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1b1a35ee 1macro_rules! uint_impl {
5869c6ff 2 ($SelfT:ty, $ActualT:ty, $BITS:expr, $MaxV:expr,
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3 $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
4 $reversed:expr, $le_bytes:expr, $be_bytes:expr,
5 $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr) => {
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6 /// The smallest value that can be represented by this integer type.
7 ///
8 /// # Examples
9 ///
10 /// Basic usage:
11 ///
12 /// ```
13 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, 0);")]
14 /// ```
15 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
16 pub const MIN: Self = 0;
1b1a35ee 17
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18 /// The largest value that can be represented by this integer type.
19 ///
20 /// # Examples
21 ///
22 /// Basic usage:
23 ///
24 /// ```
25 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($MaxV), ");")]
26 /// ```
27 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
28 pub const MAX: Self = !0;
1b1a35ee 29
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30 /// The size of this integer type in bits.
31 ///
32 /// # Examples
33 ///
34 /// ```
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35 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
36 /// ```
cdc7bbd5 37 #[stable(feature = "int_bits_const", since = "1.53.0")]
5869c6ff 38 pub const BITS: u32 = $BITS;
1b1a35ee 39
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40 /// Converts a string slice in a given base to an integer.
41 ///
42 /// The string is expected to be an optional `+` sign
43 /// followed by digits.
44 /// Leading and trailing whitespace represent an error.
45 /// Digits are a subset of these characters, depending on `radix`:
46 ///
47 /// * `0-9`
48 /// * `a-z`
49 /// * `A-Z`
50 ///
51 /// # Panics
52 ///
53 /// This function panics if `radix` is not in the range from 2 to 36.
54 ///
55 /// # Examples
56 ///
57 /// Basic usage:
58 ///
59 /// ```
60 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::from_str_radix(\"A\", 16), Ok(10));")]
61 /// ```
62 #[stable(feature = "rust1", since = "1.0.0")]
63 pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError> {
64 from_str_radix(src, radix)
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65 }
66
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67 /// Returns the number of ones in the binary representation of `self`.
68 ///
69 /// # Examples
70 ///
71 /// Basic usage:
72 ///
73 /// ```
74 #[doc = concat!("let n = 0b01001100", stringify!($SelfT), ";")]
75 ///
76 /// assert_eq!(n.count_ones(), 3);
77 /// ```
78 #[stable(feature = "rust1", since = "1.0.0")]
79 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
80 #[doc(alias = "popcount")]
81 #[doc(alias = "popcnt")]
cdc7bbd5 82 #[inline(always)]
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83 pub const fn count_ones(self) -> u32 {
84 intrinsics::ctpop(self as $ActualT) as u32
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85 }
86
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87 /// Returns the number of zeros in the binary representation of `self`.
88 ///
89 /// # Examples
90 ///
91 /// Basic usage:
92 ///
93 /// ```
94 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 0);")]
95 /// ```
96 #[stable(feature = "rust1", since = "1.0.0")]
97 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 98 #[inline(always)]
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99 pub const fn count_zeros(self) -> u32 {
100 (!self).count_ones()
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101 }
102
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103 /// Returns the number of leading zeros in the binary representation of `self`.
104 ///
105 /// # Examples
106 ///
107 /// Basic usage:
108 ///
109 /// ```
110 #[doc = concat!("let n = ", stringify!($SelfT), "::MAX >> 2;")]
111 ///
112 /// assert_eq!(n.leading_zeros(), 2);
113 /// ```
114 #[stable(feature = "rust1", since = "1.0.0")]
115 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 116 #[inline(always)]
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117 pub const fn leading_zeros(self) -> u32 {
118 intrinsics::ctlz(self as $ActualT) as u32
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119 }
120
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121 /// Returns the number of trailing zeros in the binary representation
122 /// of `self`.
123 ///
124 /// # Examples
125 ///
126 /// Basic usage:
127 ///
128 /// ```
129 #[doc = concat!("let n = 0b0101000", stringify!($SelfT), ";")]
130 ///
131 /// assert_eq!(n.trailing_zeros(), 3);
132 /// ```
133 #[stable(feature = "rust1", since = "1.0.0")]
134 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 135 #[inline(always)]
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136 pub const fn trailing_zeros(self) -> u32 {
137 intrinsics::cttz(self) as u32
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138 }
139
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140 /// Returns the number of leading ones in the binary representation of `self`.
141 ///
142 /// # Examples
143 ///
144 /// Basic usage:
145 ///
146 /// ```
147 #[doc = concat!("let n = !(", stringify!($SelfT), "::MAX >> 2);")]
148 ///
149 /// assert_eq!(n.leading_ones(), 2);
150 /// ```
151 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
152 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
cdc7bbd5 153 #[inline(always)]
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154 pub const fn leading_ones(self) -> u32 {
155 (!self).leading_zeros()
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156 }
157
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158 /// Returns the number of trailing ones in the binary representation
159 /// of `self`.
160 ///
161 /// # Examples
162 ///
163 /// Basic usage:
164 ///
165 /// ```
166 #[doc = concat!("let n = 0b1010111", stringify!($SelfT), ";")]
167 ///
168 /// assert_eq!(n.trailing_ones(), 3);
169 /// ```
170 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
171 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
cdc7bbd5 172 #[inline(always)]
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173 pub const fn trailing_ones(self) -> u32 {
174 (!self).trailing_zeros()
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175 }
176
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177 /// Shifts the bits to the left by a specified amount, `n`,
178 /// wrapping the truncated bits to the end of the resulting integer.
179 ///
180 /// Please note this isn't the same operation as the `<<` shifting operator!
181 ///
182 /// # Examples
183 ///
184 /// Basic usage:
185 ///
186 /// ```
187 #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
188 #[doc = concat!("let m = ", $rot_result, ";")]
189 ///
190 #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
191 /// ```
192 #[stable(feature = "rust1", since = "1.0.0")]
193 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
194 #[must_use = "this returns the result of the operation, \
195 without modifying the original"]
cdc7bbd5 196 #[inline(always)]
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197 pub const fn rotate_left(self, n: u32) -> Self {
198 intrinsics::rotate_left(self, n as $SelfT)
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199 }
200
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201 /// Shifts the bits to the right by a specified amount, `n`,
202 /// wrapping the truncated bits to the beginning of the resulting
203 /// integer.
204 ///
205 /// Please note this isn't the same operation as the `>>` shifting operator!
206 ///
207 /// # Examples
208 ///
209 /// Basic usage:
210 ///
211 /// ```
212 #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
213 #[doc = concat!("let m = ", $rot_op, ";")]
214 ///
215 #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
216 /// ```
217 #[stable(feature = "rust1", since = "1.0.0")]
218 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
219 #[must_use = "this returns the result of the operation, \
220 without modifying the original"]
cdc7bbd5 221 #[inline(always)]
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222 pub const fn rotate_right(self, n: u32) -> Self {
223 intrinsics::rotate_right(self, n as $SelfT)
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224 }
225
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226 /// Reverses the byte order of the integer.
227 ///
228 /// # Examples
229 ///
230 /// Basic usage:
231 ///
232 /// ```
233 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
234 /// let m = n.swap_bytes();
235 ///
236 #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
237 /// ```
238 #[stable(feature = "rust1", since = "1.0.0")]
239 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 240 #[inline(always)]
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241 pub const fn swap_bytes(self) -> Self {
242 intrinsics::bswap(self as $ActualT) as Self
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243 }
244
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245 /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
246 /// second least-significant bit becomes second most-significant bit, etc.
