1// Copyright 2019 The Fuchsia Authors
2//
3// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
4// <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT
5// license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option.
6// This file may not be copied, modified, or distributed except according to
7// those terms.
8
9//! Byte order-aware numeric primitives.
10//!
11//! This module contains equivalents of the native multi-byte integer types with
12//! no alignment requirement and supporting byte order conversions.
13//!
14//! For each native multi-byte integer type - `u16`, `i16`, `u32`, etc - and
15//! floating point type - `f32` and `f64` - an equivalent type is defined by
16//! this module - [`U16`], [`I16`], [`U32`], [`F32`], [`F64`], etc. Unlike their
17//! native counterparts, these types have alignment 1, and take a type parameter
18//! specifying the byte order in which the bytes are stored in memory. Each type
19//! implements this crate's relevant conversion and marker traits.
20//!
21//! These two properties, taken together, make these types useful for defining
22//! data structures whose memory layout matches a wire format such as that of a
23//! network protocol or a file format. Such formats often have multi-byte values
24//! at offsets that do not respect the alignment requirements of the equivalent
25//! native types, and stored in a byte order not necessarily the same as that of
26//! the target platform.
27//!
28//! Type aliases are provided for common byte orders in the [`big_endian`],
29//! [`little_endian`], [`network_endian`], and [`native_endian`] submodules.
30//!
31//! # Example
32//!
33//! One use of these types is for representing network packet formats, such as
34//! UDP:
35//!
36//! ```rust
37//! use zerocopy::{*, byteorder::network_endian::U16};
38//! # use zerocopy_derive::*;
39//!
40//! #[derive(FromBytes, IntoBytes, KnownLayout, Immutable, Unaligned)]
41//! #[repr(C)]
42//! struct UdpHeader {
43//! src_port: U16,
44//! dst_port: U16,
45//! length: U16,
46//! checksum: U16,
47//! }
48//!
49//! #[derive(FromBytes, IntoBytes, KnownLayout, Immutable, Unaligned)]
50//! #[repr(C, packed)]
51//! struct UdpPacket {
52//! header: UdpHeader,
53//! body: [u8],
54//! }
55//!
56//! impl UdpPacket {
57//! fn parse(bytes: &[u8]) -> Option<&UdpPacket> {
58//! UdpPacket::ref_from_bytes(bytes).ok()
59//! }
60//! }
61//! ```
62
63use core::{
64 convert::{TryFrom, TryInto},
65 fmt::{Binary, Debug, LowerHex, Octal, UpperHex},
66 hash::Hash,
67 num::TryFromIntError,
68};
69
70use super::*;
71
72/// A type-level representation of byte order.
73///
74/// This type is implemented by [`BigEndian`] and [`LittleEndian`], which
75/// represent big-endian and little-endian byte order respectively. This module
76/// also provides a number of useful aliases for those types: [`NativeEndian`],
77/// [`NetworkEndian`], [`BE`], and [`LE`].
78///
79/// `ByteOrder` types can be used to specify the byte order of the types in this
80/// module - for example, [`U32<BigEndian>`] is a 32-bit integer stored in
81/// big-endian byte order.
82///
83/// [`U32<BigEndian>`]: U32
84pub trait ByteOrder:
85 Copy + Clone + Debug + Display + Eq + PartialEq + Ord + PartialOrd + Hash + private::Sealed
86{
87 #[doc(hidden)]
88 const ORDER: Order;
89}
90
91mod private {
92 pub trait Sealed {}
93
94 impl Sealed for super::BigEndian {}
95 impl Sealed for super::LittleEndian {}
96}
97
98#[allow(missing_copy_implementations, missing_debug_implementations)]
99#[doc(hidden)]
100pub enum Order {
101 BigEndian,
102 LittleEndian,
103}
104
105/// Big-endian byte order.
106///
107/// See [`ByteOrder`] for more details.
108#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
109pub enum BigEndian {}
110
111impl ByteOrder for BigEndian {
112 const ORDER: Order = Order::BigEndian;
113}
114
115impl Display for BigEndian {
116 #[inline]
117 fn fmt(&self, _: &mut Formatter<'_>) -> fmt::Result {
118 match *self {}
119 }
120}
121
122/// Little-endian byte order.
123///
124/// See [`ByteOrder`] for more details.
125#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
126pub enum LittleEndian {}
127
128impl ByteOrder for LittleEndian {
129 const ORDER: Order = Order::LittleEndian;
130}
131
132impl Display for LittleEndian {
133 #[inline]
134 fn fmt(&self, _: &mut Formatter<'_>) -> fmt::Result {
135 match *self {}
136 }
137}
138
139/// The endianness used by this platform.
140///
141/// This is a type alias for [`BigEndian`] or [`LittleEndian`] depending on the
142/// endianness of the target platform.
143#[cfg(target_endian = "big")]
144pub type NativeEndian = BigEndian;
145
146/// The endianness used by this platform.
147///
148/// This is a type alias for [`BigEndian`] or [`LittleEndian`] depending on the
149/// endianness of the target platform.
150#[cfg(target_endian = "little")]
151pub type NativeEndian = LittleEndian;
152
153/// The endianness used in many network protocols.
154///
155/// This is a type alias for [`BigEndian`].
156pub type NetworkEndian = BigEndian;
157
158/// A type alias for [`BigEndian`].
159pub type BE = BigEndian;
160
161/// A type alias for [`LittleEndian`].
