4 files changed, 21 insertions, 28 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index a177cebca..346118350 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -21,8 +21,8 @@ use hir_expand::{
     MacroDefId,
 };
 use hir_ty::{
-    autoderef, display::HirFormatter, expr::ExprValidator, ApplicationTy, Canonical, InEnvironment,
-    TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
+    autoderef, display::HirFormatter, expr::ExprValidator, method_resolution::implements_trait,
+    ApplicationTy, Canonical, InEnvironment, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk,
 };
 use ra_db::{CrateId, Edition, FileId};
 use ra_prof::profile;
@@ -878,6 +878,22 @@ impl Type {
         }
     }
 
+    /// Checks that particular type `ty` implements `std::future::Future`.
+    /// This function is used in `.await` syntax completion.
+    pub fn impls_future(&self, db: &impl HirDatabase) -> bool {
+        let krate = self.krate;
+
+        let std_future_trait =
+            db.lang_item(krate, "future_trait".into()).and_then(|it| it.as_trait());
+        let std_future_trait = match std_future_trait {
+            Some(it) => it,
+            None => return false,
+        };
+
+        let canonical_ty = Canonical { value: self.ty.value.clone(), num_vars: 0 };
+        implements_trait(&canonical_ty, db, self.ty.environment.clone(), krate, std_future_trait)
+    }
+
     // FIXME: this method is broken, as it doesn't take closures into account.
     pub fn as_callable(&self) -> Option<CallableDef> {
         Some(self.ty.value.as_callable()?.0)
diff --git a/crates/ra_hir/src/source_analyzer.rs b/crates/ra_hir/src/source_analyzer.rs
index bd5ef1466..3df48842d 100644
--- a/crates/ra_hir/src/source_analyzer.rs
+++ b/crates/ra_hir/src/source_analyzer.rs
@@ -21,10 +21,7 @@ use hir_def::{
 use hir_expand::{
     hygiene::Hygiene, name::AsName, AstId, HirFileId, InFile, MacroCallId, MacroCallKind,
 };
-use hir_ty::{
-    method_resolution::{self, implements_trait},
-    Canonical, InEnvironment, InferenceResult, TraitEnvironment, Ty,
-};
+use hir_ty::{method_resolution, Canonical, InEnvironment, InferenceResult, TraitEnvironment, Ty};
 use ra_prof::profile;
 use ra_syntax::{
     ast::{self, AstNode},
@@ -395,25 +392,6 @@ impl SourceAnalyzer {
         )
     }
 
-    /// Checks that particular type `ty` implements `std::future::Future`.
-    /// This function is used in `.await` syntax completion.
-    pub fn impls_future(&self, db: &impl HirDatabase, ty: Type) -> bool {
-        let krate = match self.resolver.krate() {
-            Some(krate) => krate,
-            None => return false,
-        };
-
-        let std_future_trait =
-            db.lang_item(krate, "future_trait".into()).and_then(|it| it.as_trait());
-        let std_future_trait = match std_future_trait {
-            Some(it) => it,
-            None => return false,
-        };
-
-        let canonical_ty = Canonical { value: ty.ty.value, num_vars: 0 };
-        implements_trait(&canonical_ty, db, &self.resolver, krate, std_future_trait)
-    }
-
     pub fn expand(
         &self,
         db: &impl HirDatabase,
diff --git a/crates/ra_hir_ty/src/method_resolution.rs b/crates/ra_hir_ty/src/method_resolution.rs
index 888dc3116..55435e6ea 100644
--- a/crates/ra_hir_ty/src/method_resolution.rs
+++ b/crates/ra_hir_ty/src/method_resolution.rs
@@ -465,7 +465,7 @@ fn transform_receiver_ty(
 pub fn implements_trait(
     ty: &Canonical<Ty>,
     db: &impl HirDatabase,
-    resolver: &Resolver,
+    env: Arc<TraitEnvironment>,
     krate: CrateId,
     trait_: TraitId,
 ) -> bool {
@@ -474,7 +474,6 @@ pub fn implements_trait(
         // anyway, but currently Chalk doesn't implement `dyn/impl Trait` yet
         return true;
     }
-    let env = TraitEnvironment::lower(db, resolver);
     let goal = generic_implements_goal(db, env, trait_, ty.clone());
     let solution = db.trait_solve(krate.into(), goal);
 
diff --git a/crates/ra_ide/src/completion/complete_dot.rs b/crates/ra_ide/src/completion/complete_dot.rs
index fe02e36b3..9ab43644e 100644
--- a/crates/ra_ide/src/completion/complete_dot.rs
+++ b/crates/ra_ide/src/completion/complete_dot.rs
@@ -27,7 +27,7 @@ pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
     complete_methods(acc, ctx, &receiver_ty);
 
     // Suggest .await syntax for types that implement Future trait
-    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
+    if receiver_ty.impls_future(ctx.db) {
         CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
             .detail("expr.await")
             .insert_text("await")