': Option<u64>
+    [255; 264) '|_v| 1u64': |u32| -> u64
+    [256; 258) '_v': u32
+    [260; 264) '1u64': u64
+    [275; 276) 'y': Option<i64>
+    [292; 293) 'x': Option<u32>
+    [292; 305) 'x.map(|_v| 1)': Option<i64>
+    [298; 304) '|_v| 1': |u32| -> i64
+    [299; 301) '_v': u32
+    [303; 304) '1': i64
+    "###
+    );
+}
+
+#[test]
+fn closure_2() {
+    assert_snapshot!(
+        infer(r#"
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn test<F: FnOnce(u32) -> u64>(f: F) {
+    f(1);
+    let g = |v| v + 1;
+    g(1u64);
+    let h = |v| 1u128 + v;
+}
+"#),
+        @r###"
+    [73; 74) 'f': F
+    [79; 155) '{     ...+ v; }': ()
+    [85; 86) 'f': F
+    [85; 89) 'f(1)': {unknown}
+    [87; 88) '1': i32
+    [99; 100) 'g': |u64| -> i32
+    [103; 112) '|v| v + 1': |u64| -> i32
+    [104; 105) 'v': u64
+    [107; 108) 'v': u64
+    [107; 112) 'v + 1': i32
+    [111; 112) '1': i32
+    [118; 119) 'g': |u64| -> i32
+    [118; 125) 'g(1u64)': i32
+    [120; 124) '1u64': u64
+    [135; 136) 'h': |u128| -> u128
+    [139; 152) '|v| 1u128 + v': |u128| -> u128
+    [140; 141) 'v': u128
+    [143; 148) '1u128': u128
+    [143; 152) '1u128 + v': u128
+    [151; 152) 'v': u128
+    "###
+    );
+}
+
+#[test]
+fn closure_as_argument_inference_order() {
+    assert_snapshot!(
+        infer(r#"
+#[lang = "fn_once"]
+trait FnOnce<Args> {
+    type Output;
+}
+
+fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
+fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
+
+struct S;
+impl S {
+    fn method(self) -> u64;
+
+    fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
+    fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
+}
+
+fn test() {
+    let x1 = foo1(S, |s| s.method());
+    let x2 = foo2(|s| s.method(), S);
+    let x3 = S.foo1(S, |s| s.method());
+    let x4 = S.foo2(|s| s.method(), S);
+}
+"#),
+        @r###"
+    [95; 96) 'x': T
+    [101; 102) 'f': F
+    [112; 114) '{}': ()
+    [148; 149) 'f': F
+    [154; 155) 'x': T
+    [165; 167) '{}': ()
+    [202; 206) 'self': S
+    [254; 258) 'self': S
+    [260; 261) 'x': T
+    [266; 267) 'f': F
+    [277; 279) '{}': ()
+    [317; 321) 'self': S
+    [323; 324) 'f': F
+    [329; 330) 'x': T
+    [340; 342) '{}': ()
+    [356; 515) '{     ... S); }': ()
+    [366; 368) 'x1': u64
+    [371; 375) 'foo1': fn foo1<S, u64, |S| -> u64>(T, F) -> U
+    [371; 394) 'foo1(S...hod())': u64
+    [376; 377) 'S': S
+    [379; 393) '|s| s.method()': |S| -> u64
+    [380; 381) 's': S
+    [383; 384) 's': S
+    [383; 393) 's.method()': u64
+    [404; 406) 'x2': u64
+    [409; 413) 'foo2': fn foo2<S, u64, |S| -> u64>(F, T) -> U
+    [409; 432) 'foo2(|...(), S)': u64
+    [414; 428) '|s| s.method()': |S| -> u64
+    [415; 416) 's': S
+    [418; 419) 's': S
+    [418; 428) 's.method()': u64
+    [430; 431) 'S': S
+    [442; 444) 'x3': u64
+    [447; 448) 'S': S
+    [447; 472) 'S.foo1...hod())': u64
+    [454; 455) 'S': S
+    [457; 471) '|s| s.method()': |S| -> u64
+    [458; 459) 's': S
+    [461; 462) 's': S
+    [461; 471) 's.method()': u64
+    [482; 484) 'x4': u64
+    [487; 488) 'S': S
+    [487; 512) 'S.foo2...(), S)': u64
+    [494; 508) '|s| s.method()': |S| -> u64
+    [495; 496) 's': S
+    [498; 499) 's': S
+    [498; 508) 's.method()': u64
+    [510; 511) 'S': S
+    "###
+    );
+}
+
+#[test]
+fn unselected_projection_in_trait_env_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T: Trait>() where T::Item: Trait2 {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+trait Trait2 {
+    fn foo(&self) -> u32;
+}
+
+fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
+    let x: T::Item = no_matter;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn trait_impl_self_ty() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+   fn foo(&self);
+}
+
+struct S;
+
+impl Trait<Self> for S {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "()");
+}
+
+#[test]
+fn trait_impl_self_ty_cycle() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+   fn foo(&self);
+}
+
+struct S<T>;
+
+impl Trait for S<Self> {}
+
+fn test() {
+    S.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+}
+
+trait Trait2<T> {}
+
+fn test<T: Trait>() where T: Trait2<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unselected_projection_in_trait_env_cycle_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait<T> {
+    type Item;
+}
+
+fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
+    let x: T::Item = no_matter<|>;
+}
+"#,
+    );
+    // this is a legitimate cycle
+    assert_eq!(t, "{unknown}");
+}
+
+#[test]
+fn unify_impl_trait() {
+    covers!(insert_vars_for_impl_trait);
+    assert_snapshot!(
+        infer_with_mismatches(r#"
+trait Trait<T> {}
+
+fn foo(x: impl Trait<u32>) { loop {} }
+fn bar<T>(x: impl Trait<T>) -> T { loop {} }
+
+struct S<T>(T);
+impl<T> Trait<T> for S<T> {}
+
+fn default<T>() -> T { loop {} }
+
+fn test() -> impl Trait<i32> {
+    let s1 = S(default());
+    foo(s1);
+    let x: i32 = bar(S(default()));
+    S(default())
+}
+"#, true),
+        @r###"
+    [27; 28) 'x': impl Trait<u32>
+    [47; 58) '{ loop {} }': ()
+    [49; 56) 'loop {}': !
+    [54; 56) '{}': ()
+    [69; 70) 'x': impl Trait<T>
+    [92; 103) '{ loop {} }': T
+    [94; 101) 'loop {}': !
+    [99; 101) '{}': ()
+    [172; 183) '{ loop {} }': T
+    [174; 181) 'loop {}': !
+    [179; 181) '{}': ()
+    [214; 310) '{     ...t()) }': S<i32>
+    [224; 226) 's1': S<u32>
+    [229; 230) 'S': S<u32>(T) -> S<T>
+    [229; 241) 'S(default())': S<u32>
+    [231; 238) 'default': fn default<u32>() -> T
+    [231; 240) 'default()': u32
+    [247; 250) 'foo': fn foo(impl Trait<u32>) -> ()
+    [247; 254) 'foo(s1)': ()
+    [251; 253) 's1': S<u32>
+    [264; 265) 'x': i32
+    [273; 276) 'bar': fn bar<i32>(impl Trait<T>) -> T
+    [273; 290) 'bar(S(...lt()))': i32
+    [277; 278) 'S': S<i32>(T) -> S<T>
+    [277; 289) 'S(default())': S<i32>
+    [279; 286) 'default': fn default<i32>() -> T
+    [279; 288) 'default()': i32
+    [296; 297) 'S': S<i32>(T) -> S<T>
+    [296; 308) 'S(default())': S<i32>
+    [298; 305) 'default': fn default<i32>() -> T
+    [298; 307) 'default()': i32
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 76189a60b..c4dc857bc 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -1,7 +1,7 @@
 //! Trait solving using Chalk.
 use std::sync::{Arc, Mutex};
 
-use chalk_ir::{cast::Cast, family::ChalkIr};
+use chalk_ir::cast::Cast;
 use hir_def::{expr::ExprId, DefWithBodyId, ImplId, TraitId, TypeAliasId};
 use log::debug;
 use ra_db::{impl_intern_key, salsa, CrateId};
@@ -12,14 +12,15 @@ use crate::db::HirDatabase;
 
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
 
-use self::chalk::{from_chalk, ToChalk};
+use self::chalk::{from_chalk, ToChalk, TypeFamily};
 
 pub(crate) mod chalk;
+mod builtin;
 
