| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/bytemuck-1.13.1/src/checked.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>checked.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../bytemuck/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../bytemuck/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| <span id="523">523</span> |
| <span id="524">524</span> |
| <span id="525">525</span> |
| <span id="526">526</span> |
| <span id="527">527</span> |
| </pre><pre class="rust"><code><span class="doccomment">//! Checked versions of the casting functions exposed in crate root |
| //! that support [`CheckedBitPattern`] types. |
| |
| </span><span class="kw">use crate</span>::{ |
| internal::{<span class="self">self</span>, something_went_wrong}, |
| AnyBitPattern, NoUninit, |
| }; |
| |
| <span class="doccomment">/// A marker trait that allows types that have some invalid bit patterns to be |
| /// used in places that otherwise require [`AnyBitPattern`] or [`Pod`] types by |
| /// performing a runtime check on a perticular set of bits. This is particularly |
| /// useful for types like fieldless ('C-style') enums, [`char`], bool, and |
| /// structs containing them. |
| /// |
| /// To do this, we define a `Bits` type which is a type with equivalent layout |
| /// to `Self` other than the invalid bit patterns which disallow `Self` from |
| /// being [`AnyBitPattern`]. This `Bits` type must itself implement |
| /// [`AnyBitPattern`]. Then, we implement a function that checks whether a |
| /// certain instance of the `Bits` is also a valid bit pattern of `Self`. If |
| /// this check passes, then we can allow casting from the `Bits` to `Self` (and |
| /// therefore, any type which is able to be cast to `Bits` is also able to be |
| /// cast to `Self`). |
| /// |
| /// [`AnyBitPattern`] is a subset of [`CheckedBitPattern`], meaning that any `T: |
| /// AnyBitPattern` is also [`CheckedBitPattern`]. This means you can also use |
| /// any [`AnyBitPattern`] type in the checked versions of casting functions in |
| /// this module. If it's possible, prefer implementing [`AnyBitPattern`] for |
| /// your type directly instead of [`CheckedBitPattern`] as it gives greater |
| /// flexibility. |
| /// |
| /// # Derive |
| /// |
| /// A `#[derive(CheckedBitPattern)]` 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 enums and structs. This is |
| /// the recommended method for implementing the trait, however it's also |
| /// possible to do manually. |
| /// |
| /// # Example |
| /// |
| /// If manually implementing the trait, we can do something like so: |
| /// |
| /// ```rust |
| /// use bytemuck::{CheckedBitPattern, NoUninit}; |
| /// |
| /// #[repr(u32)] |
| /// #[derive(Copy, Clone)] |
| /// enum MyEnum { |
| /// Variant0 = 0, |
| /// Variant1 = 1, |
| /// Variant2 = 2, |
| /// } |
| /// |
| /// unsafe impl CheckedBitPattern for MyEnum { |
| /// type Bits = u32; |
| /// |
| /// fn is_valid_bit_pattern(bits: &u32) -> bool { |
| /// match *bits { |
| /// 0 | 1 | 2 => true, |
| /// _ => false, |
| /// } |
| /// } |
| /// } |
| /// |
| /// // It is often useful to also implement `NoUninit` on our `CheckedBitPattern` types. |
| /// // This will allow us to do casting of mutable references (and mutable slices). |
| /// // It is not always possible to do so, but in this case we have no padding so it is. |
| /// unsafe impl NoUninit for MyEnum {} |
| /// ``` |
| /// |
| /// We can now use relevant casting functions. For example, |
| /// |
| /// ```rust |
| /// # use bytemuck::{CheckedBitPattern, NoUninit}; |
| /// # #[repr(u32)] |
| /// # #[derive(Copy, Clone, PartialEq, Eq, Debug)] |
| /// # enum MyEnum { |
| /// # Variant0 = 0, |
| /// # Variant1 = 1, |
| /// # Variant2 = 2, |
| /// # } |
| /// # unsafe impl NoUninit for MyEnum {} |
| /// # unsafe impl CheckedBitPattern for MyEnum { |
| /// # type Bits = u32; |
| /// # fn is_valid_bit_pattern(bits: &u32) -> bool { |
| /// # match *bits { |
| /// # 0 | 1 | 2 => true, |
| /// # _ => false, |
| /// # } |
| /// # } |
| /// # } |
| /// use bytemuck::{bytes_of, bytes_of_mut}; |
| /// use bytemuck::checked; |
| /// |
| /// let bytes = bytes_of(&2u32); |
| /// let result = checked::try_from_bytes::<MyEnum>(bytes); |
| /// assert_eq!(result, Ok(&MyEnum::Variant2)); |
| /// |
| /// // Fails for invalid discriminant |
| /// let bytes = bytes_of(&100u32); |
| /// let result = checked::try_from_bytes::<MyEnum>(bytes); |
| /// assert!(result.is_err()); |
| /// |
| /// // Since we implemented NoUninit, we can also cast mutably from an original type |
