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1 macro_rules! int_impl {
2 ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr,
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) => {
6 /// The smallest value that can be represented by this integer type,
7 #[doc = concat!("&minus;2<sup>", $BITS_MINUS_ONE, "</sup>.")]
8 ///
9 /// # Examples
10 ///
11 /// Basic usage:
12 ///
13 /// ```
14 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")]
15 /// ```
16 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
17 pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
18
19 /// The largest value that can be represented by this integer type,
20 #[doc = concat!("2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1.")]
21 ///
22 /// # Examples
23 ///
24 /// Basic usage:
25 ///
26 /// ```
27 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")]
28 /// ```
29 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
30 pub const MAX: Self = !Self::MIN;
31
32 /// The size of this integer type in bits.
33 ///
34 /// # Examples
35 ///
36 /// ```
37 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
38 /// ```
39 #[stable(feature = "int_bits_const", since = "1.53.0")]
40 pub const BITS: u32 = $BITS;
41
42 /// Converts a string slice in a given base to an integer.
43 ///
44 /// The string is expected to be an optional `+` or `-` sign followed by digits.
45 /// Leading and trailing whitespace represent an error. Digits are a subset of these characters,
46 /// depending on `radix`:
47 ///
48 /// * `0-9`
49 /// * `a-z`
50 /// * `A-Z`
51 ///
52 /// # Panics
53 ///
54 /// This function panics if `radix` is not in the range from 2 to 36.
55 ///
56 /// # Examples
57 ///
58 /// Basic usage:
59 ///
60 /// ```
61 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::from_str_radix(\"A\", 16), Ok(10));")]
62 /// ```
63 #[stable(feature = "rust1", since = "1.0.0")]
64 pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError> {
65 from_str_radix(src, radix)
66 }
67
68 /// Returns the number of ones in the binary representation of `self`.
69 ///
70 /// # Examples
71 ///
72 /// Basic usage:
73 ///
74 /// ```
75 #[doc = concat!("let n = 0b100_0000", stringify!($SelfT), ";")]
76 ///
77 /// assert_eq!(n.count_ones(), 1);
78 /// ```
79 ///
80 #[stable(feature = "rust1", since = "1.0.0")]
81 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
82 #[doc(alias = "popcount")]
83 #[doc(alias = "popcnt")]
84 #[must_use = "this returns the result of the operation, \
85 without modifying the original"]
86 #[inline(always)]
87 pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() }
88
89 /// Returns the number of zeros in the binary representation of `self`.
90 ///
91 /// # Examples
92 ///
93 /// Basic usage:
94 ///
95 /// ```
96 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")]
97 /// ```
98 #[stable(feature = "rust1", since = "1.0.0")]
99 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
100 #[must_use = "this returns the result of the operation, \
101 without modifying the original"]
102 #[inline(always)]
103 pub const fn count_zeros(self) -> u32 {
104 (!self).count_ones()
105 }
106
107 /// Returns the number of leading zeros in the binary representation of `self`.
108 ///
109 /// # Examples
110 ///
111 /// Basic usage:
112 ///
113 /// ```
114 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
115 ///
116 /// assert_eq!(n.leading_zeros(), 0);
117 /// ```
118 #[stable(feature = "rust1", since = "1.0.0")]
119 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
120 #[must_use = "this returns the result of the operation, \
121 without modifying the original"]
122 #[inline(always)]
123 pub const fn leading_zeros(self) -> u32 {
124 (self as $UnsignedT).leading_zeros()
125 }
126
127 /// Returns the number of trailing zeros in the binary representation of `self`.
128 ///
129 /// # Examples
130 ///
131 /// Basic usage:
132 ///
133 /// ```
134 #[doc = concat!("let n = -4", stringify!($SelfT), ";")]
135 ///
136 /// assert_eq!(n.trailing_zeros(), 2);
137 /// ```
138 #[stable(feature = "rust1", since = "1.0.0")]
139 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
140 #[must_use = "this returns the result of the operation, \
141 without modifying the original"]
142 #[inline(always)]
143 pub const fn trailing_zeros(self) -> u32 {
144 (self as $UnsignedT).trailing_zeros()
145 }
146
147 /// Returns the number of leading ones in the binary representation of `self`.
148 ///
149 /// # Examples
150 ///
151 /// Basic usage:
152 ///
153 /// ```
154 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
155 ///
156 #[doc = concat!("assert_eq!(n.leading_ones(), ", stringify!($BITS), ");")]
157 /// ```
158 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
159 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
160 #[must_use = "this returns the result of the operation, \
161 without modifying the original"]
162 #[inline(always)]
163 pub const fn leading_ones(self) -> u32 {
164 (self as $UnsignedT).leading_ones()
165 }
166
167 /// Returns the number of trailing ones in the binary representation of `self`.
168 ///
169 /// # Examples
170 ///
171 /// Basic usage:
172 ///
173 /// ```
174 #[doc = concat!("let n = 3", stringify!($SelfT), ";")]
175 ///
176 /// assert_eq!(n.trailing_ones(), 2);
177 /// ```
178 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
179 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
180 #[must_use = "this returns the result of the operation, \
181 without modifying the original"]
182 #[inline(always)]
183 pub const fn trailing_ones(self) -> u32 {
184 (self as $UnsignedT).trailing_ones()
185 }
186
187 /// Shifts the bits to the left by a specified amount, `n`,
188 /// wrapping the truncated bits to the end of the resulting integer.
189 ///
190 /// Please note this isn't the same operation as the `<<` shifting operator!
191 ///
192 /// # Examples
193 ///
194 /// Basic usage:
195 ///
196 /// ```
197 #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
198 #[doc = concat!("let m = ", $rot_result, ";")]
199 ///
200 #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
201 /// ```
202 #[stable(feature = "rust1", since = "1.0.0")]
203 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
204 #[must_use = "this returns the result of the operation, \
205 without modifying the original"]
206 #[inline(always)]
207 pub const fn rotate_left(self, n: u32) -> Self {
208 (self as $UnsignedT).rotate_left(n) as Self
209 }
210
211 /// Shifts the bits to the right by a specified amount, `n`,
212 /// wrapping the truncated bits to the beginning of the resulting
213 /// integer.
214 ///
215 /// Please note this isn't the same operation as the `>>` shifting operator!
216 ///
217 /// # Examples
218 ///
219 /// Basic usage:
220 ///
221 /// ```
222 #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
223 #[doc = concat!("let m = ", $rot_op, ";")]
224 ///
225 #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
226 /// ```
227 #[stable(feature = "rust1", since = "1.0.0")]
228 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
229 #[must_use = "this returns the result of the operation, \
230 without modifying the original"]
231 #[inline(always)]
232 pub const fn rotate_right(self, n: u32) -> Self {
233 (self as $UnsignedT).rotate_right(n) as Self
234 }
235
236 /// Reverses the byte order of the integer.
237 ///
238 /// # Examples
239 ///
240 /// Basic usage:
241 ///
242 /// ```
243 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
244 ///
245 /// let m = n.swap_bytes();
246 ///
247 #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
248 /// ```
249 #[stable(feature = "rust1", since = "1.0.0")]
250 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
251 #[must_use = "this returns the result of the operation, \
252 without modifying the original"]
253 #[inline(always)]
254 pub const fn swap_bytes(self) -> Self {
255 (self as $UnsignedT).swap_bytes() as Self
256 }
257
258 /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
259 /// second least-significant bit becomes second most-significant bit, etc.
260 ///
261 /// # Examples
262 ///
263 /// Basic usage:
264 ///
265 /// ```
266 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
267 /// let m = n.reverse_bits();
268 ///
269 #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
270 #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
271 /// ```
272 #[stable(feature = "reverse_bits", since = "1.37.0")]
273 #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
274 #[must_use = "this returns the result of the operation, \
275 without modifying the original"]
276 #[inline(always)]
277 pub const fn reverse_bits(self) -> Self {
278 (self as $UnsignedT).reverse_bits() as Self
279 }
280
281 /// Converts an integer from big endian to the target's endianness.
282 ///
283 /// On big endian this is a no-op. On little endian the bytes are swapped.
284 ///
285 /// # Examples
286 ///
287 /// Basic usage:
288 ///
289 /// ```
290 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
291 ///
292 /// if cfg!(target_endian = "big") {
293 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
294 /// } else {
295 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
296 /// }
297 /// ```
298 #[stable(feature = "rust1", since = "1.0.0")]
299 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
300 #[must_use]
301 #[inline]
302 pub const fn from_be(x: Self) -> Self {
303 #[cfg(target_endian = "big")]
304 {
305 x
306 }
307 #[cfg(not(target_endian = "big"))]
308 {
309 x.swap_bytes()
310 }
311 }
312
313 /// Converts an integer from little endian to the target's endianness.
314 ///
315 /// On little endian this is a no-op. On big endian the bytes are swapped.
316 ///
317 /// # Examples
318 ///
319 /// Basic usage:
320 ///
321 /// ```
322 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
323 ///
324 /// if cfg!(target_endian = "little") {
325 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
326 /// } else {
327 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
328 /// }
329 /// ```
330 #[stable(feature = "rust1", since = "1.0.0")]
331 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
332 #[must_use]
333 #[inline]
334 pub const fn from_le(x: Self) -> Self {
335 #[cfg(target_endian = "little")]
336 {
337 x
338 }
339 #[cfg(not(target_endian = "little"))]
340 {
341 x.swap_bytes()
342 }
343 }
344
345 /// Converts `self` to big endian from the target's endianness.
346 ///
347 /// On big endian this is a no-op. On little endian the bytes are swapped.
