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Diffstat (limited to 'crates/hir-ty/src/mir/lower.rs')
-rw-r--r--crates/hir-ty/src/mir/lower.rs12
1 files changed, 6 insertions, 6 deletions
diff --git a/crates/hir-ty/src/mir/lower.rs b/crates/hir-ty/src/mir/lower.rs
index 2cb29b4ab9..800e490e9a 100644
--- a/crates/hir-ty/src/mir/lower.rs
+++ b/crates/hir-ty/src/mir/lower.rs
@@ -1742,17 +1742,17 @@ fn cast_kind(source_ty: &Ty, target_ty: &Ty) -> Result<CastKind> {
(TyKind::Raw(_, a) | TyKind::Ref(_, _, a), TyKind::Raw(_, b) | TyKind::Ref(_, _, b)) => {
CastKind::Pointer(if a == b {
PointerCast::MutToConstPointer
- } else if matches!(a.kind(Interner), TyKind::Slice(_) | TyKind::Str)
- && matches!(b.kind(Interner), TyKind::Slice(_) | TyKind::Str)
+ } else if matches!(b.kind(Interner), TyKind::Slice(_))
+ && matches!(a.kind(Interner), TyKind::Array(_, _))
+ || matches!(b.kind(Interner), TyKind::Dyn(_))
{
- // slice to slice cast is no-op (metadata is not touched), so we use this
- PointerCast::MutToConstPointer
- } else if matches!(b.kind(Interner), TyKind::Slice(_) | TyKind::Dyn(_)) {
PointerCast::Unsize
} else if matches!(a.kind(Interner), TyKind::Slice(s) if s == b) {
PointerCast::ArrayToPointer
} else {
- // cast between two sized pointer, like *const i32 to *const i8. There is no specific variant
+ // cast between two sized pointer, like *const i32 to *const i8, or two unsized pointer, like
+ // slice to slice, slice to str, ... . These are no-ops (even in the unsized case, no metadata
+ // will be touched) but there is no specific variant
// for it in `PointerCast` so we use `MutToConstPointer`
PointerCast::MutToConstPointer
})