 #[derive(Debug, Clone)]
 pub struct TraitSolver {
     krate: CrateId,
-    inner: Arc<Mutex<chalk_solve::Solver<ChalkIr>>>,
+    inner: Arc<Mutex<chalk_solve::Solver<TypeFamily>>>,
 }
 
 /// We need eq for salsa
@@ -35,8 +36,8 @@ impl TraitSolver {
     fn solve(
         &self,
         db: &impl HirDatabase,
-        goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal<ChalkIr>>>,
-    ) -> Option<chalk_solve::Solution<ChalkIr>> {
+        goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal<TypeFamily>>>,
+    ) -> Option<chalk_solve::Solution<TypeFamily>> {
         let context = ChalkContext { db, krate: self.krate };
         debug!("solve goal: {:?}", goal);
         let mut solver = match self.inner.lock() {
@@ -200,17 +201,17 @@ pub(crate) fn trait_solve_query(
 
 fn solution_from_chalk(
     db: &impl HirDatabase,
-    solution: chalk_solve::Solution<ChalkIr>,
+    solution: chalk_solve::Solution<TypeFamily>,
 ) -> Solution {
-    let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<ChalkIr>>| {
+    let convert_subst = |subst: chalk_ir::Canonical<chalk_ir::Substitution<TypeFamily>>| {
         let value = subst
             .value
             .parameters
             .into_iter()
             .map(|p| {
-                let ty = match p {
-                    chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
-                    chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
+                let ty = match p.ty() {
+                    Some(ty) => from_chalk(db, ty.clone()),
+                    None => unimplemented!(),
                 };
                 ty
             })
@@ -290,7 +291,7 @@ impl FnTrait {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ClosureFnTraitImplData {
     def: DefWithBodyId,
     expr: ExprId,
@@ -299,7 +300,7 @@ pub struct ClosureFnTraitImplData {
 
 /// An impl. Usually this comes from an impl block, but some built-in types get
 /// synthetic impls.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Impl {
     /// A normal impl from an impl block.
     ImplBlock(ImplId),
diff --git a/crates/ra_hir_ty/src/traits/builtin.rs b/crates/ra_hir_ty/src/traits/builtin.rs
new file mode 100644
index 000000000..dd41176f0
--- /dev/null
+++ b/crates/ra_hir_ty/src/traits/builtin.rs
@@ -0,0 +1,178 @@
+//! This module provides the built-in trait implementations, e.g. to make
+//! closures implement `Fn`.
+use hir_def::{expr::Expr, lang_item::LangItemTarget, TraitId, TypeAliasId};
+use hir_expand::name::name;
+use ra_db::CrateId;
+
+use super::{AssocTyValue, Impl};
+use crate::{db::HirDatabase, ApplicationTy, Substs, TraitRef, Ty, TypeCtor};
+
+pub(super) struct BuiltinImplData {
+    pub num_vars: usize,
+    pub trait_ref: TraitRef,
+    pub where_clauses: Vec<super::GenericPredicate>,
+    pub assoc_ty_values: Vec<AssocTyValue>,
+}
+
+pub(super) struct BuiltinImplAssocTyValueData {
+    pub impl_: Impl,
+    pub assoc_ty_id: TypeAliasId,
+    pub num_vars: usize,
+    pub value: Ty,
+}
+
+pub(super) fn get_builtin_impls(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    ty: &Ty,
+    trait_: TraitId,
+    mut callback: impl FnMut(Impl),
+) {
+    // Note: since impl_datum needs to be infallible, we need to make sure here
+    // that we have all prerequisites to build the respective impls.
+    if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Closure { def, expr }, .. }) = ty {
+        for &fn_trait in [super::FnTrait::FnOnce, super::FnTrait::FnMut, super::FnTrait::Fn].iter()
+        {
+            if let Some(actual_trait) = get_fn_trait(db, krate, fn_trait) {
+                if trait_ == actual_trait {
+                    let impl_ = super::ClosureFnTraitImplData { def: *def, expr: *expr, fn_trait };
+                    if check_closure_fn_trait_impl_prerequisites(db, krate, impl_) {
+                        callback(Impl::ClosureFnTraitImpl(impl_));
+                    }
+                }
+            }
+        }
+    }
+}
+
+pub(super) fn impl_datum(db: &impl HirDatabase, krate: CrateId, impl_: Impl) -> BuiltinImplData {
+    match impl_ {
+        Impl::ImplBlock(_) => unreachable!(),
+        Impl::ClosureFnTraitImpl(data) => closure_fn_trait_impl_datum(db, krate, data),
+    }
+}
+
+pub(super) fn associated_ty_value(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: AssocTyValue,
+) -> BuiltinImplAssocTyValueData {
+    match data {
+        AssocTyValue::TypeAlias(_) => unreachable!(),
+        AssocTyValue::ClosureFnTraitImplOutput(data) => {
+            closure_fn_trait_output_assoc_ty_value(db, krate, data)
+        }
+    }
+}
+
+fn check_closure_fn_trait_impl_prerequisites(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> bool {
+    // the respective Fn/FnOnce/FnMut trait needs to exist
+    if get_fn_trait(db, krate, data.fn_trait).is_none() {
+        return false;
+    }
+
+    // FIXME: there are more assumptions that we should probably check here:
+    // the traits having no type params, FnOnce being a supertrait
+
+    // the FnOnce trait needs to exist and have an assoc type named Output
+    let fn_once_trait = match get_fn_trait(db, krate, super::FnTrait::FnOnce) {
+        Some(t) => t,
+        None => return false,
+    };
+    db.trait_data(fn_once_trait).associated_type_by_name(&name![Output]).is_some()
+}
+
+fn closure_fn_trait_impl_datum(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> BuiltinImplData {
+    // for some closure |X, Y| -> Z:
+    // impl<T, U, V> Fn<(T, U)> for closure<fn(T, U) -> V> { Output = V }
+
+    let trait_ = get_fn_trait(db, krate, data.fn_trait) // get corresponding fn trait
+        // the existence of the Fn trait has been checked before
+        .expect("fn trait for closure impl missing");
+
+    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
+        Expr::Lambda { args, .. } => args.len() as u16,
+        _ => {
+            log::warn!("closure for closure type {:?} not found", data);
+            0
+        }
+    };
+
+    let arg_ty = Ty::apply(
+        TypeCtor::Tuple { cardinality: num_args },
+        Substs::builder(num_args as usize).fill_with_bound_vars(0).build(),
+    );
+    let sig_ty = Ty::apply(
+        TypeCtor::FnPtr { num_args },
+        Substs::builder(num_args as usize + 1).fill_with_bound_vars(0).build(),
+    );
+
+    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
+
+    let trait_ref = TraitRef {
+        trait_: trait_.into(),
+        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
+    };
+
+    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data.clone());
+
+    BuiltinImplData {
+        num_vars: num_args as usize + 1,
+        trait_ref,
+        where_clauses: Vec::new(),
+        assoc_ty_values: vec![output_ty_id],
+    }
+}
+
+fn closure_fn_trait_output_assoc_ty_value(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    data: super::ClosureFnTraitImplData,
+) -> BuiltinImplAssocTyValueData {
+    let impl_ = Impl::ClosureFnTraitImpl(data.clone());
+
+    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
+        Expr::Lambda { args, .. } => args.len() as u16,
+        _ => {
+            log::warn!("closure for closure type {:?} not found", data);
+            0
+        }
+    };
+
+    let output_ty = Ty::Bound(num_args.into());
+
+    let fn_once_trait =
+        get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
+
+    let output_ty_id = db
+        .trait_data(fn_once_trait)
+        .associated_type_by_name(&name![Output])
+        .expect("assoc ty value should not exist");
+
+    BuiltinImplAssocTyValueData {
+        impl_,
+        assoc_ty_id: output_ty_id,
+        num_vars: num_args as usize + 1,
+        value: output_ty,
+    }
+}
+
+fn get_fn_trait(
+    db: &impl HirDatabase,
+    krate: CrateId,
+    fn_trait: super::FnTrait,
+) -> Option<TraitId> {
+    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
+    match target {
+        LangItemTarget::TraitId(t) => Some(t),
+        _ => None,
+    }
+}
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 35de37e6b..555930c9b 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -1,32 +1,99 @@
 //! Conversion code from/to Chalk.
-use std::sync::Arc;
+use std::{fmt, sync::Arc};
 
 use log::debug;
 