348 ///
349 /// # Examples
350 ///
351 /// Basic usage:
352 ///
353 /// ```
354 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
355 ///
356 /// if cfg!(target_endian = "big") {
357 /// assert_eq!(n.to_be(), n)
358 /// } else {
359 /// assert_eq!(n.to_be(), n.swap_bytes())
360 /// }
361 /// ```
362 #[stable(feature = "rust1", since = "1.0.0")]
363 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
364 #[must_use = "this returns the result of the operation, \
365 without modifying the original"]
366 #[inline]
367 pub const fn to_be(self) -> Self { // or not to be?
368 #[cfg(target_endian = "big")]
369 {
370 self
371 }
372 #[cfg(not(target_endian = "big"))]
373 {
374 self.swap_bytes()
375 }
376 }
377
378 /// Converts `self` to little endian from the target's endianness.
379 ///
380 /// On little endian this is a no-op. On big endian the bytes are swapped.
381 ///
382 /// # Examples
383 ///
384 /// Basic usage:
385 ///
386 /// ```
387 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
388 ///
389 /// if cfg!(target_endian = "little") {
390 /// assert_eq!(n.to_le(), n)
391 /// } else {
392 /// assert_eq!(n.to_le(), n.swap_bytes())
393 /// }
394 /// ```
395 #[stable(feature = "rust1", since = "1.0.0")]
396 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
397 #[must_use = "this returns the result of the operation, \
398 without modifying the original"]
399 #[inline]
400 pub const fn to_le(self) -> Self {
401 #[cfg(target_endian = "little")]
402 {
403 self
404 }
405 #[cfg(not(target_endian = "little"))]
406 {
407 self.swap_bytes()
408 }
409 }
410
411 /// Checked integer addition. Computes `self + rhs`, returning `None`
412 /// if overflow occurred.
413 ///
414 /// # Examples
415 ///
416 /// Basic usage:
417 ///
418 /// ```
419 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")]
420 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
421 /// ```
422 #[stable(feature = "rust1", since = "1.0.0")]
423 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
424 #[must_use = "this returns the result of the operation, \
425 without modifying the original"]
426 #[inline]
427 pub const fn checked_add(self, rhs: Self) -> Option<Self> {
428 let (a, b) = self.overflowing_add(rhs);
429 if unlikely!(b) {None} else {Some(a)}
430 }
431
432 /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
433 /// cannot occur.
434 ///
435 /// # Safety
436 ///
437 /// This results in undefined behavior when
438 #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
439 /// i.e. when [`checked_add`] would return `None`.
440 ///
441 #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
442 #[unstable(
443 feature = "unchecked_math",
444 reason = "niche optimization path",
445 issue = "85122",
446 )]
447 #[must_use = "this returns the result of the operation, \
448 without modifying the original"]
449 #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
450 #[inline(always)]
451 pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
452 // SAFETY: the caller must uphold the safety contract for
453 // `unchecked_add`.
454 unsafe { intrinsics::unchecked_add(self, rhs) }
455 }
456
457 /// Checked addition with an unsigned integer. Computes `self + rhs`,
458 /// returning `None` if overflow occurred.
459 ///
460 /// # Examples
461 ///
462 /// Basic usage:
463 ///
464 /// ```
465 /// # #![feature(mixed_integer_ops)]
466 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")]
467 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")]
468 /// ```
469 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
470 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
471 #[must_use = "this returns the result of the operation, \
472 without modifying the original"]
473 #[inline]
474 pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
475 let (a, b) = self.overflowing_add_unsigned(rhs);
476 if unlikely!(b) {None} else {Some(a)}
477 }
478
479 /// Checked integer subtraction. Computes `self - rhs`, returning `None` if
480 /// overflow occurred.
481 ///
482 /// # Examples
483 ///
484 /// Basic usage:
485 ///
486 /// ```
487 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")]
488 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")]
489 /// ```
490 #[stable(feature = "rust1", since = "1.0.0")]
491 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
492 #[must_use = "this returns the result of the operation, \
493 without modifying the original"]
494 #[inline]
495 pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
496 let (a, b) = self.overflowing_sub(rhs);
497 if unlikely!(b) {None} else {Some(a)}
498 }
499
500 /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
501 /// cannot occur.
502 ///
503 /// # Safety
504 ///
505 /// This results in undefined behavior when
506 #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
507 /// i.e. when [`checked_sub`] would return `None`.
508 ///
509 #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
510 #[unstable(
511 feature = "unchecked_math",
512 reason = "niche optimization path",
513 issue = "85122",
514 )]
515 #[must_use = "this returns the result of the operation, \
516 without modifying the original"]
517 #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
518 #[inline(always)]
519 pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
520 // SAFETY: the caller must uphold the safety contract for
521 // `unchecked_sub`.
522 unsafe { intrinsics::unchecked_sub(self, rhs) }
523 }
524
525 /// Checked subtraction with an unsigned integer. Computes `self - rhs`,
526 /// returning `None` if overflow occurred.
527 ///
528 /// # Examples
529 ///
530 /// Basic usage:
531 ///
532 /// ```
533 /// # #![feature(mixed_integer_ops)]
534 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")]
535 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")]
536 /// ```
537 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
538 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
539 #[must_use = "this returns the result of the operation, \
540 without modifying the original"]
541 #[inline]
542 pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
543 let (a, b) = self.overflowing_sub_unsigned(rhs);
544 if unlikely!(b) {None} else {Some(a)}
545 }
546
547 /// Checked integer multiplication. Computes `self * rhs`, returning `None` if
548 /// overflow occurred.
549 ///
550 /// # Examples
551 ///
552 /// Basic usage:
553 ///
554 /// ```
555 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")]
556 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
557 /// ```
558 #[stable(feature = "rust1", since = "1.0.0")]
559 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
560 #[must_use = "this returns the result of the operation, \
561 without modifying the original"]
562 #[inline]
563 pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
564 let (a, b) = self.overflowing_mul(rhs);
565 if unlikely!(b) {None} else {Some(a)}
566 }
567
568 /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
569 /// cannot occur.
570 ///
571 /// # Safety
572 ///
573 /// This results in undefined behavior when
574 #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
575 /// i.e. when [`checked_mul`] would return `None`.
576 ///
577 #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
578 #[unstable(
579 feature = "unchecked_math",
580 reason = "niche optimization path",
581 issue = "85122",
582 )]
583 #[must_use = "this returns the result of the operation, \
584 without modifying the original"]
585 #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
586 #[inline(always)]
587 pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
588 // SAFETY: the caller must uphold the safety contract for
589 // `unchecked_mul`.
590 unsafe { intrinsics::unchecked_mul(self, rhs) }
591 }
592
593 /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
594 /// or the division results in overflow.
595 ///
596 /// # Examples
597 ///
598 /// Basic usage:
599 ///
600 /// ```
601 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")]
602 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")]
603 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")]
604 /// ```
605 #[stable(feature = "rust1", since = "1.0.0")]
606 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
607 #[must_use = "this returns the result of the operation, \
608 without modifying the original"]
609 #[inline]
610 pub const fn checked_div(self, rhs: Self) -> Option<Self> {
611 if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
612 None
613 } else {
614 // SAFETY: div by zero and by INT_MIN have been checked above
615 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
616 }
617 }
618
619 /// Checked Euclidean division. Computes `self.div_euclid(rhs)`,
620 /// returning `None` if `rhs == 0` or the division results in overflow.
621 ///
622 /// # Examples
623 ///
624 /// Basic usage:
625 ///
626 /// ```
627 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")]
628 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")]
629 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")]
630 /// ```
631 #[stable(feature = "euclidean_division", since = "1.38.0")]
632 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
633 #[must_use = "this returns the result of the operation, \
634 without modifying the original"]
635 #[inline]
636 pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
637 // Using `&` helps LLVM see that it is the same check made in division.
638 if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
639 None
640 } else {
641 Some(self.div_euclid(rhs))
642 }
643 }
644
645 /// Checked integer remainder. Computes `self % rhs`, returning `None` if
646 /// `rhs == 0` or the division results in overflow.
647 ///
648 /// # Examples
649 ///
650 /// Basic usage:
651 ///
652 /// ```
653 ///
654 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
655 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
656 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")]
657 /// ```
658 #[stable(feature = "wrapping", since = "1.7.0")]
659 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
660 #[must_use = "this returns the result of the operation, \
661 without modifying the original"]
662 #[inline]
663 pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
664 if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
665 None
666 } else {
667 // SAFETY: div by zero and by INT_MIN have been checked above
668 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
669 }
670 }
671
672 /// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None`
673 /// if `rhs == 0` or the division results in overflow.
674 ///
675 /// # Examples
676 ///
677 /// Basic usage:
678 ///
679 /// ```
680 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
681 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
682 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")]
683 /// ```
684 #[stable(feature = "euclidean_division", since = "1.38.0")]
685 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
686 #[must_use = "this returns the result of the operation, \
687 without modifying the original"]
688 #[inline]
689 pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
690 // Using `&` helps LLVM see that it is the same check made in division.
691 if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
692 None
693 } else {
694 Some(self.rem_euclid(rhs))
695 }
696 }
697
698 /// Checked negation. Computes `-self`, returning `None` if `self == MIN`.
699 ///
700 /// # Examples
701 ///
702 /// Basic usage:
703 ///
704 /// ```
705 ///
706 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")]
707 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")]
708 /// ```
709 #[stable(feature = "wrapping", since = "1.7.0")]
710 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
711 #[must_use = "this returns the result of the operation, \
712 without modifying the original"]
713 #[inline]
714 pub const fn checked_neg(self) -> Option<Self> {
715 let (a, b) = self.overflowing_neg();
716 if unlikely!(b) {None} else {Some(a)}
717 }
718
719 /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger
720 /// than or equal to the number of bits in `self`.
