async/await: improve obligation errors

[rust.git] / src / librustc_mir / borrow_check / nll / type_check / input_output.rs

diff --git a/src/librustc_mir/borrow_check/nll/type_check/input_output.rs b/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
index 3954d62ad5c77e4f241e1ec9d5cb0f84f8203cbd..99661b1f7370ab888f7b8ff1f1c5f9d2e651bf51 100644 (file)
--- a/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/input_output.rs
@@ -1,7 +1,7 @@
 //! This module contains code to equate the input/output types appearing
 //! in the MIR with the expected input/output types from the function
 //! signature. This requires a bit of processing, as the expected types
-//! are supplied to us before normalization and may contain existential
+//! are supplied to us before normalization and may contain opaque
 //! `impl Trait` instances. In contrast, the input/output types found in
 //! the MIR (specifically, in the special local variables for the
 //! `RETURN_PLACE` the MIR arguments) are always fully normalized (and
@@ -113,8 +113,7 @@ pub(super) fn equate_inputs_and_outputs(
             self.equate_normalized_input_or_output(ur_yield_ty, mir_yield_ty, yield_span);
         }
 
-        // Return types are a bit more complex. They may contain existential `impl Trait`
-        // types.
+        // Return types are a bit more complex. They may contain opaque `impl Trait` types.
         let mir_output_ty = body.local_decls[RETURN_PLACE].ty;
         let output_span = body.local_decls[RETURN_PLACE].source_info.span;
         if let Err(terr) = self.eq_opaque_type_and_type(