-use chalk_ir::{
-    cast::Cast, family::ChalkIr, Identifier, Parameter, PlaceholderIndex, TypeId, TypeKindId,
-    TypeName, UniverseIndex,
-};
-use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
-use ra_db::CrateId;
+use chalk_ir::{cast::Cast, Parameter, PlaceholderIndex, TypeName, UniverseIndex};
 
-use hir_def::{
-    expr::Expr, lang_item::LangItemTarget, AssocItemId, AstItemDef, ContainerId, GenericDefId,
-    ImplId, Lookup, TraitId, TypeAliasId,
+use hir_def::{AssocContainerId, AssocItemId, GenericDefId, HasModule, Lookup, TypeAliasId};
+use ra_db::{
+    salsa::{InternId, InternKey},
+    CrateId,
 };
-use hir_expand::name;
-
-use ra_db::salsa::{InternId, InternKey};
 
-use super::{AssocTyValue, Canonical, ChalkContext, Impl, Obligation};
+use super::{builtin, AssocTyValue, Canonical, ChalkContext, Impl, Obligation};
 use crate::{
-    db::HirDatabase, display::HirDisplay, ApplicationTy, GenericPredicate, ImplTy, ProjectionTy,
-    Substs, TraitRef, Ty, TypeCtor, TypeWalk,
+    db::HirDatabase, display::HirDisplay, utils::generics, ApplicationTy, GenericPredicate,
+    ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk,
 };
 
-/// This represents a trait whose name we could not resolve.
-const UNKNOWN_TRAIT: chalk_ir::TraitId =
-    chalk_ir::TraitId(chalk_ir::RawId { index: u32::max_value() });
+#[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
+pub struct TypeFamily {}
+
+impl chalk_ir::family::TypeFamily for TypeFamily {
+    type InternedType = Box<chalk_ir::TyData<Self>>;
+    type InternedLifetime = chalk_ir::LifetimeData<Self>;
+    type InternedParameter = chalk_ir::ParameterData<Self>;
+    type DefId = InternId;
+
+    // FIXME: implement these
+    fn debug_struct_id(
+        _type_kind_id: chalk_ir::StructId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_trait_id(
+        _type_kind_id: chalk_ir::TraitId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_assoc_type_id(
+        _id: chalk_ir::AssocTypeId<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn debug_projection(
+        _projection: &chalk_ir::ProjectionTy<Self>,
+        _fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        None
+    }
+
+    fn intern_ty(ty: chalk_ir::TyData<Self>) -> Box<chalk_ir::TyData<Self>> {
+        Box::new(ty)
+    }
+
+    fn ty_data(ty: &Box<chalk_ir::TyData<Self>>) -> &chalk_ir::TyData<Self> {
+        ty
+    }
+
+    fn intern_lifetime(lifetime: chalk_ir::LifetimeData<Self>) -> chalk_ir::LifetimeData<Self> {
+        lifetime
+    }
+
+    fn lifetime_data(lifetime: &chalk_ir::LifetimeData<Self>) -> &chalk_ir::LifetimeData<Self> {
+        lifetime
+    }
+
+    fn intern_parameter(parameter: chalk_ir::ParameterData<Self>) -> chalk_ir::ParameterData<Self> {
+        parameter
+    }
+
+    fn parameter_data(parameter: &chalk_ir::ParameterData<Self>) -> &chalk_ir::ParameterData<Self> {
+        parameter
+    }
+}
+
+impl chalk_ir::family::HasTypeFamily for TypeFamily {
+    type TypeFamily = Self;
+}
+
+pub type AssocTypeId = chalk_ir::AssocTypeId<TypeFamily>;
+pub type AssociatedTyDatum = chalk_rust_ir::AssociatedTyDatum<TypeFamily>;
+pub type TraitId = chalk_ir::TraitId<TypeFamily>;
+pub type TraitDatum = chalk_rust_ir::TraitDatum<TypeFamily>;
+pub type StructId = chalk_ir::StructId<TypeFamily>;
+pub type StructDatum = chalk_rust_ir::StructDatum<TypeFamily>;
+pub type ImplId = chalk_ir::ImplId<TypeFamily>;
+pub type ImplDatum = chalk_rust_ir::ImplDatum<TypeFamily>;
+pub type AssociatedTyValueId = chalk_rust_ir::AssociatedTyValueId;
+pub type AssociatedTyValue = chalk_rust_ir::AssociatedTyValue<TypeFamily>;
 
 pub(super) trait ToChalk {
     type Chalk;
@@ -42,21 +109,11 @@ where
 }
 
 impl ToChalk for Ty {
-    type Chalk = chalk_ir::Ty<ChalkIr>;
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty<ChalkIr> {
+    type Chalk = chalk_ir::Ty<TypeFamily>;
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Ty<TypeFamily> {
         match self {
             Ty::Apply(apply_ty) => {
-                let name = match apply_ty.ctor {
-                    TypeCtor::AssociatedType(type_alias) => {
-                        let type_id = type_alias.to_chalk(db);
-                        TypeName::AssociatedType(type_id)
-                    }
-                    _ => {
-                        // other TypeCtors get interned and turned into a chalk StructId
-                        let struct_id = apply_ty.ctor.to_chalk(db);
-                        TypeName::TypeKindId(struct_id.into())
-                    }
-                };
+                let name = apply_ty.ctor.to_chalk(db);
                 let parameters = apply_ty.parameters.to_chalk(db);
                 chalk_ir::ApplicationTy { name, parameters }.cast().intern()
             }
@@ -66,17 +123,30 @@ impl ToChalk for Ty {
                 chalk_ir::ProjectionTy { associated_ty_id, parameters }.cast().intern()
             }
             Ty::Param { idx, .. } => {
-                PlaceholderIndex { ui: UniverseIndex::ROOT, idx: idx as usize }.to_ty::<ChalkIr>()
+                PlaceholderIndex { ui: UniverseIndex::ROOT, idx: idx as usize }
+                    .to_ty::<TypeFamily>()
             }
             Ty::Bound(idx) => chalk_ir::TyData::BoundVar(idx as usize).intern(),
             Ty::Infer(_infer_ty) => panic!("uncanonicalized infer ty"),
             Ty::Dyn(predicates) => {
-                let where_clauses = predicates.iter().cloned().map(|p| p.to_chalk(db)).collect();
-                chalk_ir::TyData::Dyn(make_binders(where_clauses, 1)).intern()
+                let where_clauses = predicates
+                    .iter()
+                    .filter(|p| !p.is_error())
+                    .cloned()
+                    .map(|p| p.to_chalk(db))
+                    .collect();
+                let bounded_ty = chalk_ir::BoundedTy { bounds: make_binders(where_clauses, 1) };
+                chalk_ir::TyData::Dyn(bounded_ty).intern()
             }
             Ty::Opaque(predicates) => {
-                let where_clauses = predicates.iter().cloned().map(|p| p.to_chalk(db)).collect();
-                chalk_ir::TyData::Opaque(make_binders(where_clauses, 1)).intern()
+                let where_clauses = predicates
+                    .iter()
+                    .filter(|p| !p.is_error())
+                    .cloned()
+                    .map(|p| p.to_chalk(db))
+                    .collect();
+                let bounded_ty = chalk_ir::BoundedTy { bounds: make_binders(where_clauses, 1) };
+                chalk_ir::TyData::Opaque(bounded_ty).intern()
             }
             Ty::Unknown => {
                 let parameters = Vec::new();
@@ -85,30 +155,19 @@ impl ToChalk for Ty {
             }
         }
     }
-    fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty<ChalkIr>) -> Self {
+    fn from_chalk(db: &impl HirDatabase, chalk: chalk_ir::Ty<TypeFamily>) -> Self {
         match chalk.data().clone() {
-            chalk_ir::TyData::Apply(apply_ty) => {
-                // FIXME this is kind of hacky due to the fact that
-                // TypeName::Placeholder is a Ty::Param on our side
-                match apply_ty.name {
-                    TypeName::TypeKindId(TypeKindId::StructId(struct_id)) => {
-                        let ctor = from_chalk(db, struct_id);
-                        let parameters = from_chalk(db, apply_ty.parameters);
-                        Ty::Apply(ApplicationTy { ctor, parameters })
-                    }
-                    TypeName::AssociatedType(type_id) => {
-                        let ctor = TypeCtor::AssociatedType(from_chalk(db, type_id));
-                        let parameters = from_chalk(db, apply_ty.parameters);
-                        Ty::Apply(ApplicationTy { ctor, parameters })
-                    }
-                    TypeName::Error => Ty::Unknown,
-                    // FIXME handle TypeKindId::Trait/Type here
-                    TypeName::TypeKindId(_) => unimplemented!(),
-                    TypeName::Placeholder(idx) => {
-                        assert_eq!(idx.ui, UniverseIndex::ROOT);
-                        Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }
-                    }
+            chalk_ir::TyData::Apply(apply_ty) => match apply_ty.name {
+                TypeName::Error => Ty::Unknown,
+                _ => {
+                    let ctor = from_chalk(db, apply_ty.name);
+                    let parameters = from_chalk(db, apply_ty.parameters);
+                    Ty::Apply(ApplicationTy { ctor, parameters })
                 }
+            },
+            chalk_ir::TyData::Placeholder(idx) => {
+                assert_eq!(idx.ui, UniverseIndex::ROOT);
+                Ty::Param { idx: idx.idx as u32, name: crate::Name::missing() }
             }
             chalk_ir::TyData::Projection(proj) => {
                 let associated_ty = from_chalk(db, proj.associated_ty_id);
@@ -119,15 +178,15 @@ impl ToChalk for Ty {
             chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx as u32),
             chalk_ir::TyData::InferenceVar(_iv) => Ty::Unknown,
             chalk_ir::TyData::Dyn(where_clauses) => {
-                assert_eq!(where_clauses.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(), 1);
                 let predicates =
-                    where_clauses.value.into_iter().map(|c| from_chalk(db, c)).collect();
+                    where_clauses.bounds.value.into_iter().map(|c| from_chalk(db, c)).collect();
                 Ty::Dyn(predicates)
             }
             chalk_ir::TyData::Opaque(where_clauses) => {
-                assert_eq!(where_clauses.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(), 1);
                 let predicates =
-                    where_clauses.value.into_iter().map(|c| from_chalk(db, c)).collect();
+                    where_clauses.bounds.value.into_iter().map(|c| from_chalk(db, c)).collect();
                 Ty::Opaque(predicates)
             }
         }
@@ -135,18 +194,21 @@ impl ToChalk for Ty {
 }
 
