1 files changed, 21 insertions, 12 deletions

diff --git a/crates/ra_hir/src/ty/infer/coerce.rs b/crates/ra_hir/src/ty/infer/coerce.rs
index 0772b9df5..4b53bba73 100644
--- a/crates/ra_hir/src/ty/infer/coerce.rs
+++ b/crates/ra_hir/src/ty/infer/coerce.rs
@@ -4,18 +4,17 @@
 //!
 //! See: https://doc.rust-lang.org/nomicon/coercions.html
 
-use hir_def::resolver::Resolver;
+use hir_def::{lang_item::LangItemTarget, resolver::Resolver};
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
     db::HirDatabase,
-    lang_item::LangItemTarget,
     ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
     Adt, Mutability,
 };
 
-use super::{InferTy, InferenceContext, TypeVarValue};
+use super::{InEnvironment, InferTy, InferenceContext, TypeVarValue};
 
 impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     /// Unify two types, but may coerce the first one to the second one
@@ -50,7 +49,9 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
     ) -> FxHashMap<(TypeCtor, TypeCtor), usize> {
         let krate = resolver.krate().unwrap();
         let impls = match db.lang_item(krate.into(), "coerce_unsized".into()) {
-            Some(LangItemTarget::Trait(trait_)) => db.impls_for_trait(krate.into(), trait_),
+            Some(LangItemTarget::TraitId(trait_)) => {
+                db.impls_for_trait(krate.into(), trait_.into())
+            }
             _ => return FxHashMap::default(),
         };
 
@@ -244,14 +245,17 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 ty_app!(TypeCtor::Adt(Adt::Struct(struct1)), st1),
                 ty_app!(TypeCtor::Adt(Adt::Struct(struct2)), st2),
             ) if struct1 == struct2 => {
-                let fields = struct1.fields(self.db);
-                let (last_field, prev_fields) = fields.split_last()?;
+                let field_tys = self.db.field_types(struct1.id.into());
+                let struct_data = self.db.struct_data(struct1.id.0);
+
+                let mut fields = struct_data.variant_data.fields().iter();
+                let (last_field_id, _data) = fields.next_back()?;
 
                 // Get the generic parameter involved in the last field.
                 let unsize_generic_index = {
                     let mut index = None;
                     let mut multiple_param = false;
-                    last_field.ty(self.db).walk(&mut |ty| match ty {
+                    field_tys[last_field_id].walk(&mut |ty| match ty {
                         &Ty::Param { idx, .. } => {
                             if index.is_none() {
                                 index = Some(idx);
@@ -270,8 +274,8 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
                 // Check other fields do not involve it.
                 let mut multiple_used = false;
-                prev_fields.iter().for_each(|field| {
-                    field.ty(self.db).walk(&mut |ty| match ty {
+                fields.for_each(|(field_id, _data)| {
+                    field_tys[field_id].walk(&mut |ty| match ty {
                         &Ty::Param { idx, .. } if idx == unsize_generic_index => {
                             multiple_used = true
                         }
@@ -316,9 +320,14 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         let canonicalized = self.canonicalizer().canonicalize_ty(from_ty.clone());
         let to_ty = self.resolve_ty_shallow(&to_ty);
         // FIXME: Auto DerefMut
-        for derefed_ty in
-            autoderef::autoderef(self.db, &self.resolver.clone(), canonicalized.value.clone())
-        {
+        for derefed_ty in autoderef::autoderef(
+            self.db,
+            self.resolver.krate(),
+            InEnvironment {
+                value: canonicalized.value.clone(),
+                environment: self.trait_env.clone(),
+            },
+        ) {
             let derefed_ty = canonicalized.decanonicalize_ty(derefed_ty.value);
             match (&*self.resolve_ty_shallow(&derefed_ty), &*to_ty) {
                 // Stop when constructor matches.