162pub type LE = LittleEndian;
163
164macro_rules! impl_fmt_trait {
165 ($name:ident, $native:ident, $trait:ident) => {
166 impl<O: ByteOrder> $trait for $name<O> {
167 #[inline(always)]
168 fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
169 $trait::fmt(&self.get(), f)
170 }
171 }
172 };
173}
174
175macro_rules! impl_fmt_traits {
176 ($name:ident, $native:ident, "floating point number") => {
177 impl_fmt_trait!($name, $native, Display);
178 };
179 ($name:ident, $native:ident, "unsigned integer") => {
180 impl_fmt_traits!($name, $native, @all_types);
181 };
182 ($name:ident, $native:ident, "signed integer") => {
183 impl_fmt_traits!($name, $native, @all_types);
184 };
185 ($name:ident, $native:ident, @all_types) => {
186 impl_fmt_trait!($name, $native, Display);
187 impl_fmt_trait!($name, $native, Octal);
188 impl_fmt_trait!($name, $native, LowerHex);
189 impl_fmt_trait!($name, $native, UpperHex);
190 impl_fmt_trait!($name, $native, Binary);
191 };
192}
193
194macro_rules! impl_ops_traits {
195 ($name:ident, $native:ident, "floating point number") => {
196 impl_ops_traits!($name, $native, @all_types);
197 impl_ops_traits!($name, $native, @signed_integer_floating_point);
198
199 impl<O: ByteOrder> PartialOrd for $name<O> {
200 #[inline(always)]
201 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
202 self.get().partial_cmp(&other.get())
203 }
204 }
205 };
206 ($name:ident, $native:ident, "unsigned integer") => {
207 impl_ops_traits!($name, $native, @signed_unsigned_integer);
208 impl_ops_traits!($name, $native, @all_types);
209 };
210 ($name:ident, $native:ident, "signed integer") => {
211 impl_ops_traits!($name, $native, @signed_unsigned_integer);
212 impl_ops_traits!($name, $native, @signed_integer_floating_point);
213 impl_ops_traits!($name, $native, @all_types);
214 };
215 ($name:ident, $native:ident, @signed_unsigned_integer) => {
216 impl_ops_traits!(@without_byteorder_swap $name, $native, BitAnd, bitand, BitAndAssign, bitand_assign);
217 impl_ops_traits!(@without_byteorder_swap $name, $native, BitOr, bitor, BitOrAssign, bitor_assign);
218 impl_ops_traits!(@without_byteorder_swap $name, $native, BitXor, bitxor, BitXorAssign, bitxor_assign);
219 impl_ops_traits!(@with_byteorder_swap $name, $native, Shl, shl, ShlAssign, shl_assign);
220 impl_ops_traits!(@with_byteorder_swap $name, $native, Shr, shr, ShrAssign, shr_assign);
221
222 impl<O> core::ops::Not for $name<O> {
223 type Output = $name<O>;
224
225 #[inline(always)]
226 fn not(self) -> $name<O> {
227 let self_native = $native::from_ne_bytes(self.0);
228 $name((!self_native).to_ne_bytes(), PhantomData)
229 }
230 }
231
232 impl<O: ByteOrder> PartialOrd for $name<O> {
233 #[inline(always)]
234 fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
235 Some(self.cmp(other))
236 }
237 }
238
239 impl<O: ByteOrder> Ord for $name<O> {
240 #[inline(always)]
241 fn cmp(&self, other: &Self) -> Ordering {
242 self.get().cmp(&other.get())
243 }
244 }
245
246 impl<O: ByteOrder> PartialOrd<$native> for $name<O> {
247 #[inline(always)]
248 fn partial_cmp(&self, other: &$native) -> Option<Ordering> {
249 self.get().partial_cmp(other)
250 }
251 }
252 };
253 ($name:ident, $native:ident, @signed_integer_floating_point) => {
254 impl<O: ByteOrder> core::ops::Neg for $name<O> {
255 type Output = $name<O>;
256
257 #[inline(always)]
258 fn neg(self) -> $name<O> {
259 let self_native: $native = self.get();
260 #[allow(clippy::arithmetic_side_effects)]
261 $name::<O>::new(-self_native)
262 }
263 }
264 };
265 ($name:ident, $native:ident, @all_types) => {
266 impl_ops_traits!(@with_byteorder_swap $name, $native, Add, add, AddAssign, add_assign);
267 impl_ops_traits!(@with_byteorder_swap $name, $native, Div, div, DivAssign, div_assign);
268 impl_ops_traits!(@with_byteorder_swap $name, $native, Mul, mul, MulAssign, mul_assign);
269 impl_ops_traits!(@with_byteorder_swap $name, $native, Rem, rem, RemAssign, rem_assign);
270 impl_ops_traits!(@with_byteorder_swap $name, $native, Sub, sub, SubAssign, sub_assign);
271 };
272 (@with_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
273 impl<O: ByteOrder> core::ops::$trait<$name<O>> for $name<O> {
274 type Output = $name<O>;
275
276 #[inline(always)]
277 fn $method(self, rhs: $name<O>) -> $name<O> {
278 let self_native: $native = self.get();
279 let rhs_native: $native = rhs.get();
280 let result_native = core::ops::$trait::$method(self_native, rhs_native);
281 $name::<O>::new(result_native)
282 }
283 }
284
285 impl<O: ByteOrder> core::ops::$trait<$name<O>> for $native {
286 type Output = $name<O>;
287
288 #[inline(always)]
289 fn $method(self, rhs: $name<O>) -> $name<O> {
290 let rhs_native: $native = rhs.get();
291 let result_native = core::ops::$trait::$method(self, rhs_native);
292 $name::<O>::new(result_native)
293 }
294 }
295
296 impl<O: ByteOrder> core::ops::$trait<$native> for $name<O> {
297 type Output = $name<O>;
298
299 #[inline(always)]
300 fn $method(self, rhs: $native) -> $name<O> {
301 let self_native: $native = self.get();
302 let result_native = core::ops::$trait::$method(self_native, rhs);
303 $name::<O>::new(result_native)
304 }
305 }
306
307 impl<O: ByteOrder> core::ops::$trait_assign<$name<O>> for $name<O> {
308 #[inline(always)]
309 fn $method_assign(&mut self, rhs: $name<O>) {
310 *self = core::ops::$trait::$method(*self, rhs);
311 }
312 }
313
314 impl<O: ByteOrder> core::ops::$trait_assign<$name<O>> for $native {
315 #[inline(always)]
316 fn $method_assign(&mut self, rhs: $name<O>) {
317 let rhs_native: $native = rhs.get();
318 *self = core::ops::$trait::$method(*self, rhs_native);
319 }
320 }
321
322 impl<O: ByteOrder> core::ops::$trait_assign<$native> for $name<O> {
323 #[inline(always)]
324 fn $method_assign(&mut self, rhs: $native) {
325 *self = core::ops::$trait::$method(*self, rhs);
326 }
327 }
328 };
329 // Implement traits in terms of the same trait on the native type, but
330 // without performing a byte order swap when both operands are byteorder
331 // types. This only works for bitwise operations like `&`, `|`, etc.
332 //
333 // When only one operand is a byteorder type, we still need to perform a
334 // byteorder swap.
335 (@without_byteorder_swap $name:ident, $native:ident, $trait:ident, $method:ident, $trait_assign:ident, $method_assign:ident) => {
336 impl<O: ByteOrder> core::ops::$trait<$name<O>> for $name<O> {
337 type Output = $name<O>;
338
339 #[inline(always)]
340 fn $method(self, rhs: $name<O>) -> $name<O> {
341 let self_native = $native::from_ne_bytes(self.0);
342 let rhs_native = $native::from_ne_bytes(rhs.0);
343 let result_native = core::ops::$trait::$method(self_native, rhs_native);
344 $name(result_native.to_ne_bytes(), PhantomData)
345 }
346 }
347
348 impl<O: ByteOrder> core::ops::$trait<$name<O>> for $native {
349 type Output = $name<O>;
350
351 #[inline(always)]
352 fn $method(self, rhs: $name<O>) -> $name<O> {
353 // No runtime cost - just byte packing
354 let rhs_native = $native::from_ne_bytes(rhs.0);
355 // (Maybe) runtime cost - byte order swap
356 let slf_byteorder = $name::<O>::new(self);
357 // No runtime cost - just byte packing
358 let slf_native = $native::from_ne_bytes(slf_byteorder.0);
359 // Runtime cost - perform the operation
360 let result_native = core::ops::$trait::$method(slf_native, rhs_native);
361 // No runtime cost - just byte unpacking
362 $name(result_native.to_ne_bytes(), PhantomData)
363 }
364 }
365
366 impl<O: ByteOrder> core::ops::$trait<$native> for $name<O> {
367 type Output = $name<O>;
368
369 #[inline(always)]
370 fn $method(self, rhs: $native) -> $name<O> {
371 // (Maybe) runtime cost - byte order swap
372 let rhs_byteorder = $name::<O>::new(rhs);
373 // No runtime cost - just byte packing
374 let rhs_native = $native::from_ne_bytes(rhs_byteorder.0);
375 // No runtime cost - just byte packing
376 let slf_native = $native::from_ne_bytes(self.0);
377 // Runtime cost - perform the operation
378 let result_native = core::ops::$trait::$method(slf_native, rhs_native);
379 // No runtime cost - just byte unpacking
380 $name(result_native.to_ne_bytes(), PhantomData)
381 }
382 }
383
384 impl<O: ByteOrder> core::ops::$trait_assign<$name<O>> for $name<O> {
385 #[inline(always)]
386 fn $method_assign(&mut self, rhs: $name<O>) {
387 *self = core::ops::$trait::$method(*self, rhs);
388 }
389 }
390
391 impl<O: ByteOrder> core::ops::$trait_assign<$name<O>> for $native {
392 #[inline(always)]
393 fn $method_assign(&mut self, rhs: $name<O>) {
394 // (Maybe) runtime cost - byte order swap
395 let rhs_native = rhs.get();
396 // Runtime cost - perform the operation
397 *self = core::ops::$trait::$method(*self, rhs_native);
398 }
399 }
400
401 impl<O: ByteOrder> core::ops::$trait_assign<$native> for $name<O> {
402 #[inline(always)]
403 fn $method_assign(&mut self, rhs: $native) {
404 *self = core::ops::$trait::$method(*self, rhs);
405 }
406 }
407 };
408}
409
410macro_rules! doc_comment {
411 ($x:expr, $($tt:tt)*) => {
412 #[doc = $x]
413 $($tt)*
414 };
415}
416
417macro_rules! define_max_value_constant {
418 ($name:ident, $bytes:expr, "unsigned integer") => {
419 /// The maximum value.