721 ///
722 /// # Examples
723 ///
724 /// Basic usage:
725 ///
726 /// ```
727 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
728 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")]
729 /// ```
730 #[stable(feature = "wrapping", since = "1.7.0")]
731 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
732 #[must_use = "this returns the result of the operation, \
733 without modifying the original"]
734 #[inline]
735 pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
736 let (a, b) = self.overflowing_shl(rhs);
737 if unlikely!(b) {None} else {Some(a)}
738 }
739
740 /// Unchecked shift left. Computes `self << rhs`, assuming that
741 /// `rhs` is less than the number of bits in `self`.
742 ///
743 /// # Safety
744 ///
745 /// This results in undefined behavior if `rhs` is larger than
746 /// or equal to the number of bits in `self`,
747 /// i.e. when [`checked_shl`] would return `None`.
748 ///
749 #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
750 #[unstable(
751 feature = "unchecked_math",
752 reason = "niche optimization path",
753 issue = "85122",
754 )]
755 #[must_use = "this returns the result of the operation, \
756 without modifying the original"]
757 #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
758 #[inline(always)]
759 pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self {
760 // SAFETY: the caller must uphold the safety contract for
761 // `unchecked_shl`.
762 unsafe { intrinsics::unchecked_shl(self, rhs) }
763 }
764
765 /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is
766 /// larger than or equal to the number of bits in `self`.
767 ///
768 /// # Examples
769 ///
770 /// Basic usage:
771 ///
772 /// ```
773 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
774 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")]
775 /// ```
776 #[stable(feature = "wrapping", since = "1.7.0")]
777 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
778 #[must_use = "this returns the result of the operation, \
779 without modifying the original"]
780 #[inline]
781 pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
782 let (a, b) = self.overflowing_shr(rhs);
783 if unlikely!(b) {None} else {Some(a)}
784 }
785
786 /// Unchecked shift right. Computes `self >> rhs`, assuming that
787 /// `rhs` is less than the number of bits in `self`.
788 ///
789 /// # Safety
790 ///
791 /// This results in undefined behavior if `rhs` is larger than
792 /// or equal to the number of bits in `self`,
793 /// i.e. when [`checked_shr`] would return `None`.
794 ///
795 #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
796 #[unstable(
797 feature = "unchecked_math",
798 reason = "niche optimization path",
799 issue = "85122",
800 )]
801 #[must_use = "this returns the result of the operation, \
802 without modifying the original"]
803 #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
804 #[inline(always)]
805 pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self {
806 // SAFETY: the caller must uphold the safety contract for
807 // `unchecked_shr`.
808 unsafe { intrinsics::unchecked_shr(self, rhs) }
809 }
810
811 /// Checked absolute value. Computes `self.abs()`, returning `None` if
812 /// `self == MIN`.
813 ///
814 /// # Examples
815 ///
816 /// Basic usage:
817 ///
818 /// ```
819 ///
820 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")]
821 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")]
822 /// ```
823 #[stable(feature = "no_panic_abs", since = "1.13.0")]
824 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
825 #[must_use = "this returns the result of the operation, \
826 without modifying the original"]
827 #[inline]
828 pub const fn checked_abs(self) -> Option<Self> {
829 if self.is_negative() {
830 self.checked_neg()
831 } else {
832 Some(self)
833 }
834 }
835
836 /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
837 /// overflow occurred.
838 ///
839 /// # Examples
840 ///
841 /// Basic usage:
842 ///
843 /// ```
844 #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")]
845 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
846 /// ```
847
848 #[stable(feature = "no_panic_pow", since = "1.34.0")]
849 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
850 #[must_use = "this returns the result of the operation, \
851 without modifying the original"]
852 #[inline]
853 pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
854 if exp == 0 {
855 return Some(1);
856 }
857 let mut base = self;
858 let mut acc: Self = 1;
859
860 while exp > 1 {
861 if (exp & 1) == 1 {
862 acc = try_opt!(acc.checked_mul(base));
863 }
864 exp /= 2;
865 base = try_opt!(base.checked_mul(base));
866 }
867 // since exp!=0, finally the exp must be 1.
868 // Deal with the final bit of the exponent separately, since
869 // squaring the base afterwards is not necessary and may cause a
870 // needless overflow.
871 Some(try_opt!(acc.checked_mul(base)))
872 }
873
874 /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric
875 /// bounds instead of overflowing.
876 ///
877 /// # Examples
878 ///
879 /// Basic usage:
880 ///
881 /// ```
882 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
883 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")]
884 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")]
885 /// ```
886
887 #[stable(feature = "rust1", since = "1.0.0")]
888 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
889 #[must_use = "this returns the result of the operation, \
890 without modifying the original"]
891 #[inline(always)]
892 pub const fn saturating_add(self, rhs: Self) -> Self {
893 intrinsics::saturating_add(self, rhs)
894 }
895
896 /// Saturating addition with an unsigned integer. Computes `self + rhs`,
897 /// saturating at the numeric bounds instead of overflowing.
898 ///
899 /// # Examples
900 ///
901 /// Basic usage:
902 ///
903 /// ```
904 /// # #![feature(mixed_integer_ops)]
905 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")]
906 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")]
907 /// ```
908 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
909 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
910 #[must_use = "this returns the result of the operation, \
911 without modifying the original"]
912 #[inline]
913 pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self {
914 // Overflow can only happen at the upper bound
915 // We cannot use `unwrap_or` here because it is not `const`
916 match self.checked_add_unsigned(rhs) {
917 Some(x) => x,
918 None => Self::MAX,
919 }
920 }
921
922 /// Saturating integer subtraction. Computes `self - rhs`, saturating at the
923 /// numeric bounds instead of overflowing.
924 ///
925 /// # Examples
926 ///
927 /// Basic usage:
928 ///
929 /// ```
930 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")]
931 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")]
932 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")]
933 /// ```
934 #[stable(feature = "rust1", since = "1.0.0")]
935 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
936 #[must_use = "this returns the result of the operation, \
937 without modifying the original"]
938 #[inline(always)]
939 pub const fn saturating_sub(self, rhs: Self) -> Self {
940 intrinsics::saturating_sub(self, rhs)
941 }
942
943 /// Saturating subtraction with an unsigned integer. Computes `self - rhs`,
944 /// saturating at the numeric bounds instead of overflowing.
945 ///
946 /// # Examples
947 ///
948 /// Basic usage:
949 ///
950 /// ```
951 /// # #![feature(mixed_integer_ops)]
952 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")]
953 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")]
954 /// ```
955 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
956 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
957 #[must_use = "this returns the result of the operation, \
958 without modifying the original"]
959 #[inline]
960 pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self {
961 // Overflow can only happen at the lower bound
962 // We cannot use `unwrap_or` here because it is not `const`
963 match self.checked_sub_unsigned(rhs) {
964 Some(x) => x,
965 None => Self::MIN,
966 }
967 }
968
969 /// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN`
970 /// instead of overflowing.
971 ///
972 /// # Examples
973 ///
974 /// Basic usage:
975 ///
976 /// ```
977 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")]
978 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")]
979 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")]
980 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")]
981 /// ```
982
983 #[stable(feature = "saturating_neg", since = "1.45.0")]
984 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
985 #[must_use = "this returns the result of the operation, \
986 without modifying the original"]
987 #[inline(always)]
988 pub const fn saturating_neg(self) -> Self {
989 intrinsics::saturating_sub(0, self)
990 }
991
992 /// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self ==
993 /// MIN` instead of overflowing.
994 ///
995 /// # Examples
996 ///
997 /// Basic usage:
998 ///
999 /// ```
1000 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")]
1001 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")]
1002 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")]
1003 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")]
1004 /// ```
1005
1006 #[stable(feature = "saturating_neg", since = "1.45.0")]
1007 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1008 #[must_use = "this returns the result of the operation, \
1009 without modifying the original"]
1010 #[inline]
1011 pub const fn saturating_abs(self) -> Self {
1012 if self.is_negative() {
1013 self.saturating_neg()
1014 } else {
1015 self
1016 }
1017 }
1018
1019 /// Saturating integer multiplication. Computes `self * rhs`, saturating at the
1020 /// numeric bounds instead of overflowing.
1021 ///
1022 /// # Examples
1023 ///
1024 /// Basic usage:
1025 ///
1026 /// ```
1027 ///
1028 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")]
1029 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")]
1030 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")]
1031 /// ```
1032 #[stable(feature = "wrapping", since = "1.7.0")]
1033 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1034 #[must_use = "this returns the result of the operation, \
1035 without modifying the original"]
1036 #[inline]
1037 pub const fn saturating_mul(self, rhs: Self) -> Self {
1038 match self.checked_mul(rhs) {
1039 Some(x) => x,
1040 None => if (self < 0) == (rhs < 0) {
1041 Self::MAX
1042 } else {
1043 Self::MIN
1044 }
1045 }
1046 }
1047
1048 /// Saturating integer division. Computes `self / rhs`, saturating at the
1049 /// numeric bounds instead of overflowing.
1050 ///
1051 /// # Examples
1052 ///
1053 /// Basic usage:
1054 ///
1055 /// ```
1056 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
1057 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")]
1058 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")]
1059 ///
1060 /// ```
1061 ///
1062 /// ```should_panic
1063 #[doc = concat!("let _ = 1", stringify!($SelfT), ".saturating_div(0);")]
1064 ///
1065 /// ```
1066 #[stable(feature = "saturating_div", since = "1.58.0")]
1067 #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
1068 #[must_use = "this returns the result of the operation, \
1069 without modifying the original"]
1070 #[inline]
1071 pub const fn saturating_div(self, rhs: Self) -> Self {
1072 match self.overflowing_div(rhs) {
1073 (result, false) => result,
1074 (_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow
1075 }
1076 }
1077
1078 /// Saturating integer exponentiation. Computes `self.pow(exp)`,
1079 /// saturating at the numeric bounds instead of overflowing.
