diff options
| -rw-r--r-- | src/librustc_mir/borrow_check/nll/type_check/input_output.rs | 5 |
1 files changed, 4 insertions, 1 deletions
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 4db8e3c793d..9e88a632f5c 100644 --- a/src/librustc_mir/borrow_check/nll/type_check/input_output.rs +++ b/src/librustc_mir/borrow_check/nll/type_check/input_output.rs @@ -134,7 +134,10 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> { None }); - // Finally + // Finally, if we instantiated the anon types successfully, we + // have to solve any bounds (e.g., `-> impl Iterator` needs to + // prove that `T: Iterator` where `T` is the type we + // instantiated it with). if let Some(anon_type_map) = anon_type_map { self.fully_perform_op(start_position.at_self(), |_cx| { infcx.constrain_anon_types(&anon_type_map, universal_regions); |