| /// // that is `NoUninit + AnyBitPattern`: |
| /// let mut my_u32 = 2u32; |
| /// { |
| /// let as_enum_mut = checked::cast_mut::<_, MyEnum>(&mut my_u32); |
| /// assert_eq!(as_enum_mut, &mut MyEnum::Variant2); |
| /// *as_enum_mut = MyEnum::Variant0; |
| /// } |
| /// assert_eq!(my_u32, 0u32); |
| /// ``` |
| /// |
| /// # Safety |
| /// |
| /// * `Self` *must* have the same layout as the specified `Bits` except for |
| /// the possible invalid bit patterns being checked during |
| /// [`is_valid_bit_pattern`]. |
| /// * This almost certainly means your type must be `#[repr(C)]` or a similar |
| /// specified repr, but if you think you know better, you probably don't. If |
| /// you still think you know better, be careful and have fun. And don't mess |
| /// it up (I mean it). |
| /// * If [`is_valid_bit_pattern`] returns true, then the bit pattern contained |
| /// in `bits` must also be valid for an instance of `Self`. |
| /// * Probably more, don't mess it up (I mean it 2.0) |
| /// |
| /// [`is_valid_bit_pattern`]: CheckedBitPattern::is_valid_bit_pattern |
| /// [`Pod`]: crate::Pod |
| </span><span class="kw">pub unsafe trait </span>CheckedBitPattern: Copy { |
| <span class="doccomment">/// `Self` *must* have the same layout as the specified `Bits` except for |
| /// the possible invalid bit patterns being checked during |
| /// [`is_valid_bit_pattern`]. |
| /// |
| /// [`is_valid_bit_pattern`]: CheckedBitPattern::is_valid_bit_pattern |
| </span><span class="kw">type </span>Bits: AnyBitPattern; |
| |
| <span class="doccomment">/// If this function returns true, then it must be valid to reinterpret `bits` |
| /// as `&Self`. |
| </span><span class="kw">fn </span>is_valid_bit_pattern(bits: <span class="kw-2">&</span><span class="self">Self</span>::Bits) -> bool; |
| } |
| |
| <span class="kw">unsafe impl</span><T: AnyBitPattern> CheckedBitPattern <span class="kw">for </span>T { |
| <span class="kw">type </span>Bits = T; |
| |
| <span class="attribute">#[inline(always)] |
| </span><span class="kw">fn </span>is_valid_bit_pattern(_bits: <span class="kw-2">&</span>T) -> bool { |
| <span class="bool-val">true |
| </span>} |
| } |
| |
| <span class="kw">unsafe impl </span>CheckedBitPattern <span class="kw">for </span>char { |
| <span class="kw">type </span>Bits = u32; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>is_valid_bit_pattern(bits: <span class="kw-2">&</span><span class="self">Self</span>::Bits) -> bool { |
| core::char::from_u32(<span class="kw-2">*</span>bits).is_some() |
| } |
| } |
| |
| <span class="kw">unsafe impl </span>CheckedBitPattern <span class="kw">for </span>bool { |
| <span class="kw">type </span>Bits = u8; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>is_valid_bit_pattern(bits: <span class="kw-2">&</span><span class="self">Self</span>::Bits) -> bool { |
| <span class="kw">match </span><span class="kw-2">*</span>bits { |
| <span class="number">0 </span>| <span class="number">1 </span>=> <span class="bool-val">true</span>, |
| <span class="kw">_ </span>=> <span class="bool-val">false</span>, |
| } |
| } |
| } |
| |
| <span class="macro">macro_rules! </span>impl_checked_for_nonzero { |
| ($(<span class="macro-nonterminal">$nonzero</span>:ty: <span class="macro-nonterminal">$primitive</span>:ty),* $(,)<span class="question-mark">?</span>) => { |
| $( |
| <span class="kw">unsafe impl </span>CheckedBitPattern <span class="kw">for </span><span class="macro-nonterminal">$nonzero </span>{ |
| <span class="kw">type </span>Bits = <span class="macro-nonterminal">$primitive</span>; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>is_valid_bit_pattern(bits: <span class="kw-2">&</span><span class="self">Self</span>::Bits) -> bool { |
| <span class="comment">// Note(zachs18): The size and alignment check are almost certainly |
| // not necessary, but Rust currently doesn't explicitly document that |
| // NonZero[int] has the same layout as [int], so we check it to be safe. |
| // In a const to reduce debug-profile overhead. |
| </span><span class="kw">const </span>LAYOUT_SAME: bool = |
| core::mem::size_of::<<span class="macro-nonterminal">$nonzero</span>>() == core::mem::size_of::<<span class="macro-nonterminal">$primitive</span>>() |
| && core::mem::align_of::<<span class="macro-nonterminal">$nonzero</span>>() == core::mem::align_of::<<span class="macro-nonterminal">$primitive</span>>(); |
| LAYOUT_SAME && <span class="kw-2">*</span>bits != <span class="number">0 |
| </span>} |
| } |
| )* |
| }; |
| } |
| <span class="macro">impl_checked_for_nonzero! </span>{ |
| core::num::NonZeroU8: u8, |
| core::num::NonZeroI8: i8, |
| core::num::NonZeroU16: u16, |
| core::num::NonZeroI16: i16, |
| core::num::NonZeroU32: u32, |
| core::num::NonZeroI32: i32, |
| core::num::NonZeroU64: u64, |
| core::num::NonZeroI64: i64, |
| core::num::NonZeroI128: i128, |
| core::num::NonZeroU128: u128, |
| core::num::NonZeroUsize: usize, |
| core::num::NonZeroIsize: isize, |
| } |
| |
| <span class="doccomment">/// The things that can go wrong when casting between [`CheckedBitPattern`] data |
| /// forms. |
| </span><span class="attribute">#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] |
| </span><span class="kw">pub enum </span>CheckedCastError { |
| <span class="doccomment">/// An error occurred during a true-[`Pod`] cast |
| /// |
| /// [`Pod`]: crate::Pod |
| </span>PodCastError(<span class="kw">crate</span>::PodCastError), |
| <span class="doccomment">/// When casting to a [`CheckedBitPattern`] type, it is possible that the |
| /// original data contains an invalid bit pattern. If so, the cast will |
| /// fail and this error will be returned. Will never happen on casts |
| /// between [`Pod`] types. |
| /// |
| /// [`Pod`]: crate::Pod |
| </span>InvalidBitPattern, |
| } |
| |
| <span class="attribute">#[cfg(not(target_arch = <span class="string">"spirv"</span>))] |
| </span><span class="kw">impl </span>core::fmt::Display <span class="kw">for </span>CheckedCastError { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>core::fmt::Formatter) -> core::fmt::Result { |
| <span class="macro">write!</span>(f, <span class="string">"{:?}"</span>, <span class="self">self</span>) |
| } |
| } |
| <span class="attribute">#[cfg(feature = <span class="string">"extern_crate_std"</span>)] |
| </span><span class="kw">impl </span>std::error::Error <span class="kw">for </span>CheckedCastError {} |
| |
| <span class="kw">impl </span>From<<span class="kw">crate</span>::PodCastError> <span class="kw">for </span>CheckedCastError { |
| <span class="kw">fn </span>from(err: <span class="kw">crate</span>::PodCastError) -> CheckedCastError { |
| CheckedCastError::PodCastError(err) |
| } |
| } |
| |
| <span class="doccomment">/// Re-interprets `&[u8]` as `&T`. |
| /// |
| /// ## Failure |
| /// |
| /// * If the slice isn't aligned for the new type |
| /// * If the slice's length isn’t exactly the size of the new type |
| /// * If the slice contains an invalid bit pattern for `T` |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_from_bytes<T: CheckedBitPattern>( |
| s: <span class="kw-2">&</span>[u8], |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span>T, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_from_bytes(s) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><T <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="kw-2">&*</span>(pod <span class="kw">as </span><span class="kw-2">*const </span><T <span class="kw">as </span>CheckedBitPattern>::Bits <span class="kw">as </span><span class="kw-2">*const </span>T) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Re-interprets `&mut [u8]` as `&mut T`. |
| /// |
| /// ## Failure |
| /// |
| /// * If the slice isn't aligned for the new type |
| /// * If the slice's length isn’t exactly the size of the new type |
| /// * If the slice contains an invalid bit pattern for `T` |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_from_bytes_mut<T: CheckedBitPattern + NoUninit>( |
| s: <span class="kw-2">&mut </span>[u8], |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&mut </span>T, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_from_bytes_mut(s) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><T <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span>(pod <span class="kw">as </span><span class="kw-2">*mut </span><T <span class="kw">as </span>CheckedBitPattern>::Bits <span class="kw">as </span><span class="kw-2">*mut </span>T) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Reads from the bytes as if they were a `T`. |
| /// |
| /// ## Failure |
| /// * If the `bytes` length is not equal to `size_of::<T>()`. |
| /// * If the slice contains an invalid bit pattern for `T` |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_pod_read_unaligned<T: CheckedBitPattern>( |
| bytes: <span class="kw-2">&</span>[u8], |
| ) -> <span class="prelude-ty">Result</span><T, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_pod_read_unaligned(bytes) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><T <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(<span class="kw-2">&</span>pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="macro">transmute!</span>(pod) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Try to cast `T` into `U`. |
| /// |
| /// Note that for this particular type of cast, alignment isn't a factor. The |
| /// input value is semantically copied into the function and then returned to a |
| /// new memory location which will have whatever the required alignment of the |
| /// output type is. |
| /// |
| /// ## Failure |
| /// |
| /// * If the types don't have the same size this fails. |
| /// * If `a` contains an invalid bit pattern for `B` this fails. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_cast<A: NoUninit, B: CheckedBitPattern>( |
| a: A, |
| ) -> <span class="prelude-ty">Result</span><B, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_cast(a) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><B <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(<span class="kw-2">&</span>pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="macro">transmute!</span>(pod) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Try to convert a `&T` into `&U`. |
| /// |
| /// ## Failure |
| /// |
| /// * If the reference isn't aligned in the new type |
| /// * If the source type and target type aren't the same size. |
| /// * If `a` contains an invalid bit pattern for `B` this fails. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_cast_ref<A: NoUninit, B: CheckedBitPattern>( |
| a: <span class="kw-2">&</span>A, |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span>B, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_cast_ref(a) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><B <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="kw-2">&*</span>(pod <span class="kw">as </span><span class="kw-2">*const </span><B <span class="kw">as </span>CheckedBitPattern>::Bits <span class="kw">as </span><span class="kw-2">*const </span>B) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Try to convert a `&mut T` into `&mut U`. |
| /// |
| /// As [`try_cast_ref`], but `mut`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_cast_mut< |
| A: NoUninit + AnyBitPattern, |
| B: CheckedBitPattern + NoUninit, |
| >( |
| a: <span class="kw-2">&mut </span>A, |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&mut </span>B, CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_cast_mut(a) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span><B <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ <span class="kw-2">&mut *</span>(pod <span class="kw">as </span><span class="kw-2">*mut </span><B <span class="kw">as </span>CheckedBitPattern>::Bits <span class="kw">as </span><span class="kw-2">*mut </span>B) }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Try to convert `&[A]` into `&[B]` (possibly with a change in length). |
| /// |
| /// * `input.as_ptr() as usize == output.as_ptr() as usize` |
| /// * `input.len() * size_of::<A>() == output.len() * size_of::<B>()` |
| /// |
| /// ## Failure |
| /// |
| /// * If the target type has a greater alignment requirement and the input slice |
| /// isn't aligned. |
| /// * If the target element type is a different size from the current element |
| /// type, and the output slice wouldn't be a whole number of elements when |
| /// accounting for the size change (eg: 3 `u16` values is 1.5 `u32` values, so |
| /// that's a failure). |
| /// * Similarly, you can't convert between a [ZST](https://doc.rust-lang.org/nomicon/exotic-sizes.html#zero-sized-types-zsts) |
| /// and a non-ZST. |
| /// * If any element of the converted slice would contain an invalid bit pattern |
| /// for `B` this fails. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_cast_slice<A: NoUninit, B: CheckedBitPattern>( |
| a: <span class="kw-2">&</span>[A], |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span>[B], CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_cast_slice(a) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>pod.iter().all(|pod| <B <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod)) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ |
| core::slice::from_raw_parts(pod.as_ptr() <span class="kw">as </span><span class="kw-2">*const </span>B, pod.len()) |
| }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Try to convert `&mut [A]` into `&mut [B]` (possibly with a change in |
| /// length). |
| /// |
| /// As [`try_cast_slice`], but `&mut`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>try_cast_slice_mut< |
| A: NoUninit + AnyBitPattern, |
| B: CheckedBitPattern + NoUninit, |
| >( |
| a: <span class="kw-2">&mut </span>[A], |
| ) -> <span class="prelude-ty">Result</span><<span class="kw-2">&mut </span>[B], CheckedCastError> { |
| <span class="kw">let </span>pod = <span class="kw">unsafe </span>{ internal::try_cast_slice_mut(a) }<span class="question-mark">?</span>; |
| |
| <span class="kw">if </span>pod.iter().all(|pod| <B <span class="kw">as </span>CheckedBitPattern>::is_valid_bit_pattern(pod)) { |
| <span class="prelude-val">Ok</span>(<span class="kw">unsafe </span>{ |
| core::slice::from_raw_parts_mut(pod.as_mut_ptr() <span class="kw">as </span><span class="kw-2">*mut </span>B, pod.len()) |
| }) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">Err</span>(CheckedCastError::InvalidBitPattern) |
| } |
| } |
| |
| <span class="doccomment">/// Re-interprets `&[u8]` as `&T`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_from_bytes`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>from_bytes<T: CheckedBitPattern>(s: <span class="kw-2">&</span>[u8]) -> <span class="kw-2">&</span>T { |
| <span class="kw">match </span>try_from_bytes(s) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"from_bytes"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Re-interprets `&mut [u8]` as `&mut T`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_from_bytes_mut`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>from_bytes_mut<T: NoUninit + CheckedBitPattern>(s: <span class="kw-2">&mut </span>[u8]) -> <span class="kw-2">&mut </span>T { |
| <span class="kw">match </span>try_from_bytes_mut(s) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"from_bytes_mut"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Reads the slice into a `T` value. |
| /// |
| /// ## Panics |
| /// * This is like `try_pod_read_unaligned` but will panic on failure. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>pod_read_unaligned<T: CheckedBitPattern>(bytes: <span class="kw-2">&</span>[u8]) -> T { |
| <span class="kw">match </span>try_pod_read_unaligned(bytes) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"pod_read_unaligned"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Cast `T` into `U` |
| /// |
| /// ## Panics |
| /// |
| /// * This is like [`try_cast`](try_cast), but will panic on a size mismatch. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast<A: NoUninit, B: CheckedBitPattern>(a: A) -> B { |
| <span class="kw">match </span>try_cast(a) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"cast"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Cast `&mut T` into `&mut U`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_cast_mut`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast_mut< |
| A: NoUninit + AnyBitPattern, |
| B: NoUninit + CheckedBitPattern, |
| >( |
| a: <span class="kw-2">&mut </span>A, |
| ) -> <span class="kw-2">&mut </span>B { |
| <span class="kw">match </span>try_cast_mut(a) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"cast_mut"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Cast `&T` into `&U`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_cast_ref`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast_ref<A: NoUninit, B: CheckedBitPattern>(a: <span class="kw-2">&</span>A) -> <span class="kw-2">&</span>B { |
| <span class="kw">match </span>try_cast_ref(a) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"cast_ref"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Cast `&[A]` into `&[B]`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_cast_slice`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast_slice<A: NoUninit, B: CheckedBitPattern>(a: <span class="kw-2">&</span>[A]) -> <span class="kw-2">&</span>[B] { |
| <span class="kw">match </span>try_cast_slice(a) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"cast_slice"</span>, e), |
| } |
| } |
| |
| <span class="doccomment">/// Cast `&mut [T]` into `&mut [U]`. |
| /// |
| /// ## Panics |
| /// |
| /// This is [`try_cast_slice_mut`] but will panic on error. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast_slice_mut< |
| A: NoUninit + AnyBitPattern, |
| B: NoUninit + CheckedBitPattern, |
| >( |
| a: <span class="kw-2">&mut </span>[A], |
| ) -> <span class="kw-2">&mut </span>[B] { |
| <span class="kw">match </span>try_cast_slice_mut(a) { |
| <span class="prelude-val">Ok</span>(t) => t, |
| <span class="prelude-val">Err</span>(e) => something_went_wrong(<span class="string">"cast_slice_mut"</span>, e), |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="bytemuck" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
