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Merge pull request #1417 from joshlf/patch-3 

Guarantee that raw pointer conversions preserve slice element count
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Eric Huss 2023-11-04 17:19:39 +00:00 committed by GitHub
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10
src/expressions/operator-expr.md
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@ -478,6 +478,16 @@ unsafe {
assert_eq!(values[1], 3);
```
#### Slice DST pointer to pointer cast
For slice types like `[T]` and `[U]`, the raw pointer types `*const [T]`, `*mut [T]`,
`*const [U]`, and `*mut [U]` encode the number of elements in this slice. Casts between
these raw pointer types preserve the number of elements. Note that, as a consequence,
such casts do *not* necessarily preserve the size of the pointer's referent (e.g.,
casting `*const [u16]` to `*const [u8]` will result in a raw pointer which refers to an
object of half the size of the original). The same holds for `str` and any compound type
whose unsized tail is a slice type, such as struct `Foo(i32, [u8])` or `(u64, Foo)`.
## Assignment expressions
> **<sup>Syntax</sup>**\