Merge #1515

1515: Trait environment r=matklad a=flodiebold

This adds the environment, i.e. the set of `where` clauses in scope, when solving trait goals. That means that e.g. in
```rust
fn foo<T: SomeTrait>(t: T) {}
```
, we are able to complete methods of `SomeTrait` on the `t`. This affects the trait APIs quite a bit (since every method that needs to be able to solve for some trait needs to get this environment somehow), so I thought I'd do it rather sooner than later ;)

Co-authored-by: Florian Diebold <[email protected]>

1 files changed, 8 insertions, 2 deletions

diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 90c1ae630..c26513871 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -52,6 +52,8 @@ fn deref_by_trait(
 
     // FIXME make the Canonical handling nicer
 
+    let env = super::lower::trait_env(db, resolver);
+
     let projection = super::traits::ProjectionPredicate {
         ty: Ty::Bound(0),
         projection_ty: super::ProjectionTy {
@@ -60,9 +62,13 @@ fn deref_by_trait(
         },
     };
 
-    let canonical = super::Canonical { num_vars: 1 + ty.num_vars, value: projection };
+    let obligation = super::Obligation::Projection(projection);
+
+    let in_env = super::traits::InEnvironment { value: obligation, environment: env };
+
+    let canonical = super::Canonical { num_vars: 1 + ty.num_vars, value: in_env };
 
-    let solution = db.normalize(krate, canonical)?;
+    let solution = db.solve(krate, canonical)?;
 
     match &solution {
         Solution::Unique(vars) => {