247 ///
248 /// # Examples
249 ///
250 /// Basic usage:
251 ///
252 /// ```
253 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
254 /// let m = n.reverse_bits();
255 ///
256 #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
257 #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
258 /// ```
259 #[stable(feature = "reverse_bits", since = "1.37.0")]
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260 #[rustc_const_stable(feature = "const_math", since = "1.37.0")]
261 #[inline(always)]
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262 #[must_use]
263 pub const fn reverse_bits(self) -> Self {
264 intrinsics::bitreverse(self as $ActualT) as Self
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265 }
266
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267 /// Converts an integer from big endian to the target's endianness.
268 ///
269 /// On big endian this is a no-op. On little endian the bytes are
270 /// swapped.
271 ///
272 /// # Examples
273 ///
274 /// Basic usage:
275 ///
276 /// ```
277 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
278 ///
279 /// if cfg!(target_endian = "big") {
280 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
281 /// } else {
282 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
283 /// }
284 /// ```
285 #[stable(feature = "rust1", since = "1.0.0")]
286 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 287 #[inline(always)]
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288 pub const fn from_be(x: Self) -> Self {
289 #[cfg(target_endian = "big")]
290 {
291 x
1b1a35ee 292 }
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293 #[cfg(not(target_endian = "big"))]
294 {
295 x.swap_bytes()
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296 }
297 }
298
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299 /// Converts an integer from little endian to the target's endianness.
300 ///
301 /// On little endian this is a no-op. On big endian the bytes are
302 /// swapped.
303 ///
304 /// # Examples
305 ///
306 /// Basic usage:
307 ///
308 /// ```
309 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
310 ///
311 /// if cfg!(target_endian = "little") {
312 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
313 /// } else {
314 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
315 /// }
316 /// ```
317 #[stable(feature = "rust1", since = "1.0.0")]
318 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 319 #[inline(always)]
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320 pub const fn from_le(x: Self) -> Self {
321 #[cfg(target_endian = "little")]
322 {
323 x
1b1a35ee 324 }
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325 #[cfg(not(target_endian = "little"))]
326 {
327 x.swap_bytes()
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328 }
329 }
330
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331 /// Converts `self` to big endian from the target's endianness.
332 ///
333 /// On big endian this is a no-op. On little endian the bytes are
334 /// swapped.
335 ///
336 /// # Examples
337 ///
338 /// Basic usage:
339 ///
340 /// ```
341 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
342 ///
343 /// if cfg!(target_endian = "big") {
344 /// assert_eq!(n.to_be(), n)
345 /// } else {
346 /// assert_eq!(n.to_be(), n.swap_bytes())
347 /// }
348 /// ```
349 #[stable(feature = "rust1", since = "1.0.0")]
350 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 351 #[inline(always)]
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352 pub const fn to_be(self) -> Self { // or not to be?
353 #[cfg(target_endian = "big")]
354 {
355 self
1b1a35ee 356 }
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357 #[cfg(not(target_endian = "big"))]
358 {
359 self.swap_bytes()
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360 }
361 }
362
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363 /// Converts `self` to little endian from the target's endianness.
364 ///
365 /// On little endian this is a no-op. On big endian the bytes are
366 /// swapped.
367 ///
368 /// # Examples
369 ///
370 /// Basic usage:
371 ///
372 /// ```
373 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
374 ///
375 /// if cfg!(target_endian = "little") {
376 /// assert_eq!(n.to_le(), n)
377 /// } else {
378 /// assert_eq!(n.to_le(), n.swap_bytes())
379 /// }
380 /// ```
381 #[stable(feature = "rust1", since = "1.0.0")]
382 #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
cdc7bbd5 383 #[inline(always)]
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384 pub const fn to_le(self) -> Self {
385 #[cfg(target_endian = "little")]
386 {
387 self
1b1a35ee 388 }
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389 #[cfg(not(target_endian = "little"))]
390 {
391 self.swap_bytes()
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392 }
393 }
394
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395 /// Checked integer addition. Computes `self + rhs`, returning `None`
396 /// if overflow occurred.
397 ///
398 /// # Examples
399 ///
400 /// Basic usage:
401 ///
402 /// ```
403 #[doc = concat!(
404 "assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), ",
405 "Some(", stringify!($SelfT), "::MAX - 1));"
406 )]
407 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
408 /// ```
409 #[stable(feature = "rust1", since = "1.0.0")]
410 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
411 #[must_use = "this returns the result of the operation, \
412 without modifying the original"]
413 #[inline]
414 pub const fn checked_add(self, rhs: Self) -> Option<Self> {
415 let (a, b) = self.overflowing_add(rhs);
416 if unlikely!(b) {None} else {Some(a)}
417 }
418
419 /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
420 /// cannot occur. This results in undefined behavior when
421 #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`.")]
422 #[unstable(
423 feature = "unchecked_math",
424 reason = "niche optimization path",
425 issue = "none",
426 )]
427 #[must_use = "this returns the result of the operation, \
428 without modifying the original"]
cdc7bbd5 429 #[inline(always)]
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430 pub unsafe fn unchecked_add(self, rhs: Self) -> Self {
431 // SAFETY: the caller must uphold the safety contract for
432 // `unchecked_add`.
433 unsafe { intrinsics::unchecked_add(self, rhs) }
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434 }
435
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436 /// Checked integer subtraction. Computes `self - rhs`, returning
437 /// `None` if overflow occurred.
438 ///
439 /// # Examples
440 ///
441 /// Basic usage:
442 ///
443 /// ```
444 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub(1), Some(0));")]
445 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);")]
446 /// ```
447 #[stable(feature = "rust1", since = "1.0.0")]
448 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
449 #[must_use = "this returns the result of the operation, \
450 without modifying the original"]
451 #[inline]
452 pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
453 let (a, b) = self.overflowing_sub(rhs);
454 if unlikely!(b) {None} else {Some(a)}
455 }
456
457 /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
458 /// cannot occur. This results in undefined behavior when
459 #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`.")]
460 #[unstable(
461 feature = "unchecked_math",
462 reason = "niche optimization path",
463 issue = "none",
464 )]
465 #[must_use = "this returns the result of the operation, \
466 without modifying the original"]
cdc7bbd5 467 #[inline(always)]
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468 pub unsafe fn unchecked_sub(self, rhs: Self) -> Self {
469 // SAFETY: the caller must uphold the safety contract for
470 // `unchecked_sub`.
471 unsafe { intrinsics::unchecked_sub(self, rhs) }
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472 }
473
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474 /// Checked integer multiplication. Computes `self * rhs`, returning
475 /// `None` if overflow occurred.
476 ///
477 /// # Examples
478 ///
479 /// Basic usage:
480 ///
481 /// ```
482 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_mul(1), Some(5));")]
483 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
484 /// ```
485 #[stable(feature = "rust1", since = "1.0.0")]
486 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
487 #[must_use = "this returns the result of the operation, \
488 without modifying the original"]
489 #[inline]
490 pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
491 let (a, b) = self.overflowing_mul(rhs);
492 if unlikely!(b) {None} else {Some(a)}
493 }
494
495 /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
496 /// cannot occur. This results in undefined behavior when
497 #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`.")]