1080 ///
1081 /// # Examples
1082 ///
1083 /// Basic usage:
1084 ///
1085 /// ```
1086 ///
1087 #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")]
1088 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
1089 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")]
1090 /// ```
1091 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1092 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1093 #[must_use = "this returns the result of the operation, \
1094 without modifying the original"]
1095 #[inline]
1096 pub const fn saturating_pow(self, exp: u32) -> Self {
1097 match self.checked_pow(exp) {
1098 Some(x) => x,
1099 None if self < 0 && exp % 2 == 1 => Self::MIN,
1100 None => Self::MAX,
1101 }
1102 }
1103
1104 /// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the
1105 /// boundary of the type.
1106 ///
1107 /// # Examples
1108 ///
1109 /// Basic usage:
1110 ///
1111 /// ```
1112 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")]
1113 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")]
1114 /// ```
1115 #[stable(feature = "rust1", since = "1.0.0")]
1116 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1117 #[must_use = "this returns the result of the operation, \
1118 without modifying the original"]
1119 #[inline(always)]
1120 pub const fn wrapping_add(self, rhs: Self) -> Self {
1121 intrinsics::wrapping_add(self, rhs)
1122 }
1123
1124 /// Wrapping (modular) addition with an unsigned integer. Computes
1125 /// `self + rhs`, wrapping around at the boundary of the type.
1126 ///
1127 /// # Examples
1128 ///
1129 /// Basic usage:
1130 ///
1131 /// ```
1132 /// # #![feature(mixed_integer_ops)]
1133 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")]
1134 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")]
1135 /// ```
1136 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
1137 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
1138 #[must_use = "this returns the result of the operation, \
1139 without modifying the original"]
1140 #[inline(always)]
1141 pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self {
1142 self.wrapping_add(rhs as Self)
1143 }
1144
1145 /// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the
1146 /// boundary of the type.
1147 ///
1148 /// # Examples
1149 ///
1150 /// Basic usage:
1151 ///
1152 /// ```
1153 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")]
1154 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")]
1155 /// ```
1156 #[stable(feature = "rust1", since = "1.0.0")]
1157 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1158 #[must_use = "this returns the result of the operation, \
1159 without modifying the original"]
1160 #[inline(always)]
1161 pub const fn wrapping_sub(self, rhs: Self) -> Self {
1162 intrinsics::wrapping_sub(self, rhs)
1163 }
1164
1165 /// Wrapping (modular) subtraction with an unsigned integer. Computes
1166 /// `self - rhs`, wrapping around at the boundary of the type.
1167 ///
1168 /// # Examples
1169 ///
1170 /// Basic usage:
1171 ///
1172 /// ```
1173 /// # #![feature(mixed_integer_ops)]
1174 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")]
1175 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")]
1176 /// ```
1177 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
1178 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
1179 #[must_use = "this returns the result of the operation, \
1180 without modifying the original"]
1181 #[inline(always)]
1182 pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self {
1183 self.wrapping_sub(rhs as Self)
1184 }
1185
1186 /// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at
1187 /// the boundary of the type.
1188 ///
1189 /// # Examples
1190 ///
1191 /// Basic usage:
1192 ///
1193 /// ```
1194 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")]
1195 /// assert_eq!(11i8.wrapping_mul(12), -124);
1196 /// ```
1197 #[stable(feature = "rust1", since = "1.0.0")]
1198 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1199 #[must_use = "this returns the result of the operation, \
1200 without modifying the original"]
1201 #[inline(always)]
1202 pub const fn wrapping_mul(self, rhs: Self) -> Self {
1203 intrinsics::wrapping_mul(self, rhs)
1204 }
1205
1206 /// Wrapping (modular) division. Computes `self / rhs`, wrapping around at the
1207 /// boundary of the type.
1208 ///
1209 /// The only case where such wrapping can occur is when one divides `MIN / -1` on a signed type (where
1210 /// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
1211 /// that is too large to represent in the type. In such a case, this function returns `MIN` itself.
1212 ///
1213 /// # Panics
1214 ///
1215 /// This function will panic if `rhs` is 0.
1216 ///
1217 /// # Examples
1218 ///
1219 /// Basic usage:
1220 ///
1221 /// ```
1222 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
1223 /// assert_eq!((-128i8).wrapping_div(-1), -128);
1224 /// ```
1225 #[stable(feature = "num_wrapping", since = "1.2.0")]
1226 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
1227 #[must_use = "this returns the result of the operation, \
1228 without modifying the original"]
1229 #[inline]
1230 pub const fn wrapping_div(self, rhs: Self) -> Self {
1231 self.overflowing_div(rhs).0
1232 }
1233
1234 /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`,
1235 /// wrapping around at the boundary of the type.
1236 ///
1237 /// Wrapping will only occur in `MIN / -1` on a signed type (where `MIN` is the negative minimal value
1238 /// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the
1239 /// type. In this case, this method returns `MIN` itself.
1240 ///
1241 /// # Panics
1242 ///
1243 /// This function will panic if `rhs` is 0.
1244 ///
1245 /// # Examples
1246 ///
1247 /// Basic usage:
1248 ///
1249 /// ```
1250 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
1251 /// assert_eq!((-128i8).wrapping_div_euclid(-1), -128);
1252 /// ```
1253 #[stable(feature = "euclidean_division", since = "1.38.0")]
1254 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1255 #[must_use = "this returns the result of the operation, \
1256 without modifying the original"]
1257 #[inline]
1258 pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
1259 self.overflowing_div_euclid(rhs).0
1260 }
1261
1262 /// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the
1263 /// boundary of the type.
1264 ///
1265 /// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y`
1266 /// invalid for `MIN / -1` on a signed type (where `MIN` is the negative minimal value). In such a case,
1267 /// this function returns `0`.
1268 ///
1269 /// # Panics
1270 ///
1271 /// This function will panic if `rhs` is 0.
1272 ///
1273 /// # Examples
1274 ///
1275 /// Basic usage:
1276 ///
1277 /// ```
1278 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
1279 /// assert_eq!((-128i8).wrapping_rem(-1), 0);
1280 /// ```
1281 #[stable(feature = "num_wrapping", since = "1.2.0")]
1282 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
1283 #[must_use = "this returns the result of the operation, \
1284 without modifying the original"]
1285 #[inline]
1286 pub const fn wrapping_rem(self, rhs: Self) -> Self {
1287 self.overflowing_rem(rhs).0
1288 }
1289
1290 /// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around
1291 /// at the boundary of the type.
1292 ///
1293 /// Wrapping will only occur in `MIN % -1` on a signed type (where `MIN` is the negative minimal value
1294 /// for the type). In this case, this method returns 0.
1295 ///
1296 /// # Panics
1297 ///
1298 /// This function will panic if `rhs` is 0.
1299 ///
1300 /// # Examples
1301 ///
1302 /// Basic usage:
1303 ///
1304 /// ```
1305 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
1306 /// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0);
1307 /// ```
1308 #[stable(feature = "euclidean_division", since = "1.38.0")]
1309 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1310 #[must_use = "this returns the result of the operation, \
1311 without modifying the original"]
1312 #[inline]
1313 pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
1314 self.overflowing_rem_euclid(rhs).0
1315 }
1316
1317 /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
1318 /// of the type.
1319 ///
1320 /// The only case where such wrapping can occur is when one negates `MIN` on a signed type (where `MIN`
1321 /// is the negative minimal value for the type); this is a positive value that is too large to represent
1322 /// in the type. In such a case, this function returns `MIN` itself.
1323 ///
1324 /// # Examples
1325 ///
1326 /// Basic usage:
1327 ///
1328 /// ```
1329 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")]
1330 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")]
1331 /// ```
1332 #[stable(feature = "num_wrapping", since = "1.2.0")]
1333 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1334 #[must_use = "this returns the result of the operation, \
1335 without modifying the original"]
1336 #[inline(always)]
1337 pub const fn wrapping_neg(self) -> Self {
1338 (0 as $SelfT).wrapping_sub(self)
1339 }
1340
1341 /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes
1342 /// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
1343 ///
1344 /// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to
1345 /// the range of the type, rather than the bits shifted out of the LHS being returned to the other end.
1346 /// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function,
1347 /// which may be what you want instead.
1348 ///
1349 /// # Examples
1350 ///
1351 /// Basic usage:
1352 ///
1353 /// ```
1354 #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(7), -128);")]
1355 #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(128), -1);")]
1356 /// ```
1357 #[stable(feature = "num_wrapping", since = "1.2.0")]
1358 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1359 #[must_use = "this returns the result of the operation, \
1360 without modifying the original"]
1361 #[inline(always)]
1362 pub const fn wrapping_shl(self, rhs: u32) -> Self {
1363 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
1364 // out of bounds
1365 unsafe {
1366 intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT)
1367 }
1368 }
1369
1370 /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask`
1371 /// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
1372 ///
1373 /// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted
1374 /// to the range of the type, rather than the bits shifted out of the LHS being returned to the other
1375 /// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function,
1376 /// which may be what you want instead.
1377 ///
1378 /// # Examples
1379 ///
1380 /// Basic usage:
1381 ///
1382 /// ```
1383 #[doc = concat!("assert_eq!((-128", stringify!($SelfT), ").wrapping_shr(7), -1);")]
1384 /// assert_eq!((-128i16).wrapping_shr(64), -128);
1385 /// ```
1386 #[stable(feature = "num_wrapping", since = "1.2.0")]
1387 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1388 #[must_use = "this returns the result of the operation, \
1389 without modifying the original"]
1390 #[inline(always)]
1391 pub const fn wrapping_shr(self, rhs: u32) -> Self {
1392 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
1393 // out of bounds
1394 unsafe {
1395 intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT)
1396 }
1397 }
1398
1399 /// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at
1400 /// the boundary of the type.
1401 ///
1402 /// The only case where such wrapping can occur is when one takes the absolute value of the negative
1403 /// minimal value for the type; this is a positive value that is too large to represent in the type. In
1404 /// such a case, this function returns `MIN` itself.
