Add Show and Clone trait to arrays
#18951
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Due to not being able to parametrize over array sizes, `Clone` is only implemented for element types that are `Copy`able.
There was a problem hiding this comment.
You should be able to implement for non-Copy Ts unsafely:
fn clone(&self) -> [T, ..$N] {
let mut cloned: [T, ..$N] = unsafe { mem::zeroed() };
for i in range(0, $N) {
cloned[i] = x[i].clone();
}
cloned
}I think this is safe with regards to destructors and clone() failing but someone else should confirm. :-)
Contributor
There was a problem hiding this comment.
That's not safe because clone can throw, and calling a destructor on zeroed memory is not well-defined. Drop flags are an implementation detail and removing them is planned. It is possible to write this code correctly, but you need to handle the unwinding case manually.
Contributor
There was a problem hiding this comment.
Exceptions are just plain awful.
Contributor
|
cc @aturon I'm assuming there'd be no objections, particularly as these impls are marked unstable. |
Contributor
|
Yep, LGTM |
lnicola
pushed a commit
to lnicola/rust
that referenced
this pull request
Jan 20, 2025
Add missing `#[rust_analyzer::rust_fixture]` annotations
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Due to not being able to parametrize over array sizes,
Cloneis onlyimplemented for element types that are
Copyable.