5 files changed, 34 insertions, 39 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9e7a1deec..50e6409b1 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -740,10 +740,6 @@ impl Trait {
         db.trait_data(self.id).items.iter().map(|(_name, it)| (*it).into()).collect()
     }
 
-    pub fn associated_type_by_name(self, db: &impl DefDatabase, name: &Name) -> Option<TypeAlias> {
-        db.trait_data(self.id).associated_type_by_name(name).map(TypeAlias::from)
-    }
-
     pub fn associated_type_by_name_including_super_traits(
         self,
         db: &impl HirDatabase,
@@ -751,8 +747,8 @@ impl Trait {
     ) -> Option<TypeAlias> {
         all_super_traits(db, self.id)
             .into_iter()
-            .map(Trait::from)
-            .find_map(|t| t.associated_type_by_name(db, name))
+            .find_map(|t| db.trait_data(t).associated_type_by_name(name))
+            .map(TypeAlias::from)
     }
 
     pub fn trait_ref(self, db: &impl HirDatabase) -> TraitRef {
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 9e7593b8b..ae68234ac 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -10,7 +10,7 @@ use hir_expand::name;
 use log::{info, warn};
 use ra_db::CrateId;
 
-use crate::{db::HirDatabase, Trait};
+use crate::db::HirDatabase;
 
 use super::{
     traits::{InEnvironment, Solution},
@@ -49,12 +49,12 @@ fn deref_by_trait(
     ty: InEnvironment<&Canonical<Ty>>,
 ) -> Option<Canonical<Ty>> {
     let deref_trait = match db.lang_item(krate.into(), "deref".into())? {
-        LangItemTarget::TraitId(t) => Trait::from(t),
+        LangItemTarget::TraitId(it) => it,
         _ => return None,
     };
-    let target = deref_trait.associated_type_by_name(db, &name::TARGET_TYPE)?;
+    let target = db.trait_data(deref_trait).associated_type_by_name(&name::TARGET_TYPE)?;
 
-    let generic_params = db.generic_params(target.id.into());
+    let generic_params = db.generic_params(target.into());
     if generic_params.count_params_including_parent() != 1 {
         // the Target type + Deref trait should only have one generic parameter,
         // namely Deref's Self type
@@ -69,7 +69,7 @@ fn deref_by_trait(
 
     let projection = super::traits::ProjectionPredicate {
         ty: Ty::Bound(0),
-        projection_ty: super::ProjectionTy { associated_ty: target.id, parameters },
+        projection_ty: super::ProjectionTy { associated_ty: target, parameters },
     };
 
     let obligation = super::Obligation::Projection(projection);
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index fce45321d..b023ae690 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -43,7 +43,7 @@ use crate::{
     db::HirDatabase,
     expr::{BindingAnnotation, Body, ExprId, PatId},
     ty::infer::diagnostics::InferenceDiagnostic,
-    Adt, AssocItem, DefWithBody, FloatTy, Function, IntTy, Path, StructField, Trait, VariantDef,
+    Adt, AssocItem, DefWithBody, FloatTy, Function, IntTy, Path, StructField, VariantDef,
 };
 
 macro_rules! ty_app {
@@ -582,20 +582,20 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
     fn resolve_into_iter_item(&self) -> Option<TypeAlias> {
         let path = known::std_iter_into_iterator();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::ITEM_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::ITEM_TYPE).map(TypeAlias::from)
     }
 
     fn resolve_ops_try_ok(&self) -> Option<TypeAlias> {
         let path = known::std_ops_try();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::OK_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::OK_TYPE).map(TypeAlias::from)
     }
 
     fn resolve_future_future_output(&self) -> Option<TypeAlias> {
         let path = known::std_future_future();
-        let trait_: Trait = self.resolver.resolve_known_trait(self.db, &path)?.into();
-        trait_.associated_type_by_name(self.db, &name::OUTPUT_TYPE)
+        let trait_ = self.resolver.resolve_known_trait(self.db, &path)?;
+        self.db.trait_data(trait_).associated_type_by_name(&name::OUTPUT_TYPE).map(TypeAlias::from)
     }
 
     fn resolve_boxed_box(&self) -> Option<AdtId> {
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index 9e3afabe0..0ac7920bb 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -263,16 +263,14 @@ impl Ty {
         });
         let traits = traits_from_env.flat_map(|t| all_super_traits(db, t.id)).map(Trait::from);
         for t in traits {
-            if let Some(associated_ty) = t.associated_type_by_name(db, &segment.name) {
+            if let Some(associated_ty) = db.trait_data(t.id).associated_type_by_name(&segment.name)
+            {
                 let substs = Substs::build_for_def(db, t.id)
                     .push(self_ty.clone())
                     .fill_with_unknown()
                     .build();
                 // FIXME handle type parameters on the segment
-                return Ty::Projection(ProjectionTy {
-                    associated_ty: associated_ty.id,
-                    parameters: substs,
-                });
+                return Ty::Projection(ProjectionTy { associated_ty, parameters: substs });
             }
         }
         Ty::Unknown
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 06388a3ce..78f4b3e27 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -9,7 +9,7 @@ use chalk_ir::{
 };
 use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum, TraitDatum};
 
