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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/traits/assignability-trait.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/traits/assignability-trait.rs')
-rw-r--r-- | src/test/ui/traits/assignability-trait.rs | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/test/ui/traits/assignability-trait.rs b/src/test/ui/traits/assignability-trait.rs new file mode 100644 index 000000000..a8547c1d2 --- /dev/null +++ b/src/test/ui/traits/assignability-trait.rs @@ -0,0 +1,47 @@ +// run-pass +#![allow(non_camel_case_types)] + +// Tests that type assignability is used to search for instances when +// making method calls, but only if there aren't any matches without +// it. + +trait iterable<A> { + fn iterate<F>(&self, blk: F) -> bool where F: FnMut(&A) -> bool; +} + +impl<'a,A> iterable<A> for &'a [A] { + fn iterate<F>(&self, f: F) -> bool where F: FnMut(&A) -> bool { + self.iter().all(f) + } +} + +impl<A> iterable<A> for Vec<A> { + fn iterate<F>(&self, f: F) -> bool where F: FnMut(&A) -> bool { + self.iter().all(f) + } +} + +fn length<A, T: iterable<A>>(x: T) -> usize { + let mut len = 0; + x.iterate(|_y| { + len += 1; + true + }); + return len; +} + +pub fn main() { + let x: Vec<isize> = vec![0,1,2,3]; + // Call a method + x.iterate(|y| { assert_eq!(x[*y as usize], *y); true }); + // Call a parameterized function + assert_eq!(length(x.clone()), x.len()); + // Call a parameterized function, with type arguments that require + // a borrow + assert_eq!(length::<isize, &[isize]>(&*x), x.len()); + + // Now try it with a type that *needs* to be borrowed + let z = [0,1,2,3]; + // Call a parameterized function + assert_eq!(length::<isize, &[isize]>(&z), z.len()); +} |