core/num/int_macros.rs
1macro_rules! int_impl {
2 (
3 Self = $SelfT:ty,
4 ActualT = $ActualT:ident,
5 UnsignedT = $UnsignedT:ty,
6
7 // These are all for use *only* in doc comments.
8 // As such, they're all passed as literals -- passing them as a string
9 // literal is fine if they need to be multiple code tokens.
10 // In non-comments, use the associated constants rather than these.
11 BITS = $BITS:literal,
12 BITS_MINUS_ONE = $BITS_MINUS_ONE:literal,
13 Min = $Min:literal,
14 Max = $Max:literal,
15 rot = $rot:literal,
16 rot_op = $rot_op:literal,
17 rot_result = $rot_result:literal,
18 swap_op = $swap_op:literal,
19 swapped = $swapped:literal,
20 reversed = $reversed:literal,
21 le_bytes = $le_bytes:literal,
22 be_bytes = $be_bytes:literal,
23 to_xe_bytes_doc = $to_xe_bytes_doc:expr,
24 from_xe_bytes_doc = $from_xe_bytes_doc:expr,
25 bound_condition = $bound_condition:literal,
26 ) => {
27 /// The smallest value that can be represented by this integer type
28 #[doc = concat!("(−2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ").")]
29 ///
30 /// # Examples
31 ///
32 /// ```
33 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")]
34 /// ```
35 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
36 pub const MIN: Self = !Self::MAX;
37
38 /// The largest value that can be represented by this integer type
39 #[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> − 1", $bound_condition, ").")]
40 ///
41 /// # Examples
42 ///
43 /// ```
44 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")]
45 /// ```
46 #[stable(feature = "assoc_int_consts", since = "1.43.0")]
47 pub const MAX: Self = (<$UnsignedT>::MAX >> 1) as Self;
48
49 /// The size of this integer type in bits.
50 ///
51 /// # Examples
52 ///
53 /// ```
54 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
55 /// ```
56 #[stable(feature = "int_bits_const", since = "1.53.0")]
57 pub const BITS: u32 = <$UnsignedT>::BITS;
58
59 /// Returns the number of ones in the binary representation of `self`.
60 ///
61 /// # Examples
62 ///
63 /// ```
64 #[doc = concat!("let n = 0b100_0000", stringify!($SelfT), ";")]
65 ///
66 /// assert_eq!(n.count_ones(), 1);
67 /// ```
68 ///
69 #[stable(feature = "rust1", since = "1.0.0")]
70 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
71 #[doc(alias = "popcount")]
72 #[doc(alias = "popcnt")]
73 #[must_use = "this returns the result of the operation, \
74 without modifying the original"]
75 #[inline(always)]
76 pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() }
77
78 /// Returns the number of zeros in the binary representation of `self`.
79 ///
80 /// # Examples
81 ///
82 /// ```
83 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")]
84 /// ```
85 #[stable(feature = "rust1", since = "1.0.0")]
86 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
87 #[must_use = "this returns the result of the operation, \
88 without modifying the original"]
89 #[inline(always)]
90 pub const fn count_zeros(self) -> u32 {
91 (!self).count_ones()
92 }
93
94 /// Returns the number of leading zeros in the binary representation of `self`.
95 ///
96 /// Depending on what you're doing with the value, you might also be interested in the
97 /// [`ilog2`] function which returns a consistent number, even if the type widens.
98 ///
99 /// # Examples
100 ///
101 /// ```
102 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
103 ///
104 /// assert_eq!(n.leading_zeros(), 0);
105 /// ```
106 #[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")]
107 #[stable(feature = "rust1", since = "1.0.0")]
108 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
109 #[must_use = "this returns the result of the operation, \
110 without modifying the original"]
111 #[inline(always)]
112 pub const fn leading_zeros(self) -> u32 {
113 (self as $UnsignedT).leading_zeros()
114 }
115
116 /// Returns the number of trailing zeros in the binary representation of `self`.
117 ///
118 /// # Examples
119 ///
120 /// ```
121 #[doc = concat!("let n = -4", stringify!($SelfT), ";")]
122 ///
123 /// assert_eq!(n.trailing_zeros(), 2);
124 /// ```
125 #[stable(feature = "rust1", since = "1.0.0")]
126 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
127 #[must_use = "this returns the result of the operation, \
128 without modifying the original"]
129 #[inline(always)]
130 pub const fn trailing_zeros(self) -> u32 {
131 (self as $UnsignedT).trailing_zeros()
132 }
133
134 /// Returns the number of leading ones in the binary representation of `self`.
135 ///
136 /// # Examples
137 ///
138 /// ```
139 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
140 ///
141 #[doc = concat!("assert_eq!(n.leading_ones(), ", stringify!($BITS), ");")]
142 /// ```
143 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
144 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
145 #[must_use = "this returns the result of the operation, \
146 without modifying the original"]
147 #[inline(always)]
148 pub const fn leading_ones(self) -> u32 {
149 (self as $UnsignedT).leading_ones()
150 }
151
152 /// Returns the number of trailing ones in the binary representation of `self`.
153 ///
154 /// # Examples
155 ///
156 /// ```
157 #[doc = concat!("let n = 3", stringify!($SelfT), ";")]
158 ///
159 /// assert_eq!(n.trailing_ones(), 2);
160 /// ```
161 #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
162 #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
163 #[must_use = "this returns the result of the operation, \
164 without modifying the original"]
165 #[inline(always)]
166 pub const fn trailing_ones(self) -> u32 {
167 (self as $UnsignedT).trailing_ones()
168 }
169
170 /// Returns `self` with only the most significant bit set, or `0` if
171 /// the input is `0`.
172 ///
173 /// # Examples
174 ///
175 /// ```
176 /// #![feature(isolate_most_least_significant_one)]
177 ///
178 #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
179 ///
180 /// assert_eq!(n.isolate_highest_one(), 0b_01000000);
181 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_highest_one(), 0);")]
182 /// ```
183 #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
184 #[must_use = "this returns the result of the operation, \
185 without modifying the original"]
186 #[inline(always)]
187 pub const fn isolate_highest_one(self) -> Self {
188 self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros()))
189 }
190
191 /// Returns `self` with only the least significant bit set, or `0` if
192 /// the input is `0`.
193 ///
194 /// # Examples
195 ///
196 /// ```
197 /// #![feature(isolate_most_least_significant_one)]
198 ///
199 #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
200 ///
201 /// assert_eq!(n.isolate_lowest_one(), 0b_00000100);
202 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_lowest_one(), 0);")]
203 /// ```
204 #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
205 #[must_use = "this returns the result of the operation, \
206 without modifying the original"]
207 #[inline(always)]
208 pub const fn isolate_lowest_one(self) -> Self {
209 self & self.wrapping_neg()
210 }
211
212 /// Returns the index of the highest bit set to one in `self`, or `None`
213 /// if `self` is `0`.
214 ///
215 /// # Examples
216 ///
217 /// ```
218 /// #![feature(int_lowest_highest_one)]
219 ///
220 #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".highest_one(), None);")]
221 #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".highest_one(), Some(0));")]
222 #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".highest_one(), Some(4));")]
223 #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".highest_one(), Some(4));")]
224 /// ```
225 #[unstable(feature = "int_lowest_highest_one", issue = "145203")]
226 #[must_use = "this returns the result of the operation, \
227 without modifying the original"]
228 #[inline(always)]
229 pub const fn highest_one(self) -> Option<u32> {
230 (self as $UnsignedT).highest_one()
231 }
232
233 /// Returns the index of the lowest bit set to one in `self`, or `None`
234 /// if `self` is `0`.