420 ///
421 /// This constant should be preferred to constructing a new value using
422 /// `new`, as `new` may perform an endianness swap depending on the
423 /// endianness `O` and the endianness of the platform.
424 pub const MAX_VALUE: $name<O> = $name([0xFFu8; $bytes], PhantomData);
425 };
426 // We don't provide maximum and minimum value constants for signed values
427 // and floats because there's no way to do it generically - it would require
428 // a different value depending on the value of the `ByteOrder` type
429 // parameter. Currently, one workaround would be to provide implementations
430 // for concrete implementations of that trait. In the long term, if we are
431 // ever able to make the `new` constructor a const fn, we could use that
432 // instead.
433 ($name:ident, $bytes:expr, "signed integer") => {};
434 ($name:ident, $bytes:expr, "floating point number") => {};
435}
436
437macro_rules! define_type {
438 (
439 $article:ident,
440 $description:expr,
441 $name:ident,
442 $native:ident,
443 $bits:expr,
444 $bytes:expr,
445 $from_be_fn:path,
446 $to_be_fn:path,
447 $from_le_fn:path,
448 $to_le_fn:path,
449 $number_kind:tt,
450 [$($larger_native:ty),*],
451 [$($larger_native_try:ty),*],
452 [$($larger_byteorder:ident),*],
453 [$($larger_byteorder_try:ident),*]
454 ) => {
455 doc_comment! {
456 concat!($description, " stored in a given byte order.
457
458`", stringify!($name), "` is like the native `", stringify!($native), "` type with
459two major differences: First, it has no alignment requirement (its alignment is 1).
460Second, the endianness of its memory layout is given by the type parameter `O`,
461which can be any type which implements [`ByteOrder`]. In particular, this refers
462to [`BigEndian`], [`LittleEndian`], [`NativeEndian`], and [`NetworkEndian`].
463
464", stringify!($article), " `", stringify!($name), "` can be constructed using
465the [`new`] method, and its contained value can be obtained as a native
466`",stringify!($native), "` using the [`get`] method, or updated in place with
467the [`set`] method. In all cases, if the endianness `O` is not the same as the
468endianness of the current platform, an endianness swap will be performed in
469order to uphold the invariants that a) the layout of `", stringify!($name), "`
470has endianness `O` and that, b) the layout of `", stringify!($native), "` has
471the platform's native endianness.
472
473`", stringify!($name), "` implements [`FromBytes`], [`IntoBytes`], and [`Unaligned`],
474making it useful for parsing and serialization. See the module documentation for an
475example of how it can be used for parsing UDP packets.
476
477[`new`]: crate::byteorder::", stringify!($name), "::new
478[`get`]: crate::byteorder::", stringify!($name), "::get
479[`set`]: crate::byteorder::", stringify!($name), "::set
480[`FromBytes`]: crate::FromBytes
481[`IntoBytes`]: crate::IntoBytes
482[`Unaligned`]: crate::Unaligned"),
483 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
484 #[cfg_attr(any(feature = "derive", test), derive(KnownLayout, Immutable, FromBytes, IntoBytes, Unaligned))]
485 #[repr(transparent)]
486 pub struct $name<O>([u8; $bytes], PhantomData<O>);
487 }
488
489 #[cfg(not(any(feature = "derive", test)))]
490 impl_known_layout!(O => $name<O>);
491
492 safety_comment! {
493 /// SAFETY:
494 /// `$name<O>` is `repr(transparent)`, and so it has the same layout
495 /// as its only non-zero field, which is a `u8` array. `u8` arrays
496 /// are `Immutable`, `TryFromBytes`, `FromZeros`, `FromBytes`,
497 /// `IntoBytes`, and `Unaligned`.
498 impl_or_verify!(O => Immutable for $name<O>);
499 impl_or_verify!(O => TryFromBytes for $name<O>);
500 impl_or_verify!(O => FromZeros for $name<O>);
501 impl_or_verify!(O => FromBytes for $name<O>);
502 impl_or_verify!(O => IntoBytes for $name<O>);
503 impl_or_verify!(O => Unaligned for $name<O>);
504 }
505
506 impl<O> Default for $name<O> {
507 #[inline(always)]
508 fn default() -> $name<O> {
509 $name::ZERO
510 }
511 }
512
513 impl<O> $name<O> {
514 /// The value zero.
515 ///
516 /// This constant should be preferred to constructing a new value
517 /// using `new`, as `new` may perform an endianness swap depending
518 /// on the endianness and platform.
519 pub const ZERO: $name<O> = $name([0u8; $bytes], PhantomData);
520
521 define_max_value_constant!($name, $bytes, $number_kind);
522
523 /// Constructs a new value from bytes which are already in `O` byte
524 /// order.
525 #[must_use = "has no side effects"]
526 #[inline(always)]
527 pub const fn from_bytes(bytes: [u8; $bytes]) -> $name<O> {
528 $name(bytes, PhantomData)
529 }
530
531 /// Extracts the bytes of `self` without swapping the byte order.
532 ///
533 /// The returned bytes will be in `O` byte order.
534 #[must_use = "has no side effects"]
535 #[inline(always)]
536 pub const fn to_bytes(self) -> [u8; $bytes] {
537 self.0
538 }
539 }
540
541 impl<O: ByteOrder> $name<O> {
542 maybe_const_trait_bounded_fn! {
543 /// Constructs a new value, possibly performing an endianness
544 /// swap to guarantee that the returned value has endianness
545 /// `O`.
546 #[must_use = "has no side effects"]
547 #[inline(always)]
548 pub const fn new(n: $native) -> $name<O> {
549 let bytes = match O::ORDER {
550 Order::BigEndian => $to_be_fn(n),
551 Order::LittleEndian => $to_le_fn(n),
552 };
553
554 $name(bytes, PhantomData)
555 }
556 }
557
558 maybe_const_trait_bounded_fn! {
559 /// Returns the value as a primitive type, possibly performing
560 /// an endianness swap to guarantee that the return value has
561 /// the endianness of the native platform.
