diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/solve/assembly/mod.rs | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs index 73cf15ff94b..68e931aac8c 100644 --- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs @@ -324,6 +324,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { candidates } + /// HACK: `_: Trait` is ambiguous, because it may be satisfied via a builtin rule, + /// object bound, alias bound, etc. We are unable to determine this until we can at + /// least structurally resolve the type one layer. + /// + /// It would also require us to consider all impls of the trait, which is both pretty + /// bad for perf and would also constrain the self type if there is just a single impl. fn self_ty_infer_ambiguity_hack<G: GoalKind<'tcx>>( &mut self, goal: Goal<'tcx, G>, |