Implement completion for the .await syntax

1 files changed, 15 insertions, 1 deletions

diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index d421bf9ef..2e2f88138 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -15,7 +15,7 @@ use crate::{
     resolve::Resolver,
     traits::TraitItem,
     ty::primitive::{FloatBitness, UncertainFloatTy, UncertainIntTy},
-    ty::{Ty, TypeCtor},
+    ty::{Ty, TypeCtor, traits::Solution},
     Crate, Function, HirDatabase, Module, Name, Trait,
 };
 
@@ -255,6 +255,20 @@ fn iterate_inherent_methods<T>(
     None
 }
 
+pub(crate) fn implements_trait(ty: &Canonical<Ty>, db: &impl HirDatabase, resolver: &Resolver, krate: Crate, trait_: Trait) -> bool {
+    let env = lower::trait_env(db, resolver);
+    let goal = generic_implements_goal(db, env.clone(), trait_, ty.clone());
+    let solution = db.trait_solve(krate, goal);
+
+    if let Some(solution) = solution {
+        if let Solution::Unique(_) = solution {
+            return true
+        }
+    }
+
+    false
+}
+
 impl Ty {
     // This would be nicer if it just returned an iterator, but that runs into
     // lifetime problems, because we need to borrow temp `CrateImplBlocks`.