 impl ToChalk for Substs {
-    type Chalk = Vec<chalk_ir::Parameter<ChalkIr>>;
+    type Chalk = Vec<chalk_ir::Parameter<TypeFamily>>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> Vec<Parameter<ChalkIr>> {
+    fn to_chalk(self, db: &impl HirDatabase) -> Vec<Parameter<TypeFamily>> {
         self.iter().map(|ty| ty.clone().to_chalk(db).cast()).collect()
     }
 
-    fn from_chalk(db: &impl HirDatabase, parameters: Vec<chalk_ir::Parameter<ChalkIr>>) -> Substs {
+    fn from_chalk(
+        db: &impl HirDatabase,
+        parameters: Vec<chalk_ir::Parameter<TypeFamily>>,
+    ) -> Substs {
         let tys = parameters
             .into_iter()
-            .map(|p| match p {
-                chalk_ir::Parameter(chalk_ir::ParameterKind::Ty(ty)) => from_chalk(db, ty),
-                chalk_ir::Parameter(chalk_ir::ParameterKind::Lifetime(_)) => unimplemented!(),
+            .map(|p| match p.ty() {
+                Some(ty) => from_chalk(db, ty.clone()),
+                None => unimplemented!(),
             })
             .collect();
         Substs(tys)
@@ -154,88 +216,102 @@ impl ToChalk for Substs {
 }
 
 impl ToChalk for TraitRef {
-    type Chalk = chalk_ir::TraitRef<ChalkIr>;
+    type Chalk = chalk_ir::TraitRef<TypeFamily>;
 
-    fn to_chalk(self: TraitRef, db: &impl HirDatabase) -> chalk_ir::TraitRef<ChalkIr> {
+    fn to_chalk(self: TraitRef, db: &impl HirDatabase) -> chalk_ir::TraitRef<TypeFamily> {
         let trait_id = self.trait_.to_chalk(db);
         let parameters = self.substs.to_chalk(db);
         chalk_ir::TraitRef { trait_id, parameters }
     }
 
-    fn from_chalk(db: &impl HirDatabase, trait_ref: chalk_ir::TraitRef<ChalkIr>) -> Self {
+    fn from_chalk(db: &impl HirDatabase, trait_ref: chalk_ir::TraitRef<TypeFamily>) -> Self {
         let trait_ = from_chalk(db, trait_ref.trait_id);
         let substs = from_chalk(db, trait_ref.parameters);
         TraitRef { trait_, substs }
     }
 }
 
-impl ToChalk for TraitId {
-    type Chalk = chalk_ir::TraitId;
+impl ToChalk for hir_def::TraitId {
+    type Chalk = TraitId;
 
-    fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TraitId {
-        chalk_ir::TraitId(id_to_chalk(self))
+    fn to_chalk(self, _db: &impl HirDatabase) -> TraitId {
+        chalk_ir::TraitId(self.as_intern_id())
     }
 
-    fn from_chalk(_db: &impl HirDatabase, trait_id: chalk_ir::TraitId) -> TraitId {
-        id_from_chalk(trait_id.0)
+    fn from_chalk(_db: &impl HirDatabase, trait_id: TraitId) -> hir_def::TraitId {
+        InternKey::from_intern_id(trait_id.0)
     }
 }
 
 impl ToChalk for TypeCtor {
-    type Chalk = chalk_ir::StructId;
+    type Chalk = TypeName<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::StructId {
-        db.intern_type_ctor(self).into()
+    fn to_chalk(self, db: &impl HirDatabase) -> TypeName<TypeFamily> {
+        match self {
+            TypeCtor::AssociatedType(type_alias) => {
+                let type_id = type_alias.to_chalk(db);
+                TypeName::AssociatedType(type_id)
+            }
+            _ => {
+                // other TypeCtors get interned and turned into a chalk StructId
+                let struct_id = db.intern_type_ctor(self).into();
+                TypeName::Struct(struct_id)
+            }
+        }
     }
 
-    fn from_chalk(db: &impl HirDatabase, struct_id: chalk_ir::StructId) -> TypeCtor {
-        db.lookup_intern_type_ctor(struct_id.into())
+    fn from_chalk(db: &impl HirDatabase, type_name: TypeName<TypeFamily>) -> TypeCtor {
+        match type_name {
+            TypeName::Struct(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
+            TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
+            TypeName::Error => {
+                // this should not be reached, since we don't represent TypeName::Error with TypeCtor
+                unreachable!()
+            }
+        }
     }
 }
 
 impl ToChalk for Impl {
-    type Chalk = chalk_ir::ImplId;
+    type Chalk = ImplId;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ImplId {
+    fn to_chalk(self, db: &impl HirDatabase) -> ImplId {
         db.intern_chalk_impl(self).into()
     }
 
-    fn from_chalk(db: &impl HirDatabase, impl_id: chalk_ir::ImplId) -> Impl {
+    fn from_chalk(db: &impl HirDatabase, impl_id: ImplId) -> Impl {
         db.lookup_intern_chalk_impl(impl_id.into())
     }
 }
 
 impl ToChalk for TypeAliasId {
-    type Chalk = chalk_ir::TypeId;
+    type Chalk = AssocTypeId;
 
-    fn to_chalk(self, _db: &impl HirDatabase) -> chalk_ir::TypeId {
-        chalk_ir::TypeId(id_to_chalk(self))
+    fn to_chalk(self, _db: &impl HirDatabase) -> AssocTypeId {
+        chalk_ir::AssocTypeId(self.as_intern_id())
     }
 
-    fn from_chalk(_db: &impl HirDatabase, type_alias_id: chalk_ir::TypeId) -> TypeAliasId {
-        id_from_chalk(type_alias_id.0)
+    fn from_chalk(_db: &impl HirDatabase, type_alias_id: AssocTypeId) -> TypeAliasId {
+        InternKey::from_intern_id(type_alias_id.0)
     }
 }
 
 impl ToChalk for AssocTyValue {
-    type Chalk = chalk_rust_ir::AssociatedTyValueId;
+    type Chalk = AssociatedTyValueId;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_rust_ir::AssociatedTyValueId {
+    fn to_chalk(self, db: &impl HirDatabase) -> AssociatedTyValueId {
         db.intern_assoc_ty_value(self).into()
     }
 
