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</pre><pre class="rust"><code><span class="kw">use crate</span>::{Pod, Zeroable};
<span class="doccomment">/// Marker trait for &quot;plain old data&quot; 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&#39;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&#39;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&#39;s probably more, don&#39;t mess it up (I mean it).
</span><span class="kw">pub unsafe trait </span>AnyBitPattern:
Zeroable + Sized + Copy + <span class="lifetime">&#39;static
</span>{
}
<span class="kw">unsafe impl</span>&lt;T: Pod&gt; AnyBitPattern <span class="kw">for </span>T {}
<span class="attribute">#[cfg(feature = <span class="string">&quot;zeroable_maybe_uninit&quot;</span>)]
</span><span class="kw">unsafe impl</span>&lt;T&gt; AnyBitPattern <span class="kw">for </span>core::mem::MaybeUninit&lt;T&gt; <span class="kw">where </span>T: AnyBitPattern
{}
</code></pre></div>
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