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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/array-slice-vec/variance-vec-covariant.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/array-slice-vec/variance-vec-covariant.rs')
-rw-r--r-- | src/test/ui/array-slice-vec/variance-vec-covariant.rs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/test/ui/array-slice-vec/variance-vec-covariant.rs b/src/test/ui/array-slice-vec/variance-vec-covariant.rs new file mode 100644 index 000000000..d7e64132f --- /dev/null +++ b/src/test/ui/array-slice-vec/variance-vec-covariant.rs @@ -0,0 +1,20 @@ +// run-pass + +// Test that vec is now covariant in its argument type. + +#![allow(dead_code)] + +fn foo<'a,'b>(v1: Vec<&'a i32>, v2: Vec<&'b i32>) -> i32 { + bar(v1, v2).cloned().unwrap_or(0) // only type checks if we can intersect 'a and 'b +} + +fn bar<'c>(v1: Vec<&'c i32>, v2: Vec<&'c i32>) -> Option<&'c i32> { + v1.get(0).cloned().or_else(|| v2.get(0).cloned()) +} + +fn main() { + let x = 22; + let y = 44; + assert_eq!(foo(vec![&x], vec![&y]), 22); + assert_eq!(foo(vec![&y], vec![&x]), 44); +} |