diff options
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index a390691c675..ed20ed4a84f 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -179,7 +179,7 @@ impl<'tcx> ConstToPat<'tcx> { } if let Some(non_sm_ty) = structural { - if !self.type_may_have_partial_eq_impl(cv.ty()) { + if !self.type_has_partial_eq_impl(cv.ty()) { if let ty::Adt(def, ..) = non_sm_ty.kind() { if def.is_union() { let err = UnionPattern { span: self.span }; @@ -244,7 +244,7 @@ impl<'tcx> ConstToPat<'tcx> { // Always check for `PartialEq`, even if we emitted other lints. (But not if there were // any errors.) This ensures it shows up in cargo's future-compat reports as well. - if !self.type_may_have_partial_eq_impl(cv.ty()) { + if !self.type_has_partial_eq_impl(cv.ty()) { self.tcx().emit_spanned_lint( lint::builtin::MATCH_WITHOUT_PARTIAL_EQ, self.id, @@ -258,7 +258,7 @@ impl<'tcx> ConstToPat<'tcx> { } #[instrument(level = "trace", skip(self), ret)] - fn type_may_have_partial_eq_impl(&self, ty: Ty<'tcx>) -> bool { + fn type_has_partial_eq_impl(&self, ty: Ty<'tcx>) -> bool { // double-check there even *is* a semantic `PartialEq` to dispatch to. // // (If there isn't, then we can safely issue a hard @@ -273,8 +273,13 @@ impl<'tcx> ConstToPat<'tcx> { ty::TraitRef::new(self.tcx(), partial_eq_trait_id, [ty, ty]), ); - // FIXME: should this call a `predicate_must_hold` variant instead? - self.infcx.predicate_may_hold(&partial_eq_obligation) + // This *could* accept a type that isn't actually `PartialEq`, because region bounds get + // ignored. However that should be pretty much impossible since consts that do not depend on + // generics can only mention the `'static` lifetime, and how would one have a type that's + // `PartialEq` for some lifetime but *not* for `'static`? If this ever becomes a problem + // we'll need to leave some sort of trace of this requirement in the MIR so that borrowck + // can ensure that the type really implements `PartialEq`. + self.infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation) } fn field_pats( |