1405 ///
1406 /// # Examples
1407 ///
1408 /// Basic usage:
1409 ///
1410 /// ```
1411 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")]
1412 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")]
1413 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")]
1414 /// assert_eq!((-128i8).wrapping_abs() as u8, 128);
1415 /// ```
1416 #[stable(feature = "no_panic_abs", since = "1.13.0")]
1417 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1418 #[must_use = "this returns the result of the operation, \
1419 without modifying the original"]
1420 #[allow(unused_attributes)]
1421 #[inline]
1422 pub const fn wrapping_abs(self) -> Self {
1423 if self.is_negative() {
1424 self.wrapping_neg()
1425 } else {
1426 self
1427 }
1428 }
1429
1430 /// Computes the absolute value of `self` without any wrapping
1431 /// or panicking.
1432 ///
1433 ///
1434 /// # Examples
1435 ///
1436 /// Basic usage:
1437 ///
1438 /// ```
1439 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")]
1440 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")]
1441 /// assert_eq!((-128i8).unsigned_abs(), 128u8);
1442 /// ```
1443 #[stable(feature = "unsigned_abs", since = "1.51.0")]
1444 #[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")]
1445 #[must_use = "this returns the result of the operation, \
1446 without modifying the original"]
1447 #[inline]
1448 pub const fn unsigned_abs(self) -> $UnsignedT {
1449 self.wrapping_abs() as $UnsignedT
1450 }
1451
1452 /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
1453 /// wrapping around at the boundary of the type.
1454 ///
1455 /// # Examples
1456 ///
1457 /// Basic usage:
1458 ///
1459 /// ```
1460 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")]
1461 /// assert_eq!(3i8.wrapping_pow(5), -13);
1462 /// assert_eq!(3i8.wrapping_pow(6), -39);
1463 /// ```
1464 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1465 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1466 #[must_use = "this returns the result of the operation, \
1467 without modifying the original"]
1468 #[inline]
1469 pub const fn wrapping_pow(self, mut exp: u32) -> Self {
1470 if exp == 0 {
1471 return 1;
1472 }
1473 let mut base = self;
1474 let mut acc: Self = 1;
1475
1476 while exp > 1 {
1477 if (exp & 1) == 1 {
1478 acc = acc.wrapping_mul(base);
1479 }
1480 exp /= 2;
1481 base = base.wrapping_mul(base);
1482 }
1483
1484 // since exp!=0, finally the exp must be 1.
1485 // Deal with the final bit of the exponent separately, since
1486 // squaring the base afterwards is not necessary and may cause a
1487 // needless overflow.
1488 acc.wrapping_mul(base)
1489 }
1490
1491 /// Calculates `self` + `rhs`
1492 ///
1493 /// Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would
1494 /// occur. If an overflow would have occurred then the wrapped value is returned.
1495 ///
1496 /// # Examples
1497 ///
1498 /// Basic usage:
1499 ///
1500 /// ```
1501 ///
1502 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
1503 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")]
1504 /// ```
1505 #[stable(feature = "wrapping", since = "1.7.0")]
1506 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1507 #[must_use = "this returns the result of the operation, \
1508 without modifying the original"]
1509 #[inline(always)]
1510 pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
1511 let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
1512 (a as Self, b)
1513 }
1514
1515 /// Calculates `self` + `rhs` with an unsigned `rhs`
1516 ///
1517 /// Returns a tuple of the addition along with a boolean indicating
1518 /// whether an arithmetic overflow would occur. If an overflow would
1519 /// have occurred then the wrapped value is returned.
1520 ///
1521 /// # Examples
1522 ///
1523 /// Basic usage:
1524 ///
1525 /// ```
1526 /// # #![feature(mixed_integer_ops)]
1527 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")]
1528 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")]
1529 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")]
1530 /// ```
1531 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
1532 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
1533 #[must_use = "this returns the result of the operation, \
1534 without modifying the original"]
1535 #[inline]
1536 pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
1537 let rhs = rhs as Self;
1538 let (res, overflowed) = self.overflowing_add(rhs);
1539 (res, overflowed ^ (rhs < 0))
1540 }
1541
1542 /// Calculates `self` - `rhs`
1543 ///
1544 /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
1545 /// would occur. If an overflow would have occurred then the wrapped value is returned.
1546 ///
1547 /// # Examples
1548 ///
1549 /// Basic usage:
1550 ///
1551 /// ```
1552 ///
1553 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
1554 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
1555 /// ```
1556 #[stable(feature = "wrapping", since = "1.7.0")]
1557 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1558 #[must_use = "this returns the result of the operation, \
1559 without modifying the original"]
1560 #[inline(always)]
1561 pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
1562 let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
1563 (a as Self, b)
1564 }
1565
1566 /// Calculates `self` - `rhs` with an unsigned `rhs`
1567 ///
1568 /// Returns a tuple of the subtraction along with a boolean indicating
1569 /// whether an arithmetic overflow would occur. If an overflow would
1570 /// have occurred then the wrapped value is returned.
1571 ///
1572 /// # Examples
1573 ///
1574 /// Basic usage:
1575 ///
1576 /// ```
1577 /// # #![feature(mixed_integer_ops)]
1578 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")]
1579 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")]
1580 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")]
1581 /// ```
1582 #[unstable(feature = "mixed_integer_ops", issue = "87840")]
1583 #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")]
1584 #[must_use = "this returns the result of the operation, \
1585 without modifying the original"]
1586 #[inline]
1587 pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
1588 let rhs = rhs as Self;
1589 let (res, overflowed) = self.overflowing_sub(rhs);
1590 (res, overflowed ^ (rhs < 0))
1591 }
1592
1593 /// Calculates the multiplication of `self` and `rhs`.
1594 ///
1595 /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow
1596 /// would occur. If an overflow would have occurred then the wrapped value is returned.
1597 ///
1598 /// # Examples
1599 ///
1600 /// Basic usage:
1601 ///
1602 /// ```
1603 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")]
1604 /// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true));
1605 /// ```
1606 #[stable(feature = "wrapping", since = "1.7.0")]
1607 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1608 #[must_use = "this returns the result of the operation, \
1609 without modifying the original"]
1610 #[inline(always)]
1611 pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
1612 let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
1613 (a as Self, b)
1614 }
1615
1616 /// Calculates the divisor when `self` is divided by `rhs`.
1617 ///
1618 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
1619 /// occur. If an overflow would occur then self is returned.
1620 ///
1621 /// # Panics
1622 ///
1623 /// This function will panic if `rhs` is 0.
1624 ///
1625 /// # Examples
1626 ///
1627 /// Basic usage:
1628 ///
1629 /// ```
1630 ///
1631 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
1632 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")]
1633 /// ```
1634 #[inline]
1635 #[stable(feature = "wrapping", since = "1.7.0")]
1636 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
1637 #[must_use = "this returns the result of the operation, \
1638 without modifying the original"]
1639 pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
1640 // Using `&` helps LLVM see that it is the same check made in division.
1641 if unlikely!((self == Self::MIN) & (rhs == -1)) {
1642 (self, true)
1643 } else {
1644 (self / rhs, false)
1645 }
1646 }
1647
1648 /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
1649 ///
1650 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
1651 /// occur. If an overflow would occur then `self` is returned.
1652 ///
1653 /// # Panics
1654 ///
1655 /// This function will panic if `rhs` is 0.
1656 ///
1657 /// # Examples
1658 ///
1659 /// Basic usage:
1660 ///
1661 /// ```
1662 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
1663 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")]
1664 /// ```
1665 #[inline]
1666 #[stable(feature = "euclidean_division", since = "1.38.0")]
1667 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1668 #[must_use = "this returns the result of the operation, \
1669 without modifying the original"]
1670 pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
1671 // Using `&` helps LLVM see that it is the same check made in division.
1672 if unlikely!((self == Self::MIN) & (rhs == -1)) {
1673 (self, true)
1674 } else {
1675 (self.div_euclid(rhs), false)
1676 }
1677 }
1678
1679 /// Calculates the remainder when `self` is divided by `rhs`.
1680 ///
1681 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
1682 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
1683 ///
1684 /// # Panics
1685 ///
1686 /// This function will panic if `rhs` is 0.
1687 ///
1688 /// # Examples
1689 ///
1690 /// Basic usage:
1691 ///
1692 /// ```
1693 ///
1694 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
1695 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")]
1696 /// ```
1697 #[inline]
1698 #[stable(feature = "wrapping", since = "1.7.0")]
1699 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
1700 #[must_use = "this returns the result of the operation, \
1701 without modifying the original"]
1702 pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
1703 if unlikely!(rhs == -1) {
1704 (0, self == Self::MIN)
1705 } else {
1706 (self % rhs, false)
1707 }
1708 }
1709
1710
1711 /// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`.
1712 ///
1713 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
1714 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
1715 ///
1716 /// # Panics
1717 ///
1718 /// This function will panic if `rhs` is 0.
1719 ///
1720 /// # Examples
1721 ///
1722 /// Basic usage:
1723 ///
1724 /// ```
1725 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
1726 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")]
1727 /// ```
1728 #[stable(feature = "euclidean_division", since = "1.38.0")]
1729 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1730 #[must_use = "this returns the result of the operation, \
1731 without modifying the original"]
1732 #[inline]
1733 pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
1734 if unlikely!(rhs == -1) {
1735 (0, self == Self::MIN)
1736 } else {
1737 (self.rem_euclid(rhs), false)
1738 }
1739 }
1740
1741
1742 /// Negates self, overflowing if this is equal to the minimum value.
1743 ///
1744 /// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow
1745 /// happened. If `self` is the minimum value (e.g., `i32::MIN` for values of type `i32`), then the
1746 /// minimum value will be returned again and `true` will be returned for an overflow happening.
