diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs | 4 |
1 files changed, 4 insertions, 0 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 aed00aecefc..2b3c98db966 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 @@ -491,6 +491,10 @@ fn type_has_partial_eq_impl<'tcx>( // `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`. + // We also do *not* require `const PartialEq`, not even in `const fn`. This violates the model + // that patterns can only do things that the code could also do without patterns, but it is + // needed for backwards compatibility. The actual pattern matching compares primitive values, + // `PartialEq::eq` never gets invoked, so there's no risk of us running non-const code. ( infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation), automatically_derived, |