-    fn from_chalk(
-        db: &impl HirDatabase,
-        assoc_ty_value_id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> AssocTyValue {
+    fn from_chalk(db: &impl HirDatabase, assoc_ty_value_id: AssociatedTyValueId) -> AssocTyValue {
         db.lookup_intern_assoc_ty_value(assoc_ty_value_id.into())
     }
 }
 
 impl ToChalk for GenericPredicate {
-    type Chalk = chalk_ir::QuantifiedWhereClause<ChalkIr>;
+    type Chalk = chalk_ir::QuantifiedWhereClause<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::QuantifiedWhereClause<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::QuantifiedWhereClause<TypeFamily> {
         match self {
             GenericPredicate::Implemented(trait_ref) => {
                 make_binders(chalk_ir::WhereClause::Implemented(trait_ref.to_chalk(db)), 0)
@@ -247,26 +323,16 @@ impl ToChalk for GenericPredicate {
                 }),
                 0,
             ),
-            GenericPredicate::Error => {
-                let impossible_trait_ref = chalk_ir::TraitRef {
-                    trait_id: UNKNOWN_TRAIT,
-                    parameters: vec![Ty::Unknown.to_chalk(db).cast()],
-                };
-                make_binders(chalk_ir::WhereClause::Implemented(impossible_trait_ref), 0)
-            }
+            GenericPredicate::Error => panic!("tried passing GenericPredicate::Error to Chalk"),
         }
     }
 
     fn from_chalk(
         db: &impl HirDatabase,
-        where_clause: chalk_ir::QuantifiedWhereClause<ChalkIr>,
+        where_clause: chalk_ir::QuantifiedWhereClause<TypeFamily>,
     ) -> GenericPredicate {
         match where_clause.value {
             chalk_ir::WhereClause::Implemented(tr) => {
-                if tr.trait_id == UNKNOWN_TRAIT {
-                    // FIXME we need an Error enum on the Chalk side to avoid this
-                    return GenericPredicate::Error;
-                }
                 GenericPredicate::Implemented(from_chalk(db, tr))
             }
             chalk_ir::WhereClause::ProjectionEq(projection_eq) => {
@@ -279,9 +345,9 @@ impl ToChalk for GenericPredicate {
 }
 
 impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::ProjectionTy<ChalkIr>;
+    type Chalk = chalk_ir::ProjectionTy<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ProjectionTy<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::ProjectionTy<TypeFamily> {
         chalk_ir::ProjectionTy {
             associated_ty_id: self.associated_ty.to_chalk(db),
             parameters: self.parameters.to_chalk(db),
@@ -290,7 +356,7 @@ impl ToChalk for ProjectionTy {
 
     fn from_chalk(
         db: &impl HirDatabase,
-        projection_ty: chalk_ir::ProjectionTy<ChalkIr>,
+        projection_ty: chalk_ir::ProjectionTy<TypeFamily>,
     ) -> ProjectionTy {
         ProjectionTy {
             associated_ty: from_chalk(db, projection_ty.associated_ty_id),
@@ -300,31 +366,31 @@ impl ToChalk for ProjectionTy {
 }
 
 impl ToChalk for super::ProjectionPredicate {
-    type Chalk = chalk_ir::Normalize<ChalkIr>;
+    type Chalk = chalk_ir::Normalize<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Normalize<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Normalize<TypeFamily> {
         chalk_ir::Normalize {
             projection: self.projection_ty.to_chalk(db),
             ty: self.ty.to_chalk(db),
         }
     }
 
-    fn from_chalk(_db: &impl HirDatabase, _normalize: chalk_ir::Normalize<ChalkIr>) -> Self {
+    fn from_chalk(_db: &impl HirDatabase, _normalize: chalk_ir::Normalize<TypeFamily>) -> Self {
         unimplemented!()
     }
 }
 
 impl ToChalk for Obligation {
-    type Chalk = chalk_ir::DomainGoal<ChalkIr>;
+    type Chalk = chalk_ir::DomainGoal<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::DomainGoal<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::DomainGoal<TypeFamily> {
         match self {
             Obligation::Trait(tr) => tr.to_chalk(db).cast(),
             Obligation::Projection(pr) => pr.to_chalk(db).cast(),
         }
     }
 
-    fn from_chalk(_db: &impl HirDatabase, _goal: chalk_ir::DomainGoal<ChalkIr>) -> Self {
+    fn from_chalk(_db: &impl HirDatabase, _goal: chalk_ir::DomainGoal<TypeFamily>) -> Self {
         unimplemented!()
     }
 }
@@ -348,16 +414,17 @@ where
 }
 
 impl ToChalk for Arc<super::TraitEnvironment> {
-    type Chalk = chalk_ir::Environment<ChalkIr>;
+    type Chalk = chalk_ir::Environment<TypeFamily>;
 
-    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Environment<ChalkIr> {
+    fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Environment<TypeFamily> {
         let mut clauses = Vec::new();
         for pred in &self.predicates {
             if pred.is_error() {
                 // for env, we just ignore errors
                 continue;
             }
-            let program_clause: chalk_ir::ProgramClause<ChalkIr> = pred.clone().to_chalk(db).cast();
+            let program_clause: chalk_ir::ProgramClause<TypeFamily> =
+                pred.clone().to_chalk(db).cast();
             clauses.push(program_clause.into_from_env_clause());
         }
         chalk_ir::Environment::new().add_clauses(clauses)
@@ -365,7 +432,7 @@ impl ToChalk for Arc<super::TraitEnvironment> {
 
     fn from_chalk(
         _db: &impl HirDatabase,
-        _env: chalk_ir::Environment<ChalkIr>,
+        _env: chalk_ir::Environment<TypeFamily>,
     ) -> Arc<super::TraitEnvironment> {
         unimplemented!()
     }
@@ -373,7 +440,7 @@ impl ToChalk for Arc<super::TraitEnvironment> {
 
 impl<T: ToChalk> ToChalk for super::InEnvironment<T>
 where
-    T::Chalk: chalk_ir::family::HasTypeFamily<TypeFamily = ChalkIr>,
+    T::Chalk: chalk_ir::family::HasTypeFamily<TypeFamily = TypeFamily>,
 {
     type Chalk = chalk_ir::InEnvironment<T::Chalk>;
 
@@ -395,6 +462,51 @@ where
     }
 }
 
+impl ToChalk for builtin::BuiltinImplData {
+    type Chalk = ImplDatum;
+
+    fn to_chalk(self, db: &impl HirDatabase) -> ImplDatum {
+        let impl_type = chalk_rust_ir::ImplType::External;
+        let where_clauses = self.where_clauses.into_iter().map(|w| w.to_chalk(db)).collect();
+
+        let impl_datum_bound =
+            chalk_rust_ir::ImplDatumBound { trait_ref: self.trait_ref.to_chalk(db), where_clauses };
+        let associated_ty_value_ids =
+            self.assoc_ty_values.into_iter().map(|v| v.to_chalk(db)).collect();
+        chalk_rust_ir::ImplDatum {
+            binders: make_binders(impl_datum_bound, self.num_vars),
+            impl_type,
+            polarity: chalk_rust_ir::Polarity::Positive,
+            associated_ty_value_ids,
+        }
+    }
+
+    fn from_chalk(_db: &impl HirDatabase, _data: ImplDatum) -> Self {
+        unimplemented!()
+    }
+}
+
+impl ToChalk for builtin::BuiltinImplAssocTyValueData {
+    type Chalk = AssociatedTyValue;
+
+    fn to_chalk(self, db: &impl HirDatabase) -> AssociatedTyValue {
+        let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: self.value.to_chalk(db) };
+
+        chalk_rust_ir::AssociatedTyValue {
+            associated_ty_id: self.assoc_ty_id.to_chalk(db),
+            impl_id: self.impl_.to_chalk(db),
+            value: make_binders(value_bound, self.num_vars),
+        }
+    }
+
+    fn from_chalk(
+        _db: &impl HirDatabase,
+        _data: AssociatedTyValue,
+    ) -> builtin::BuiltinImplAssocTyValueData {
+        unimplemented!()
+    }
+}
+
 fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
     chalk_ir::Binders {
         value,
@@ -406,46 +518,46 @@ fn convert_where_clauses(
     db: &impl HirDatabase,
     def: GenericDefId,
     substs: &Substs,
-) -> Vec<chalk_ir::QuantifiedWhereClause<ChalkIr>> {
+) -> Vec<chalk_ir::QuantifiedWhereClause<TypeFamily>> {
     let generic_predicates = db.generic_predicates(def);
     let mut result = Vec::with_capacity(generic_predicates.len());
     for pred in generic_predicates.iter() {
         if pred.is_error() {
-            // HACK: Return just the single predicate (which is always false
-            // anyway), otherwise Chalk can easily get into slow situations
-            return vec![pred.clone().subst(substs).to_chalk(db)];
+            // skip errored predicates completely
+            continue;
         }
         result.push(pred.clone().subst(substs).to_chalk(db));
     }
     result
 }
 
