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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:13 +0000 |
commit | 218caa410aa38c29984be31a5229b9fa717560ee (patch) | |
tree | c54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs | |
parent | Releasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs')
-rw-r--r-- | tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs b/tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs new file mode 100644 index 000000000..721890db4 --- /dev/null +++ b/tests/ui/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs @@ -0,0 +1,66 @@ +// Check that we can manually implement an object-unsafe trait for its trait object. + +// run-pass + +#![feature(object_safe_for_dispatch)] + +trait Bad { + fn stat() -> char { + 'A' + } + fn virt(&self) -> char { + 'B' + } + fn indirect(&self) -> char { + Self::stat() + } +} + +trait Good { + fn good_virt(&self) -> char { + panic!() + } + fn good_indirect(&self) -> char { + panic!() + } +} + +impl<'a> Bad for dyn Bad + 'a { + fn stat() -> char { + 'C' + } + fn virt(&self) -> char { + 'D' + } +} + +struct Struct {} + +impl Bad for Struct {} + +impl Good for Struct {} + +fn main() { + let s = Struct {}; + + let mut res = String::new(); + + // Directly call static. + res.push(Struct::stat()); // "A" + res.push(<dyn Bad>::stat()); // "AC" + + let good: &dyn Good = &s; + + // These look similar enough... + let bad = unsafe { std::mem::transmute::<&dyn Good, &dyn Bad>(good) }; + + // Call virtual. + res.push(s.virt()); // "ACB" + res.push(bad.virt()); // "ACBD" + + // Indirectly call static. + res.push(s.indirect()); // "ACBDA" + res.push(bad.indirect()); // "ACBDAC" + + assert_eq!(&res, "ACBDAC"); +} |