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Auto merge of #86433 - paolobarbolini:string-overlapping, r=m-ou-se

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Use `copy_nonoverlapping` to copy `bytes` in `String::insert_bytes`

The second copy could be made using `ptr::copy_nonoverlapping` instead of `ptr::copy`, since aliasing won't allow `self` and `bytes` to overlap. LLVM even seems to recognize this, [replacing the second `memmove` with a `memcopy`](https://rust.godbolt.org/z/Yoaa6rrGn), so this makes it so it's always applied.
This commit is contained in:
bors 2021-06-19 23:10:55 +00:00
commit f639657fe4
1 changed files with 1 additions and 1 deletions
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library/alloc/src/string.rs
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@ -1451,7 +1451,7 @@ impl String {
unsafe {
ptr::copy(self.vec.as_ptr().add(idx), self.vec.as_mut_ptr().add(idx + amt), len - idx);
ptr::copy(bytes.as_ptr(), self.vec.as_mut_ptr().add(idx), amt);
ptr::copy_nonoverlapping(bytes.as_ptr(), self.vec.as_mut_ptr().add(idx), amt);
self.vec.set_len(len + amt);
}
}