-impl<'a, DB> chalk_solve::RustIrDatabase<ChalkIr> for ChalkContext<'a, DB>
+impl<'a, DB> chalk_solve::RustIrDatabase<TypeFamily> for ChalkContext<'a, DB>
 where
     DB: HirDatabase,
 {
-    fn associated_ty_data(&self, id: TypeId) -> Arc<AssociatedTyDatum<ChalkIr>> {
+    fn associated_ty_data(&self, id: AssocTypeId) -> Arc<AssociatedTyDatum> {
         self.db.associated_ty_data(id)
     }
-    fn trait_datum(&self, trait_id: chalk_ir::TraitId) -> Arc<TraitDatum<ChalkIr>> {
+    fn trait_datum(&self, trait_id: TraitId) -> Arc<TraitDatum> {
         self.db.trait_datum(self.krate, trait_id)
     }
-    fn struct_datum(&self, struct_id: chalk_ir::StructId) -> Arc<StructDatum<ChalkIr>> {
+    fn struct_datum(&self, struct_id: StructId) -> Arc<StructDatum> {
         self.db.struct_datum(self.krate, struct_id)
     }
-    fn impl_datum(&self, impl_id: chalk_ir::ImplId) -> Arc<ImplDatum<ChalkIr>> {
+    fn impl_datum(&self, impl_id: ImplId) -> Arc<ImplDatum> {
         self.db.impl_datum(self.krate, impl_id)
     }
     fn impls_for_trait(
         &self,
-        trait_id: chalk_ir::TraitId,
-        parameters: &[Parameter<ChalkIr>],
-    ) -> Vec<chalk_ir::ImplId> {
+        trait_id: TraitId,
+        parameters: &[Parameter<TypeFamily>],
+    ) -> Vec<ImplId> {
         debug!("impls_for_trait {:?}", trait_id);
-        if trait_id == UNKNOWN_TRAIT {
-            return Vec::new();
-        }
-        let trait_: TraitId = from_chalk(self.db, trait_id);
+        let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
+
+        // Note: Since we're using impls_for_trait, only impls where the trait
+        // can be resolved should ever reach Chalk. `impl_datum` relies on that
+        // and will panic if the trait can't be resolved.
         let mut result: Vec<_> = self
             .db
             .impls_for_trait(self.krate, trait_.into())
@@ -456,62 +568,47 @@ where
             .collect();
 
         let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref().clone());
-        if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Closure { def, expr }, .. }) = ty {
-            for &fn_trait in
-                [super::FnTrait::FnOnce, super::FnTrait::FnMut, super::FnTrait::Fn].iter()
-            {
-                if let Some(actual_trait) = get_fn_trait(self.db, self.krate, fn_trait) {
-                    if trait_ == actual_trait {
-                        let impl_ = super::ClosureFnTraitImplData { def, expr, fn_trait };
-                        result.push(Impl::ClosureFnTraitImpl(impl_).to_chalk(self.db));
-                    }
-                }
-            }
-        }
+
+        builtin::get_builtin_impls(self.db, self.krate, &ty, trait_, |i| {
+            result.push(i.to_chalk(self.db))
+        });
 
         debug!("impls_for_trait returned {} impls", result.len());
         result
     }
-    fn impl_provided_for(
-        &self,
-        auto_trait_id: chalk_ir::TraitId,
-        struct_id: chalk_ir::StructId,
-    ) -> bool {
+    fn impl_provided_for(&self, auto_trait_id: TraitId, struct_id: StructId) -> bool {
         debug!("impl_provided_for {:?}, {:?}", auto_trait_id, struct_id);
         false // FIXME
     }
-    fn type_name(&self, _id: TypeKindId) -> Identifier {
-        unimplemented!()
-    }
-    fn associated_ty_value(
-        &self,
-        id: chalk_rust_ir::AssociatedTyValueId,
-    ) -> Arc<AssociatedTyValue<ChalkIr>> {
+    fn associated_ty_value(&self, id: AssociatedTyValueId) -> Arc<AssociatedTyValue> {
         self.db.associated_ty_value(self.krate.into(), id)
     }
-    fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<ChalkIr>> {
+    fn custom_clauses(&self) -> Vec<chalk_ir::ProgramClause<TypeFamily>> {
         vec![]
     }
-    fn local_impls_to_coherence_check(
-        &self,
-        _trait_id: chalk_ir::TraitId,
-    ) -> Vec<chalk_ir::ImplId> {
+    fn local_impls_to_coherence_check(&self, _trait_id: TraitId) -> Vec<ImplId> {
         // We don't do coherence checking (yet)
         unimplemented!()
     }
+    fn as_struct_id(&self, id: &TypeName<TypeFamily>) -> Option<StructId> {
+        match id {
+            TypeName::Struct(struct_id) => Some(*struct_id),
+            _ => None,
+        }
+    }
 }
 
 pub(crate) fn associated_ty_data_query(
     db: &impl HirDatabase,
-    id: TypeId,
-) -> Arc<AssociatedTyDatum<ChalkIr>> {
+    id: AssocTypeId,
+) -> Arc<AssociatedTyDatum> {
     debug!("associated_ty_data {:?}", id);
     let type_alias: TypeAliasId = from_chalk(db, id);
     let trait_ = match type_alias.lookup(db).container {
-        ContainerId::TraitId(t) => t,
+        AssocContainerId::TraitId(t) => t,
         _ => panic!("associated type not in trait"),
     };
-    let generic_params = db.generic_params(type_alias.into());
+    let generic_params = generics(db, type_alias.into());
     let bound_data = chalk_rust_ir::AssociatedTyDatumBound {
         // FIXME add bounds and where clauses
         bounds: vec![],
@@ -521,7 +618,7 @@ pub(crate) fn associated_ty_data_query(
         trait_id: trait_.to_chalk(db),
         id,
         name: lalrpop_intern::intern(&db.type_alias_data(type_alias).name.to_string()),
-        binders: make_binders(bound_data, generic_params.count_params_including_parent()),
+        binders: make_binders(bound_data, generic_params.len()),
     };
     Arc::new(datum)
 }
@@ -529,35 +626,17 @@ pub(crate) fn associated_ty_data_query(
 pub(crate) fn trait_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    trait_id: chalk_ir::TraitId,
-) -> Arc<TraitDatum<ChalkIr>> {
+    trait_id: TraitId,
+) -> Arc<TraitDatum> {
     debug!("trait_datum {:?}", trait_id);
-    if trait_id == UNKNOWN_TRAIT {
-        let trait_datum_bound = chalk_rust_ir::TraitDatumBound { where_clauses: Vec::new() };
-
-        let flags = chalk_rust_ir::TraitFlags {
-            auto: false,
-            marker: false,
-            upstream: true,
-            fundamental: false,
-            non_enumerable: true,
-            coinductive: false,
-        };
-        return Arc::new(TraitDatum {
-            id: trait_id,
-            binders: make_binders(trait_datum_bound, 1),
-            flags,
-            associated_ty_ids: vec![],
-        });
-    }
-    let trait_: TraitId = from_chalk(db, trait_id);
+    let trait_: hir_def::TraitId = from_chalk(db, trait_id);
     let trait_data = db.trait_data(trait_);
     debug!("trait {:?} = {:?}", trait_id, trait_data.name);
-    let generic_params = db.generic_params(trait_.into());
+    let generic_params = generics(db, trait_.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let flags = chalk_rust_ir::TraitFlags {
         auto: trait_data.auto,
-        upstream: trait_.module(db).krate != krate,
+        upstream: trait_.lookup(db).container.module(db).krate != krate,
         non_enumerable: true,
         coinductive: false, // only relevant for Chalk testing
         // FIXME set these flags correctly
@@ -580,17 +659,17 @@ pub(crate) fn trait_datum_query(
 pub(crate) fn struct_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    struct_id: chalk_ir::StructId,
-) -> Arc<StructDatum<ChalkIr>> {
+    struct_id: StructId,
+) -> Arc<StructDatum> {
     debug!("struct_datum {:?}", struct_id);
-    let type_ctor: TypeCtor = from_chalk(db, struct_id);
+    let type_ctor: TypeCtor = from_chalk(db, TypeName::Struct(struct_id));
     debug!("struct {:?} = {:?}", struct_id, type_ctor);
     let num_params = type_ctor.num_ty_params(db);
     let upstream = type_ctor.krate(db) != Some(krate);
     let where_clauses = type_ctor
         .as_generic_def()
         .map(|generic_def| {
-            let generic_params = db.generic_params(generic_def.into());
+            let generic_params = generics(db, generic_def.into());
             let bound_vars = Substs::bound_vars(&generic_params);
             convert_where_clauses(db, generic_def, &bound_vars)
         })
@@ -612,35 +691,34 @@ pub(crate) fn struct_datum_query(
 pub(crate) fn impl_datum_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    impl_id: chalk_ir::ImplId,
-) -> Arc<ImplDatum<ChalkIr>> {
+    impl_id: ImplId,
+) -> Arc<ImplDatum> {
     let _p = ra_prof::profile("impl_datum");
     debug!("impl_datum {:?}", impl_id);
     let impl_: Impl = from_chalk(db, impl_id);
     match impl_ {
         Impl::ImplBlock(impl_block) => impl_block_datum(db, krate, impl_id, impl_block),
-        Impl::ClosureFnTraitImpl(data) => closure_fn_trait_impl_datum(db, krate, data),
+        _ => Arc::new(builtin::impl_datum(db, krate, impl_).to_chalk(db)),
     }
-    .unwrap_or_else(invalid_impl_datum)
 }
 