562 #[must_use = "has no side effects"]
563 #[inline(always)]
564 pub const fn get(self) -> $native {
565 match O::ORDER {
566 Order::BigEndian => $from_be_fn(self.0),
567 Order::LittleEndian => $from_le_fn(self.0),
568 }
569 }
570 }
571
572 /// Updates the value in place as a primitive type, possibly
573 /// performing an endianness swap to guarantee that the stored value
574 /// has the endianness `O`.
575 #[inline(always)]
576 pub fn set(&mut self, n: $native) {
577 *self = Self::new(n);
578 }
579 }
580
581 // The reasoning behind which traits to implement here is to only
582 // implement traits which won't cause inference issues. Notably,
583 // comparison traits like PartialEq and PartialOrd tend to cause
584 // inference issues.
585
586 impl<O: ByteOrder> From<$name<O>> for [u8; $bytes] {
587 #[inline(always)]
588 fn from(x: $name<O>) -> [u8; $bytes] {
589 x.0
590 }
591 }
592
593 impl<O: ByteOrder> From<[u8; $bytes]> for $name<O> {
594 #[inline(always)]
595 fn from(bytes: [u8; $bytes]) -> $name<O> {
596 $name(bytes, PhantomData)
597 }
598 }
599
600 impl<O: ByteOrder> From<$name<O>> for $native {
601 #[inline(always)]
602 fn from(x: $name<O>) -> $native {
603 x.get()
604 }
605 }
606
607 impl<O: ByteOrder> From<$native> for $name<O> {
608 #[inline(always)]
609 fn from(x: $native) -> $name<O> {
610 $name::new(x)
611 }
612 }
613
614 $(
615 impl<O: ByteOrder> From<$name<O>> for $larger_native {
616 #[inline(always)]
617 fn from(x: $name<O>) -> $larger_native {
618 x.get().into()
619 }
620 }
621 )*
622
623 $(
624 impl<O: ByteOrder> TryFrom<$larger_native_try> for $name<O> {
625 type Error = TryFromIntError;
626 #[inline(always)]
627 fn try_from(x: $larger_native_try) -> Result<$name<O>, TryFromIntError> {
628 $native::try_from(x).map($name::new)
629 }
630 }
631 )*
632
633 $(
634 impl<O: ByteOrder, P: ByteOrder> From<$name<O>> for $larger_byteorder<P> {
635 #[inline(always)]
636 fn from(x: $name<O>) -> $larger_byteorder<P> {
637 $larger_byteorder::new(x.get().into())
638 }
639 }
640 )*
641
642 $(
643 impl<O: ByteOrder, P: ByteOrder> TryFrom<$larger_byteorder_try<P>> for $name<O> {
644 type Error = TryFromIntError;
645 #[inline(always)]
646 fn try_from(x: $larger_byteorder_try<P>) -> Result<$name<O>, TryFromIntError> {
647 x.get().try_into().map($name::new)
648 }
649 }
650 )*
651
652 impl<O> AsRef<[u8; $bytes]> for $name<O> {
653 #[inline(always)]
654 fn as_ref(&self) -> &[u8; $bytes] {
655 &self.0
656 }
657 }
658
659 impl<O> AsMut<[u8; $bytes]> for $name<O> {
660 #[inline(always)]
661 fn as_mut(&mut self) -> &mut [u8; $bytes] {
662 &mut self.0
663 }
664 }
665
666 impl<O> PartialEq<$name<O>> for [u8; $bytes] {
667 #[inline(always)]
668 fn eq(&self, other: &$name<O>) -> bool {
669 self.eq(&other.0)
670 }
671 }
672
673 impl<O> PartialEq<[u8; $bytes]> for $name<O> {
674 #[inline(always)]
675 fn eq(&self, other: &[u8; $bytes]) -> bool {
676 self.0.eq(other)
677 }
678 }
679
680 impl<O: ByteOrder> PartialEq<$native> for $name<O> {
681 #[inline(always)]
682 fn eq(&self, other: &$native) -> bool {
683 self.get().eq(other)
684 }
685 }
686
687 impl_fmt_traits!($name, $native, $number_kind);
688 impl_ops_traits!($name, $native, $number_kind);
689
690 impl<O: ByteOrder> Debug for $name<O> {
691 #[inline]
692 fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
693 // This results in a format like "U16(42)".
694 f.debug_tuple(stringify!($name)).field(&self.get()).finish()
695 }
696 }
697 };
698}
699
700define_type!(
701 A,
702 "A 16-bit unsigned integer",
703 U16,
704 u16,
705 16,
706 2,
707 u16::from_be_bytes,
708 u16::to_be_bytes,
709 u16::from_le_bytes,
710 u16::to_le_bytes,
711 "unsigned integer",
712 [u32, u64, u128, usize],
713 [u32, u64, u128, usize],
714 [U32, U64, U128, Usize],
715 [U32, U64, U128, Usize]
716);
717define_type!(
718 A,
719 "A 32-bit unsigned integer",
720 U32,
721 u32,
722 32,
723 4,
724 u32::from_be_bytes,
725 u32::to_be_bytes,
726 u32::from_le_bytes,
727 u32::to_le_bytes,
728 "unsigned integer",
729 [u64, u128],
730 [u64, u128],
731 [U64, U128],
732 [U64, U128]
733);
734define_type!(
735 A,
736 "A 64-bit unsigned integer",
737 U64,
738 u64,
739 64,
740 8,
741 u64::from_be_bytes,
742 u64::to_be_bytes,
743 u64::from_le_bytes,
744 u64::to_le_bytes,
745 "unsigned integer",
746 [u128],
747 [u128],
748 [U128],
749 [U128]
750);
751define_type!(
752 A,
753 "A 128-bit unsigned integer",
754 U128,
755 u128,
756 128,
757 16,
758 u128::from_be_bytes,
759 u128::to_be_bytes,
760 u128::from_le_bytes,
761 u128::to_le_bytes,
762 "unsigned integer",
763 [],
764 [],
765 [],
766 []
767);
768define_type!(
769 A,
770 "A word-sized unsigned integer",
771 Usize,
772 usize,
773 mem::size_of::<usize>() * 8,
774 mem::size_of::<usize>(),
775 usize::from_be_bytes,
776 usize::to_be_bytes,
777 usize::from_le_bytes,
778 usize::to_le_bytes,
779 "unsigned integer",
780 [],
781 [],
782 [],
783 []
784);
785define_type!(
786 An,
787 "A 16-bit signed integer",
788 I16,
789 i16,
790 16,
791 2,
792 i16::from_be_bytes,
793 i16::to_be_bytes,
794 i16::from_le_bytes,
795 i16::to_le_bytes,
796 "signed integer",
797 [i32, i64, i128, isize],
798 [i32, i64, i128, isize],
799 [I32, I64, I128, Isize],
800 [I32, I64, I128, Isize]
801);
802define_type!(
803 An,
804 "A 32-bit signed integer",
805 I32,
806 i32,
807 32,
808 4,
809 i32::from_be_bytes,
810 i32::to_be_bytes,
811 i32::from_le_bytes,
812 i32::to_le_bytes,
813 "signed integer",
814 [i64, i128],
815 [i64, i128],
816 [I64, I128],
817 [I64, I128]
818);
819define_type!(
820 An,
821 "A 64-bit signed integer",
822 I64,
823 i64,
824 64,
825 8,
826 i64::from_be_bytes,
827 i64::to_be_bytes,
828 i64::from_le_bytes,
829 i64::to_le_bytes,
830 "signed integer",
831 [i128],
832 [i128],
833 [I128],
834 [I128]
835);
836define_type!(
837 An,
838 "A 128-bit signed integer",
839 I128,
840 i128,
841 128,
842 16,
843 i128::from_be_bytes,
844 i128::to_be_bytes,
845 i128::from_le_bytes,
846 i128::to_le_bytes,
847 "signed integer",
848 [],
849 [],
850 [],
851 []
852);
853define_type!(
854 An,
855 "A word-sized signed integer",
856 Isize,
857 isize,
858 mem::size_of::<isize>() * 8,
859 mem::size_of::<isize>(),
860 isize::from_be_bytes,
861 isize::to_be_bytes,
862 isize::from_le_bytes,
863 isize::to_le_bytes,
864 "signed integer",
865 [],
866 [],
867 [],
868 []
869);
870
871// TODO(https://github.com/rust-lang/rust/issues/72447): Use the endianness
872// conversion methods directly once those are const-stable.
873macro_rules! define_float_conversion {
874 ($ty:ty, $bits:ident, $bytes:expr, $mod:ident) => {
875 mod $mod {
876 use super::*;
877
878 define_float_conversion!($ty, $bits, $bytes, from_be_bytes, to_be_bytes);
879 define_float_conversion!($ty, $bits, $bytes, from_le_bytes, to_le_bytes);
880 }
881 };
882 ($ty:ty, $bits:ident, $bytes:expr, $from:ident, $to:ident) => {
883 // Clippy: The suggestion of using `from_bits()` instead doesn't work
884 // because `from_bits` is not const-stable on our MSRV.
885 #[allow(clippy::transmute_int_to_float)]
886 pub(crate) const fn $from(bytes: [u8; $bytes]) -> $ty {
887 transmute!($bits::$from(bytes))
888 }
889
890 pub(crate) const fn $to(f: $ty) -> [u8; $bytes] {
891 // Clippy: The suggestion of using `f.to_bits()` instead doesn't
892 // work because `to_bits` is not const-stable on our MSRV.
893 #[allow(clippy::transmute_float_to_int)]
894 let bits: $bits = transmute!(f);
895 bits.$to()
896 }
897 };
898}
899
900define_float_conversion!(f32, u32, 4, f32_ext);
901define_float_conversion!(f64, u64, 8, f64_ext);
902
903define_type!(
904 An,
905 "A 32-bit floating point number",
906 F32,
907 f32,
908 32,
909 4,
910 f32_ext::from_be_bytes,
911 f32_ext::to_be_bytes,
912 f32_ext::from_le_bytes,
913 f32_ext::to_le_bytes,
914 "floating point number",
915 [f64],
916 [],
917 [F64],
918 []
919);
920define_type!(
921 An,
922 "A 64-bit floating point number",
923 F64,
924 f64,
925 64,
926 8,
927 f64_ext::from_be_bytes,
928 f64_ext::to_be_bytes,
929 f64_ext::from_le_bytes,
930 f64_ext::to_le_bytes,
931 "floating point number",
932 [],
933 [],
934 [],
935 []
936);
937
938macro_rules! module {
939 ($name:ident, $trait:ident, $endianness_str:expr) => {
940 /// Numeric primitives stored in
941 #[doc = $endianness_str]
942 /// byte order.
943 pub mod $name {
944 use super::$trait;
945
946 module!(@ty U16, $trait, "16-bit unsigned integer", $endianness_str);
947 module!(@ty U32, $trait, "32-bit unsigned integer", $endianness_str);
948 module!(@ty U64, $trait, "64-bit unsigned integer", $endianness_str);
949 module!(@ty U128, $trait, "128-bit unsigned integer", $endianness_str);
950 module!(@ty I16, $trait, "16-bit signed integer", $endianness_str);
951 module!(@ty I32, $trait, "32-bit signed integer", $endianness_str);
952 module!(@ty I64, $trait, "64-bit signed integer", $endianness_str);
953 module!(@ty I128, $trait, "128-bit signed integer", $endianness_str);
954 module!(@ty F32, $trait, "32-bit floating point number", $endianness_str);
955 module!(@ty F64, $trait, "64-bit floating point number", $endianness_str);
956 }
957 };
958 (@ty $ty:ident, $trait:ident, $desc_str:expr, $endianness_str:expr) => {
959 /// A
960 #[doc = $desc_str]
961 /// stored in
962 #[doc = $endianness_str]
963 /// byte order.
964 pub type $ty = crate::byteorder::$ty<$trait>;
965 };
966}
967
968module!(big_endian, BigEndian, "big-endian");
969module!(little_endian, LittleEndian, "little-endian");
970module!(network_endian, NetworkEndian, "network-endian");
971module!(native_endian, NativeEndian, "native-endian");
972
973#[cfg(any(test, kani))]
974mod tests {
975 use super::*;
976
977 #[cfg(not(kani))]
978 mod compatibility {
979 pub(super) use rand::{
980 distributions::{Distribution, Standard},
981 rngs::SmallRng,
982 Rng, SeedableRng,
983 };
984
985 pub(crate) trait Arbitrary {}
986
987 impl<T> Arbitrary for T {}
988 }
989
990 #[cfg(kani)]
991 mod compatibility {
992 pub(crate) use kani::Arbitrary;
993
994 pub(crate) struct SmallRng;
995
996 impl SmallRng {
997 pub(crate) fn seed_from_u64(_state: u64) -> Self {
998 Self
999 }
1000 }
1001
1002 pub(crate) trait Rng {
1003 fn sample<T, D: Distribution<T>>(&mut self, _distr: D) -> T
1004 where
1005 T: Arbitrary,
1006 {
1007 kani::any()
1008 }
1009 }
1010
1011 impl Rng for SmallRng {}
1012
1013 pub(crate) trait Distribution<T> {}
1014 impl<T, U> Distribution<T> for U {}
1015
1016 pub(crate) struct Standard;
1017 }
1018
1019 use compatibility::*;
1020
1021 // A native integer type (u16, i32, etc).
1022 trait Native: Arbitrary + FromBytes + IntoBytes + Immutable + Copy + PartialEq + Debug {
1023 const ZERO: Self;
1024 const MAX_VALUE: Self;
1025
1026 type Distribution: Distribution<Self>;
1027 const DIST: Self::Distribution;
1028
1029 fn rand<R: Rng>(rng: &mut R) -> Self {
1030 rng.sample(Self::DIST)
1031 }
1032
1033 #[cfg_attr(kani, allow(unused))]
1034 fn checked_add(self, rhs: Self) -> Option<Self>;
1035
1036 #[cfg_attr(kani, allow(unused))]
1037 fn checked_div(self, rhs: Self) -> Option<Self>;
1038
1039 #[cfg_attr(kani, allow(unused))]
1040 fn checked_mul(self, rhs: Self) -> Option<Self>;
1041
1042 #[cfg_attr(kani, allow(unused))]
1043 fn checked_rem(self, rhs: Self) -> Option<Self>;
1044
1045 #[cfg_attr(kani, allow(unused))]
1046 fn checked_sub(self, rhs: Self) -> Option<Self>;
1047
1048 #[cfg_attr(kani, allow(unused))]
1049 fn checked_shl(self, rhs: Self) -> Option<Self>;
1050
1051 #[cfg_attr(kani, allow(unused))]
1052 fn checked_shr(self, rhs: Self) -> Option<Self>;
1053
1054 fn is_nan(self) -> bool;
1055
1056 /// For `f32` and `f64`, NaN values are not considered equal to
1057 /// themselves. This method is like `assert_eq!`, but it treats NaN
1058 /// values as equal.
1059 fn assert_eq_or_nan(self, other: Self) {
1060 let slf = (!self.is_nan()).then(|| self);
1061 let other = (!other.is_nan()).then(|| other);
1062 assert_eq!(slf, other);
1063 }
1064 }
1065
1066 trait ByteArray:
1067 FromBytes + IntoBytes + Immutable + Copy + AsRef<[u8]> + AsMut<[u8]> + Debug + Default + Eq
1068 {
1069 /// Invert the order of the bytes in the array.
1070 fn invert(self) -> Self;
1071 }
1072
1073 trait ByteOrderType:
1074 FromBytes + IntoBytes + Unaligned + Copy + Eq + Debug + Hash + From<Self::Native>
1075 {
1076 type Native: Native;
1077 type ByteArray: ByteArray;
1078
1079 const ZERO: Self;
1080
1081 fn new(native: Self::Native) -> Self;
1082 fn get(self) -> Self::Native;
1083 fn set(&mut self, native: Self::Native);
1084 fn from_bytes(bytes: Self::ByteArray) -> Self;
1085 fn into_bytes(self) -> Self::ByteArray;
1086
1087 /// For `f32` and `f64`, NaN values are not considered equal to
1088 /// themselves. This method is like `assert_eq!`, but it treats NaN
1089 /// values as equal.
1090 fn assert_eq_or_nan(self, other: Self) {
1091 let slf = (!self.get().is_nan()).then(|| self);
1092 let other = (!other.get().is_nan()).then(|| other);
1093 assert_eq!(slf, other);
1094 }
1095 }
1096
1097 trait ByteOrderTypeUnsigned: ByteOrderType {
1098 const MAX_VALUE: Self;
1099 }
1100
1101 macro_rules! impl_byte_array {
1102 ($bytes:expr) => {
1103 impl ByteArray for [u8; $bytes] {
1104 fn invert(mut self) -> [u8; $bytes] {
1105 self.reverse();
1106 self
1107 }
1108 }
1109 };
1110 }
1111
1112 impl_byte_array!(2);
1113 impl_byte_array!(4);
1114 impl_byte_array!(8);
1115 impl_byte_array!(16);
1116
1117 macro_rules! impl_byte_order_type_unsigned {
1118 ($name:ident, unsigned) => {
1119 impl<O: ByteOrder> ByteOrderTypeUnsigned for $name<O> {
1120 const MAX_VALUE: $name<O> = $name::MAX_VALUE;
1121 }
1122 };
1123 ($name:ident, signed) => {};
1124 }
1125
1126 macro_rules! impl_traits {
1127 ($name:ident, $native:ident, $sign:ident $(, @$float:ident)?) => {
1128 impl Native for $native {
1129 // For some types, `0 as $native` is required (for example, when
1130 // `$native` is a floating-point type; `0` is an integer), but
1131 // for other types, it's a trivial cast. In all cases, Clippy
1132 // thinks it's dangerous.
1133 #[allow(trivial_numeric_casts, clippy::as_conversions)]
1134 const ZERO: $native = 0 as $native;
1135 const MAX_VALUE: $native = $native::MAX;
1136
1137 type Distribution = Standard;
1138 const DIST: Standard = Standard;
1139
1140 impl_traits!(@float_dependent_methods $(@$float)?);
1141 }
1142
1143 impl<O: ByteOrder> ByteOrderType for $name<O> {
1144 type Native = $native;
1145 type ByteArray = [u8; mem::size_of::<$native>()];
1146
1147 const ZERO: $name<O> = $name::ZERO;
1148
1149 fn new(native: $native) -> $name<O> {
1150 $name::new(native)
1151 }
1152
1153 fn get(self) -> $native {
1154 $name::get(self)
1155 }
1156
1157 fn set(&mut self, native: $native) {
1158 $name::set(self, native)
1159 }
1160
1161 fn from_bytes(bytes: [u8; mem::size_of::<$native>()]) -> $name<O> {
1162 $name::from(bytes)
1163 }
1164
1165 fn into_bytes(self) -> [u8; mem::size_of::<$native>()] {
1166 <[u8; mem::size_of::<$native>()]>::from(self)
1167 }
1168 }
1169
1170 impl_byte_order_type_unsigned!($name, $sign);
1171 };
1172 (@float_dependent_methods) => {
1173 fn checked_add(self, rhs: Self) -> Option<Self> { self.checked_add(rhs) }
1174 fn checked_div(self, rhs: Self) -> Option<Self> { self.checked_div(rhs) }
1175 fn checked_mul(self, rhs: Self) -> Option<Self> { self.checked_mul(rhs) }
1176 fn checked_rem(self, rhs: Self) -> Option<Self> { self.checked_rem(rhs) }
1177 fn checked_sub(self, rhs: Self) -> Option<Self> { self.checked_sub(rhs) }
1178 fn checked_shl(self, rhs: Self) -> Option<Self> { self.checked_shl(rhs.try_into().unwrap_or(u32::MAX)) }
1179 fn checked_shr(self, rhs: Self) -> Option<Self> { self.checked_shr(rhs.try_into().unwrap_or(u32::MAX)) }
1180 fn is_nan(self) -> bool { false }
1181 };
1182 (@float_dependent_methods @float) => {
1183 fn checked_add(self, rhs: Self) -> Option<Self> { Some(self + rhs) }
1184 fn checked_div(self, rhs: Self) -> Option<Self> { Some(self / rhs) }
1185 fn checked_mul(self, rhs: Self) -> Option<Self> { Some(self * rhs) }
1186 fn checked_rem(self, rhs: Self) -> Option<Self> { Some(self % rhs) }
1187 fn checked_sub(self, rhs: Self) -> Option<Self> { Some(self - rhs) }
1188 fn checked_shl(self, _rhs: Self) -> Option<Self> { unimplemented!() }
1189 fn checked_shr(self, _rhs: Self) -> Option<Self> { unimplemented!() }
1190 fn is_nan(self) -> bool { self.is_nan() }
1191 };
1192 }
1193
1194 impl_traits!(U16, u16, unsigned);
1195 impl_traits!(U32, u32, unsigned);
1196 impl_traits!(U64, u64, unsigned);
1197 impl_traits!(U128, u128, unsigned);
1198 impl_traits!(Usize, usize, unsigned);
1199 impl_traits!(I16, i16, signed);
1200 impl_traits!(I32, i32, signed);
1201 impl_traits!(I64, i64, signed);
1202 impl_traits!(I128, i128, signed);
1203 impl_traits!(Isize, isize, unsigned);
1204 impl_traits!(F32, f32, signed, @float);
1205 impl_traits!(F64, f64, signed, @float);
1206
1207 macro_rules! call_for_unsigned_types {
1208 ($fn:ident, $byteorder:ident) => {
1209 $fn::<U16<$byteorder>>();
1210 $fn::<U32<$byteorder>>();
1211 $fn::<U64<$byteorder>>();
1212 $fn::<U128<$byteorder>>();
1213 $fn::<Usize<$byteorder>>();
1214 };
1215 }
1216
1217 macro_rules! call_for_signed_types {
1218 ($fn:ident, $byteorder:ident) => {
1219 $fn::<I16<$byteorder>>();
1220 $fn::<I32<$byteorder>>();
1221 $fn::<I64<$byteorder>>();
1222 $fn::<I128<$byteorder>>();
1223 $fn::<Isize<$byteorder>>();
1224 };
1225 }
1226
1227 macro_rules! call_for_float_types {
1228 ($fn:ident, $byteorder:ident) => {
1229 $fn::<F32<$byteorder>>();
1230 $fn::<F64<$byteorder>>();
1231 };
1232 }
1233
1234 macro_rules! call_for_all_types {
1235 ($fn:ident, $byteorder:ident) => {
1236 call_for_unsigned_types!($fn, $byteorder);
1237 call_for_signed_types!($fn, $byteorder);
1238 call_for_float_types!($fn, $byteorder);
1239 };
1240 }
1241
1242 #[cfg(target_endian = "big")]
1243 type NonNativeEndian = LittleEndian;
1244 #[cfg(target_endian = "little")]
1245 type NonNativeEndian = BigEndian;
1246
1247 // We use a `u64` seed so that we can use `SeedableRng::seed_from_u64`.
1248 // `SmallRng`'s `SeedableRng::Seed` differs by platform, so if we wanted to
1249 // call `SeedableRng::from_seed`, which takes a `Seed`, we would need
1250 // conditional compilation by `target_pointer_width`.
1251 const RNG_SEED: u64 = 0x7A03CAE2F32B5B8F;
1252
1253 const RAND_ITERS: usize = if cfg!(any(miri, kani)) {
1254 // The tests below which use this constant used to take a very long time
1255 // on Miri, which slows down local development and CI jobs. We're not
1256 // using Miri to check for the correctness of our code, but rather its
1257 // soundness, and at least in the context of these particular tests, a
1258 // single loop iteration is just as good for surfacing UB as multiple
1259 // iterations are.
1260 //
1261 // As of the writing of this comment, here's one set of measurements:
1262 //
1263 // $ # RAND_ITERS == 1
1264 // $ cargo miri test -- -Z unstable-options --report-time endian
1265 // test byteorder::tests::test_native_endian ... ok <0.049s>
1266 // test byteorder::tests::test_non_native_endian ... ok <0.061s>
1267 //
1268 // $ # RAND_ITERS == 1024
1269 // $ cargo miri test -- -Z unstable-options --report-time endian
1270 // test byteorder::tests::test_native_endian ... ok <25.716s>
1271 // test byteorder::tests::test_non_native_endian ... ok <38.127s>
1272 1
1273 } else {
1274 1024
1275 };
1276
1277 #[test]
1278 fn test_const_methods() {
1279 use big_endian::*;
1280
1281 #[rustversion::since(1.61.0)]
1282 const _U: U16 = U16::new(0);
1283 #[rustversion::since(1.61.0)]
1284 const _NATIVE: u16 = _U.get();
1285 const _FROM_BYTES: U16 = U16::from_bytes([0, 1]);
1286 const _BYTES: [u8; 2] = _FROM_BYTES.to_bytes();
1287 }
1288
1289 #[cfg_attr(test, test)]
1290 #[cfg_attr(kani, kani::proof)]
1291 fn test_zero() {
1292 fn test_zero<T: ByteOrderType>() {
1293 assert_eq!(T::ZERO.get(), T::Native::ZERO);
1294 }
1295
1296 call_for_all_types!(test_zero, NativeEndian);
1297 call_for_all_types!(test_zero, NonNativeEndian);
1298 }
1299
1300 #[cfg_attr(test, test)]
1301 #[cfg_attr(kani, kani::proof)]
1302 fn test_max_value() {
1303 fn test_max_value<T: ByteOrderTypeUnsigned>() {
1304 assert_eq!(T::MAX_VALUE.get(), T::Native::MAX_VALUE);
1305 }
1306
1307 call_for_unsigned_types!(test_max_value, NativeEndian);
1308 call_for_unsigned_types!(test_max_value, NonNativeEndian);
1309 }
1310
1311 #[cfg_attr(test, test)]
1312 #[cfg_attr(kani, kani::proof)]
1313 fn test_endian() {
1314 fn test<T: ByteOrderType>(invert: bool) {
1315 let mut r = SmallRng::seed_from_u64(RNG_SEED);
1316 for _ in 0..RAND_ITERS {
1317 let native = T::Native::rand(&mut r);
1318 let mut bytes = T::ByteArray::default();
1319 bytes.as_mut_bytes().copy_from_slice(native.as_bytes());
1320 if invert {
1321 bytes = bytes.invert();
1322 }
1323 let mut from_native = T::new(native);
1324 let from_bytes = T::from_bytes(bytes);
1325
1326 from_native.assert_eq_or_nan(from_bytes);
1327 from_native.get().assert_eq_or_nan(native);
1328 from_bytes.get().assert_eq_or_nan(native);
1329
1330 assert_eq!(from_native.into_bytes(), bytes);
1331 assert_eq!(from_bytes.into_bytes(), bytes);
1332
1333 let updated = T::Native::rand(&mut r);
1334 from_native.set(updated);
1335 from_native.get().assert_eq_or_nan(updated);
1336 }
1337 }
1338
1339 fn test_native<T: ByteOrderType>() {
1340 test::<T>(false);
1341 }
1342
1343 fn test_non_native<T: ByteOrderType>() {
1344 test::<T>(true);
1345 }
1346
1347 call_for_all_types!(test_native, NativeEndian);
1348 call_for_all_types!(test_non_native, NonNativeEndian);
1349 }
1350
1351 #[test]
1352 fn test_ops_impls() {
1353 // Test implementations of traits in `core::ops`. Some of these are
1354 // fairly banal, but some are optimized to perform the operation without
1355 // swapping byte order (namely, bit-wise operations which are identical
1356 // regardless of byte order). These are important to test, and while
1357 // we're testing those anyway, it's trivial to test all of the impls.
1358
1359 fn test<T, FTT, FTN, FNT, FNN, FNNChecked, FATT, FATN, FANT>(
1360 op_t_t: FTT,
1361 op_t_n: FTN,
1362 op_n_t: FNT,
1363 op_n_n: FNN,
1364 op_n_n_checked: Option<FNNChecked>,
1365 op_assign: Option<(FATT, FATN, FANT)>,
1366 ) where
1367 T: ByteOrderType,
1368 FTT: Fn(T, T) -> T,
1369 FTN: Fn(T, T::Native) -> T,
1370 FNT: Fn(T::Native, T) -> T,
1371 FNN: Fn(T::Native, T::Native) -> T::Native,
1372 FNNChecked: Fn(T::Native, T::Native) -> Option<T::Native>,
1373
1374 FATT: Fn(&mut T, T),
1375 FATN: Fn(&mut T, T::Native),
1376 FANT: Fn(&mut T::Native, T),
1377 {
1378 let mut r = SmallRng::seed_from_u64(RNG_SEED);
1379 for _ in 0..RAND_ITERS {
1380 let n0 = T::Native::rand(&mut r);
1381 let n1 = T::Native::rand(&mut r);
1382 let t0 = T::new(n0);
1383 let t1 = T::new(n1);
1384
1385 // If this operation would overflow/underflow, skip it rather
1386 // than attempt to catch and recover from panics.
1387 if matches!(&op_n_n_checked, Some(checked) if checked(n0, n1).is_none()) {
1388 continue;
1389 }
1390
1391 let t_t_res = op_t_t(t0, t1);
1392 let t_n_res = op_t_n(t0, n1);
1393 let n_t_res = op_n_t(n0, t1);
1394 let n_n_res = op_n_n(n0, n1);
1395
1396 // For `f32` and `f64`, NaN values are not considered equal to
1397 // themselves. We store `Option<f32>`/`Option<f64>` and store
1398 // NaN as `None` so they can still be compared.
1399 let val_or_none = |t: T| (!T::Native::is_nan(t.get())).then(|| t.get());
1400 let t_t_res = val_or_none(t_t_res);
1401 let t_n_res = val_or_none(t_n_res);
1402 let n_t_res = val_or_none(n_t_res);
1403 let n_n_res = (!T::Native::is_nan(n_n_res)).then(|| n_n_res);
1404 assert_eq!(t_t_res, n_n_res);
1405 assert_eq!(t_n_res, n_n_res);
1406 assert_eq!(n_t_res, n_n_res);
1407
1408 if let Some((op_assign_t_t, op_assign_t_n, op_assign_n_t)) = &op_assign {
1409 let mut t_t_res = t0;
1410 op_assign_t_t(&mut t_t_res, t1);
1411 let mut t_n_res = t0;
1412 op_assign_t_n(&mut t_n_res, n1);
1413 let mut n_t_res = n0;
1414 op_assign_n_t(&mut n_t_res, t1);
1415
1416 // For `f32` and `f64`, NaN values are not considered equal to
1417 // themselves. We store `Option<f32>`/`Option<f64>` and store
1418 // NaN as `None` so they can still be compared.
1419 let t_t_res = val_or_none(t_t_res);
1420 let t_n_res = val_or_none(t_n_res);
1421 let n_t_res = (!T::Native::is_nan(n_t_res)).then(|| n_t_res);
1422 assert_eq!(t_t_res, n_n_res);
1423 assert_eq!(t_n_res, n_n_res);
1424 assert_eq!(n_t_res, n_n_res);
1425 }
1426 }
1427 }
1428
1429 macro_rules! test {
1430 (
1431 @binary
1432 $trait:ident,
1433 $method:ident $([$checked_method:ident])?,
1434 $trait_assign:ident,
1435 $method_assign:ident,
1436 $($call_for_macros:ident),*
1437 ) => {{
1438 fn t<T>()
1439 where
1440 T: ByteOrderType,
1441 T: core::ops::$trait<T, Output = T>,
1442 T: core::ops::$trait<T::Native, Output = T>,
1443 T::Native: core::ops::$trait<T, Output = T>,
1444 T::Native: core::ops::$trait<T::Native, Output = T::Native>,
1445
1446 T: core::ops::$trait_assign<T>,
1447 T: core::ops::$trait_assign<T::Native>,
1448 T::Native: core::ops::$trait_assign<T>,
1449 T::Native: core::ops::$trait_assign<T::Native>,
1450 {
1451 test::<T, _, _, _, _, _, _, _, _>(
1452 core::ops::$trait::$method,
1453 core::ops::$trait::$method,
1454 core::ops::$trait::$method,
1455 core::ops::$trait::$method,
1456 {
1457 #[allow(unused_mut, unused_assignments)]
1458 let mut op_native_checked = None::<fn(T::Native, T::Native) -> Option<T::Native>>;
1459 $(
1460 op_native_checked = Some(T::Native::$checked_method);
1461 )?
1462 op_native_checked
1463 },
1464 Some((
1465 <T as core::ops::$trait_assign<T>>::$method_assign,
1466 <T as core::ops::$trait_assign::<T::Native>>::$method_assign,
1467 <T::Native as core::ops::$trait_assign::<T>>::$method_assign
1468 )),
1469 );
1470 }
1471
1472 $(
1473 $call_for_macros!(t, NativeEndian);
1474 $call_for_macros!(t, NonNativeEndian);
1475 )*
1476 }};
1477 (
1478 @unary
1479 $trait:ident,
1480 $method:ident,
1481 $($call_for_macros:ident),*
1482 ) => {{
1483 fn t<T>()
1484 where
1485 T: ByteOrderType,
1486 T: core::ops::$trait<Output = T>,
1487 T::Native: core::ops::$trait<Output = T::Native>,
1488 {
1489 test::<T, _, _, _, _, _, _, _, _>(
1490 |slf, _rhs| core::ops::$trait::$method(slf),
1491 |slf, _rhs| core::ops::$trait::$method(slf),
1492 |slf, _rhs| core::ops::$trait::$method(slf).into(),
1493 |slf, _rhs| core::ops::$trait::$method(slf),
1494 None::<fn(T::Native, T::Native) -> Option<T::Native>>,
1495 None::<(fn(&mut T, T), fn(&mut T, T::Native), fn(&mut T::Native, T))>,
1496 );
1497 }
1498
1499 $(
1500 $call_for_macros!(t, NativeEndian);
1501 $call_for_macros!(t, NonNativeEndian);
1502 )*
1503 }};
1504 }
1505
1506 test!(@binary Add, add[checked_add], AddAssign, add_assign, call_for_all_types);
1507 test!(@binary Div, div[checked_div], DivAssign, div_assign, call_for_all_types);
1508 test!(@binary Mul, mul[checked_mul], MulAssign, mul_assign, call_for_all_types);
1509 test!(@binary Rem, rem[checked_rem], RemAssign, rem_assign, call_for_all_types);
1510 test!(@binary Sub, sub[checked_sub], SubAssign, sub_assign, call_for_all_types);
1511
1512 test!(@binary BitAnd, bitand, BitAndAssign, bitand_assign, call_for_unsigned_types, call_for_signed_types);
1513 test!(@binary BitOr, bitor, BitOrAssign, bitor_assign, call_for_unsigned_types, call_for_signed_types);
1514 test!(@binary BitXor, bitxor, BitXorAssign, bitxor_assign, call_for_unsigned_types, call_for_signed_types);
1515 test!(@binary Shl, shl[checked_shl], ShlAssign, shl_assign, call_for_unsigned_types, call_for_signed_types);
1516 test!(@binary Shr, shr[checked_shr], ShrAssign, shr_assign, call_for_unsigned_types, call_for_signed_types);
1517
1518 test!(@unary Not, not, call_for_signed_types, call_for_unsigned_types);
1519 test!(@unary Neg, neg, call_for_signed_types, call_for_float_types);
1520 }
1521
1522 #[test]
1523 fn test_debug_impl() {
1524 // Ensure that Debug applies format options to the inner value.
1525 let val = U16::<LE>::new(10);
1526 assert_eq!(format!("{:?}", val), "U16(10)");
1527 assert_eq!(format!("{:03?}", val), "U16(010)");
1528 assert_eq!(format!("{:x?}", val), "U16(a)");
1529 }
1530}
1531