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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/destructuring-assignment/warn-unused-duplication.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/destructuring-assignment/warn-unused-duplication.rs')
-rw-r--r-- | src/test/ui/destructuring-assignment/warn-unused-duplication.rs | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/destructuring-assignment/warn-unused-duplication.rs b/src/test/ui/destructuring-assignment/warn-unused-duplication.rs new file mode 100644 index 000000000..390f44b8a --- /dev/null +++ b/src/test/ui/destructuring-assignment/warn-unused-duplication.rs @@ -0,0 +1,21 @@ +// run-pass + +#![warn(unused_assignments)] + +fn main() { + let mut a; + // Assignment occurs left-to-right. + // However, we emit warnings when this happens, so it is clear that this is happening. + (a, a) = (0, 1); //~ WARN value assigned to `a` is never read + assert_eq!(a, 1); + + // We can't always tell when a variable is being assigned to twice, which is why we don't try + // to emit an error, which would be fallible. + let mut x = 1; + (*foo(&mut x), *foo(&mut x)) = (5, 6); + assert_eq!(x, 6); +} + +fn foo<'a>(x: &'a mut u32) -> &'a mut u32 { + x +} |