diff options
| -rw-r--r-- | compiler/rustc_typeck/src/check/compare_method.rs | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs index 1152a2477a2..13a96df77b6 100644 --- a/compiler/rustc_typeck/src/check/compare_method.rs +++ b/compiler/rustc_typeck/src/check/compare_method.rs @@ -295,12 +295,26 @@ pub(super) fn compare_predicates_and_trait_impl_trait_tys<'tcx>( // type would be more appropriate. In other places we have a `Vec<Span>` // corresponding to their `Vec<Predicate>`, but we don't have that here. // Fixing this would improve the output of test `issue-83765.rs`. - let sub_result = infcx + let mut result = infcx .at(&cause, param_env) .sup(trait_fty, impl_fty) .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok)); - if let Err(terr) = sub_result { + // HACK(RPITIT): #101614. When we are trying to infer the hidden types for + // RPITITs, we need to equate the output tys instead of just subtyping. If + // we just use `sup` above, we'll end up `&'static str <: _#1t`, which causes + // us to infer `_#1t = #'_#2r str`, where `'_#2r` is unconstrained, which gets + // fixed up to `ReEmpty`, and which is certainly not what we want. + if trait_fty.has_infer_types() { + result = result.and_then(|()| { + infcx + .at(&cause, param_env) + .eq(trait_sig.output(), impl_sig.output()) + .map(|infer_ok| ocx.register_infer_ok_obligations(infer_ok)) + }); + } + + if let Err(terr) = result { debug!("sub_types failed: impl ty {:?}, trait ty {:?}", impl_fty, trait_fty); let (impl_err_span, trait_err_span) = @@ -445,6 +459,7 @@ pub(super) fn compare_predicates_and_trait_impl_trait_tys<'tcx>( region } }); + debug!(%ty); collected_tys.insert(def_id, ty); } Err(err) => { |