Merging upstream version 127.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1075 insertions, 0 deletions

diff --git a/third_party/rust/zerocopy/src/byteorder.rs b/third_party/rust/zerocopy/src/byteorder.rs
new file mode 100644
index 0000000000..2769410451
--- /dev/null
+++ b/third_party/rust/zerocopy/src/byteorder.rs
@@ -0,0 +1,1075 @@
+// Copyright 2019 The Fuchsia Authors
+//
+// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
+// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
+// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
+// This file may not be copied, modified, or distributed except according to
+// those terms.
+
+//! Byte order-aware numeric primitives.
+//!
+//! This module contains equivalents of the native multi-byte integer types with
+//! no alignment requirement and supporting byte order conversions.
+//!
+//! For each native multi-byte integer type - `u16`, `i16`, `u32`, etc - and
+//! floating point type - `f32` and `f64` - an equivalent type is defined by
+//! this module - [`U16`], [`I16`], [`U32`], [`F64`], etc. Unlike their native
+//! counterparts, these types have alignment 1, and take a type parameter
+//! specifying the byte order in which the bytes are stored in memory. Each type
+//! implements the [`FromBytes`], [`AsBytes`], and [`Unaligned`] traits.
+//!
+//! These two properties, taken together, make these types useful for defining
+//! data structures whose memory layout matches a wire format such as that of a
+//! network protocol or a file format. Such formats often have multi-byte values
+//! at offsets that do not respect the alignment requirements of the equivalent
+//! native types, and stored in a byte order not necessarily the same as that of
+//! the target platform.
+//!
+//! Type aliases are provided for common byte orders in the [`big_endian`],
+//! [`little_endian`], [`network_endian`], and [`native_endian`] submodules.
+//!
+//! # Example
+//!
+//! One use of these types is for representing network packet formats, such as
+//! UDP:
+//!
+//! ```rust,edition2021
+//! # #[cfg(feature = "derive")] { // This example uses derives, and won't compile without them
+//! use zerocopy::{AsBytes, ByteSlice, FromBytes, FromZeroes, Ref, Unaligned};
+//! use zerocopy::byteorder::network_endian::U16;
+//!
+//! #[derive(FromZeroes, FromBytes, AsBytes, Unaligned)]
+//! #[repr(C)]
+//! struct UdpHeader {
+//!     src_port: U16,
+//!     dst_port: U16,
+//!     length: U16,
+//!     checksum: U16,
+//! }
+//!
+//! struct UdpPacket<B: ByteSlice> {
+//!     header: Ref<B, UdpHeader>,
+//!     body: B,
+//! }
+//!
+//! impl<B: ByteSlice> UdpPacket<B> {
+//!     fn parse(bytes: B) -> Option<UdpPacket<B>> {
+//!         let (header, body) = Ref::new_from_prefix(bytes)?;
+//!         Some(UdpPacket { header, body })
+//!     }
+//!
+//!     fn src_port(&self) -> u16 {
+//!         self.header.src_port.get()
+//!     }
+//!
+//!     // more getters...
+//! }
+//! # }
+//! ```
+
+use core::{
+    convert::{TryFrom, TryInto},
+    fmt::{self, Binary, Debug, Display, Formatter, LowerHex, Octal, UpperHex},
+    marker::PhantomData,
+    num::TryFromIntError,
+};
+
+// We don't reexport `WriteBytesExt` or `ReadBytesExt` because those are only
+// available with the `std` feature enabled, and zerocopy is `no_std` by
+// default.
+pub use ::byteorder::{BigEndian, ByteOrder, LittleEndian, NativeEndian, NetworkEndian, BE, LE};
+
+use super::*;
+
+macro_rules! impl_fmt_trait {
+    ($name:ident, $native:ident, $trait:ident) => {
+        impl<O: ByteOrder> $trait for $name<O> {
+            #[inline(always)]
+            fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+                $trait::fmt(&self.get(), f)
+            }
+        }
+    };
+}
+
+macro_rules! impl_fmt_traits {
+    ($name:ident, $native:ident, "floating point number") => {
+        impl_fmt_trait!($name, $native, Display);
+    };
+    ($name:ident, $native:ident, "unsigned integer") => {
+        impl_fmt_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, "signed integer") => {
+        impl_fmt_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, @all_types) => {
+        impl_fmt_trait!($name, $native, Display);
+        impl_fmt_trait!($name, $native, Octal);
+        impl_fmt_trait!($name, $native, LowerHex);
+        impl_fmt_trait!($name, $native, UpperHex);
+        impl_fmt_trait!($name, $native, Binary);
+    };
+}
+
+macro_rules! impl_ops_traits {
+    ($name:ident, $native:ident, "floating point number") => {
+        impl_ops_traits!($name, $native, @all_types);
+        impl_ops_traits!($name, $native, @signed_integer_floating_point);
+    };
+    ($name:ident, $native:ident, "unsigned integer") => {
+        impl_ops_traits!($name, $native, @signed_unsigned_integer);
+        impl_ops_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, "signed integer") => {
+        impl_ops_traits!($name, $native, @signed_unsigned_integer);
+        impl_ops_traits!($name, $native, @signed_integer_floating_point);
+        impl_ops_traits!($name, $native, @all_types);
+    };
+    ($name:ident, $native:ident, @signed_unsigned_integer) => {
+        impl_ops_traits!(@without_byteorder_swap $name, $native, BitAnd, bitand, BitAndAssign, bitand_assign);
+        impl_ops_traits!(@without_byteorder_swap $name, $native, BitOr, bitor, BitOrAssign, bitor_assign);
+        impl_ops_traits!(@without_byteorder_swap $name, $native, BitXor, bitxor, BitXorAssign, bitxor_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Shl, shl, ShlAssign, shl_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Shr, shr, ShrAssign, shr_assign);
+
+        impl<O> core::ops::Not for $name<O> {
+            type Output = $name<O>;
+
+            #[inline(always)]
+            fn not(self) -> $name<O> {
+                 let self_native = $native::from_ne_bytes(self.0);
+                 $name((!self_native).to_ne_bytes(), PhantomData)
+            }
+        }
+    };
+    ($name:ident, $native:ident, @signed_integer_floating_point) => {
+        impl<O: ByteOrder> core::ops::Neg for $name<O> {
+            type Output = $name<O>;
+
+            #[inline(always)]
+            fn neg(self) -> $name<O> {
+                let self_native: $native = self.get();
+                #[allow(clippy::arithmetic_side_effects)]
+                $name::<O>::new(-self_native)
+            }
+        }
+    };
+    ($name:ident, $native:ident, @all_types) => {
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Add, add, AddAssign, add_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Div, div, DivAssign, div_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Mul, mul, MulAssign, mul_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Rem, rem, RemAssign, rem_assign);
+        impl_ops_traits!(@with_byteorder_swap $name, $native, Sub, sub, SubAssign, sub_assign);
+    };
+    (@with_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
+        impl<O: ByteOrder> core::ops::$trait for $name<O> {
+            type Output = $name<O>;
+
+            #[inline(always)]
+            fn $method(self, rhs: $name<O>) -> $name<O> {
+                let self_native: $native = self.get();
+                let rhs_native: $native = rhs.get();
+                let result_native = core::ops::$trait::$method(self_native, rhs_native);
+                $name::<O>::new(result_native)
+            }
+        }
+
+        impl<O: ByteOrder> core::ops::$trait_assign for $name<O> {
+            #[inline(always)]
+            fn $method_assign(&mut self, rhs: $name<O>) {
+                *self = core::ops::$trait::$method(*self, rhs);
+            }
+        }
+    };
+    // Implement traits in terms of the same trait on the native type, but
+    // without performing a byte order swap. This only works for bitwise
+    // operations like `&`, `|`, etc.
+    (@without_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
+        impl<O: ByteOrder> core::ops::$trait for $name<O> {
+            type Output = $name<O>;
+
+            #[inline(always)]
+            fn $method(self, rhs: $name<O>) -> $name<O> {
+                let self_native = $native::from_ne_bytes(self.0);
+                let rhs_native = $native::from_ne_bytes(rhs.0);
+                let result_native = core::ops::$trait::$method(self_native, rhs_native);
+                $name(result_native.to_ne_bytes(), PhantomData)
+            }
+        }
+
+        impl<O: ByteOrder> core::ops::$trait_assign for $name<O> {
+            #[inline(always)]
+            fn $method_assign(&mut self, rhs: $name<O>) {
+                *self = core::ops::$trait::$method(*self, rhs);
+            }
+        }
+    };
+}
+
+macro_rules! doc_comment {
+    ($x:expr, $($tt:tt)*) => {
+        #[doc = $x]
+        $($tt)*
+    };
+}
+
+macro_rules! define_max_value_constant {
+    ($name:ident, $bytes:expr, "unsigned integer") => {
+        /// The maximum value.
+        ///
+        /// This constant should be preferred to constructing a new value using
+        /// `new`, as `new` may perform an endianness swap depending on the
+        /// endianness `O` and the endianness of the platform.
+        pub const MAX_VALUE: $name<O> = $name([0xFFu8; $bytes], PhantomData);
+    };
+    // We don't provide maximum and minimum value constants for signed values
+    // and floats because there's no way to do it generically - it would require
+    // a different value depending on the value of the `ByteOrder` type
+    // parameter. Currently, one workaround would be to provide implementations
+    // for concrete implementations of that trait. In the long term, if we are
+    // ever able to make the `new` constructor a const fn, we could use that
+    // instead.
+    ($name:ident, $bytes:expr, "signed integer") => {};
+    ($name:ident, $bytes:expr, "floating point number") => {};
+}
+
+macro_rules! define_type {
+    ($article:ident,
+        $name:ident,
+        $native:ident,
+        $bits:expr,
+        $bytes:expr,
+        $read_method:ident,
+        $write_method:ident,
+        $number_kind:tt,
+        [$($larger_native:ty),*],
+        [$($larger_native_try:ty),*],
+        [$($larger_byteorder:ident),*],
+        [$($larger_byteorder_try:ident),*]) => {
+        doc_comment! {
+            concat!("A ", stringify!($bits), "-bit ", $number_kind,
+            " stored in a given byte order.
+
+`", stringify!($name), "` is like the native `", stringify!($native), "` type with
+two major differences: First, it has no alignment requirement (its alignment is 1).
+Second, the endianness of its memory layout is given by the type parameter `O`,
+which can be any type which implements [`ByteOrder`]. In particular, this refers
+to [`BigEndian`], [`LittleEndian`], [`NativeEndian`], and [`NetworkEndian`].
+
+", stringify!($article), " `", stringify!($name), "` can be constructed using
+the [`new`] method, and its contained value can be obtained as a native
+`",stringify!($native), "` using the [`get`] method, or updated in place with
+the [`set`] method. In all cases, if the endianness `O` is not the same as the
+endianness of the current platform, an endianness swap will be performed in
+order to uphold the invariants that a) the layout of `", stringify!($name), "`
+has endianness `O` and that, b) the layout of `", stringify!($native), "` has
+the platform's native endianness.
+
+`", stringify!($name), "` implements [`FromBytes`], [`AsBytes`], and [`Unaligned`],
+making it useful for parsing and serialization. See the module documentation for an
+example of how it can be used for parsing UDP packets.
+
+[`new`]: crate::byteorder::", stringify!($name), "::new
+[`get`]: crate::byteorder::", stringify!($name), "::get
+[`set`]: crate::byteorder::", stringify!($name), "::set
+[`FromBytes`]: crate::FromBytes
+[`AsBytes`]: crate::AsBytes
+[`Unaligned`]: crate::Unaligned"),
+            #[derive(Copy, Clone, Eq, PartialEq, Hash)]
+            #[cfg_attr(any(feature = "derive", test), derive(KnownLayout, FromZeroes, FromBytes, AsBytes, Unaligned))]
+            #[repr(transparent)]
+            pub struct $name<O>([u8; $bytes], PhantomData<O>);
+        }
+
+        #[cfg(not(any(feature = "derive", test)))]
+        impl_known_layout!(O => $name<O>);
+
+        safety_comment! {
+            /// SAFETY:
+            /// `$name<O>` is `repr(transparent)`, and so it has the same layout
+            /// as its only non-zero field, which is a `u8` array. `u8` arrays
+            /// are `FromZeroes`, `FromBytes`, `AsBytes`, and `Unaligned`.
+            impl_or_verify!(O => FromZeroes for $name<O>);
+            impl_or_verify!(O => FromBytes for $name<O>);
+            impl_or_verify!(O => AsBytes for $name<O>);
+            impl_or_verify!(O => Unaligned for $name<O>);
+        }
+
+        impl<O> Default for $name<O> {
+            #[inline(always)]
+            fn default() -> $name<O> {
+                $name::ZERO
+            }
+        }
+
+        impl<O> $name<O> {
+            /// The value zero.
+            ///
+            /// This constant should be preferred to constructing a new value
+            /// using `new`, as `new` may perform an endianness swap depending
+            /// on the endianness and platform.
+            pub const ZERO: $name<O> = $name([0u8; $bytes], PhantomData);
+
+            define_max_value_constant!($name, $bytes, $number_kind);
+
+            /// Constructs a new value from bytes which are already in the
+            /// endianness `O`.
+            #[inline(always)]
+            pub const fn from_bytes(bytes: [u8; $bytes]) -> $name<O> {
+                $name(bytes, PhantomData)
+            }
+        }
+
+        impl<O: ByteOrder> $name<O> {
+            // TODO(joshlf): Make these const fns if the `ByteOrder` methods
+            // ever become const fns.
+
+            /// Constructs a new value, possibly performing an endianness swap
+            /// to guarantee that the returned value has endianness `O`.
+            #[inline(always)]
+            pub fn new(n: $native) -> $name<O> {
+                let mut out = $name::default();
+                O::$write_method(&mut out.0[..], n);
+                out
+            }
+
+            /// Returns the value as a primitive type, possibly performing an
+            /// endianness swap to guarantee that the return value has the
+            /// endianness of the native platform.
+            #[inline(always)]
+            pub fn get(self) -> $native {
+                O::$read_method(&self.0[..])
+            }
+
+            /// Updates the value in place as a primitive type, possibly
+            /// performing an endianness swap to guarantee that the stored value
+            /// has the endianness `O`.
+            #[inline(always)]
+            pub fn set(&mut self, n: $native) {
+                O::$write_method(&mut self.0[..], n);
+            }
+        }
+
+        // The reasoning behind which traits to implement here is to only
+        // implement traits which won't cause inference issues. Notably,
+        // comparison traits like PartialEq and PartialOrd tend to cause
+        // inference issues.
+
+        impl<O: ByteOrder> From<$name<O>> for [u8; $bytes] {
+            #[inline(always)]
+            fn from(x: $name<O>) -> [u8; $bytes] {
+                x.0
+            }
+        }
+
+        impl<O: ByteOrder> From<[u8; $bytes]> for $name<O> {
+            #[inline(always)]
+            fn from(bytes: [u8; $bytes]) -> $name<O> {
+                $name(bytes, PhantomData)
+            }
+        }
+
+        impl<O: ByteOrder> From<$name<O>> for $native {
+            #[inline(always)]
+            fn from(x: $name<O>) -> $native {
+                x.get()
+            }
+        }
+
+        impl<O: ByteOrder> From<$native> for $name<O> {
+            #[inline(always)]
+            fn from(x: $native) -> $name<O> {
+                $name::new(x)
+            }
+        }
+
+        $(
+            impl<O: ByteOrder> From<$name<O>> for $larger_native {
+                #[inline(always)]
+                fn from(x: $name<O>) -> $larger_native {
+                    x.get().into()
+                }
+            }
+        )*
+
+        $(
+            impl<O: ByteOrder> TryFrom<$larger_native_try> for $name<O> {
+                type Error = TryFromIntError;
+                #[inline(always)]
+                fn try_from(x: $larger_native_try) -> Result<$name<O>, TryFromIntError> {
+                    $native::try_from(x).map($name::new)
+                }
+            }
+        )*
+
+        $(
+            impl<O: ByteOrder, P: ByteOrder> From<$name<O>> for $larger_byteorder<P> {
+                #[inline(always)]
+                fn from(x: $name<O>) -> $larger_byteorder<P> {
+                    $larger_byteorder::new(x.get().into())
+                }
+            }
+        )*
+
+        $(
+            impl<O: ByteOrder, P: ByteOrder> TryFrom<$larger_byteorder_try<P>> for $name<O> {
+                type Error = TryFromIntError;
+                #[inline(always)]
+                fn try_from(x: $larger_byteorder_try<P>) -> Result<$name<O>, TryFromIntError> {
+                    x.get().try_into().map($name::new)
+                }
+            }
+        )*
+
+        impl<O: ByteOrder> AsRef<[u8; $bytes]> for $name<O> {
+            #[inline(always)]
+            fn as_ref(&self) -> &[u8; $bytes] {
+                &self.0
+            }
+        }
+
+        impl<O: ByteOrder> AsMut<[u8; $bytes]> for $name<O> {
+            #[inline(always)]
+            fn as_mut(&mut self) -> &mut [u8; $bytes] {
+                &mut self.0
+            }
+        }
+
+        impl<O: ByteOrder> PartialEq<$name<O>> for [u8; $bytes] {
+            #[inline(always)]
+            fn eq(&self, other: &$name<O>) -> bool {
+                self.eq(&other.0)
+            }
+        }
+
+        impl<O: ByteOrder> PartialEq<[u8; $bytes]> for $name<O> {
+            #[inline(always)]
+            fn eq(&self, other: &[u8; $bytes]) -> bool {
+                self.0.eq(other)
+            }
+        }
+
+        impl_fmt_traits!($name, $native, $number_kind);
+        impl_ops_traits!($name, $native, $number_kind);
+
+        impl<O: ByteOrder> Debug for $name<O> {
+            #[inline]
+            fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+                // This results in a format like "U16(42)".
+                f.debug_tuple(stringify!($name)).field(&self.get()).finish()
+            }
+        }
+    };
+}
+
+define_type!(
+    A,
+    U16,
+    u16,
+    16,
+    2,
+    read_u16,
+    write_u16,
+    "unsigned integer",
+    [u32, u64, u128, usize],
+    [u32, u64, u128, usize],
+    [U32, U64, U128],
+    [U32, U64, U128]
+);
+define_type!(
+    A,
+    U32,
+    u32,
+    32,
+    4,
+    read_u32,
+    write_u32,
+    "unsigned integer",
+    [u64, u128],
+    [u64, u128],
+    [U64, U128],
+    [U64, U128]
+);
+define_type!(
+    A,
+    U64,
+    u64,
+    64,
+    8,
+    read_u64,
+    write_u64,
+    "unsigned integer",
+    [u128],
+    [u128],
+    [U128],
+    [U128]
+);
+define_type!(A, U128, u128, 128, 16, read_u128, write_u128, "unsigned integer", [], [], [], []);
+define_type!(
+    An,
+    I16,
+    i16,
+    16,
+    2,
+    read_i16,
+    write_i16,
+    "signed integer",
+    [i32, i64, i128, isize],
+    [i32, i64, i128, isize],
+    [I32, I64, I128],
+    [I32, I64, I128]
+);
+define_type!(
+    An,
+    I32,
+    i32,
+    32,
+    4,
+    read_i32,
+    write_i32,
+    "signed integer",
+    [i64, i128],
+    [i64, i128],
+    [I64, I128],
+    [I64, I128]
+);
+define_type!(
+    An,
+    I64,
+    i64,
+    64,
+    8,
+    read_i64,
+    write_i64,
+    "signed integer",
+    [i128],
+    [i128],
+    [I128],
+    [I128]
+);
+define_type!(An, I128, i128, 128, 16, read_i128, write_i128, "signed integer", [], [], [], []);
+define_type!(
+    An,
+    F32,
+    f32,
+    32,
+    4,
+    read_f32,
+    write_f32,
+    "floating point number",
+    [f64],
+    [],
+    [F64],
+    []
+);
+define_type!(An, F64, f64, 64, 8, read_f64, write_f64, "floating point number", [], [], [], []);
+
+macro_rules! module {
+    ($name:ident, $trait:ident, $endianness_str:expr) => {
+        /// Numeric primitives stored in
+        #[doc = $endianness_str]
+        /// byte order.
+        pub mod $name {
+            use byteorder::$trait;
+
+            module!(@ty U16,  $trait, "16-bit unsigned integer", $endianness_str);
+            module!(@ty U32,  $trait, "32-bit unsigned integer", $endianness_str);
+            module!(@ty U64,  $trait, "64-bit unsigned integer", $endianness_str);
+            module!(@ty U128, $trait, "128-bit unsigned integer", $endianness_str);
+            module!(@ty I16,  $trait, "16-bit signed integer", $endianness_str);
+            module!(@ty I32,  $trait, "32-bit signed integer", $endianness_str);
+            module!(@ty I64,  $trait, "64-bit signed integer", $endianness_str);
+            module!(@ty I128, $trait, "128-bit signed integer", $endianness_str);
+            module!(@ty F32,  $trait, "32-bit floating point number", $endianness_str);
+            module!(@ty F64,  $trait, "64-bit floating point number", $endianness_str);
+        }
+    };
+    (@ty $ty:ident, $trait:ident, $desc_str:expr, $endianness_str:expr) => {
+        /// A
+        #[doc = $desc_str]
+        /// stored in
+        #[doc = $endianness_str]
+        /// byte order.
+        pub type $ty = crate::byteorder::$ty<$trait>;
+    };
+}
+
+module!(big_endian, BigEndian, "big-endian");
+module!(little_endian, LittleEndian, "little-endian");
+module!(network_endian, NetworkEndian, "network-endian");
+module!(native_endian, NativeEndian, "native-endian");
+
+#[cfg(any(test, kani))]
+mod tests {
+    use ::byteorder::NativeEndian;
+
+    use {
+        super::*,
+        crate::{AsBytes, FromBytes, Unaligned},
+    };
+
+    #[cfg(not(kani))]
+    mod compatibility {
+        pub(super) use rand::{
+            distributions::{Distribution, Standard},
+            rngs::SmallRng,
+            Rng, SeedableRng,
+        };
+
+        pub(crate) trait Arbitrary {}
+
+        impl<T> Arbitrary for T {}
+    }
+
+    #[cfg(kani)]
+    mod compatibility {
+        pub(crate) use kani::Arbitrary;
+
+        pub(crate) struct SmallRng;
+
+        impl SmallRng {
+            pub(crate) fn seed_from_u64(_state: u64) -> Self {
+                Self
+            }
+        }
+
+        pub(crate) trait Rng {
+            fn sample<T, D: Distribution<T>>(&mut self, _distr: D) -> T
+            where
+                T: Arbitrary,
+            {
+                kani::any()
+            }
+        }
+
+        impl Rng for SmallRng {}
+
+        pub(crate) trait Distribution<T> {}
+        impl<T, U> Distribution<T> for U {}
+
+        pub(crate) struct Standard;
+    }
+
+    use compatibility::*;
+
+    // A native integer type (u16, i32, etc).
+    trait Native: Arbitrary + FromBytes + AsBytes + Copy + PartialEq + Debug {
+        const ZERO: Self;
+        const MAX_VALUE: Self;
+
+        type Distribution: Distribution<Self>;
+        const DIST: Self::Distribution;
+
+        fn rand<R: Rng>(rng: &mut R) -> Self {
+            rng.sample(Self::DIST)
+        }
+
+        #[cfg(kani)]
+        fn any() -> Self {
+            kani::any()
+        }
+
+        fn checked_add(self, rhs: Self) -> Option<Self>;
+        fn checked_div(self, rhs: Self) -> Option<Self>;
+        fn checked_mul(self, rhs: Self) -> Option<Self>;
+        fn checked_rem(self, rhs: Self) -> Option<Self>;
+        fn checked_sub(self, rhs: Self) -> Option<Self>;
+        fn checked_shl(self, rhs: Self) -> Option<Self>;
+        fn checked_shr(self, rhs: Self) -> Option<Self>;
+
+        fn is_nan(self) -> bool;
+
+        /// For `f32` and `f64`, NaN values are not considered equal to
+        /// themselves. This method is like `assert_eq!`, but it treats NaN
+        /// values as equal.
+        fn assert_eq_or_nan(self, other: Self) {
+            let slf = (!self.is_nan()).then(|| self);
+            let other = (!other.is_nan()).then(|| other);
+            assert_eq!(slf, other);
+        }
+    }
+
+    trait ByteArray:
+        FromBytes + AsBytes + Copy + AsRef<[u8]> + AsMut<[u8]> + Debug + Default + Eq
+    {
+        /// Invert the order of the bytes in the array.
+        fn invert(self) -> Self;
+    }
+
+    trait ByteOrderType: FromBytes + AsBytes + Unaligned + Copy + Eq + Debug {
+        type Native: Native;
+        type ByteArray: ByteArray;
+
+        const ZERO: Self;
+
+        fn new(native: Self::Native) -> Self;
+        fn get(self) -> Self::Native;
+        fn set(&mut self, native: Self::Native);
+        fn from_bytes(bytes: Self::ByteArray) -> Self;
+        fn into_bytes(self) -> Self::ByteArray;
+
+        /// For `f32` and `f64`, NaN values are not considered equal to
+        /// themselves. This method is like `assert_eq!`, but it treats NaN
+        /// values as equal.
+        fn assert_eq_or_nan(self, other: Self) {
+            let slf = (!self.get().is_nan()).then(|| self);
+            let other = (!other.get().is_nan()).then(|| other);
+            assert_eq!(slf, other);
+        }
+    }
+
+    trait ByteOrderTypeUnsigned: ByteOrderType {
+        const MAX_VALUE: Self;
+    }
+
+    macro_rules! impl_byte_array {
+        ($bytes:expr) => {
+            impl ByteArray for [u8; $bytes] {
+                fn invert(mut self) -> [u8; $bytes] {
+                    self.reverse();
+                    self
+                }
+            }
+        };
+    }
+
+    impl_byte_array!(2);
+    impl_byte_array!(4);
+    impl_byte_array!(8);
+    impl_byte_array!(16);
+
+    macro_rules! impl_byte_order_type_unsigned {
+        ($name:ident, unsigned) => {
+            impl<O: ByteOrder> ByteOrderTypeUnsigned for $name<O> {
+                const MAX_VALUE: $name<O> = $name::MAX_VALUE;
+            }
+        };
+        ($name:ident, signed) => {};
+    }
+
+    macro_rules! impl_traits {
+        ($name:ident, $native:ident, $bytes:expr, $sign:ident $(, @$float:ident)?) => {
+            impl Native for $native {
+                // For some types, `0 as $native` is required (for example, when
+                // `$native` is a floating-point type; `0` is an integer), but
+                // for other types, it's a trivial cast. In all cases, Clippy
+                // thinks it's dangerous.
+                #[allow(trivial_numeric_casts, clippy::as_conversions)]
+                const ZERO: $native = 0 as $native;
+                const MAX_VALUE: $native = $native::MAX;
+
+                type Distribution = Standard;
+                const DIST: Standard = Standard;
+
+                impl_traits!(@float_dependent_methods $(@$float)?);
+            }
+
+            impl<O: ByteOrder> ByteOrderType for $name<O> {
+                type Native = $native;
+                type ByteArray = [u8; $bytes];
+
+                const ZERO: $name<O> = $name::ZERO;
+
+                fn new(native: $native) -> $name<O> {
+                    $name::new(native)
+                }
+
+                fn get(self) -> $native {
+                    $name::get(self)
+                }
+
+                fn set(&mut self, native: $native) {
+                    $name::set(self, native)
+                }
+
+                fn from_bytes(bytes: [u8; $bytes]) -> $name<O> {
+                    $name::from(bytes)
+                }
+
+                fn into_bytes(self) -> [u8; $bytes] {
+                    <[u8; $bytes]>::from(self)
+                }
+            }
+
+            impl_byte_order_type_unsigned!($name, $sign);
+        };
+        (@float_dependent_methods) => {
+            fn checked_add(self, rhs: Self) -> Option<Self> { self.checked_add(rhs) }
+            fn checked_div(self, rhs: Self) -> Option<Self> { self.checked_div(rhs) }
+            fn checked_mul(self, rhs: Self) -> Option<Self> { self.checked_mul(rhs) }
+            fn checked_rem(self, rhs: Self) -> Option<Self> { self.checked_rem(rhs) }
+            fn checked_sub(self, rhs: Self) -> Option<Self> { self.checked_sub(rhs) }
+            fn checked_shl(self, rhs: Self) -> Option<Self> { self.checked_shl(rhs.try_into().unwrap_or(u32::MAX)) }
+            fn checked_shr(self, rhs: Self) -> Option<Self> { self.checked_shr(rhs.try_into().unwrap_or(u32::MAX)) }
+            fn is_nan(self) -> bool { false }
+        };
+        (@float_dependent_methods @float) => {
+            fn checked_add(self, rhs: Self) -> Option<Self> { Some(self + rhs) }
+            fn checked_div(self, rhs: Self) -> Option<Self> { Some(self / rhs) }
+            fn checked_mul(self, rhs: Self) -> Option<Self> { Some(self * rhs) }
+            fn checked_rem(self, rhs: Self) -> Option<Self> { Some(self % rhs) }
+            fn checked_sub(self, rhs: Self) -> Option<Self> { Some(self - rhs) }
+            fn checked_shl(self, _rhs: Self) -> Option<Self> { unimplemented!() }
+            fn checked_shr(self, _rhs: Self) -> Option<Self> { unimplemented!() }
+            fn is_nan(self) -> bool { self.is_nan() }
+        };
+    }
+
+    impl_traits!(U16, u16, 2, unsigned);
+    impl_traits!(U32, u32, 4, unsigned);
+    impl_traits!(U64, u64, 8, unsigned);
+    impl_traits!(U128, u128, 16, unsigned);
+    impl_traits!(I16, i16, 2, signed);
+    impl_traits!(I32, i32, 4, signed);
+    impl_traits!(I64, i64, 8, signed);
+    impl_traits!(I128, i128, 16, signed);
+    impl_traits!(F32, f32, 4, signed, @float);
+    impl_traits!(F64, f64, 8, signed, @float);
+
+    macro_rules! call_for_unsigned_types {
+        ($fn:ident, $byteorder:ident) => {
+            $fn::<U16<$byteorder>>();
+            $fn::<U32<$byteorder>>();
+            $fn::<U64<$byteorder>>();
+            $fn::<U128<$byteorder>>();
+        };
+    }
+
+    macro_rules! call_for_signed_types {
+        ($fn:ident, $byteorder:ident) => {
+            $fn::<I16<$byteorder>>();
+            $fn::<I32<$byteorder>>();
+            $fn::<I64<$byteorder>>();
+            $fn::<I128<$byteorder>>();
+        };
+    }
+
+    macro_rules! call_for_float_types {
+        ($fn:ident, $byteorder:ident) => {
+            $fn::<F32<$byteorder>>();
+            $fn::<F64<$byteorder>>();
+        };
+    }
+
+    macro_rules! call_for_all_types {
+        ($fn:ident, $byteorder:ident) => {
+            call_for_unsigned_types!($fn, $byteorder);
+            call_for_signed_types!($fn, $byteorder);
+            call_for_float_types!($fn, $byteorder);
+        };
+    }
+
+    #[cfg(target_endian = "big")]
+    type NonNativeEndian = LittleEndian;
+    #[cfg(target_endian = "little")]
+    type NonNativeEndian = BigEndian;
+
+    // We use a `u64` seed so that we can use `SeedableRng::seed_from_u64`.
+    // `SmallRng`'s `SeedableRng::Seed` differs by platform, so if we wanted to
+    // call `SeedableRng::from_seed`, which takes a `Seed`, we would need
+    // conditional compilation by `target_pointer_width`.
+    const RNG_SEED: u64 = 0x7A03CAE2F32B5B8F;
+
+    const RAND_ITERS: usize = if cfg!(any(miri, kani)) {
+        // The tests below which use this constant used to take a very long time
+        // on Miri, which slows down local development and CI jobs. We're not
+        // using Miri to check for the correctness of our code, but rather its
+        // soundness, and at least in the context of these particular tests, a
+        // single loop iteration is just as good for surfacing UB as multiple
+        // iterations are.
+        //
+        // As of the writing of this comment, here's one set of measurements:
+        //
+        //   $ # RAND_ITERS == 1
+        //   $ cargo miri test -- -Z unstable-options --report-time endian
+        //   test byteorder::tests::test_native_endian ... ok <0.049s>
+        //   test byteorder::tests::test_non_native_endian ... ok <0.061s>
+        //
+        //   $ # RAND_ITERS == 1024
+        //   $ cargo miri test -- -Z unstable-options --report-time endian
+        //   test byteorder::tests::test_native_endian ... ok <25.716s>
+        //   test byteorder::tests::test_non_native_endian ... ok <38.127s>
+        1
+    } else {
+        1024
+    };
+
+    #[cfg_attr(test, test)]
+    #[cfg_attr(kani, kani::proof)]
+    fn test_zero() {
+        fn test_zero<T: ByteOrderType>() {
+            assert_eq!(T::ZERO.get(), T::Native::ZERO);
+        }
+
+        call_for_all_types!(test_zero, NativeEndian);
+        call_for_all_types!(test_zero, NonNativeEndian);
+    }
+
+    #[cfg_attr(test, test)]
+    #[cfg_attr(kani, kani::proof)]
+    fn test_max_value() {
+        fn test_max_value<T: ByteOrderTypeUnsigned>() {
+            assert_eq!(T::MAX_VALUE.get(), T::Native::MAX_VALUE);
+        }
+
+        call_for_unsigned_types!(test_max_value, NativeEndian);
+        call_for_unsigned_types!(test_max_value, NonNativeEndian);
+    }
+
+    #[cfg_attr(test, test)]
+    #[cfg_attr(kani, kani::proof)]
+    fn test_endian() {
+        fn test<T: ByteOrderType>(invert: bool) {
+            let mut r = SmallRng::seed_from_u64(RNG_SEED);
+            for _ in 0..RAND_ITERS {
+                let native = T::Native::rand(&mut r);
+                let mut bytes = T::ByteArray::default();
+                bytes.as_bytes_mut().copy_from_slice(native.as_bytes());
+                if invert {
+                    bytes = bytes.invert();
+                }
+                let mut from_native = T::new(native);
+                let from_bytes = T::from_bytes(bytes);
+
+                from_native.assert_eq_or_nan(from_bytes);
+                from_native.get().assert_eq_or_nan(native);
+                from_bytes.get().assert_eq_or_nan(native);
+
+                assert_eq!(from_native.into_bytes(), bytes);
+                assert_eq!(from_bytes.into_bytes(), bytes);
+
+                let updated = T::Native::rand(&mut r);
+                from_native.set(updated);
+                from_native.get().assert_eq_or_nan(updated);
+            }
+        }
+
+        fn test_native<T: ByteOrderType>() {
+            test::<T>(false);
+        }
+
+        fn test_non_native<T: ByteOrderType>() {
+            test::<T>(true);
+        }
+
+        call_for_all_types!(test_native, NativeEndian);
+        call_for_all_types!(test_non_native, NonNativeEndian);
+    }
+
+    #[test]
+    fn test_ops_impls() {
+        // Test implementations of traits in `core::ops`. Some of these are
+        // fairly banal, but some are optimized to perform the operation without
+        // swapping byte order (namely, bit-wise operations which are identical
+        // regardless of byte order). These are important to test, and while
+        // we're testing those anyway, it's trivial to test all of the impls.
+
+        fn test<T, F, G, H>(op: F, op_native: G, op_native_checked: Option<H>)
+        where
+            T: ByteOrderType,
+            F: Fn(T, T) -> T,
+            G: Fn(T::Native, T::Native) -> T::Native,
+            H: Fn(T::Native, T::Native) -> Option<T::Native>,
+        {
+            let mut r = SmallRng::seed_from_u64(RNG_SEED);
+            for _ in 0..RAND_ITERS {
+                let n0 = T::Native::rand(&mut r);
+                let n1 = T::Native::rand(&mut r);
+                let t0 = T::new(n0);
+                let t1 = T::new(n1);
+
+                // If this operation would overflow/underflow, skip it rather
+                // than attempt to catch and recover from panics.
+                if matches!(&op_native_checked, Some(checked) if checked(n0, n1).is_none()) {
+                    continue;
+                }
+
+                let n_res = op_native(n0, n1);
+                let t_res = op(t0, t1);
+
+                // For `f32` and `f64`, NaN values are not considered equal to
+                // themselves. We store `Option<f32>`/`Option<f64>` and store
+                // NaN as `None` so they can still be compared.
+                let n_res = (!T::Native::is_nan(n_res)).then(|| n_res);
+                let t_res = (!T::Native::is_nan(t_res.get())).then(|| t_res.get());
+                assert_eq!(n_res, t_res);
+            }
+        }
+
+        macro_rules! test {
+            (@binary $trait:ident, $method:ident $([$checked_method:ident])?, $($call_for_macros:ident),*) => {{
+                test!(
+                    @inner $trait,
+                    core::ops::$trait::$method,
+                    core::ops::$trait::$method,
+                    {
+                        #[allow(unused_mut, unused_assignments)]
+                        let mut op_native_checked = None::<fn(T::Native, T::Native) -> Option<T::Native>>;
+                        $(
+                            op_native_checked = Some(T::Native::$checked_method);
+                        )?
+                        op_native_checked
+                    },
+                    $($call_for_macros),*
+                );
+            }};
+            (@unary $trait:ident, $method:ident $([$checked_method:ident])?, $($call_for_macros:ident),*) => {{
+                test!(
+                    @inner $trait,
+                    |slf, _rhs| core::ops::$trait::$method(slf),
+                    |slf, _rhs| core::ops::$trait::$method(slf),
+                    {
+                        #[allow(unused_mut, unused_assignments)]
+                        let mut op_native_checked = None::<fn(T::Native, T::Native) -> Option<T::Native>>;
+                        $(
+                            op_native_checked = Some(|slf, _rhs| T::Native::$checked_method(slf));
+                        )?
+                        op_native_checked
+                    },
+                    $($call_for_macros),*
+                );
+            }};
+            (@inner $trait:ident, $op:expr, $op_native:expr, $op_native_checked:expr, $($call_for_macros:ident),*) => {{
+                fn t<T: ByteOrderType + core::ops::$trait<Output = T>>()
+                where
+                    T::Native: core::ops::$trait<Output = T::Native>,
+                {
+                    test::<T, _, _, _>(
+                        $op,
+                        $op_native,
+                        $op_native_checked,
+                    );
+                }
+
+                $(
+                    $call_for_macros!(t, NativeEndian);
+                    $call_for_macros!(t, NonNativeEndian);
+                )*
+            }};
+        }
+
+        test!(@binary Add, add[checked_add], call_for_all_types);
+        test!(@binary Div, div[checked_div], call_for_all_types);
+        test!(@binary Mul, mul[checked_mul], call_for_all_types);
+        test!(@binary Rem, rem[checked_rem], call_for_all_types);
+        test!(@binary Sub, sub[checked_sub], call_for_all_types);
+
+        test!(@binary BitAnd, bitand, call_for_unsigned_types, call_for_signed_types);
+        test!(@binary BitOr, bitor, call_for_unsigned_types, call_for_signed_types);
+        test!(@binary BitXor, bitxor, call_for_unsigned_types, call_for_signed_types);
+        test!(@binary Shl, shl[checked_shl], call_for_unsigned_types, call_for_signed_types);
+        test!(@binary Shr, shr[checked_shr], call_for_unsigned_types, call_for_signed_types);
+
+        test!(@unary Not, not, call_for_signed_types, call_for_unsigned_types);
+        test!(@unary Neg, neg, call_for_signed_types, call_for_float_types);
+    }
+
+    #[test]
+    fn test_debug_impl() {
+        // Ensure that Debug applies format options to the inner value.
+        let val = U16::<LE>::new(10);
+        assert_eq!(format!("{:?}", val), "U16(10)");
+        assert_eq!(format!("{:03?}", val), "U16(010)");
+        assert_eq!(format!("{:x?}", val), "U16(a)");
+    }
+}