-use hir_def::{lang_item::LangItemTarget, ContainerId, GenericDefId, Lookup, TypeAliasId};
+use hir_def::{lang_item::LangItemTarget, ContainerId, GenericDefId, Lookup, TraitId, TypeAliasId};
 use hir_expand::name;
 
 use ra_db::salsa::{InternId, InternKey};
@@ -459,7 +459,7 @@ where
                 [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 {
+                    if trait_.id == actual_trait {
                         let impl_ = super::ClosureFnTraitImplData { def, expr, fn_trait };
                         result.push(Impl::ClosureFnTraitImpl(impl_).to_chalk(self.db));
                     }
@@ -661,6 +661,7 @@ fn impl_block_datum(
     };
 
     let impl_datum_bound = chalk_rust_ir::ImplDatumBound { trait_ref, where_clauses };
+    let trait_data = db.trait_data(trait_.id);
     let associated_ty_value_ids = impl_block
         .items(db)
         .into_iter()
@@ -670,7 +671,7 @@ fn impl_block_datum(
         })
         .filter(|type_alias| {
             // don't include associated types that don't exist in the trait
-            trait_.associated_type_by_name(db, &type_alias.name(db)).is_some()
+            trait_data.associated_type_by_name(&type_alias.name(db)).is_some()
         })
         .map(|type_alias| AssocTyValue::TypeAlias(type_alias).to_chalk(db))
         .collect();
@@ -713,7 +714,7 @@ fn closure_fn_trait_impl_datum(
     // 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)?;
-    fn_once_trait.associated_type_by_name(db, &name::OUTPUT_TYPE)?;
+    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] {
         crate::expr::Expr::Lambda { args, .. } => args.len() as u16,
@@ -735,8 +736,8 @@ fn closure_fn_trait_impl_datum(
     let self_ty = Ty::apply_one(TypeCtor::Closure { def: data.def, expr: data.expr }, sig_ty);
 
     let trait_ref = TraitRef {
-        trait_,
-        substs: Substs::build_for_def(db, trait_.id).push(self_ty).push(arg_ty).build(),
+        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);
@@ -783,10 +784,10 @@ fn type_alias_associated_ty_value(
         .target_trait_ref(db)
         .expect("assoc ty value should not exist") // we don't return any assoc ty values if the impl'd trait can't be resolved
         .trait_;
-    let assoc_ty = trait_
-        .associated_type_by_name(db, &type_alias.name(db))
-        .expect("assoc ty value should not exist") // validated when building the impl data as well
-        .id;
+    let assoc_ty = db
+        .trait_data(trait_.id)
+        .associated_type_by_name(&type_alias.name(db))
+        .expect("assoc ty value should not exist"); // validated when building the impl data as well
     let generic_params = db.generic_params(impl_block.id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
     let ty = db.type_for_def(type_alias.into(), crate::ty::Namespace::Types).subst(&bound_vars);
@@ -819,10 +820,10 @@ fn closure_fn_trait_output_assoc_ty_value(
     let fn_once_trait =
         get_fn_trait(db, krate, super::FnTrait::FnOnce).expect("assoc ty value should not exist");
 
-    let output_ty_id = fn_once_trait
-        .associated_type_by_name(db, &name::OUTPUT_TYPE)
-        .expect("assoc ty value should not exist")
-        .id;
+    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) };
 
@@ -834,10 +835,10 @@ fn closure_fn_trait_output_assoc_ty_value(
     Arc::new(value)
 }
 
-fn get_fn_trait(db: &impl HirDatabase, krate: Crate, fn_trait: super::FnTrait) -> Option<Trait> {
+fn get_fn_trait(db: &impl HirDatabase, krate: Crate, fn_trait: super::FnTrait) -> Option<TraitId> {
     let target = db.lang_item(krate.crate_id, fn_trait.lang_item_name().into())?;
     match target {
-        LangItemTarget::TraitId(t) => Some(t.into()),
+        LangItemTarget::TraitId(t) => Some(t),
         _ => None,
     }
 }