 fn impl_block_datum(
     db: &impl HirDatabase,
     krate: CrateId,
-    chalk_id: chalk_ir::ImplId,
-    impl_id: ImplId,
-) -> Option<Arc<ImplDatum<ChalkIr>>> {
-    let trait_ref = match db.impl_ty(impl_id) {
-        ImplTy::TraitRef(it) => it,
-        ImplTy::Inherent(_) => return None,
-    };
+    chalk_id: ImplId,
+    impl_id: hir_def::ImplId,
+) -> Arc<ImplDatum> {
+    let trait_ref = db
+        .impl_trait(impl_id)
+        // ImplIds for impls where the trait ref can't be resolved should never reach Chalk
+        .expect("invalid impl passed to Chalk");
     let impl_data = db.impl_data(impl_id);
 
-    let generic_params = db.generic_params(impl_id.into());
+    let generic_params = generics(db, impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let trait_ref = trait_ref.subst(&bound_vars);
     let trait_ = trait_ref.trait_;
-    let impl_type = if impl_id.module(db).krate == krate {
+    let impl_type = if impl_id.lookup(db).container.module(db).krate == krate {
         chalk_rust_ir::ImplType::Local
     } else {
         chalk_rust_ir::ImplType::External
@@ -685,94 +763,20 @@ fn impl_block_datum(
         polarity,
         associated_ty_value_ids,
     };
-    Some(Arc::new(impl_datum))
-}
-
-fn invalid_impl_datum() -> Arc<ImplDatum<ChalkIr>> {
-    let trait_ref = chalk_ir::TraitRef {
-        trait_id: UNKNOWN_TRAIT,
-        parameters: vec![chalk_ir::TyData::BoundVar(0).cast().intern().cast()],
-    };
-    let impl_datum_bound = chalk_rust_ir::ImplDatumBound { trait_ref, where_clauses: Vec::new() };
-    let impl_datum = ImplDatum {
-        binders: make_binders(impl_datum_bound, 1),
-        impl_type: chalk_rust_ir::ImplType::External,
-        polarity: chalk_rust_ir::Polarity::Positive,
-        associated_ty_value_ids: Vec::new(),
-    };
     Arc::new(impl_datum)
 }
 
-fn closure_fn_trait_impl_datum(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> Option<Arc<ImplDatum<ChalkIr>>> {
-    // for some closure |X, Y| -> Z:
-    // impl<T, U, V> Fn<(T, U)> for closure<fn(T, U) -> V> { Output = V }
-
-    let trait_ = get_fn_trait(db, krate, data.fn_trait)?; // get corresponding fn trait
-
-    // validate FnOnce trait, since we need it in the assoc ty value definition
-    // and don't want to return a valid value only to find out later that FnOnce
-    // is broken
-    let fn_once_trait = get_fn_trait(db, krate, super::FnTrait::FnOnce)?;
-    let _output = db.trait_data(fn_once_trait).associated_type_by_name(&name::OUTPUT_TYPE)?;
-
-    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let arg_ty = Ty::apply(
-        TypeCtor::Tuple { cardinality: num_args },
-        Substs::builder(num_args as usize).fill_with_bound_vars(0).build(),
-    );
-    let sig_ty = Ty::apply(
-        TypeCtor::FnPtr { num_args },
-        Substs::builder(num_args as usize + 1).fill_with_bound_vars(0).build(),
-    );
-
-    let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
-
-    let trait_ref = TraitRef {
-        trait_: trait_.into(),
-        substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
-    };
-
-    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data.clone()).to_chalk(db);
-
-    let impl_type = chalk_rust_ir::ImplType::External;
-
-    let impl_datum_bound = chalk_rust_ir::ImplDatumBound {
-        trait_ref: trait_ref.to_chalk(db),
-        where_clauses: Vec::new(),
-    };
-    let impl_datum = ImplDatum {
-        binders: make_binders(impl_datum_bound, num_args as usize + 1),
-        impl_type,
-        polarity: chalk_rust_ir::Polarity::Positive,
-        associated_ty_value_ids: vec![output_ty_id],
-    };
-    Some(Arc::new(impl_datum))
-}
-
 pub(crate) fn associated_ty_value_query(
     db: &impl HirDatabase,
     krate: CrateId,
-    id: chalk_rust_ir::AssociatedTyValueId,
-) -> Arc<chalk_rust_ir::AssociatedTyValue<ChalkIr>> {
+    id: AssociatedTyValueId,
+) -> Arc<AssociatedTyValue> {
     let data: AssocTyValue = from_chalk(db, id);
     match data {
         AssocTyValue::TypeAlias(type_alias) => {
             type_alias_associated_ty_value(db, krate, type_alias)
         }
-        AssocTyValue::ClosureFnTraitImplOutput(data) => {
-            closure_fn_trait_output_assoc_ty_value(db, krate, data)
-        }
+        _ => Arc::new(builtin::associated_ty_value(db, krate, data).to_chalk(db)),
     }
 }
 
@@ -780,24 +784,20 @@ fn type_alias_associated_ty_value(
     db: &impl HirDatabase,
     _krate: CrateId,
     type_alias: TypeAliasId,
-) -> Arc<AssociatedTyValue<ChalkIr>> {
+) -> Arc<AssociatedTyValue> {
     let type_alias_data = db.type_alias_data(type_alias);
     let impl_id = match type_alias.lookup(db).container {
-        ContainerId::ImplId(it) => it,
+        AssocContainerId::ImplId(it) => it,
         _ => panic!("assoc ty value should be in impl"),
     };
 
-    let trait_ref = match db.impl_ty(impl_id) {
-        ImplTy::TraitRef(it) => it,
-        // we don't return any assoc ty values if the impl'd trait can't be resolved
-        ImplTy::Inherent(_) => panic!("assoc ty value should not exist"),
-    };
+    let trait_ref = db.impl_trait(impl_id).expect("assoc ty value should not exist"); // we don't return any assoc ty values if the impl'd trait can't be resolved
 
     let assoc_ty = db
         .trait_data(trait_ref.trait_)
         .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
-    let generic_params = db.generic_params(impl_id.into());
+    let generic_params = generics(db, impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let ty = db.ty(type_alias.into()).subst(&bound_vars);
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
@@ -809,53 +809,6 @@ fn type_alias_associated_ty_value(
     Arc::new(value)
 }
 
