diff options
| -rw-r--r-- | compiler/rustc_builtin_macros/src/deriving/generic/mod.rs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs index 0f51b26de09..9865b6a72ee 100644 --- a/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs +++ b/compiler/rustc_builtin_macros/src/deriving/generic/mod.rs @@ -1149,8 +1149,9 @@ impl<'a> MethodDef<'a> { let unify_fieldless_variants = self.fieldless_variants_strategy == FieldlessVariantsStrategy::Unify; - // For zero-variant enum, this function body is unreachable. - // Generate `match *self {}`. + // For zero-variant enum, this function body is unreachable. Generate + // `match *self {}`. This produces machine code identical to `unsafe { + // core::intrinsics::unreachable() }` while being safe and stable. if variants.is_empty() { selflike_args.truncate(1); let match_arg = cx.expr_deref(span, selflike_args.pop().unwrap()); |