mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-22 06:44:35 +00:00
b90277e37b
Add documentation about the memory layout of `Cell` https://github.com/rust-lang/rust/pull/101717 guaranteed the memory layout of `UnsafeCell<T>`. This property (a guaranteed memory layout) can be useful to have on `Cell<T>` as well. (Note that `Cell<u8>` [already doesn't trigger the `improper_ctypes` lint](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=34af59ef60b96d8a8bdaec1d52cb5420) since it is `#[repr(transparent)]`). The concrete use-case is for the crate [`objc2`](https://github.com/madsmtm/objc2) to specify that `Cell<T>` is safe to use as an instance variable when `T` is. Fixes https://github.com/rust-lang/rust/issues/79303. --- I'm unsure if we should specify less, for example say that the `Cell` may have extra restrictions on when it may be accessed, or if that's implicit in the (deliberately minimal) way I've worded it here? |
||
|---|---|---|
| .. | ||
| alloc | ||
| backtrace@07872f28cd | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| portable-simd | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@a0c30f3e3c | ||
| test | ||
| unwind | ||