add projection_ty_from_predicates query

1 files changed, 4 insertions, 0 deletions

diff --git a/src/librustc_middle/query/mod.rs b/src/librustc_middle/query/mod.rs
index d6836d2ee36..e05752f08f6 100644
--- a/src/librustc_middle/query/mod.rs
+++ b/src/librustc_middle/query/mod.rs
@@ -173,6 +173,10 @@ rustc_queries! {
             desc { |tcx| "finding projection predicates for `{}`", tcx.def_path_str(key) }
         }
 
+        query projection_ty_from_predicates(key: (DefId, DefId)) -> Option<ty::ProjectionTy<'tcx>> {
+            desc { |tcx| "finding projection type inside predicates of `{}`", tcx.def_path_str(key.0) }
+        }
+
         query native_libraries(_: CrateNum) -> Lrc<Vec<NativeLib>> {
             desc { "looking up the native libraries of a linked crate" }
         }