refine wording and describe alternatives

This commit is contained in:
Ralf Jung 2022-04-02 10:25:06 -04:00
parent 2d74528c21
commit dd85a7682c

View file

@ -993,9 +993,13 @@ extern "rust-intrinsic" {
///
/// Note that using `transmute` to turn a pointer to a `usize` is (as noted above) [undefined
/// behavior][ub] in `const` contexts. Also outside of consts, this operation might not behave
/// as expected -- this is touching on many unspecified aspects of the Rust memory model. To
/// make sure your code is well-defined, the conversion of pointers to integers and back should
/// always be done explicitly via casts.
/// as expected -- this is touching on many unspecified aspects of the Rust memory model.
/// Depending on what the code is doing, the following alternatives are preferrable to
/// pointer-to-integer transmutation:
/// - If the code just wants to store data of arbitrary type in some buffer and needs to pick a
/// type for that buffer, it can use [`MaybeUninit`][mem::MaybeUninit].
/// - If the code actually wants to work on the address the pointer points to, it can use `as`
/// casts or [`ptr.addr()`][pointer::addr].
///
/// Turning a `*mut T` into an `&mut T`:
///