235 ///
236 /// # Examples
237 ///
238 /// ```
239 /// #![feature(int_lowest_highest_one)]
240 ///
241 #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".lowest_one(), None);")]
242 #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".lowest_one(), Some(0));")]
243 #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".lowest_one(), Some(4));")]
244 #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".lowest_one(), Some(0));")]
245 /// ```
246 #[unstable(feature = "int_lowest_highest_one", issue = "145203")]
247 #[must_use = "this returns the result of the operation, \
248 without modifying the original"]
249 #[inline(always)]
250 pub const fn lowest_one(self) -> Option<u32> {
251 (self as $UnsignedT).lowest_one()
252 }
253
254 /// Returns the bit pattern of `self` reinterpreted as an unsigned integer of the same size.
255 ///
256 /// This produces the same result as an `as` cast, but ensures that the bit-width remains
257 /// the same.
258 ///
259 /// # Examples
260 ///
261 /// ```
262 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
263 ///
264 #[doc = concat!("assert_eq!(n.cast_unsigned(), ", stringify!($UnsignedT), "::MAX);")]
265 /// ```
266 #[stable(feature = "integer_sign_cast", since = "1.87.0")]
267 #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
268 #[must_use = "this returns the result of the operation, \
269 without modifying the original"]
270 #[inline(always)]
271 pub const fn cast_unsigned(self) -> $UnsignedT {
272 self as $UnsignedT
273 }
274
275 /// Shifts the bits to the left by a specified amount, `n`,
276 /// wrapping the truncated bits to the end of the resulting integer.
277 ///
278 /// `rotate_left(n)` is equivalent to applying `rotate_left(1)` a total of `n` times. In
279 /// particular, a rotation by the number of bits in `self` returns the input value
280 /// unchanged.
281 ///
282 /// Please note this isn't the same operation as the `<<` shifting operator!
283 ///
284 /// # Examples
285 ///
286 /// ```
287 #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
288 #[doc = concat!("let m = ", $rot_result, ";")]
289 ///
290 #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
291 #[doc = concat!("assert_eq!(n.rotate_left(1024), n);")]
292 /// ```
293 #[stable(feature = "rust1", since = "1.0.0")]
294 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
295 #[must_use = "this returns the result of the operation, \
296 without modifying the original"]
297 #[inline(always)]
298 pub const fn rotate_left(self, n: u32) -> Self {
299 (self as $UnsignedT).rotate_left(n) as Self
300 }
301
302 /// Shifts the bits to the right by a specified amount, `n`,
303 /// wrapping the truncated bits to the beginning of the resulting
304 /// integer.
305 ///
306 /// `rotate_right(n)` is equivalent to applying `rotate_right(1)` a total of `n` times. In
307 /// particular, a rotation by the number of bits in `self` returns the input value
308 /// unchanged.
309 ///
310 /// Please note this isn't the same operation as the `>>` shifting operator!
311 ///
312 /// # Examples
313 ///
314 /// ```
315 #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
316 #[doc = concat!("let m = ", $rot_op, ";")]
317 ///
318 #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
319 #[doc = concat!("assert_eq!(n.rotate_right(1024), n);")]
320 /// ```
321 #[stable(feature = "rust1", since = "1.0.0")]
322 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
323 #[must_use = "this returns the result of the operation, \
324 without modifying the original"]
325 #[inline(always)]
326 pub const fn rotate_right(self, n: u32) -> Self {
327 (self as $UnsignedT).rotate_right(n) as Self
328 }
329
330 /// Reverses the byte order of the integer.
331 ///
332 /// # Examples
333 ///
334 /// ```
335 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
336 ///
337 /// let m = n.swap_bytes();
338 ///
339 #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
340 /// ```
341 #[stable(feature = "rust1", since = "1.0.0")]
342 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
343 #[must_use = "this returns the result of the operation, \
344 without modifying the original"]
345 #[inline(always)]
346 pub const fn swap_bytes(self) -> Self {
347 (self as $UnsignedT).swap_bytes() as Self
348 }
349
350 /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
351 /// second least-significant bit becomes second most-significant bit, etc.
