use raw-ptr-addr-of for slice::swap #81160
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use raw-ptr-addr-of for slice::swap Fixes rust-lang#80682
bluss
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Jan 20, 2021
| let pb: *mut T = &mut self[b]; | ||
| // Can't take two mutable loans from one vector, so instead use raw pointers. | ||
| let pa = ptr::raw_mut!(self[a]); | ||
| let pb = ptr::raw_mut!(self[b]); |
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I'm just curious - the reason that this works, is that we use intrinsic indexing of the slice? If we would go through IndexMut, the problem wouldn't be solved (?)
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Yes, indexing a slice directly translates to a MIR instruction without any function calls. This is the same as what we do for arithmetic operators for primitive integers. The trait impls only exist for the type system and generics.
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Fixes #80682