1747 ///
1748 /// # Examples
1749 ///
1750 /// Basic usage:
1751 ///
1752 /// ```
1753 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")]
1754 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")]
1755 /// ```
1756 #[inline]
1757 #[stable(feature = "wrapping", since = "1.7.0")]
1758 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1759 #[must_use = "this returns the result of the operation, \
1760 without modifying the original"]
1761 #[allow(unused_attributes)]
1762 pub const fn overflowing_neg(self) -> (Self, bool) {
1763 if unlikely!(self == Self::MIN) {
1764 (Self::MIN, true)
1765 } else {
1766 (-self, false)
1767 }
1768 }
1769
1770 /// Shifts self left by `rhs` bits.
1771 ///
1772 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
1773 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
1774 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
1775 ///
1776 /// # Examples
1777 ///
1778 /// Basic usage:
1779 ///
1780 /// ```
1781 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")]
1782 /// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));
1783 /// ```
1784 #[stable(feature = "wrapping", since = "1.7.0")]
1785 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1786 #[must_use = "this returns the result of the operation, \
1787 without modifying the original"]
1788 #[inline]
1789 pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
1790 (self.wrapping_shl(rhs), (rhs > ($BITS - 1)))
1791 }
1792
1793 /// Shifts self right by `rhs` bits.
1794 ///
1795 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
1796 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
1797 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
1798 ///
1799 /// # Examples
1800 ///
1801 /// Basic usage:
1802 ///
1803 /// ```
1804 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
1805 /// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
1806 /// ```
1807 #[stable(feature = "wrapping", since = "1.7.0")]
1808 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1809 #[must_use = "this returns the result of the operation, \
1810 without modifying the original"]
1811 #[inline]
1812 pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
1813 (self.wrapping_shr(rhs), (rhs > ($BITS - 1)))
1814 }
1815
1816 /// Computes the absolute value of `self`.
1817 ///
1818 /// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow
1819 /// happened. If self is the minimum value
1820 #[doc = concat!("(e.g., ", stringify!($SelfT), "::MIN for values of type ", stringify!($SelfT), "),")]
1821 /// then the minimum value will be returned again and true will be returned
1822 /// for an overflow happening.
1823 ///
1824 /// # Examples
1825 ///
1826 /// Basic usage:
1827 ///
1828 /// ```
1829 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")]
1830 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")]
1831 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")]
1832 /// ```
1833 #[stable(feature = "no_panic_abs", since = "1.13.0")]
1834 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
1835 #[must_use = "this returns the result of the operation, \
1836 without modifying the original"]
1837 #[inline]
1838 pub const fn overflowing_abs(self) -> (Self, bool) {
1839 (self.wrapping_abs(), self == Self::MIN)
1840 }
1841
1842 /// Raises self to the power of `exp`, using exponentiation by squaring.
1843 ///
1844 /// Returns a tuple of the exponentiation along with a bool indicating
1845 /// whether an overflow happened.
1846 ///
1847 /// # Examples
1848 ///
1849 /// Basic usage:
1850 ///
1851 /// ```
1852 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")]
1853 /// assert_eq!(3i8.overflowing_pow(5), (-13, true));
1854 /// ```
1855 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1856 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1857 #[must_use = "this returns the result of the operation, \
1858 without modifying the original"]
1859 #[inline]
1860 pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
1861 if exp == 0 {
1862 return (1,false);
1863 }
1864 let mut base = self;
1865 let mut acc: Self = 1;
1866 let mut overflown = false;
1867 // Scratch space for storing results of overflowing_mul.
1868 let mut r;
1869
1870 while exp > 1 {
1871 if (exp & 1) == 1 {
1872 r = acc.overflowing_mul(base);
1873 acc = r.0;
1874 overflown |= r.1;
1875 }
1876 exp /= 2;
1877 r = base.overflowing_mul(base);
1878 base = r.0;
1879 overflown |= r.1;
1880 }
1881
1882 // since exp!=0, finally the exp must be 1.
1883 // Deal with the final bit of the exponent separately, since
1884 // squaring the base afterwards is not necessary and may cause a
1885 // needless overflow.
1886 r = acc.overflowing_mul(base);
1887 r.1 |= overflown;
1888 r
1889 }
1890
1891 /// Raises self to the power of `exp`, using exponentiation by squaring.
1892 ///
1893 /// # Examples
1894 ///
1895 /// Basic usage:
1896 ///
1897 /// ```
1898 #[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")]
1899 ///
1900 /// assert_eq!(x.pow(5), 32);
1901 /// ```
1902 #[stable(feature = "rust1", since = "1.0.0")]
1903 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1904 #[must_use = "this returns the result of the operation, \
1905 without modifying the original"]
1906 #[inline]
1907 #[rustc_inherit_overflow_checks]
1908 pub const fn pow(self, mut exp: u32) -> Self {
1909 if exp == 0 {
1910 return 1;
1911 }
1912 let mut base = self;
1913 let mut acc = 1;
1914
1915 while exp > 1 {
1916 if (exp & 1) == 1 {
1917 acc = acc * base;
1918 }
1919 exp /= 2;
1920 base = base * base;
1921 }
1922
1923 // since exp!=0, finally the exp must be 1.
1924 // Deal with the final bit of the exponent separately, since
1925 // squaring the base afterwards is not necessary and may cause a
1926 // needless overflow.
1927 acc * base
1928 }
1929
1930 /// Calculates the quotient of Euclidean division of `self` by `rhs`.
1931 ///
1932 /// This computes the integer `q` such that `self = q * rhs + r`, with
1933 /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`.
1934 ///
1935 /// In other words, the result is `self / rhs` rounded to the integer `q`
1936 /// such that `self >= q * rhs`.
1937 /// If `self > 0`, this is equal to round towards zero (the default in Rust);
1938 /// if `self < 0`, this is equal to round towards +/- infinity.
1939 ///
1940 /// # Panics
1941 ///
1942 /// This function will panic if `rhs` is 0 or the division results in overflow.
1943 ///
1944 /// # Examples
1945 ///
1946 /// Basic usage:
1947 ///
1948 /// ```
1949 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
1950 /// let b = 4;
1951 ///
1952 /// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
1953 /// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
1954 /// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
1955 /// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
1956 /// ```
1957 #[stable(feature = "euclidean_division", since = "1.38.0")]
1958 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1959 #[must_use = "this returns the result of the operation, \
1960 without modifying the original"]
1961 #[inline]
1962 #[rustc_inherit_overflow_checks]
1963 pub const fn div_euclid(self, rhs: Self) -> Self {
1964 let q = self / rhs;
1965 if self % rhs < 0 {
1966 return if rhs > 0 { q - 1 } else { q + 1 }
1967 }
1968 q
1969 }
1970
1971
1972 /// Calculates the least nonnegative remainder of `self (mod rhs)`.
1973 ///
1974 /// This is done as if by the Euclidean division algorithm -- given
1975 /// `r = self.rem_euclid(rhs)`, `self = rhs * self.div_euclid(rhs) + r`, and
1976 /// `0 <= r < abs(rhs)`.
1977 ///
1978 /// # Panics
1979 ///
1980 /// This function will panic if `rhs` is 0 or the division results in overflow.
1981 ///
1982 /// # Examples
1983 ///
1984 /// Basic usage:
1985 ///
1986 /// ```
1987 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
1988 /// let b = 4;
1989 ///
1990 /// assert_eq!(a.rem_euclid(b), 3);
1991 /// assert_eq!((-a).rem_euclid(b), 1);
1992 /// assert_eq!(a.rem_euclid(-b), 3);
1993 /// assert_eq!((-a).rem_euclid(-b), 1);
1994 /// ```
1995 #[stable(feature = "euclidean_division", since = "1.38.0")]
1996 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1997 #[must_use = "this returns the result of the operation, \
1998 without modifying the original"]
1999 #[inline]
2000 #[rustc_inherit_overflow_checks]
2001 pub const fn rem_euclid(self, rhs: Self) -> Self {
2002 let r = self % rhs;
2003 if r < 0 {
2004 if rhs < 0 {
2005 r - rhs
2006 } else {
2007 r + rhs
2008 }
2009 } else {
2010 r
2011 }
2012 }
2013
2014 /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
2015 ///
2016 /// # Panics
2017 ///
2018 /// This function will panic if `rhs` is zero.
2019 ///
2020 /// ## Overflow behavior
2021 ///
2022 /// On overflow, this function will panic if overflow checks are enabled (default in debug
2023 /// mode) and wrap if overflow checks are disabled (default in release mode).
2024 ///
2025 /// # Examples
2026 ///
2027 /// Basic usage:
2028 ///
2029 /// ```
2030 /// #![feature(int_roundings)]
2031 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
2032 /// let b = 3;
2033 ///
2034 /// assert_eq!(a.div_floor(b), 2);
2035 /// assert_eq!(a.div_floor(-b), -3);
2036 /// assert_eq!((-a).div_floor(b), -3);
2037 /// assert_eq!((-a).div_floor(-b), 2);
2038 /// ```
2039 #[unstable(feature = "int_roundings", issue = "88581")]
2040 #[must_use = "this returns the result of the operation, \
2041 without modifying the original"]
2042 #[inline]
2043 #[rustc_inherit_overflow_checks]
2044 pub const fn div_floor(self, rhs: Self) -> Self {
2045 let d = self / rhs;
2046 let r = self % rhs;
2047 if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
2048 d - 1
2049 } else {
2050 d
2051 }
2052 }
2053
2054 /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
2055 ///
2056 /// # Panics
2057 ///
2058 /// This function will panic if `rhs` is zero.
2059 ///
2060 /// ## Overflow behavior
2061 ///
2062 /// On overflow, this function will panic if overflow checks are enabled (default in debug
2063 /// mode) and wrap if overflow checks are disabled (default in release mode).