-fn closure_fn_trait_output_assoc_ty_value(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    data: super::ClosureFnTraitImplData,
-) -> Arc<AssociatedTyValue<ChalkIr>> {
-    let impl_id = Impl::ClosureFnTraitImpl(data.clone()).to_chalk(db);
-
-    let num_args: u16 = match &db.body(data.def.into())[data.expr] {
-        Expr::Lambda { args, .. } => args.len() as u16,
-        _ => {
-            log::warn!("closure for closure type {:?} not found", data);
-            0
-        }
-    };
-
-    let output_ty = Ty::Bound(num_args.into());
-
-    let fn_once_trait =
-        get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
-
-    let output_ty_id = db
-        .trait_data(fn_once_trait)
-        .associated_type_by_name(&name::OUTPUT_TYPE)
-        .expect("assoc ty value should not exist");
-
-    let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: output_ty.to_chalk(db) };
-
-    let value = chalk_rust_ir::AssociatedTyValue {
-        associated_ty_id: output_ty_id.to_chalk(db),
-        impl_id,
-        value: make_binders(value_bound, num_args as usize + 1),
-    };
-    Arc::new(value)
-}
-
-fn get_fn_trait(
-    db: &impl HirDatabase,
-    krate: CrateId,
-    fn_trait: super::FnTrait,
-) -> Option<TraitId> {
-    let target = db.lang_item(krate, fn_trait.lang_item_name().into())?;
-    match target {
-        LangItemTarget::TraitId(t) => Some(t),
-        _ => None,
-    }
-}
-
 fn id_from_chalk<T: InternKey>(chalk_id: chalk_ir::RawId) -> T {
     T::from_intern_id(InternId::from(chalk_id.index))
 }
@@ -863,27 +816,27 @@ fn id_to_chalk<T: InternKey>(salsa_id: T) -> chalk_ir::RawId {
     chalk_ir::RawId { index: salsa_id.as_intern_id().as_u32() }
 }
 
-impl From<chalk_ir::StructId> for crate::TypeCtorId {
-    fn from(struct_id: chalk_ir::StructId) -> Self {
-        id_from_chalk(struct_id.0)
+impl From<StructId> for crate::TypeCtorId {
+    fn from(struct_id: StructId) -> Self {
+        InternKey::from_intern_id(struct_id.0)
     }
 }
 
-impl From<crate::TypeCtorId> for chalk_ir::StructId {
+impl From<crate::TypeCtorId> for StructId {
     fn from(type_ctor_id: crate::TypeCtorId) -> Self {
-        chalk_ir::StructId(id_to_chalk(type_ctor_id))
+        chalk_ir::StructId(type_ctor_id.as_intern_id())
     }
 }
 
-impl From<chalk_ir::ImplId> for crate::traits::GlobalImplId {
-    fn from(impl_id: chalk_ir::ImplId) -> Self {
-        id_from_chalk(impl_id.0)
+impl From<ImplId> for crate::traits::GlobalImplId {
+    fn from(impl_id: ImplId) -> Self {
+        InternKey::from_intern_id(impl_id.0)
     }
 }
 
-impl From<crate::traits::GlobalImplId> for chalk_ir::ImplId {
+impl From<crate::traits::GlobalImplId> for ImplId {
     fn from(impl_id: crate::traits::GlobalImplId) -> Self {
-        chalk_ir::ImplId(id_to_chalk(impl_id))
+        chalk_ir::ImplId(impl_id.as_intern_id())
     }
 }
 
diff --git a/crates/ra_hir_ty/src/utils.rs b/crates/ra_hir_ty/src/utils.rs
index e4ba890ef..0b1806a84 100644
--- a/crates/ra_hir_ty/src/utils.rs
+++ b/crates/ra_hir_ty/src/utils.rs
@@ -5,14 +5,14 @@ use std::sync::Arc;
 use hir_def::{
     adt::VariantData,
     db::DefDatabase,
+    generics::{GenericParams, TypeParamData},
+    path::Path,
     resolver::{HasResolver, TypeNs},
     type_ref::TypeRef,
-    TraitId, TypeAliasId, VariantId,
+    AssocContainerId, GenericDefId, Lookup, TraitId, TypeAliasId, TypeParamId, VariantId,
 };
-use hir_expand::name::{self, Name};
+use hir_expand::name::{name, Name};
 
-// FIXME: this is wrong, b/c it can't express `trait T: PartialEq<()>`.
-// We should return a `TraitREf` here.
 fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
     let resolver = trait_.resolver(db);
     // returning the iterator directly doesn't easily work because of
@@ -23,10 +23,10 @@ fn direct_super_traits(db: &impl DefDatabase, trait_: TraitId) -> Vec<TraitId> {
         .where_predicates
         .iter()
         .filter_map(|pred| match &pred.type_ref {
-            TypeRef::Path(p) if p.as_ident() == Some(&name::SELF_TYPE) => pred.bound.as_path(),
+            TypeRef::Path(p) if p == &Path::from(name![Self]) => pred.bound.as_path(),
             _ => None,
         })
-        .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path) {
+        .filter_map(|path| match resolver.resolve_path_in_type_ns_fully(db, path.mod_path()) {
             Some(TypeNs::TraitId(t)) => Some(t),
             _ => None,
         })
@@ -82,3 +82,81 @@ pub(crate) fn make_mut_slice<T: Clone>(a: &mut Arc<[T]>) -> &mut [T] {
     }
     Arc::get_mut(a).unwrap()
 }
+
+pub(crate) fn generics(db: &impl DefDatabase, def: GenericDefId) -> Generics {
+    let parent_generics = parent_generic_def(db, def).map(|def| Box::new(generics(db, def)));
+    Generics { def, params: db.generic_params(def), parent_generics }
+}
+
+pub(crate) struct Generics {
+    def: GenericDefId,
+    pub(crate) params: Arc<GenericParams>,
+    parent_generics: Option<Box<Generics>>,
+}
+
+impl Generics {
+    pub(crate) fn iter<'a>(&'a self) -> impl Iterator<Item = (u32, &'a TypeParamData)> + 'a {
+        self.parent_generics
+            .as_ref()
+            .into_iter()
+            .flat_map(|it| it.params.types.iter())
+            .chain(self.params.types.iter())
+            .enumerate()
+            .map(|(i, (_local_id, p))| (i as u32, p))
+    }
+
+    pub(crate) fn iter_parent<'a>(&'a self) -> impl Iterator<Item = (u32, &'a TypeParamData)> + 'a {
+        self.parent_generics
+            .as_ref()
+            .into_iter()
+            .flat_map(|it| it.params.types.iter())
+            .enumerate()
+            .map(|(i, (_local_id, p))| (i as u32, p))
+    }
+
+    pub(crate) fn len(&self) -> usize {
+        self.len_split().0
+    }
+    /// (total, parents, child)
+    pub(crate) fn len_split(&self) -> (usize, usize, usize) {
+        let parent = self.parent_generics.as_ref().map_or(0, |p| p.len());
+        let child = self.params.types.len();
+        (parent + child, parent, child)
+    }
+    pub(crate) fn param_idx(&self, param: TypeParamId) -> u32 {
+        self.find_param(param).0
+    }
+    pub(crate) fn param_name(&self, param: TypeParamId) -> Name {
+        self.find_param(param).1.name.clone()
+    }
+    fn find_param(&self, param: TypeParamId) -> (u32, &TypeParamData) {
+        if param.parent == self.def {
+            let (idx, (_local_id, data)) = self
+                .params
+                .types
+                .iter()
+                .enumerate()
+                .find(|(_, (idx, _))| *idx == param.local_id)
+                .unwrap();
+            let (_total, parent_len, _child) = self.len_split();
+            return ((parent_len + idx) as u32, data);
+        }
+        self.parent_generics.as_ref().unwrap().find_param(param)
+    }
+}
+
+fn parent_generic_def(db: &impl DefDatabase, def: GenericDefId) -> Option<GenericDefId> {
+    let container = match def {
+        GenericDefId::FunctionId(it) => it.lookup(db).container,
+        GenericDefId::TypeAliasId(it) => it.lookup(db).container,
+        GenericDefId::ConstId(it) => it.lookup(db).container,
+        GenericDefId::EnumVariantId(it) => return Some(it.parent.into()),
+        GenericDefId::AdtId(_) | GenericDefId::TraitId(_) | GenericDefId::ImplId(_) => return None,
+    };
+
+    match container {
+        AssocContainerId::ImplId(it) => Some(it.into()),
+        AssocContainerId::TraitId(it) => Some(it.into()),
+        AssocContainerId::ContainerId(_) => None,
+    }
+}