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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/deriving/deriving-copyclone.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/ui/deriving/deriving-copyclone.rs')
-rw-r--r-- | src/test/ui/deriving/deriving-copyclone.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/test/ui/deriving/deriving-copyclone.rs b/src/test/ui/deriving/deriving-copyclone.rs new file mode 100644 index 000000000..f8403b1fe --- /dev/null +++ b/src/test/ui/deriving/deriving-copyclone.rs @@ -0,0 +1,38 @@ +// run-pass +//! Test that #[derive(Copy, Clone)] produces a shallow copy +//! even when a member violates RFC 1521 + +use std::sync::atomic::{AtomicBool, Ordering}; + +/// A struct that pretends to be Copy, but actually does something +/// in its Clone impl +#[derive(Copy)] +struct Liar; + +/// Static cooperating with the rogue Clone impl +static CLONED: AtomicBool = AtomicBool::new(false); + +impl Clone for Liar { + fn clone(&self) -> Self { + // this makes Clone vs Copy observable + CLONED.store(true, Ordering::SeqCst); + + *self + } +} + +/// This struct is actually Copy... at least, it thinks it is! +#[derive(Copy, Clone)] +struct Innocent(#[allow(unused_tuple_struct_fields)] Liar); + +impl Innocent { + fn new() -> Self { + Innocent(Liar) + } +} + +fn main() { + let _ = Innocent::new().clone(); + // if Innocent was byte-for-byte copied, CLONED will still be false + assert!(!CLONED.load(Ordering::SeqCst)); +} |