2064 ///
2065 /// # Examples
2066 ///
2067 /// Basic usage:
2068 ///
2069 /// ```
2070 /// #![feature(int_roundings)]
2071 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
2072 /// let b = 3;
2073 ///
2074 /// assert_eq!(a.div_ceil(b), 3);
2075 /// assert_eq!(a.div_ceil(-b), -2);
2076 /// assert_eq!((-a).div_ceil(b), -2);
2077 /// assert_eq!((-a).div_ceil(-b), 3);
2078 /// ```
2079 #[unstable(feature = "int_roundings", issue = "88581")]
2080 #[must_use = "this returns the result of the operation, \
2081 without modifying the original"]
2082 #[inline]
2083 #[rustc_inherit_overflow_checks]
2084 pub const fn div_ceil(self, rhs: Self) -> Self {
2085 let d = self / rhs;
2086 let r = self % rhs;
2087 if (r > 0 && rhs > 0) || (r < 0 && rhs < 0) {
2088 d + 1
2089 } else {
2090 d
2091 }
2092 }
2093
2094 /// If `rhs` is positive, calculates the smallest value greater than or
2095 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
2096 /// calculates the largest value less than or equal to `self` that is a
2097 /// multiple of `rhs`.
2098 ///
2099 /// # Panics
2100 ///
2101 /// This function will panic if `rhs` is zero.
2102 ///
2103 /// ## Overflow behavior
2104 ///
2105 /// On overflow, this function will panic if overflow checks are enabled (default in debug
2106 /// mode) and wrap if overflow checks are disabled (default in release mode).
2107 ///
2108 /// # Examples
2109 ///
2110 /// Basic usage:
2111 ///
2112 /// ```
2113 /// #![feature(int_roundings)]
2114 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
2115 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
2116 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
2117 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
2118 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
2119 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
2120 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")]
2121 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")]
2122 /// ```
2123 #[unstable(feature = "int_roundings", issue = "88581")]
2124 #[must_use = "this returns the result of the operation, \
2125 without modifying the original"]
2126 #[inline]
2127 #[rustc_inherit_overflow_checks]
2128 pub const fn next_multiple_of(self, rhs: Self) -> Self {
2129 // This would otherwise fail when calculating `r` when self == T::MIN.
2130 if rhs == -1 {
2131 return self;
2132 }
2133
2134 let r = self % rhs;
2135 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
2136 r + rhs
2137 } else {
2138 r
2139 };
2140
2141 if m == 0 {
2142 self
2143 } else {
2144 self + (rhs - m)
2145 }
2146 }
2147
2148 /// If `rhs` is positive, calculates the smallest value greater than or
2149 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
2150 /// calculates the largest value less than or equal to `self` that is a
2151 /// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
2152 /// would result in overflow.
2153 ///
2154 /// # Examples
2155 ///
2156 /// Basic usage:
2157 ///
2158 /// ```
2159 /// #![feature(int_roundings)]
2160 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
2161 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
2162 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
2163 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
2164 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
2165 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
2166 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")]
2167 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")]
2168 #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
2169 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
2170 /// ```
2171 #[unstable(feature = "int_roundings", issue = "88581")]
2172 #[must_use = "this returns the result of the operation, \
2173 without modifying the original"]
2174 #[inline]
2175 pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
2176 // This would otherwise fail when calculating `r` when self == T::MIN.
2177 if rhs == -1 {
2178 return Some(self);
2179 }
2180
2181 let r = try_opt!(self.checked_rem(rhs));
2182 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
2183 // r + rhs cannot overflow because they have opposite signs
2184 r + rhs
2185 } else {
2186 r
2187 };
2188
2189 if m == 0 {
2190 Some(self)
2191 } else {
2192 // rhs - m cannot overflow because m has the same sign as rhs
2193 self.checked_add(rhs - m)
2194 }
2195 }
2196
2197 /// Returns the logarithm of the number with respect to an arbitrary base,
2198 /// rounded down.
2199 ///
2200 /// This method might not be optimized owing to implementation details;
2201 /// `log2` can produce results more efficiently for base 2, and `log10`
2202 /// can produce results more efficiently for base 10.
2203 ///
2204 /// # Panics
2205 ///
2206 /// When the number is negative, zero, or if the base is not at least 2; it
2207 /// panics in debug mode and the return value is 0 in release
2208 /// mode.
2209 ///
2210 /// # Examples
2211 ///
2212 /// ```
2213 /// #![feature(int_log)]
2214 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")]
2215 /// ```
2216 #[unstable(feature = "int_log", issue = "70887")]
2217 #[must_use = "this returns the result of the operation, \
2218 without modifying the original"]
2219 #[inline]
2220 #[track_caller]
2221 #[rustc_inherit_overflow_checks]
2222 #[allow(arithmetic_overflow)]
2223 pub const fn log(self, base: Self) -> u32 {
2224 match self.checked_log(base) {
2225 Some(n) => n,
2226 None => {
2227 // In debug builds, trigger a panic on None.
2228 // This should optimize completely out in release builds.
2229 let _ = Self::MAX + 1;
2230
2231 0
2232 },
2233 }
2234 }
2235
2236 /// Returns the base 2 logarithm of the number, rounded down.
2237 ///
2238 /// # Panics
2239 ///
2240 /// When the number is negative or zero it panics in debug mode and the return value
2241 /// is 0 in release mode.
2242 ///
2243 /// # Examples
2244 ///
2245 /// ```
2246 /// #![feature(int_log)]
2247 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")]
2248 /// ```
2249 #[unstable(feature = "int_log", issue = "70887")]
2250 #[must_use = "this returns the result of the operation, \
2251 without modifying the original"]
2252 #[inline]
2253 #[track_caller]
2254 #[rustc_inherit_overflow_checks]
2255 #[allow(arithmetic_overflow)]
2256 pub const fn log2(self) -> u32 {
2257 match self.checked_log2() {
2258 Some(n) => n,
2259 None => {
2260 // In debug builds, trigger a panic on None.
2261 // This should optimize completely out in release builds.
2262 let _ = Self::MAX + 1;
2263
2264 0
2265 },
2266 }
2267 }
2268
2269 /// Returns the base 10 logarithm of the number, rounded down.
2270 ///
2271 /// # Panics
2272 ///
2273 /// When the number is negative or zero it panics in debug mode and the return value
2274 /// is 0 in release mode.
2275 ///
2276 /// # Example
2277 ///
2278 /// ```
2279 /// #![feature(int_log)]
2280 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")]
2281 /// ```
2282 #[unstable(feature = "int_log", issue = "70887")]
2283 #[must_use = "this returns the result of the operation, \
2284 without modifying the original"]
2285 #[inline]
2286 #[track_caller]
2287 #[rustc_inherit_overflow_checks]
2288 #[allow(arithmetic_overflow)]
2289 pub const fn log10(self) -> u32 {
2290 match self.checked_log10() {
2291 Some(n) => n,
2292 None => {
2293 // In debug builds, trigger a panic on None.
2294 // This should optimize completely out in release builds.
2295 let _ = Self::MAX + 1;
2296
2297 0
2298 },
2299 }
2300 }
2301
2302 /// Returns the logarithm of the number with respect to an arbitrary base,
2303 /// rounded down.
2304 ///
2305 /// Returns `None` if the number is negative or zero, or if the base is not at least 2.
2306 ///
2307 /// This method might not be optimized owing to implementation details;
2308 /// `checked_log2` can produce results more efficiently for base 2, and
2309 /// `checked_log10` can produce results more efficiently for base 10.
2310 ///
2311 /// # Examples
2312 ///
2313 /// ```
2314 /// #![feature(int_log)]
2315 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")]
2316 /// ```
2317 #[unstable(feature = "int_log", issue = "70887")]
2318 #[must_use = "this returns the result of the operation, \
2319 without modifying the original"]
2320 #[inline]
2321 pub const fn checked_log(self, base: Self) -> Option<u32> {
2322 if self <= 0 || base <= 1 {
2323 None
2324 } else {
2325 let mut n = 0;
2326 let mut r = self;
2327
2328 // Optimization for 128 bit wide integers.
2329 if Self::BITS == 128 {
2330 let b = Self::log2(self) / (Self::log2(base) + 1);
2331 n += b;
2332 r /= base.pow(b as u32);
2333 }
2334
2335 while r >= base {
2336 r /= base;
2337 n += 1;
2338 }
2339 Some(n)
2340 }
2341 }
2342
2343 /// Returns the base 2 logarithm of the number, rounded down.
2344 ///
2345 /// Returns `None` if the number is negative or zero.
2346 ///
2347 /// # Examples
2348 ///
2349 /// ```
2350 /// #![feature(int_log)]
2351 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")]
2352 /// ```
2353 #[unstable(feature = "int_log", issue = "70887")]
2354 #[must_use = "this returns the result of the operation, \
2355 without modifying the original"]
2356 #[inline]
2357 pub const fn checked_log2(self) -> Option<u32> {
2358 if self <= 0 {
2359 None
2360 } else {
2361 // SAFETY: We just checked that this number is positive
2362 let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 };
2363 Some(log)
2364 }
2365 }
2366
2367 /// Returns the base 10 logarithm of the number, rounded down.
2368 ///
2369 /// Returns `None` if the number is negative or zero.
2370 ///
2371 /// # Example
2372 ///
2373 /// ```
2374 /// #![feature(int_log)]
2375 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")]
2376 /// ```
2377 #[unstable(feature = "int_log", issue = "70887")]
2378 #[must_use = "this returns the result of the operation, \
2379 without modifying the original"]
2380 #[inline]
2381 pub const fn checked_log10(self) -> Option<u32> {
2382 if self > 0 {
2383 Some(int_log10::$ActualT(self as $ActualT))
2384 } else {
2385 None
2386 }
2387 }
2388
2389 /// Computes the absolute value of `self`.
2390 ///
2391 /// # Overflow behavior
2392 ///
2393 /// The absolute value of
2394 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
2395 /// cannot be represented as an
2396 #[doc = concat!("`", stringify!($SelfT), "`,")]
2397 /// and attempting to calculate it will cause an overflow. This means
2398 /// that code in debug mode will trigger a panic on this case and
2399 /// optimized code will return
2400 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
2401 /// without a panic.
2402 ///
2403 /// # Examples
2404 ///
2405 /// Basic usage:
2406 ///
2407 /// ```
2408 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")]
2409 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")]
2410 /// ```
2411 #[stable(feature = "rust1", since = "1.0.0")]
2412 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2413 #[allow(unused_attributes)]
2414 #[must_use = "this returns the result of the operation, \
2415 without modifying the original"]
2416 #[inline]
2417 #[rustc_inherit_overflow_checks]
2418 pub const fn abs(self) -> Self {
2419 // Note that the #[rustc_inherit_overflow_checks] and #[inline]
2420 // above mean that the overflow semantics of the subtraction
2421 // depend on the crate we're being called from.
2422 if self.is_negative() {
2423 -self
2424 } else {
2425 self
2426 }
2427 }
2428
2429 /// Computes the absolute difference between `self` and `other`.
2430 ///
2431 /// This function always returns the correct answer without overflow or
2432 /// panics by returning an unsigned integer.
2433 ///
2434 /// # Examples
2435 ///
2436 /// Basic usage:
2437 ///
2438 /// ```
2439 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")]
2440 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")]
2441 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")]
2442 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")]
2443 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")]
2444 /// ```
2445 #[stable(feature = "int_abs_diff", since = "1.60.0")]
2446 #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
2447 #[must_use = "this returns the result of the operation, \
2448 without modifying the original"]
2449 #[inline]
2450 pub const fn abs_diff(self, other: Self) -> $UnsignedT {
2451 if self < other {
2452 // Converting a non-negative x from signed to unsigned by using
2453 // `x as U` is left unchanged, but a negative x is converted
2454 // to value x + 2^N. Thus if `s` and `o` are binary variables
2455 // respectively indicating whether `self` and `other` are
2456 // negative, we are computing the mathematical value:
2457 //
2458 // (other + o*2^N) - (self + s*2^N) mod 2^N
2459 // other - self + (o-s)*2^N mod 2^N
2460 // other - self mod 2^N
2461 //
2462 // Finally, taking the mod 2^N of the mathematical value of
2463 // `other - self` does not change it as it already is
2464 // in the range [0, 2^N).
2465 (other as $UnsignedT).wrapping_sub(self as $UnsignedT)
2466 } else {
2467 (self as $UnsignedT).wrapping_sub(other as $UnsignedT)
2468 }
2469 }
2470
2471 /// Returns a number representing sign of `self`.
2472 ///
2473 /// - `0` if the number is zero
2474 /// - `1` if the number is positive
2475 /// - `-1` if the number is negative
2476 ///
2477 /// # Examples
2478 ///
2479 /// Basic usage:
2480 ///
2481 /// ```
2482 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")]
2483 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")]
2484 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")]
2485 /// ```
2486 #[stable(feature = "rust1", since = "1.0.0")]
2487 #[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")]
2488 #[must_use = "this returns the result of the operation, \
2489 without modifying the original"]
2490 #[inline(always)]
2491 pub const fn signum(self) -> Self {
2492 match self {
2493 n if n > 0 => 1,
2494 0 => 0,
2495 _ => -1,
2496 }
2497 }
2498
2499 /// Returns `true` if `self` is positive and `false` if the number is zero or
2500 /// negative.
2501 ///
2502 /// # Examples
2503 ///
2504 /// Basic usage:
2505 ///
2506 /// ```
2507 #[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")]
2508 #[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")]
2509 /// ```
2510 #[must_use]
2511 #[stable(feature = "rust1", since = "1.0.0")]
2512 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2513 #[inline(always)]
2514 pub const fn is_positive(self) -> bool { self > 0 }
2515
2516 /// Returns `true` if `self` is negative and `false` if the number is zero or
2517 /// positive.
2518 ///
2519 /// # Examples
2520 ///
2521 /// Basic usage:
2522 ///
2523 /// ```
2524 #[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")]
2525 #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")]
2526 /// ```
2527 #[must_use]
2528 #[stable(feature = "rust1", since = "1.0.0")]
2529 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2530 #[inline(always)]
2531 pub const fn is_negative(self) -> bool { self < 0 }
2532
2533 /// Return the memory representation of this integer as a byte array in
2534 /// big-endian (network) byte order.
2535 ///
2536 #[doc = $to_xe_bytes_doc]
2537 ///
2538 /// # Examples
2539 ///
2540 /// ```
2541 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
2542 #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
2543 /// ```
2544 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2545 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2546 #[must_use = "this returns the result of the operation, \
2547 without modifying the original"]
2548 #[inline]
2549 pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
2550 self.to_be().to_ne_bytes()
2551 }
2552
2553 /// Return the memory representation of this integer as a byte array in
2554 /// little-endian byte order.
2555 ///
2556 #[doc = $to_xe_bytes_doc]
2557 ///
2558 /// # Examples
2559 ///
2560 /// ```
2561 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
2562 #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
2563 /// ```
2564 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2565 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2566 #[must_use = "this returns the result of the operation, \
2567 without modifying the original"]
2568 #[inline]
2569 pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
2570 self.to_le().to_ne_bytes()
2571 }
2572
2573 /// Return the memory representation of this integer as a byte array in
2574 /// native byte order.
2575 ///
2576 /// As the target platform's native endianness is used, portable code
2577 /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
2578 /// instead.
2579 ///
2580 #[doc = $to_xe_bytes_doc]
2581 ///
2582 /// [`to_be_bytes`]: Self::to_be_bytes
2583 /// [`to_le_bytes`]: Self::to_le_bytes
2584 ///
2585 /// # Examples
2586 ///
2587 /// ```
2588 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
2589 /// assert_eq!(
2590 /// bytes,
2591 /// if cfg!(target_endian = "big") {
2592 #[doc = concat!(" ", $be_bytes)]
2593 /// } else {
2594 #[doc = concat!(" ", $le_bytes)]
2595 /// }
2596 /// );
2597 /// ```
2598 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2599 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2600 // SAFETY: const sound because integers are plain old datatypes so we can always
2601 // transmute them to arrays of bytes
2602 #[must_use = "this returns the result of the operation, \
2603 without modifying the original"]
2604 #[inline]
2605 pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
2606 // SAFETY: integers are plain old datatypes so we can always transmute them to
2607 // arrays of bytes
2608 unsafe { mem::transmute(self) }
2609 }
2610
2611 /// Create an integer value from its representation as a byte array in
2612 /// big endian.
2613 ///
2614 #[doc = $to_xe_bytes_doc]
2615 ///
2616 /// # Examples
2617 ///
2618 /// ```
2619 #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
2620 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
2621 /// ```
2622 ///
2623 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
2624 ///
2625 /// ```
2626 #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
2627 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
2628 /// *input = rest;
2629 #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
2630 /// }
2631 /// ```
2632 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2633 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2634 #[must_use]
2635 #[inline]
2636 pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
2637 Self::from_be(Self::from_ne_bytes(bytes))
2638 }
2639
2640 /// Create an integer value from its representation as a byte array in
2641 /// little endian.
2642 ///
2643 #[doc = $to_xe_bytes_doc]
2644 ///
2645 /// # Examples
2646 ///
2647 /// ```
2648 #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
2649 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
2650 /// ```
2651 ///
2652 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
2653 ///
2654 /// ```
2655 #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
2656 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
2657 /// *input = rest;
2658 #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
2659 /// }
2660 /// ```
2661 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2662 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2663 #[must_use]
2664 #[inline]
2665 pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
2666 Self::from_le(Self::from_ne_bytes(bytes))
2667 }
2668
2669 /// Create an integer value from its memory representation as a byte
2670 /// array in native endianness.
2671 ///
2672 /// As the target platform's native endianness is used, portable code
2673 /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
2674 /// appropriate instead.
2675 ///
2676 /// [`from_be_bytes`]: Self::from_be_bytes
2677 /// [`from_le_bytes`]: Self::from_le_bytes
2678 ///
2679 #[doc = $to_xe_bytes_doc]
2680 ///
2681 /// # Examples
2682 ///
2683 /// ```
2684 #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
2685 #[doc = concat!(" ", $be_bytes)]
2686 /// } else {
2687 #[doc = concat!(" ", $le_bytes)]
2688 /// });
2689 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
2690 /// ```
2691 ///
2692 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
2693 ///
2694 /// ```
2695 #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
2696 #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
2697 /// *input = rest;
2698 #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
2699 /// }
2700 /// ```
2701 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
2702 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
2703 #[must_use]
2704 // SAFETY: const sound because integers are plain old datatypes so we can always
2705 // transmute to them
2706 #[inline]
2707 pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
2708 // SAFETY: integers are plain old datatypes so we can always transmute to them
2709 unsafe { mem::transmute(bytes) }
2710 }
2711
2712 /// New code should prefer to use
2713 #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
2714 ///
2715 /// Returns the smallest value that can be represented by this integer type.
2716 #[stable(feature = "rust1", since = "1.0.0")]
2717 #[inline(always)]
2718 #[rustc_promotable]
2719 #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
2720 #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")]
2721 pub const fn min_value() -> Self {
2722 Self::MIN
2723 }
2724
2725 /// New code should prefer to use
2726 #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
2727 ///
2728 /// Returns the largest value that can be represented by this integer type.
2729 #[stable(feature = "rust1", since = "1.0.0")]
2730 #[inline(always)]
2731 #[rustc_promotable]
2732 #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
2733 #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")]
2734 pub const fn max_value() -> Self {
2735 Self::MAX
2736 }
2737 }
2738 }