352 ///
353 /// # Examples
354 ///
355 /// ```
356 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
357 /// let m = n.reverse_bits();
358 ///
359 #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
360 #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
361 /// ```
362 #[stable(feature = "reverse_bits", since = "1.37.0")]
363 #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
364 #[must_use = "this returns the result of the operation, \
365 without modifying the original"]
366 #[inline(always)]
367 pub const fn reverse_bits(self) -> Self {
368 (self as $UnsignedT).reverse_bits() as Self
369 }
370
371 /// Converts an integer from big endian to the target's endianness.
372 ///
373 /// On big endian this is a no-op. On little endian the bytes are swapped.
374 ///
375 /// See also [from_be_bytes()](Self::from_be_bytes).
376 ///
377 /// # Examples
378 ///
379 /// ```
380 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
381 ///
382 /// if cfg!(target_endian = "big") {
383 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
384 /// } else {
385 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
386 /// }
387 /// ```
388 #[stable(feature = "rust1", since = "1.0.0")]
389 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
390 #[must_use]
391 #[inline]
392 pub const fn from_be(x: Self) -> Self {
393 #[cfg(target_endian = "big")]
394 {
395 x
396 }
397 #[cfg(not(target_endian = "big"))]
398 {
399 x.swap_bytes()
400 }
401 }
402
403 /// Converts an integer from little endian to the target's endianness.
404 ///
405 /// On little endian this is a no-op. On big endian the bytes are swapped.
406 ///
407 /// See also [from_le_bytes()](Self::from_le_bytes).
408 ///
409 /// # Examples
410 ///
411 /// ```
412 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
413 ///
414 /// if cfg!(target_endian = "little") {
415 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
416 /// } else {
417 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
418 /// }
419 /// ```
420 #[stable(feature = "rust1", since = "1.0.0")]
421 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
422 #[must_use]
423 #[inline]
424 pub const fn from_le(x: Self) -> Self {
425 #[cfg(target_endian = "little")]
426 {
427 x
428 }
429 #[cfg(not(target_endian = "little"))]
430 {
431 x.swap_bytes()
432 }
433 }
434
435 /// Swaps bytes of `self` on little endian targets.
436 ///
437 /// On big endian this is a no-op.
438 ///
439 /// The returned value has the same type as `self`, and will be interpreted
440 /// as (a potentially different) value of a native-endian
441 #[doc = concat!("`", stringify!($SelfT), "`.")]
442 ///
443 /// See [`to_be_bytes()`](Self::to_be_bytes) for a type-safe alternative.
444 ///
445 /// # Examples
446 ///
447 /// ```
448 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
449 ///
450 /// if cfg!(target_endian = "big") {
451 /// assert_eq!(n.to_be(), n)
452 /// } else {
453 /// assert_eq!(n.to_be(), n.swap_bytes())
454 /// }
455 /// ```
456 #[stable(feature = "rust1", since = "1.0.0")]
457 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
458 #[must_use = "this returns the result of the operation, \
459 without modifying the original"]
460 #[inline]
461 pub const fn to_be(self) -> Self { // or not to be?
462 #[cfg(target_endian = "big")]
463 {
464 self
465 }
466 #[cfg(not(target_endian = "big"))]
467 {
468 self.swap_bytes()
469 }
470 }
471
472 /// Swaps bytes of `self` on big endian targets.
473 ///
474 /// On little endian this is a no-op.
475 ///
476 /// The returned value has the same type as `self`, and will be interpreted
477 /// as (a potentially different) value of a native-endian
478 #[doc = concat!("`", stringify!($SelfT), "`.")]
479 ///
480 /// See [`to_le_bytes()`](Self::to_le_bytes) for a type-safe alternative.
