12 files changed, 38 insertions, 54 deletions

diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 5054189cc..6eafdc8f6 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -40,7 +40,7 @@ impl Diagnostic for MissingFields {
         use std::fmt::Write;
         let mut message = String::from("Missing structure fields:\n");
         for field in &self.missed_fields {
-            write!(message, "- {}\n", field).unwrap();
+            writeln!(message, "- {}", field).unwrap();
         }
         message
     }
diff --git a/crates/ra_hir_ty/src/expr.rs b/crates/ra_hir_ty/src/expr.rs
index f752a9f09..0d11b537c 100644
--- a/crates/ra_hir_ty/src/expr.rs
+++ b/crates/ra_hir_ty/src/expr.rs
@@ -138,7 +138,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
             _ => return,
         };
 
-        if params.len() == 2 && &params[0] == &mismatch.actual {
+        if params.len() == 2 && params[0] == mismatch.actual {
             let (_, source_map) = db.body_with_source_map(self.func.into());
 
             if let Some(source_ptr) = source_map.expr_syntax(id) {
diff --git a/crates/ra_hir_ty/src/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 4a0eabdfc..fb6a51b12 100644
--- a/crates/ra_hir_ty/src/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -26,7 +26,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// Note that it is only possible that one type are coerced to another.
     /// Coercing both types to another least upper bound type is not possible in rustc,
     /// which will simply result in "incompatible types" error.
-    pub(super) fn coerce_merge_branch<'t>(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
+    pub(super) fn coerce_merge_branch(&mut self, ty1: &Ty, ty2: &Ty) -> Ty {
         if self.coerce(ty1, ty2) {
             ty2.clone()
         } else if self.coerce(ty2, ty1) {
@@ -252,15 +252,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 let unsize_generic_index = {
                     let mut index = None;
                     let mut multiple_param = false;
-                    field_tys[last_field_id].value.walk(&mut |ty| match ty {
-                        &Ty::Bound(idx) => {
+                    field_tys[last_field_id].value.walk(&mut |ty| {
+                        if let &Ty::Bound(idx) = ty {
                             if index.is_none() {
                                 index = Some(idx);
                             } else if Some(idx) != index {
                                 multiple_param = true;
                             }
                         }
-                        _ => {}
                     });
 
                     if multiple_param {
diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs
index 0af94ae32..9d5f75625 100644
--- a/crates/ra_hir_ty/src/infer/expr.rs
+++ b/crates/ra_hir_ty/src/infer/expr.rs
@@ -35,8 +35,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() },
             );
         }
-        let ty = self.resolve_ty_as_possible(ty);
-        ty
+        self.resolve_ty_as_possible(ty)
     }
 
     /// Infer type of expression with possibly implicit coerce to the expected type.
@@ -155,8 +154,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 };
                 self.register_obligations_for_call(&callee_ty);
                 self.check_call_arguments(args, &param_tys);
-                let ret_ty = self.normalize_associated_types_in(ret_ty);
-                ret_ty
+                self.normalize_associated_types_in(ret_ty)
             }
             Expr::MethodCall { receiver, args, method_name, generic_args } => self
                 .infer_method_call(tgt_expr, *receiver, &args, &method_name, generic_args.as_ref()),
@@ -280,14 +278,11 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
             Expr::Await { expr } => {
                 let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
-                let ty =
-                    self.resolve_associated_type(inner_ty, self.resolve_future_future_output());
-                ty
+                self.resolve_associated_type(inner_ty, self.resolve_future_future_output())
             }
             Expr::Try { expr } => {
                 let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
-                let ty = self.resolve_associated_type(inner_ty, self.resolve_ops_try_ok());
-                ty
+                self.resolve_associated_type(inner_ty, self.resolve_ops_try_ok())
             }
             Expr::Cast { expr, type_ref } => {
                 let _inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
@@ -611,8 +606,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         self.unify(&expected_receiver_ty, &actual_receiver_ty);
 
         self.check_call_arguments(args, &param_tys);
-        let ret_ty = self.normalize_associated_types_in(ret_ty);
-        ret_ty
+        self.normalize_associated_types_in(ret_ty)
     }
 
     fn check_call_arguments(&mut self, args: &[ExprId], param_tys: &[Ty]) {
diff --git a/crates/ra_hir_ty/src/infer/unify.rs b/crates/ra_hir_ty/src/infer/unify.rs
index 1dc842f40..9c7996572 100644
--- a/crates/ra_hir_ty/src/infer/unify.rs
+++ b/crates/ra_hir_ty/src/infer/unify.rs
@@ -140,13 +140,12 @@ where
 impl<T> Canonicalized<T> {
     pub fn decanonicalize_ty(&self, mut ty: Ty) -> Ty {
         ty.walk_mut_binders(
-            &mut |ty, binders| match ty {
-                &mut Ty::Bound(idx) => {
+            &mut |ty, binders| {
+                if let &mut Ty::Bound(idx) = ty {
                     if idx as usize >= binders && (idx as usize - binders) < self.free_vars.len() {
                         *ty = Ty::Infer(self.free_vars[idx as usize - binders]);
                     }
                 }
-                _ => {}
             },
             0,
         );
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 302bb8aa2..13c5e6c6b 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -763,8 +763,8 @@ pub trait TypeWalk {
         Self: Sized,
     {
         self.walk_mut_binders(
-            &mut |ty, binders| match ty {
-                &mut Ty::Bound(idx) => {
+            &mut |ty, binders| {
+                if let &mut Ty::Bound(idx) = ty {
                     if idx as usize >= binders && (idx as usize - binders) < substs.len() {
                         *ty = substs.0[idx as usize - binders].clone();
                     } else if idx as usize >= binders + substs.len() {
@@ -772,7 +772,6 @@ pub trait TypeWalk {
                         *ty = Ty::Bound(idx - substs.len() as u32);
                     }
                 }
-                _ => {}
             },
             0,
         );
diff --git a/crates/ra_hir_ty/src/op.rs b/crates/ra_hir_ty/src/op.rs
index ae253ca04..54e2bd05a 100644
--- a/crates/ra_hir_ty/src/op.rs
+++ b/crates/ra_hir_ty/src/op.rs
@@ -30,20 +30,18 @@ pub(super) fn binary_op_return_ty(op: BinaryOp, lhs_ty: Ty, rhs_ty: Ty) -> Ty {
 pub(super) fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
     match op {
         BinaryOp::LogicOp(..) => Ty::simple(TypeCtor::Bool),
-        BinaryOp::Assignment { op: None } | BinaryOp::CmpOp(CmpOp::Eq { negated: _ }) => {
-            match lhs_ty {
-                Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
-                    TypeCtor::Int(..)
-                    | TypeCtor::Float(..)
-                    | TypeCtor::Str
-                    | TypeCtor::Char
-                    | TypeCtor::Bool => lhs_ty,
-                    _ => Ty::Unknown,
-                },
-                Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => lhs_ty,
+        BinaryOp::Assignment { op: None } | BinaryOp::CmpOp(CmpOp::Eq { .. }) => match lhs_ty {
+            Ty::Apply(ApplicationTy { ctor, .. }) => match ctor {
+                TypeCtor::Int(..)
+                | TypeCtor::Float(..)
+                | TypeCtor::Str
+                | TypeCtor::Char
+                | TypeCtor::Bool => lhs_ty,
                 _ => Ty::Unknown,
-            }
-        }
+            },
+            Ty::Infer(InferTy::IntVar(..)) | Ty::Infer(InferTy::FloatVar(..)) => lhs_ty,
+            _ => Ty::Unknown,
+        },
         BinaryOp::ArithOp(ArithOp::Shl) | BinaryOp::ArithOp(ArithOp::Shr) => Ty::Unknown,
         BinaryOp::CmpOp(CmpOp::Ord { .. })
         | BinaryOp::Assignment { op: Some(_) }
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 1a31b587b..c794f7b84 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -86,15 +86,14 @@ impl TestDB {
     pub fn diagnostics(&self) -> String {
         let mut buf = String::new();
         let crate_graph = self.crate_graph();
-        for krate in crate_graph.iter().next() {
+        for krate in crate_graph.iter() {
             let crate_def_map = self.crate_def_map(krate);
 
             let mut fns = Vec::new();
             for (module_id, _) in crate_def_map.modules.iter() {
                 for decl in crate_def_map[module_id].scope.declarations() {
-                    match decl {
-                        ModuleDefId::FunctionId(f) => fns.push(f),
-                        _ => (),
+                    if let ModuleDefId::FunctionId(f) = decl {
+                        fns.push(f)
                     }
                 }
 
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index d1f10e675..240cc03a2 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -101,9 +101,9 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
                 (src_ptr.value.range(), node.text().to_string().replace("\n", " "))
             };
             let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
-            write!(
+            writeln!(
                 acc,
-                "{}{} '{}': {}\n",
+                "{}{} '{}': {}",
                 macro_prefix,
                 range,
                 ellipsize(text, 15),
@@ -118,9 +118,9 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
             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!(
+                writeln!(
                     acc,
-                    "{}{}: expected {}, got {}\n",
+                    "{}{}: expected {}, got {}",
                     macro_prefix,
                     range,
                     mismatch.expected.display(&db),
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index ff8e75b48..e83449957 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -248,12 +248,9 @@ fn solution_from_chalk(
         let value = subst
             .value
             .into_iter()
-            .map(|p| {
-                let ty = match p.ty() {
-                    Some(ty) => from_chalk(db, ty.clone()),
-                    None => unimplemented!(),
-                };
-                ty
+            .map(|p| match p.ty() {
+                Some(ty) => from_chalk(db, ty.clone()),
+                None => unimplemented!(),
             })
             .collect();
         let result = Canonical { value, num_vars: subst.binders.len() };
diff --git a/crates/ra_hir_ty/src/traits/builtin.rs b/crates/ra_hir_ty/src/traits/builtin.rs
index 67120abf6..a537420a5 100644
--- a/crates/ra_hir_ty/src/traits/builtin.rs
+++ b/crates/ra_hir_ty/src/traits/builtin.rs
@@ -122,7 +122,7 @@ fn closure_fn_trait_impl_datum(
         substs: Substs::build_for_def(db, trait_).push(self_ty).push(arg_ty).build(),
     };
 
-    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data.clone());
+    let output_ty_id = AssocTyValue::ClosureFnTraitImplOutput(data);
 
     BuiltinImplData {
         num_vars: num_args as usize + 1,
@@ -137,7 +137,7 @@ fn closure_fn_trait_output_assoc_ty_value(
     krate: CrateId,
     data: super::ClosureFnTraitImplData,
 ) -> BuiltinImplAssocTyValueData {
-    let impl_ = Impl::ClosureFnTraitImpl(data.clone());
+    let impl_ = Impl::ClosureFnTraitImpl(data);
 
     let num_args: u16 = match &db.body(data.def)[data.expr] {
         Expr::Lambda { args, .. } => args.len() as u16,
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index 306909ec2..1bdf13e48 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -409,8 +409,7 @@ where
     fn to_chalk(self, db: &impl HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
         let parameter = chalk_ir::ParameterKind::Ty(chalk_ir::UniverseIndex::ROOT);
         let value = self.value.to_chalk(db);
-        let canonical = chalk_ir::Canonical { value, binders: vec![parameter; self.num_vars] };
-        canonical
+        chalk_ir::Canonical { value, binders: vec![parameter; self.num_vars] }
     }
 
     fn from_chalk(db: &impl HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {