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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:03 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:03 +0000 |
commit | 64d98f8ee037282c35007b64c2649055c56af1db (patch) | |
tree | 5492bcf97fce41ee1c0b1cc2add283f3e66cdab0 /tests/ui/specialization/issue-33017.rs | |
parent | Adding debian version 1.67.1+dfsg1-1. (diff) | |
download | rustc-64d98f8ee037282c35007b64c2649055c56af1db.tar.xz rustc-64d98f8ee037282c35007b64c2649055c56af1db.zip |
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/ui/specialization/issue-33017.rs')
-rw-r--r-- | tests/ui/specialization/issue-33017.rs | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/tests/ui/specialization/issue-33017.rs b/tests/ui/specialization/issue-33017.rs new file mode 100644 index 000000000..8dbadf58d --- /dev/null +++ b/tests/ui/specialization/issue-33017.rs @@ -0,0 +1,45 @@ +// Test to ensure that trait bounds are properly +// checked on specializable associated types + +#![allow(incomplete_features)] +#![feature(specialization)] + +trait UncheckedCopy: Sized { + type Output: From<Self> + Copy + Into<Self>; +} + +impl<T> UncheckedCopy for T { + default type Output = Self; + //~^ ERROR: the trait bound `T: Copy` is not satisfied +} + +fn unchecked_copy<T: UncheckedCopy>(other: &T::Output) -> T { + (*other).into() +} + +fn bug(origin: String) { + // Turn the String into it's Output type... + // Which we can just do by `.into()`, the assoc type states `From<Self>`. + let origin_output = origin.into(); + + // Make a copy of String::Output, which is a String... + let mut copy: String = unchecked_copy::<String>(&origin_output); + + // Turn the Output type into a String again, + // Which we can just do by `.into()`, the assoc type states `Into<Self>`. + let mut origin: String = origin_output.into(); + + // assert both Strings use the same buffer. + assert_eq!(copy.as_ptr(), origin.as_ptr()); + + // Any use of the copy we made becomes invalid, + drop(origin); + + // OH NO! UB UB UB UB! + copy.push_str(" world!"); + println!("{}", copy); +} + +fn main() { + bug(String::from("hello")); +} |