481 ///
482 /// # Examples
483 ///
484 /// ```
485 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
486 ///
487 /// if cfg!(target_endian = "little") {
488 /// assert_eq!(n.to_le(), n)
489 /// } else {
490 /// assert_eq!(n.to_le(), n.swap_bytes())
491 /// }
492 /// ```
493 #[stable(feature = "rust1", since = "1.0.0")]
494 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
495 #[must_use = "this returns the result of the operation, \
496 without modifying the original"]
497 #[inline]
498 pub const fn to_le(self) -> Self {
499 #[cfg(target_endian = "little")]
500 {
501 self
502 }
503 #[cfg(not(target_endian = "little"))]
504 {
505 self.swap_bytes()
506 }
507 }
508
509 /// Checked integer addition. Computes `self + rhs`, returning `None`
510 /// if overflow occurred.
511 ///
512 /// # Examples
513 ///
514 /// ```
515 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")]
516 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
517 /// ```
518 #[stable(feature = "rust1", since = "1.0.0")]
519 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
520 #[must_use = "this returns the result of the operation, \
521 without modifying the original"]
522 #[inline]
523 pub const fn checked_add(self, rhs: Self) -> Option<Self> {
524 let (a, b) = self.overflowing_add(rhs);
525 if intrinsics::unlikely(b) { None } else { Some(a) }
526 }
527
528 /// Strict integer addition. Computes `self + rhs`, panicking
529 /// if overflow occurred.
530 ///
531 /// # Panics
532 ///
533 /// ## Overflow behavior
534 ///
535 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
536 ///
537 /// # Examples
538 ///
539 /// ```
540 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
541 /// ```
542 ///
543 /// The following panics because of overflow:
544 ///
545 /// ```should_panic
546 #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
547 /// ```
548 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
549 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
550 #[must_use = "this returns the result of the operation, \
551 without modifying the original"]
552 #[inline]
553 #[track_caller]
554 pub const fn strict_add(self, rhs: Self) -> Self {
555 let (a, b) = self.overflowing_add(rhs);
556 if b { overflow_panic::add() } else { a }
557 }
558
559 /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
560 /// cannot occur.
561 ///
562 /// Calling `x.unchecked_add(y)` is semantically equivalent to calling
563 /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
564 ///
565 /// If you're just trying to avoid the panic in debug mode, then **do not**
566 /// use this. Instead, you're looking for [`wrapping_add`].
567 ///
568 /// # Safety
569 ///
570 /// This results in undefined behavior when
571 #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
572 /// i.e. when [`checked_add`] would return `None`.
573 ///
574 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
575 #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
576 #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
577 #[stable(feature = "unchecked_math", since = "1.79.0")]
578 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
579 #[must_use = "this returns the result of the operation, \
580 without modifying the original"]
581 #[inline(always)]
582 #[track_caller]
583 pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
584 assert_unsafe_precondition!(
585 check_language_ub,
586 concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
587 (
588 lhs: $SelfT = self,
589 rhs: $SelfT = rhs,
590 ) => !lhs.overflowing_add(rhs).1,
591 );
592
593 // SAFETY: this is guaranteed to be safe by the caller.
594 unsafe {
595 intrinsics::unchecked_add(self, rhs)
596 }
597 }
598
599 /// Checked addition with an unsigned integer. Computes `self + rhs`,
600 /// returning `None` if overflow occurred.
601 ///
602 /// # Examples
603 ///
604 /// ```
605 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")]
606 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")]
607 /// ```
608 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
609 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
610 #[must_use = "this returns the result of the operation, \
611 without modifying the original"]
612 #[inline]
613 pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
614 let (a, b) = self.overflowing_add_unsigned(rhs);
615 if intrinsics::unlikely(b) { None } else { Some(a) }
616 }
617
618 /// Strict addition with an unsigned integer. Computes `self + rhs`,
619 /// panicking if overflow occurred.
620 ///
621 /// # Panics
622 ///
623 /// ## Overflow behavior
624 ///
625 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
626 ///
627 /// # Examples
628 ///
629 /// ```
630 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_unsigned(2), 3);")]
631 /// ```
632 ///
633 /// The following panics because of overflow:
634 ///
635 /// ```should_panic
636 #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_unsigned(3);")]
637 /// ```
638 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
639 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
640 #[must_use = "this returns the result of the operation, \
641 without modifying the original"]
642 #[inline]
643 #[track_caller]
644 pub const fn strict_add_unsigned(self, rhs: $UnsignedT) -> Self {
645 let (a, b) = self.overflowing_add_unsigned(rhs);
646 if b { overflow_panic::add() } else { a }
647 }
648
649 /// Checked integer subtraction. Computes `self - rhs`, returning `None` if
650 /// overflow occurred.
651 ///
652 /// # Examples
653 ///
654 /// ```
655 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")]
656 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")]
657 /// ```
658 #[stable(feature = "rust1", since = "1.0.0")]
659 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
660 #[must_use = "this returns the result of the operation, \
661 without modifying the original"]
662 #[inline]
663 pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
664 let (a, b) = self.overflowing_sub(rhs);
665 if intrinsics::unlikely(b) { None } else { Some(a) }
666 }
667
668 /// Strict integer subtraction. Computes `self - rhs`, panicking if
669 /// overflow occurred.
670 ///
671 /// # Panics
672 ///
673 /// ## Overflow behavior
674 ///
675 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
676 ///
677 /// # Examples
678 ///
679 /// ```
680 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).strict_sub(1), ", stringify!($SelfT), "::MIN + 1);")]
681 /// ```
682 ///
683 /// The following panics because of overflow:
684 ///
685 /// ```should_panic
686 #[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub(3);")]
687 /// ```
688 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
689 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
690 #[must_use = "this returns the result of the operation, \
691 without modifying the original"]
692 #[inline]
693 #[track_caller]
694 pub const fn strict_sub(self, rhs: Self) -> Self {
695 let (a, b) = self.overflowing_sub(rhs);
696 if b { overflow_panic::sub() } else { a }
697 }
698
699 /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
700 /// cannot occur.
701 ///
702 /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
703 /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
704 ///
705 /// If you're just trying to avoid the panic in debug mode, then **do not**
706 /// use this. Instead, you're looking for [`wrapping_sub`].
707 ///
708 /// # Safety
709 ///
710 /// This results in undefined behavior when
711 #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
712 /// i.e. when [`checked_sub`] would return `None`.
713 ///
714 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
715 #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
716 #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
717 #[stable(feature = "unchecked_math", since = "1.79.0")]
718 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
719 #[must_use = "this returns the result of the operation, \
720 without modifying the original"]
721 #[inline(always)]
722 #[track_caller]
723 pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
724 assert_unsafe_precondition!(
725 check_language_ub,
726 concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
727 (
728 lhs: $SelfT = self,
729 rhs: $SelfT = rhs,
730 ) => !lhs.overflowing_sub(rhs).1,
731 );
732
733 // SAFETY: this is guaranteed to be safe by the caller.
734 unsafe {
735 intrinsics::unchecked_sub(self, rhs)
736 }
737 }
738
739 /// Checked subtraction with an unsigned integer. Computes `self - rhs`,
740 /// returning `None` if overflow occurred.
741 ///
742 /// # Examples
743 ///
744 /// ```
745 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")]
746 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")]
747 /// ```
748 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
749 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
750 #[must_use = "this returns the result of the operation, \
751 without modifying the original"]
752 #[inline]
753 pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
754 let (a, b) = self.overflowing_sub_unsigned(rhs);
755 if intrinsics::unlikely(b) { None } else { Some(a) }
756 }
757
758 /// Strict subtraction with an unsigned integer. Computes `self - rhs`,
759 /// panicking if overflow occurred.
