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Diffstat (limited to '')
-rw-r--r-- | compiler/rustc_infer/src/infer/equate.rs | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/compiler/rustc_infer/src/infer/equate.rs b/compiler/rustc_infer/src/infer/equate.rs index 3b1798ca7..59728148a 100644 --- a/compiler/rustc_infer/src/infer/equate.rs +++ b/compiler/rustc_infer/src/infer/equate.rs @@ -110,6 +110,25 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> { .obligations, ); } + // Optimization of GeneratorWitness relation since we know that all + // free regions are replaced with bound regions during construction. + // This greatly speeds up equating of GeneratorWitness. + (&ty::GeneratorWitness(a_types), &ty::GeneratorWitness(b_types)) => { + let a_types = infcx.tcx.anonymize_bound_vars(a_types); + let b_types = infcx.tcx.anonymize_bound_vars(b_types); + if a_types.bound_vars() == b_types.bound_vars() { + let (a_types, b_types) = infcx.replace_bound_vars_with_placeholders( + a_types.map_bound(|a_types| (a_types, b_types.skip_binder())), + ); + for (a, b) in std::iter::zip(a_types, b_types) { + self.relate(a, b)?; + } + } else { + return Err(ty::error::TypeError::Sorts(ty::relate::expected_found( + self, a, b, + ))); + } + } _ => { self.fields.infcx.super_combine_tys(self, a, b)?; |