diff options
Diffstat (limited to 'vendor/bytemuck/src/anybitpattern.rs')
| -rw-r--r-- | vendor/bytemuck/src/anybitpattern.rs | 61 |
1 files changed, 0 insertions, 61 deletions
diff --git a/vendor/bytemuck/src/anybitpattern.rs b/vendor/bytemuck/src/anybitpattern.rs deleted file mode 100644 index a759738..0000000 --- a/vendor/bytemuck/src/anybitpattern.rs +++ /dev/null @@ -1,61 +0,0 @@ -use crate::{Pod, Zeroable}; - -/// Marker trait for "plain old data" types that are valid for any bit pattern. -/// -/// The requirements for this is very similar to [`Pod`], -/// except that the type can allow uninit (or padding) bytes. -/// This limits what you can do with a type of this kind, but also broadens the -/// included types to `repr(C)` `struct`s that contain padding as well as -/// `union`s. Notably, you can only cast *immutable* references and *owned* -/// values into [`AnyBitPattern`] types, not *mutable* references. -/// -/// [`Pod`] is a subset of [`AnyBitPattern`], meaning that any `T: Pod` is also -/// [`AnyBitPattern`] but any `T: AnyBitPattern` is not necessarily [`Pod`]. -/// -/// [`AnyBitPattern`] is a subset of [`Zeroable`], meaning that any `T: -/// AnyBitPattern` is also [`Zeroable`], but any `T: Zeroable` is not -/// necessarily [`AnyBitPattern ] -/// -/// # Derive -/// -/// A `#[derive(AnyBitPattern)]` macro is provided under the `derive` feature -/// flag which will automatically validate the requirements of this trait and -/// implement the trait for you for both structs and enums. This is the -/// recommended method for implementing the trait, however it's also possible to -/// do manually. If you implement it manually, you *must* carefully follow the -/// below safety rules. -/// -/// * *NOTE: even `C-style`, fieldless enums are intentionally **excluded** from -/// this trait, since it is **unsound** for an enum to have a discriminant value -/// that is not one of its defined variants. -/// -/// # Safety -/// -/// Similar to [`Pod`] except we disregard the rule about it must not contain -/// uninit bytes. Still, this is a quite strong guarantee about a type, so *be -/// careful* when implementing it manually. -/// -/// * The type must be inhabited (eg: no -/// [Infallible](core::convert::Infallible)). -/// * The type must be valid for any bit pattern of its backing memory. -/// * Structs need to have all fields also be `AnyBitPattern`. -/// * It is disallowed for types to contain pointer types, `Cell`, `UnsafeCell`, -/// atomics, and any other forms of interior mutability. -/// * More precisely: A shared reference to the type must allow reads, and -/// *only* reads. RustBelt's separation logic is based on the notion that a -/// type is allowed to define a sharing predicate, its own invariant that must -/// hold for shared references, and this predicate is the reasoning that allow -/// it to deal with atomic and cells etc. We require the sharing predicate to -/// be trivial and permit only read-only access. -/// * There's probably more, don't mess it up (I mean it). -pub unsafe trait AnyBitPattern: - Zeroable + Sized + Copy + 'static -{ -} - -unsafe impl<T: Pod> AnyBitPattern for T {} - -#[cfg(feature = "zeroable_maybe_uninit")] -#[cfg_attr(feature = "nightly_docs", doc(cfg(feature = "zeroable_maybe_uninit")))] -unsafe impl<T> AnyBitPattern for core::mem::MaybeUninit<T> where T: AnyBitPattern -{} |