760 ///
761 /// # Panics
762 ///
763 /// ## Overflow behavior
764 ///
765 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
766 ///
767 /// # Examples
768 ///
769 /// ```
770 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub_unsigned(2), -1);")]
771 /// ```
772 ///
773 /// The following panics because of overflow:
774 ///
775 /// ```should_panic
776 #[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub_unsigned(3);")]
777 /// ```
778 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
779 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
780 #[must_use = "this returns the result of the operation, \
781 without modifying the original"]
782 #[inline]
783 #[track_caller]
784 pub const fn strict_sub_unsigned(self, rhs: $UnsignedT) -> Self {
785 let (a, b) = self.overflowing_sub_unsigned(rhs);
786 if b { overflow_panic::sub() } else { a }
787 }
788
789 /// Checked integer multiplication. Computes `self * rhs`, returning `None` if
790 /// overflow occurred.
791 ///
792 /// # Examples
793 ///
794 /// ```
795 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")]
796 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
797 /// ```
798 #[stable(feature = "rust1", since = "1.0.0")]
799 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
800 #[must_use = "this returns the result of the operation, \
801 without modifying the original"]
802 #[inline]
803 pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
804 let (a, b) = self.overflowing_mul(rhs);
805 if intrinsics::unlikely(b) { None } else { Some(a) }
806 }
807
808 /// Strict integer multiplication. Computes `self * rhs`, panicking if
809 /// overflow occurred.
810 ///
811 /// # Panics
812 ///
813 /// ## Overflow behavior
814 ///
815 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
816 ///
817 /// # Examples
818 ///
819 /// ```
820 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.strict_mul(1), ", stringify!($SelfT), "::MAX);")]
821 /// ```
822 ///
823 /// The following panics because of overflow:
824 ///
825 /// ``` should_panic
826 #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
827 /// ```
828 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
829 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
830 #[must_use = "this returns the result of the operation, \
831 without modifying the original"]
832 #[inline]
833 #[track_caller]
834 pub const fn strict_mul(self, rhs: Self) -> Self {
835 let (a, b) = self.overflowing_mul(rhs);
836 if b { overflow_panic::mul() } else { a }
837 }
838
839 /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
840 /// cannot occur.
841 ///
842 /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
843 /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
844 ///
845 /// If you're just trying to avoid the panic in debug mode, then **do not**
846 /// use this. Instead, you're looking for [`wrapping_mul`].
847 ///
848 /// # Safety
849 ///
850 /// This results in undefined behavior when
851 #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
852 /// i.e. when [`checked_mul`] would return `None`.
853 ///
854 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
855 #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
856 #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
857 #[stable(feature = "unchecked_math", since = "1.79.0")]
858 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
859 #[must_use = "this returns the result of the operation, \
860 without modifying the original"]
861 #[inline(always)]
862 #[track_caller]
863 pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
864 assert_unsafe_precondition!(
865 check_language_ub,
866 concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
867 (
868 lhs: $SelfT = self,
869 rhs: $SelfT = rhs,
870 ) => !lhs.overflowing_mul(rhs).1,
871 );
872
873 // SAFETY: this is guaranteed to be safe by the caller.
874 unsafe {
875 intrinsics::unchecked_mul(self, rhs)
876 }
877 }
878
879 /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
880 /// or the division results in overflow.
881 ///
882 /// # Examples
883 ///
884 /// ```
885 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")]
886 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")]
887 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")]
888 /// ```
889 #[stable(feature = "rust1", since = "1.0.0")]
890 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
891 #[must_use = "this returns the result of the operation, \
892 without modifying the original"]
893 #[inline]
894 pub const fn checked_div(self, rhs: Self) -> Option<Self> {
895 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
896 None
897 } else {
898 // SAFETY: div by zero and by INT_MIN have been checked above
899 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
900 }
901 }
902
903 /// Strict integer division. Computes `self / rhs`, panicking
904 /// if overflow occurred.
905 ///
906 /// # Panics
907 ///
908 /// This function will panic if `rhs` is zero.
909 ///
910 /// ## Overflow behavior
911 ///
912 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
913 ///
914 /// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
915 /// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
916 /// that is too large to represent in the type.
917 ///
918 /// # Examples
919 ///
920 /// ```
921 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div(-1), ", stringify!($Max), ");")]
922 /// ```
923 ///
924 /// The following panics because of overflow:
925 ///
926 /// ```should_panic
927 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div(-1);")]
928 /// ```
929 ///
930 /// The following panics because of division by zero:
931 ///
932 /// ```should_panic
933 #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
934 /// ```
935 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
936 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
937 #[must_use = "this returns the result of the operation, \
938 without modifying the original"]
939 #[inline]
940 #[track_caller]
941 pub const fn strict_div(self, rhs: Self) -> Self {
942 let (a, b) = self.overflowing_div(rhs);
943 if b { overflow_panic::div() } else { a }
944 }
945
946 /// Checked Euclidean division. Computes `self.div_euclid(rhs)`,
947 /// returning `None` if `rhs == 0` or the division results in overflow.
948 ///
949 /// # Examples
950 ///
951 /// ```
952 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")]
953 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")]
954 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")]
955 /// ```
956 #[stable(feature = "euclidean_division", since = "1.38.0")]
957 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
958 #[must_use = "this returns the result of the operation, \
959 without modifying the original"]
960 #[inline]
961 pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
962 // Using `&` helps LLVM see that it is the same check made in division.
963 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
964 None
965 } else {
966 Some(self.div_euclid(rhs))
967 }
968 }
969
970 /// Strict Euclidean division. Computes `self.div_euclid(rhs)`, panicking
971 /// if overflow occurred.
972 ///
973 /// # Panics
974 ///
975 /// This function will panic if `rhs` is zero.
976 ///
977 /// ## Overflow behavior
978 ///
979 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
980 ///
981 /// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
982 /// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
983 /// that is too large to represent in the type.
984 ///
985 /// # Examples
986 ///
987 /// ```
988 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div_euclid(-1), ", stringify!($Max), ");")]
989 /// ```
990 ///
991 /// The following panics because of overflow:
992 ///
993 /// ```should_panic
994 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div_euclid(-1);")]
995 /// ```
996 ///
997 /// The following panics because of division by zero:
998 ///
999 /// ```should_panic
1000 #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
1001 /// ```
1002 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1003 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1004 #[must_use = "this returns the result of the operation, \
1005 without modifying the original"]
1006 #[inline]
1007 #[track_caller]
1008 pub const fn strict_div_euclid(self, rhs: Self) -> Self {
1009 let (a, b) = self.overflowing_div_euclid(rhs);
1010 if b { overflow_panic::div() } else { a }
1011 }
1012
1013 /// Checked integer division without remainder. Computes `self / rhs`,
1014 /// returning `None` if `rhs == 0`, the division results in overflow,
1015 /// or `self % rhs != 0`.
1016 ///
1017 /// # Examples
1018 ///
1019 /// ```
1020 /// #![feature(exact_div)]
1021 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_exact(-1), Some(", stringify!($Max), "));")]
1022 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_div_exact(2), None);")]
1023 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_exact(-1), None);")]
1024 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_exact(0), None);")]
1025 /// ```
1026 #[unstable(
1027 feature = "exact_div",
1028 issue = "139911",
1029 )]
1030 #[must_use = "this returns the result of the operation, \
1031 without modifying the original"]
1032 #[inline]
1033 pub const fn checked_div_exact(self, rhs: Self) -> Option<Self> {
1034 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
1035 None
1036 } else {
1037 // SAFETY: division by zero and overflow are checked above
1038 unsafe {
1039 if intrinsics::unlikely(intrinsics::unchecked_rem(self, rhs) != 0) {
1040 None
1041 } else {
1042 Some(intrinsics::exact_div(self, rhs))
1043 }
1044 }
1045 }
1046 }
1047
1048 /// Integer division without remainder. Computes `self / rhs`, returning `None` if `self % rhs != 0`.
1049 ///
1050 /// # