diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/select/confirmation.rs | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index 21c158fd0fd..ee41d840bae 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -601,10 +601,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { debug!(?obligation, "confirm_fn_pointer_candidate"); let tcx = self.tcx(); - let self_ty = self + + let Some(self_ty) = self .infcx - .shallow_resolve(obligation.self_ty().no_bound_vars()) - .expect("fn pointer should not capture bound vars from predicate"); + .shallow_resolve(obligation.self_ty().no_bound_vars()) else + { + // FIXME: Ideally we'd support `for<'a> fn(&'a ()): Fn(&'a ())`, + // but we do not currently. Luckily, such a bound is not + // particularly useful, so we don't expect users to write + // them often. + return Err(SelectionError::Unimplemented); + }; + let sig = self_ty.fn_sig(tcx); let trait_ref = closure_trait_ref_and_return_type( tcx, |