diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/type_check/mod.rs | 4 | ||||
| -rw-r--r-- | tests/ui/traits/trait-upcasting/dyn-to-dyn-star.rs | 19 |
2 files changed, 21 insertions, 2 deletions
diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 6d05696e146..480d90932b9 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -2120,8 +2120,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { // // Note that other checks (such as denying `dyn Send` -> `dyn // Debug`) are in `rustc_hir_typeck`. - if let ty::Dynamic(src_tty, _src_lt, _) = *src_tail.kind() - && let ty::Dynamic(dst_tty, dst_lt, _) = *dst_tail.kind() + if let ty::Dynamic(src_tty, _src_lt, ty::Dyn) = *src_tail.kind() + && let ty::Dynamic(dst_tty, dst_lt, ty::Dyn) = *dst_tail.kind() && src_tty.principal().is_some() && dst_tty.principal().is_some() { diff --git a/tests/ui/traits/trait-upcasting/dyn-to-dyn-star.rs b/tests/ui/traits/trait-upcasting/dyn-to-dyn-star.rs new file mode 100644 index 00000000000..5936c93efad --- /dev/null +++ b/tests/ui/traits/trait-upcasting/dyn-to-dyn-star.rs @@ -0,0 +1,19 @@ +// While somewhat nonsensical, this is a cast from a wide pointer to a thin pointer. +// Thus, we don't need to check an unsize goal here; there isn't any vtable casting +// happening at all. + +// Regression test for <https://github.com/rust-lang/rust/issues/137579>. + +//@ check-pass + +#![allow(incomplete_features)] +#![feature(dyn_star)] + +trait Foo {} +trait Bar {} + +fn cast(x: *const dyn Foo) { + x as *const dyn* Bar; +} + +fn main() {} |