498 #[unstable(
499 feature = "unchecked_math",
500 reason = "niche optimization path",
501 issue = "none",
502 )]
503 #[must_use = "this returns the result of the operation, \
504 without modifying the original"]
cdc7bbd5 505 #[inline(always)]
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506 pub unsafe fn unchecked_mul(self, rhs: Self) -> Self {
507 // SAFETY: the caller must uphold the safety contract for
508 // `unchecked_mul`.
509 unsafe { intrinsics::unchecked_mul(self, rhs) }
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510 }
511
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512 /// Checked integer division. Computes `self / rhs`, returning `None`
513 /// if `rhs == 0`.
514 ///
515 /// # Examples
516 ///
517 /// Basic usage:
518 ///
519 /// ```
520 #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div(2), Some(64));")]
521 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div(0), None);")]
522 /// ```
523 #[stable(feature = "rust1", since = "1.0.0")]
6a06907d 524 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.52.0")]
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525 #[must_use = "this returns the result of the operation, \
526 without modifying the original"]
527 #[inline]
528 pub const fn checked_div(self, rhs: Self) -> Option<Self> {
529 if unlikely!(rhs == 0) {
530 None
531 } else {
532 // SAFETY: div by zero has been checked above and unsigned types have no other
533 // failure modes for division
534 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
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535 }
536 }
537
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538 /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, returning `None`
539 /// if `rhs == 0`.
540 ///
541 /// # Examples
542 ///
543 /// Basic usage:
544 ///
545 /// ```
546 #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div_euclid(2), Some(64));")]
547 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div_euclid(0), None);")]
548 /// ```
549 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 550 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
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551 #[must_use = "this returns the result of the operation, \
552 without modifying the original"]
553 #[inline]
554 pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
555 if unlikely!(rhs == 0) {
556 None
557 } else {
558 Some(self.div_euclid(rhs))
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559 }
560 }
561
562
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563 /// Checked integer remainder. Computes `self % rhs`, returning `None`
564 /// if `rhs == 0`.
565 ///
566 /// # Examples
567 ///
568 /// Basic usage:
569 ///
570 /// ```
571 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
572 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
573 /// ```
574 #[stable(feature = "wrapping", since = "1.7.0")]
6a06907d 575 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.52.0")]
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576 #[must_use = "this returns the result of the operation, \
577 without modifying the original"]
578 #[inline]
579 pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
580 if unlikely!(rhs == 0) {
581 None
582 } else {
583 // SAFETY: div by zero has been checked above and unsigned types have no other
584 // failure modes for division
585 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
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586 }
587 }
588
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589 /// Checked Euclidean modulo. Computes `self.rem_euclid(rhs)`, returning `None`
590 /// if `rhs == 0`.
591 ///
592 /// # Examples
593 ///
594 /// Basic usage:
595 ///
596 /// ```
597 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
598 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
599 /// ```
600 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 601 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
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602 #[must_use = "this returns the result of the operation, \
603 without modifying the original"]
604 #[inline]
605 pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
606 if unlikely!(rhs == 0) {
607 None
608 } else {
609 Some(self.rem_euclid(rhs))
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610 }
611 }
612
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613 /// Checked negation. Computes `-self`, returning `None` unless `self ==
614 /// 0`.
615 ///
616 /// Note that negating any positive integer will overflow.
617 ///
618 /// # Examples
619 ///
620 /// Basic usage:
621 ///
622 /// ```
623 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_neg(), Some(0));")]
624 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_neg(), None);")]
625 /// ```
626 #[stable(feature = "wrapping", since = "1.7.0")]
627 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
628 #[inline]
629 pub const fn checked_neg(self) -> Option<Self> {
630 let (a, b) = self.overflowing_neg();
631 if unlikely!(b) {None} else {Some(a)}
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632 }
633
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634 /// Checked shift left. Computes `self << rhs`, returning `None`
635 /// if `rhs` is larger than or equal to the number of bits in `self`.
636 ///
637 /// # Examples
638 ///
639 /// Basic usage:
640 ///
641 /// ```
642 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
643 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(129), None);")]
644 /// ```
645 #[stable(feature = "wrapping", since = "1.7.0")]
646 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
647 #[must_use = "this returns the result of the operation, \
648 without modifying the original"]
649 #[inline]
650 pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
651 let (a, b) = self.overflowing_shl(rhs);
652 if unlikely!(b) {None} else {Some(a)}
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653 }
654
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655 /// Checked shift right. Computes `self >> rhs`, returning `None`
656 /// if `rhs` is larger than or equal to the number of bits in `self`.
657 ///
658 /// # Examples
659 ///
660 /// Basic usage:
661 ///
662 /// ```
663 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
664 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(129), None);")]
665 /// ```
666 #[stable(feature = "wrapping", since = "1.7.0")]
667 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
668 #[must_use = "this returns the result of the operation, \
669 without modifying the original"]
670 #[inline]
671 pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
672 let (a, b) = self.overflowing_shr(rhs);
673 if unlikely!(b) {None} else {Some(a)}
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674 }
675
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676 /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
677 /// overflow occurred.
678 ///
679 /// # Examples
680 ///
681 /// Basic usage:
682 ///
683 /// ```
684 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_pow(5), Some(32));")]
685 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
686 /// ```
687 #[stable(feature = "no_panic_pow", since = "1.34.0")]
688 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
689 #[must_use = "this returns the result of the operation, \
690 without modifying the original"]
691 #[inline]
692 pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
693 if exp == 0 {
694 return Some(1);
695 }
696 let mut base = self;
697 let mut acc: Self = 1;
1b1a35ee 698
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699 while exp > 1 {
700 if (exp & 1) == 1 {
701 acc = try_opt!(acc.checked_mul(base));
1b1a35ee 702 }
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703 exp /= 2;
704 base = try_opt!(base.checked_mul(base));
1b1a35ee 705 }
1b1a35ee 706
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707 // since exp!=0, finally the exp must be 1.
708 // Deal with the final bit of the exponent separately, since
709 // squaring the base afterwards is not necessary and may cause a
710 // needless overflow.
1b1a35ee 711
5869c6ff 712 Some(try_opt!(acc.checked_mul(base)))
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713 }
714
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715 /// Saturating integer addition. Computes `self + rhs`, saturating at
716 /// the numeric bounds instead of overflowing.
717 ///
718 /// # Examples
719 ///
720 /// Basic usage:
721 ///
722 /// ```
723 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
724 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(127), ", stringify!($SelfT), "::MAX);")]
725 /// ```
726 #[stable(feature = "rust1", since = "1.0.0")]
727 #[must_use = "this returns the result of the operation, \
728 without modifying the original"]
729 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
cdc7bbd5 730 #[inline(always)]
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731 pub const fn saturating_add(self, rhs: Self) -> Self {
732 intrinsics::saturating_add(self, rhs)
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733 }
734
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735 /// Saturating integer subtraction. Computes `self - rhs`, saturating
736 /// at the numeric bounds instead of overflowing.
737 ///
738 /// # Examples
739 ///
740 /// Basic usage:
741 ///
742 /// ```
743 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(27), 73);")]
744 #[doc = concat!("assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);")]
745 /// ```
746 #[stable(feature = "rust1", since = "1.0.0")]
747 #[must_use = "this returns the result of the operation, \
748 without modifying the original"]
749 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
cdc7bbd5 750 #[inline(always)]
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751 pub const fn saturating_sub(self, rhs: Self) -> Self {
752 intrinsics::saturating_sub(self, rhs)
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753 }
754
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755 /// Saturating integer multiplication. Computes `self * rhs`,
756 /// saturating at the numeric bounds instead of overflowing.
757 ///
758 /// # Examples
759 ///
760 /// Basic usage:
761 ///
762 /// ```
763 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".saturating_mul(10), 20);")]
764 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).saturating_mul(10), ", stringify!($SelfT),"::MAX);")]
765 /// ```
766 #[stable(feature = "wrapping", since = "1.7.0")]
767 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
768 #[must_use = "this returns the result of the operation, \
769 without modifying the original"]
770 #[inline]
771 pub const fn saturating_mul(self, rhs: Self) -> Self {
772 match self.checked_mul(rhs) {
773 Some(x) => x,
774 None => Self::MAX,
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775 }
776 }
777
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778 /// Saturating integer exponentiation. Computes `self.pow(exp)`,
779 /// saturating at the numeric bounds instead of overflowing.
780 ///
781 /// # Examples
782 ///
783 /// Basic usage:
784 ///
785 /// ```
786 #[doc = concat!("assert_eq!(4", stringify!($SelfT), ".saturating_pow(3), 64);")]
787 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
788 /// ```
789 #[stable(feature = "no_panic_pow", since = "1.34.0")]
790 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
791 #[must_use = "this returns the result of the operation, \
792 without modifying the original"]
793 #[inline]
794 pub const fn saturating_pow(self, exp: u32) -> Self {
795 match self.checked_pow(exp) {
796 Some(x) => x,
797 None => Self::MAX,
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798 }
799 }
800
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801 /// Wrapping (modular) addition. Computes `self + rhs`,
802 /// wrapping around at the boundary of the type.
803 ///
804 /// # Examples
805 ///
806 /// Basic usage:
807 ///
808 /// ```
809 #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(55), 255);")]
810 #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::MAX), 199);")]
811 /// ```
812 #[stable(feature = "rust1", since = "1.0.0")]
813 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
814 #[must_use = "this returns the result of the operation, \
815 without modifying the original"]
cdc7bbd5 816 #[inline(always)]
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817 pub const fn wrapping_add(self, rhs: Self) -> Self {
818 intrinsics::wrapping_add(self, rhs)
819 }
1b1a35ee 820
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821 /// Wrapping (modular) subtraction. Computes `self - rhs`,
822 /// wrapping around at the boundary of the type.
823 ///
824 /// # Examples
825 ///
826 /// Basic usage:
827 ///
828 /// ```
829 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(100), 0);")]
830 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::MAX), 101);")]
831 /// ```
832 #[stable(feature = "rust1", since = "1.0.0")]
833 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
834 #[must_use = "this returns the result of the operation, \
835 without modifying the original"]
cdc7bbd5 836 #[inline(always)]
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837 pub const fn wrapping_sub(self, rhs: Self) -> Self {
838 intrinsics::wrapping_sub(self, rhs)
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839 }
840
841 /// Wrapping (modular) multiplication. Computes `self *
842 /// rhs`, wrapping around at the boundary of the type.
843 ///
844 /// # Examples
845 ///
846 /// Basic usage:
847 ///
848 /// Please note that this example is shared between integer types.
849 /// Which explains why `u8` is used here.
850 ///
851 /// ```
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852 /// assert_eq!(10u8.wrapping_mul(12), 120);
853 /// assert_eq!(25u8.wrapping_mul(12), 44);
854 /// ```
855 #[stable(feature = "rust1", since = "1.0.0")]
856 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
857 #[must_use = "this returns the result of the operation, \
858 without modifying the original"]
cdc7bbd5 859 #[inline(always)]
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860 pub const fn wrapping_mul(self, rhs: Self) -> Self {
861 intrinsics::wrapping_mul(self, rhs)
862 }
863
864 /// Wrapping (modular) division. Computes `self / rhs`.
865 /// Wrapped division on unsigned types is just normal division.
866 /// There's no way wrapping could ever happen.
867 /// This function exists, so that all operations
868 /// are accounted for in the wrapping operations.
869 ///
870 /// # Examples
871 ///
872 /// Basic usage:
873 ///
874 /// ```
875 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
876 /// ```
877 #[stable(feature = "num_wrapping", since = "1.2.0")]
6a06907d 878 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
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879 #[must_use = "this returns the result of the operation, \
880 without modifying the original"]
cdc7bbd5 881 #[inline(always)]
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882 pub const fn wrapping_div(self, rhs: Self) -> Self {
883 self / rhs
884 }
885
886 /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`.
887 /// Wrapped division on unsigned types is just normal division.
888 /// There's no way wrapping could ever happen.
889 /// This function exists, so that all operations
890 /// are accounted for in the wrapping operations.
891 /// Since, for the positive integers, all common
892 /// definitions of division are equal, this
893 /// is exactly equal to `self.wrapping_div(rhs)`.
894 ///
895 /// # Examples
896 ///
897 /// Basic usage:
898 ///
899 /// ```
900 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
901 /// ```
902 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 903 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
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904 #[must_use = "this returns the result of the operation, \
905 without modifying the original"]
cdc7bbd5 906 #[inline(always)]
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907 pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
908 self / rhs
909 }
910
911 /// Wrapping (modular) remainder. Computes `self % rhs`.
912 /// Wrapped remainder calculation on unsigned types is
913 /// just the regular remainder calculation.
914 /// There's no way wrapping could ever happen.
915 /// This function exists, so that all operations
916 /// are accounted for in the wrapping operations.
917 ///
918 /// # Examples
919 ///
920 /// Basic usage:
921 ///
922 /// ```
923 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
924 /// ```
925 #[stable(feature = "num_wrapping", since = "1.2.0")]
6a06907d 926 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
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927 #[must_use = "this returns the result of the operation, \
928 without modifying the original"]
cdc7bbd5 929 #[inline(always)]
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930 pub const fn wrapping_rem(self, rhs: Self) -> Self {
931 self % rhs
932 }
933
934 /// Wrapping Euclidean modulo. Computes `self.rem_euclid(rhs)`.
935 /// Wrapped modulo calculation on unsigned types is
936 /// just the regular remainder calculation.
937 /// There's no way wrapping could ever happen.
938 /// This function exists, so that all operations
939 /// are accounted for in the wrapping operations.
940 /// Since, for the positive integers, all common
941 /// definitions of division are equal, this
942 /// is exactly equal to `self.wrapping_rem(rhs)`.
943 ///
944 /// # Examples
945 ///
946 /// Basic usage:
947 ///
948 /// ```
949 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
1b1a35ee 950 /// ```
5869c6ff 951 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 952 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1b1a35ee 953 #[must_use = "this returns the result of the operation, \
5869c6ff 954 without modifying the original"]
cdc7bbd5 955 #[inline(always)]
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956 pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
957 self % rhs
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958 }
959
960 /// Wrapping (modular) negation. Computes `-self`,
961 /// wrapping around at the boundary of the type.
962 ///
963 /// Since unsigned types do not have negative equivalents
964 /// all applications of this function will wrap (except for `-0`).
965 /// For values smaller than the corresponding signed type's maximum
966 /// the result is the same as casting the corresponding signed value.
967 /// Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)` where
968 /// `MAX` is the corresponding signed type's maximum.
969 ///
970 /// # Examples
971 ///
972 /// Basic usage:
973 ///
974 /// Please note that this example is shared between integer types.
975 /// Which explains why `i8` is used here.
976 ///
977 /// ```
978 /// assert_eq!(100i8.wrapping_neg(), -100);
979 /// assert_eq!((-128i8).wrapping_neg(), -128);
980 /// ```
981 #[stable(feature = "num_wrapping", since = "1.2.0")]
982 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
983 #[inline]
984 pub const fn wrapping_neg(self) -> Self {
985 self.overflowing_neg().0
986 }
987
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988 /// Panic-free bitwise shift-left; yields `self << mask(rhs)`,
989 /// where `mask` removes any high-order bits of `rhs` that
990 /// would cause the shift to exceed the bitwidth of the type.
991 ///
992 /// Note that this is *not* the same as a rotate-left; the
993 /// RHS of a wrapping shift-left is restricted to the range
994 /// of the type, rather than the bits shifted out of the LHS
995 /// being returned to the other end. The primitive integer
6a06907d 996 /// types all implement a [`rotate_left`](Self::rotate_left) function,
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997 /// which may be what you want instead.
998 ///
999 /// # Examples
1000 ///
1001 /// Basic usage:
1002 ///
1003 /// ```
1004 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(7), 128);")]
1005 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(128), 1);")]
1006 /// ```
1007 #[stable(feature = "num_wrapping", since = "1.2.0")]
1008 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1009 #[must_use = "this returns the result of the operation, \
1010 without modifying the original"]
cdc7bbd5 1011 #[inline(always)]
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1012 pub const fn wrapping_shl(self, rhs: u32) -> Self {
1013 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
1014 // out of bounds
1015 unsafe {
1016 intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT)
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1017 }
1018 }
1019
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1020 /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`,
1021 /// where `mask` removes any high-order bits of `rhs` that
1022 /// would cause the shift to exceed the bitwidth of the type.
1023 ///
1024 /// Note that this is *not* the same as a rotate-right; the
1025 /// RHS of a wrapping shift-right is restricted to the range
1026 /// of the type, rather than the bits shifted out of the LHS
1027 /// being returned to the other end. The primitive integer
6a06907d 1028 /// types all implement a [`rotate_right`](Self::rotate_right) function,
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1029 /// which may be what you want instead.
1030 ///
1031 /// # Examples
1032 ///
1033 /// Basic usage:
1034 ///
1035 /// ```
1036 #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(7), 1);")]
1037 #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(128), 128);")]
1038 /// ```
1039 #[stable(feature = "num_wrapping", since = "1.2.0")]
1040 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1041 #[must_use = "this returns the result of the operation, \
1042 without modifying the original"]
cdc7bbd5 1043 #[inline(always)]
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1044 pub const fn wrapping_shr(self, rhs: u32) -> Self {
1045 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
1046 // out of bounds
1047 unsafe {
1048 intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT)
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1049 }
1050 }
1051
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1052 /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
1053 /// wrapping around at the boundary of the type.
1054 ///
1055 /// # Examples
1056 ///
1057 /// Basic usage:
1058 ///
1059 /// ```
1060 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(5), 243);")]
1061 /// assert_eq!(3u8.wrapping_pow(6), 217);
1062 /// ```
1063 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1064 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1065 #[must_use = "this returns the result of the operation, \
1066 without modifying the original"]
1067 #[inline]
1068 pub const fn wrapping_pow(self, mut exp: u32) -> Self {
1069 if exp == 0 {
1070 return 1;
1071 }
1072 let mut base = self;
1073 let mut acc: Self = 1;
1b1a35ee 1074
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1075 while exp > 1 {
1076 if (exp & 1) == 1 {
1077 acc = acc.wrapping_mul(base);
1b1a35ee 1078 }
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1079 exp /= 2;
1080 base = base.wrapping_mul(base);
1b1a35ee 1081 }
1b1a35ee 1082
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1083 // since exp!=0, finally the exp must be 1.
1084 // Deal with the final bit of the exponent separately, since
1085 // squaring the base afterwards is not necessary and may cause a
1086 // needless overflow.
1087 acc.wrapping_mul(base)
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1088 }
1089
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1090 /// Calculates `self` + `rhs`
1091 ///
1092 /// Returns a tuple of the addition along with a boolean indicating
1093 /// whether an arithmetic overflow would occur. If an overflow would
1094 /// have occurred then the wrapped value is returned.
1095 ///
1096 /// # Examples
1097 ///
1098 /// Basic usage
1099 ///
1100 /// ```
1101 ///
1102 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
1103 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));")]
1104 /// ```
1105 #[stable(feature = "wrapping", since = "1.7.0")]
1106 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1107 #[must_use = "this returns the result of the operation, \
1108 without modifying the original"]
cdc7bbd5 1109 #[inline(always)]
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1110 pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
1111 let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
1112 (a as Self, b)
1113 }
1b1a35ee 1114
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1115 /// Calculates `self` - `rhs`
1116 ///
1117 /// Returns a tuple of the subtraction along with a boolean indicating
1118 /// whether an arithmetic overflow would occur. If an overflow would
1119 /// have occurred then the wrapped value is returned.
1120 ///
1121 /// # Examples
1122 ///
1123 /// Basic usage
1124 ///
1125 /// ```
1126 ///
1127 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
1128 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
1129 /// ```
1130 #[stable(feature = "wrapping", since = "1.7.0")]
1131 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1132 #[must_use = "this returns the result of the operation, \
1133 without modifying the original"]
cdc7bbd5 1134 #[inline(always)]
5869c6ff
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1135 pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
1136 let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
1137 (a as Self, b)
1b1a35ee
XL
1138 }
1139
1140 /// Calculates the multiplication of `self` and `rhs`.
1141 ///
1142 /// Returns a tuple of the multiplication along with a boolean
1143 /// indicating whether an arithmetic overflow would occur. If an
1144 /// overflow would have occurred then the wrapped value is returned.
1145 ///
1146 /// # Examples
1147 ///
1148 /// Basic usage:
1149 ///
1150 /// Please note that this example is shared between integer types.
1151 /// Which explains why `u32` is used here.
1152 ///
1153 /// ```
1154 /// assert_eq!(5u32.overflowing_mul(2), (10, false));
1155 /// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
1156 /// ```
1157 #[stable(feature = "wrapping", since = "1.7.0")]
1158 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1159 #[must_use = "this returns the result of the operation, \
1160 without modifying the original"]
cdc7bbd5 1161 #[inline(always)]
1b1a35ee
XL
1162 pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
1163 let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
1164 (a as Self, b)
1165 }
1166
5869c6ff
XL
1167 /// Calculates the divisor when `self` is divided by `rhs`.
1168 ///
1169 /// Returns a tuple of the divisor along with a boolean indicating
1170 /// whether an arithmetic overflow would occur. Note that for unsigned
1171 /// integers overflow never occurs, so the second value is always
1172 /// `false`.
1173 ///
1174 /// # Panics
1175 ///
1176 /// This function will panic if `rhs` is 0.
1177 ///
1178 /// # Examples
1179 ///
1180 /// Basic usage
1181 ///
1182 /// ```
1183 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
1184 /// ```
cdc7bbd5 1185 #[inline(always)]
5869c6ff 1186 #[stable(feature = "wrapping", since = "1.7.0")]
6a06907d 1187 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
5869c6ff
XL
1188 #[must_use = "this returns the result of the operation, \
1189 without modifying the original"]
1190 pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
1191 (self / rhs, false)
1b1a35ee
XL
1192 }
1193
5869c6ff
XL
1194 /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
1195 ///
1196 /// Returns a tuple of the divisor along with a boolean indicating
1197 /// whether an arithmetic overflow would occur. Note that for unsigned
1198 /// integers overflow never occurs, so the second value is always
1199 /// `false`.
1200 /// Since, for the positive integers, all common
1201 /// definitions of division are equal, this
1202 /// is exactly equal to `self.overflowing_div(rhs)`.
1203 ///
1204 /// # Panics
1205 ///
1206 /// This function will panic if `rhs` is 0.
1207 ///
1208 /// # Examples
1209 ///
1210 /// Basic usage
1211 ///
1212 /// ```
1213 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
1214 /// ```
cdc7bbd5 1215 #[inline(always)]
5869c6ff 1216 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 1217 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
5869c6ff
XL
1218 #[must_use = "this returns the result of the operation, \
1219 without modifying the original"]
1220 pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
1221 (self / rhs, false)
1b1a35ee
XL
1222 }
1223
5869c6ff
XL
1224 /// Calculates the remainder when `self` is divided by `rhs`.
1225 ///
1226 /// Returns a tuple of the remainder after dividing along with a boolean
1227 /// indicating whether an arithmetic overflow would occur. Note that for
1228 /// unsigned integers overflow never occurs, so the second value is
1229 /// always `false`.
1230 ///
1231 /// # Panics
1232 ///
1233 /// This function will panic if `rhs` is 0.
1234 ///
1235 /// # Examples
1236 ///
1237 /// Basic usage
1238 ///
1239 /// ```
1240 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
1241 /// ```
cdc7bbd5 1242 #[inline(always)]
5869c6ff 1243 #[stable(feature = "wrapping", since = "1.7.0")]
6a06907d 1244 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
5869c6ff
XL
1245 #[must_use = "this returns the result of the operation, \
1246 without modifying the original"]
1247 pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
1248 (self % rhs, false)
1b1a35ee
XL
1249 }
1250
5869c6ff
XL
1251 /// Calculates the remainder `self.rem_euclid(rhs)` as if by Euclidean division.
1252 ///
1253 /// Returns a tuple of the modulo after dividing along with a boolean
1254 /// indicating whether an arithmetic overflow would occur. Note that for
1255 /// unsigned integers overflow never occurs, so the second value is
1256 /// always `false`.
1257 /// Since, for the positive integers, all common
1258 /// definitions of division are equal, this operation
1259 /// is exactly equal to `self.overflowing_rem(rhs)`.
1260 ///
1261 /// # Panics
1262 ///
1263 /// This function will panic if `rhs` is 0.
1264 ///
1265 /// # Examples
1266 ///
1267 /// Basic usage
1268 ///
1269 /// ```
1270 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
1271 /// ```
cdc7bbd5 1272 #[inline(always)]
5869c6ff 1273 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 1274 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
5869c6ff
XL
1275 #[must_use = "this returns the result of the operation, \
1276 without modifying the original"]
1277 pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
1278 (self % rhs, false)
1b1a35ee
XL
1279 }
1280
5869c6ff
XL
1281 /// Negates self in an overflowing fashion.
1282 ///
1283 /// Returns `!self + 1` using wrapping operations to return the value
1284 /// that represents the negation of this unsigned value. Note that for
1285 /// positive unsigned values overflow always occurs, but negating 0 does
1286 /// not overflow.
1287 ///
1288 /// # Examples
1289 ///
1290 /// Basic usage
1291 ///
1292 /// ```
1293 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_neg(), (0, false));")]
1294 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!($SelfT), ", true));")]
1295 /// ```
cdc7bbd5 1296 #[inline(always)]
5869c6ff
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1297 #[stable(feature = "wrapping", since = "1.7.0")]
1298 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1299 pub const fn overflowing_neg(self) -> (Self, bool) {
1300 ((!self).wrapping_add(1), self != 0)
1b1a35ee
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1301 }
1302
5869c6ff
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1303 /// Shifts self left by `rhs` bits.
1304 ///
1305 /// Returns a tuple of the shifted version of self along with a boolean
1306 /// indicating whether the shift value was larger than or equal to the
1307 /// number of bits. If the shift value is too large, then value is
1308 /// masked (N-1) where N is the number of bits, and this value is then
1309 /// used to perform the shift.
1310 ///
1311 /// # Examples
1312 ///
1313 /// Basic usage
1314 ///
1315 /// ```
1316 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(4), (0x10, false));")]
1317 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));")]
1318 /// ```
1319 #[stable(feature = "wrapping", since = "1.7.0")]
1320 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1321 #[must_use = "this returns the result of the operation, \
1322 without modifying the original"]
cdc7bbd5 1323 #[inline(always)]
5869c6ff
XL
1324 pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
1325 (self.wrapping_shl(rhs), (rhs > ($BITS - 1)))
1b1a35ee
XL
1326 }
1327
5869c6ff
XL
1328 /// Shifts self right by `rhs` bits.
1329 ///
1330 /// Returns a tuple of the shifted version of self along with a boolean
1331 /// indicating whether the shift value was larger than or equal to the
1332 /// number of bits. If the shift value is too large, then value is
1333 /// masked (N-1) where N is the number of bits, and this value is then
1334 /// used to perform the shift.
1335 ///
1336 /// # Examples
1337 ///
1338 /// Basic usage
1339 ///
1340 /// ```
1341 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
1342 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));")]
1343 /// ```
1344 #[stable(feature = "wrapping", since = "1.7.0")]
1345 #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
1346 #[must_use = "this returns the result of the operation, \
1347 without modifying the original"]
cdc7bbd5 1348 #[inline(always)]
5869c6ff
XL
1349 pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
1350 (self.wrapping_shr(rhs), (rhs > ($BITS - 1)))
1351 }
1b1a35ee 1352
5869c6ff
XL
1353 /// Raises self to the power of `exp`, using exponentiation by squaring.
1354 ///
1355 /// Returns a tuple of the exponentiation along with a bool indicating
1356 /// whether an overflow happened.
1357 ///
1358 /// # Examples
1359 ///
1360 /// Basic usage:
1361 ///
1362 /// ```
1363 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(5), (243, false));")]
1364 /// assert_eq!(3u8.overflowing_pow(6), (217, true));
1365 /// ```
1366 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1367 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1368 #[must_use = "this returns the result of the operation, \
1369 without modifying the original"]
1370 #[inline]
1371 pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
1372 if exp == 0{
1373 return (1,false);
1374 }
1375 let mut base = self;
1376 let mut acc: Self = 1;
1377 let mut overflown = false;
1378 // Scratch space for storing results of overflowing_mul.
1379 let mut r;
1b1a35ee 1380
5869c6ff
XL
1381 while exp > 1 {
1382 if (exp & 1) == 1 {
1383 r = acc.overflowing_mul(base);
1384 acc = r.0;
1b1a35ee
XL
1385 overflown |= r.1;
1386 }
5869c6ff
XL
1387 exp /= 2;
1388 r = base.overflowing_mul(base);
1389 base = r.0;
1390 overflown |= r.1;
1b1a35ee 1391 }
1b1a35ee 1392
5869c6ff
XL
1393 // since exp!=0, finally the exp must be 1.
1394 // Deal with the final bit of the exponent separately, since
1395 // squaring the base afterwards is not necessary and may cause a
1396 // needless overflow.
1397 r = acc.overflowing_mul(base);
1398 r.1 |= overflown;
1b1a35ee 1399
5869c6ff
XL
1400 r
1401 }
1b1a35ee 1402
5869c6ff
XL
1403 /// Raises self to the power of `exp`, using exponentiation by squaring.
1404 ///
1405 /// # Examples
1406 ///
1407 /// Basic usage:
1408 ///
1409 /// ```
1410 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".pow(5), 32);")]
1411 /// ```
1b1a35ee 1412 #[stable(feature = "rust1", since = "1.0.0")]
fc512014 1413 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1b1a35ee
XL
1414 #[must_use = "this returns the result of the operation, \
1415 without modifying the original"]
1416 #[inline]
1417 #[rustc_inherit_overflow_checks]
1418 pub const fn pow(self, mut exp: u32) -> Self {
1419 if exp == 0 {
1420 return 1;
1421 }
1422 let mut base = self;
1423 let mut acc = 1;
1424
1425 while exp > 1 {
1426 if (exp & 1) == 1 {
1427 acc = acc * base;
1428 }
1429 exp /= 2;
1430 base = base * base;
1431 }
1432
1433 // since exp!=0, finally the exp must be 1.
1434 // Deal with the final bit of the exponent separately, since
1435 // squaring the base afterwards is not necessary and may cause a
1436 // needless overflow.
1437 acc * base
1438 }
1b1a35ee 1439
5869c6ff
XL
1440 /// Performs Euclidean division.
1441 ///
1442 /// Since, for the positive integers, all common
1443 /// definitions of division are equal, this
1444 /// is exactly equal to `self / rhs`.
1445 ///
1446 /// # Panics
1447 ///
1448 /// This function will panic if `rhs` is 0.
1449 ///
1450 /// # Examples
1451 ///
1452 /// Basic usage:
1453 ///
1454 /// ```
1455 #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".div_euclid(4), 1); // or any other integer type")]
1456 /// ```
1457 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 1458 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
5869c6ff
XL
1459 #[must_use = "this returns the result of the operation, \
1460 without modifying the original"]
cdc7bbd5 1461 #[inline(always)]
5869c6ff
XL
1462 #[rustc_inherit_overflow_checks]
1463 pub const fn div_euclid(self, rhs: Self) -> Self {
1464 self / rhs
1b1a35ee
XL
1465 }
1466
1467
5869c6ff
XL
1468 /// Calculates the least remainder of `self (mod rhs)`.
1469 ///
1470 /// Since, for the positive integers, all common
1471 /// definitions of division are equal, this
1472 /// is exactly equal to `self % rhs`.
1473 ///
1474 /// # Panics
1475 ///
1476 /// This function will panic if `rhs` is 0.
1477 ///
1478 /// # Examples
1479 ///
1480 /// Basic usage:
1481 ///
1482 /// ```
1483 #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".rem_euclid(4), 3); // or any other integer type")]
1484 /// ```
1485 #[stable(feature = "euclidean_division", since = "1.38.0")]
6a06907d 1486 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
5869c6ff
XL
1487 #[must_use = "this returns the result of the operation, \
1488 without modifying the original"]
cdc7bbd5 1489 #[inline(always)]
5869c6ff
XL
1490 #[rustc_inherit_overflow_checks]
1491 pub const fn rem_euclid(self, rhs: Self) -> Self {
1492 self % rhs
1b1a35ee
XL
1493 }
1494
5869c6ff
XL
1495 /// Returns `true` if and only if `self == 2^k` for some `k`.
1496 ///
1497 /// # Examples
1498 ///
1499 /// Basic usage:
1500 ///
1501 /// ```
1502 #[doc = concat!("assert!(16", stringify!($SelfT), ".is_power_of_two());")]
1503 #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_power_of_two());")]
1504 /// ```
1505 #[stable(feature = "rust1", since = "1.0.0")]
1506 #[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")]
cdc7bbd5 1507 #[inline(always)]
5869c6ff
XL
1508 pub const fn is_power_of_two(self) -> bool {
1509 self.count_ones() == 1
1b1a35ee
XL
1510 }
1511
1512 // Returns one less than next power of two.
1513 // (For 8u8 next power of two is 8u8 and for 6u8 it is 8u8)
1514 //
1515 // 8u8.one_less_than_next_power_of_two() == 7
1516 // 6u8.one_less_than_next_power_of_two() == 7
1517 //
1518 // This method cannot overflow, as in the `next_power_of_two`
1519 // overflow cases it instead ends up returning the maximum value
1520 // of the type, and can return 0 for 0.
1521 #[inline]
fc512014 1522 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1b1a35ee
XL
1523 const fn one_less_than_next_power_of_two(self) -> Self {
1524 if self <= 1 { return 0; }
1525
1526 let p = self - 1;
1527 // SAFETY: Because `p > 0`, it cannot consist entirely of leading zeros.
1528 // That means the shift is always in-bounds, and some processors
1529 // (such as intel pre-haswell) have more efficient ctlz
1530 // intrinsics when the argument is non-zero.
1531 let z = unsafe { intrinsics::ctlz_nonzero(p) };
1532 <$SelfT>::MAX >> z
1533 }
1534
5869c6ff
XL
1535 /// Returns the smallest power of two greater than or equal to `self`.
1536 ///
1537 /// When return value overflows (i.e., `self > (1 << (N-1))` for type
1538 /// `uN`), it panics in debug mode and return value is wrapped to 0 in
1539 /// release mode (the only situation in which method can return 0).
1540 ///
1541 /// # Examples
1542 ///
1543 /// Basic usage:
1544 ///
1545 /// ```
1546 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".next_power_of_two(), 2);")]
1547 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);")]
1548 /// ```
1549 #[stable(feature = "rust1", since = "1.0.0")]
1550 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1551 #[inline]
1552 #[rustc_inherit_overflow_checks]
1553 pub const fn next_power_of_two(self) -> Self {
1554 self.one_less_than_next_power_of_two() + 1
1b1a35ee
XL
1555 }
1556
5869c6ff
XL
1557 /// Returns the smallest power of two greater than or equal to `n`. If
1558 /// the next power of two is greater than the type's maximum value,
1559 /// `None` is returned, otherwise the power of two is wrapped in `Some`.
1560 ///
1561 /// # Examples
1562 ///
1563 /// Basic usage:
1564 ///
1565 /// ```
1566 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_next_power_of_two(), Some(2));")]
1567 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));")]
1568 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_power_of_two(), None);")]
1569 /// ```
1570 #[inline]
1571 #[stable(feature = "rust1", since = "1.0.0")]
1572 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1573 pub const fn checked_next_power_of_two(self) -> Option<Self> {
1574 self.one_less_than_next_power_of_two().checked_add(1)
1b1a35ee
XL
1575 }
1576
5869c6ff
XL
1577 /// Returns the smallest power of two greater than or equal to `n`. If
1578 /// the next power of two is greater than the type's maximum value,
1579 /// the return value is wrapped to `0`.
1580 ///
1581 /// # Examples
1582 ///
1583 /// Basic usage:
1584 ///
1585 /// ```
1586 /// #![feature(wrapping_next_power_of_two)]
1587 ///
1588 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".wrapping_next_power_of_two(), 2);")]
1589 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_next_power_of_two(), 4);")]
1590 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_next_power_of_two(), 0);")]
1591 /// ```
1592 #[unstable(feature = "wrapping_next_power_of_two", issue = "32463",
1593 reason = "needs decision on wrapping behaviour")]
1594 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1595 pub const fn wrapping_next_power_of_two(self) -> Self {
1596 self.one_less_than_next_power_of_two().wrapping_add(1)
1b1a35ee
XL
1597 }
1598
5869c6ff
XL
1599 /// Return the memory representation of this integer as a byte array in
1600 /// big-endian (network) byte order.
1601 ///
1602 #[doc = $to_xe_bytes_doc]
1603 ///
1604 /// # Examples
1605 ///
1606 /// ```
1607 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
1608 #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
1609 /// ```
1610 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1611 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1612 #[inline]
1613 pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
1614 self.to_be().to_ne_bytes()
1b1a35ee
XL
1615 }
1616
5869c6ff
XL
1617 /// Return the memory representation of this integer as a byte array in
1618 /// little-endian byte order.
1619 ///
1620 #[doc = $to_xe_bytes_doc]
1621 ///
1622 /// # Examples
1623 ///
1624 /// ```
1625 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
1626 #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
1627 /// ```
1628 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1629 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1630 #[inline]
1631 pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
1632 self.to_le().to_ne_bytes()
1b1a35ee
XL
1633 }
1634
5869c6ff
XL
1635 /// Return the memory representation of this integer as a byte array in
1636 /// native byte order.
1637 ///
1638 /// As the target platform's native endianness is used, portable code
1639 /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
1640 /// instead.
1641 ///
1642 #[doc = $to_xe_bytes_doc]
1643 ///
6a06907d
XL
1644 /// [`to_be_bytes`]: Self::to_be_bytes
1645 /// [`to_le_bytes`]: Self::to_le_bytes
5869c6ff
XL
1646 ///
1647 /// # Examples
1648 ///
1649 /// ```
1650 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
1651 /// assert_eq!(
1652 /// bytes,
1653 /// if cfg!(target_endian = "big") {
1654 #[doc = concat!(" ", $be_bytes)]
1655 /// } else {
1656 #[doc = concat!(" ", $le_bytes)]
1657 /// }
1658 /// );
1659 /// ```
1660 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1661 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1662 // SAFETY: const sound because integers are plain old datatypes so we can always
1663 // transmute them to arrays of bytes
1664 #[rustc_allow_const_fn_unstable(const_fn_transmute)]
1665 #[inline]
1666 pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
1667 // SAFETY: integers are plain old datatypes so we can always transmute them to
1668 // arrays of bytes
1669 unsafe { mem::transmute(self) }
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1670 }
1671
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1672 /// Return the memory representation of this integer as a byte array in
1673 /// native byte order.
1674 ///
1675 /// [`to_ne_bytes`] should be preferred over this whenever possible.
1676 ///
6a06907d 1677 /// [`to_ne_bytes`]: Self::to_ne_bytes
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1678 ///
1679 /// # Examples
1680 ///
1681 /// ```
1682 /// #![feature(num_as_ne_bytes)]
1683 #[doc = concat!("let num = ", $swap_op, stringify!($SelfT), ";")]
1684 /// let bytes = num.as_ne_bytes();
1685 /// assert_eq!(
1686 /// bytes,
1687 /// if cfg!(target_endian = "big") {
1688 #[doc = concat!(" &", $be_bytes)]
1689 /// } else {
1690 #[doc = concat!(" &", $le_bytes)]
1691 /// }
1692 /// );
1693 /// ```
1694 #[unstable(feature = "num_as_ne_bytes", issue = "76976")]
1695 #[inline]
1696 pub fn as_ne_bytes(&self) -> &[u8; mem::size_of::<Self>()] {
1697 // SAFETY: integers are plain old datatypes so we can always transmute them to
1698 // arrays of bytes
1699 unsafe { &*(self as *const Self as *const _) }
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1700 }
1701
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1702 /// Create a native endian integer value from its representation
1703 /// as a byte array in big endian.
1704 ///
1705 #[doc = $from_xe_bytes_doc]
1706 ///
1707 /// # Examples
1708 ///
1709 /// ```
1710 #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
1711 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
1712 /// ```
1713 ///
1714 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
1715 ///
1716 /// ```
1717 /// use std::convert::TryInto;
1718 ///
1719 #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
1720 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
1721 /// *input = rest;
1722 #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
1723 /// }
1724 /// ```
1725 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1726 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1727 #[inline]
1728 pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
1729 Self::from_be(Self::from_ne_bytes(bytes))
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1730 }
1731
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1732 /// Create a native endian integer value from its representation
1733 /// as a byte array in little endian.
1734 ///
1735 #[doc = $from_xe_bytes_doc]
1736 ///
1737 /// # Examples
1738 ///
1739 /// ```
1740 #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
1741 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
1742 /// ```
1743 ///
1744 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
1745 ///
1746 /// ```
1747 /// use std::convert::TryInto;
1748 ///
1749 #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
1750 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
1751 /// *input = rest;
1752 #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
1753 /// }
1754 /// ```
1755 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1756 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1757 #[inline]
1758 pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
1759 Self::from_le(Self::from_ne_bytes(bytes))
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1760 }
1761
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1762 /// Create a native endian integer value from its memory representation
1763 /// as a byte array in native endianness.
1764 ///
1765 /// As the target platform's native endianness is used, portable code
1766 /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
1767 /// appropriate instead.
1768 ///
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1769 /// [`from_be_bytes`]: Self::from_be_bytes
1770 /// [`from_le_bytes`]: Self::from_le_bytes
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1771 ///
1772 #[doc = $from_xe_bytes_doc]
1773 ///
1774 /// # Examples
1775 ///
1776 /// ```
1777 #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
1778 #[doc = concat!(" ", $be_bytes, "")]
1779 /// } else {
1780 #[doc = concat!(" ", $le_bytes, "")]
1781 /// });
1782 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
1783 /// ```
1784 ///
1785 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
1786 ///
1787 /// ```
1788 /// use std::convert::TryInto;
1789 ///
1790 #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
1791 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
1792 /// *input = rest;
1793 #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
1794 /// }
1795 /// ```
1796 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
1797 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
1798 // SAFETY: const sound because integers are plain old datatypes so we can always
1799 // transmute to them
1800 #[rustc_allow_const_fn_unstable(const_fn_transmute)]
1801 #[inline]
1802 pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
1803 // SAFETY: integers are plain old datatypes so we can always transmute to them
1804 unsafe { mem::transmute(bytes) }
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1805 }
1806
5869c6ff 1807 /// New code should prefer to use
6a06907d 1808 #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
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1809 ///
1810 /// Returns the smallest value that can be represented by this integer type.
1811 #[stable(feature = "rust1", since = "1.0.0")]
1812 #[rustc_promotable]
1813 #[inline(always)]
1814 #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
1815 #[rustc_deprecated(since = "TBD", reason = "replaced by the `MIN` associated constant on this type")]
1816 pub const fn min_value() -> Self { Self::MIN }
1817
1818 /// New code should prefer to use
6a06907d 1819 #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
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1820 ///
1821 /// Returns the largest value that can be represented by this integer type.
1822 #[stable(feature = "rust1", since = "1.0.0")]
1823 #[rustc_promotable]
1824 #[inline(always)]
1825 #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
1826 #[rustc_deprecated(since = "TBD", reason = "replaced by the `MAX` associated constant on this type")]
1827 pub const fn max_value() -> Self { Self::MAX }
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1828 }
1829}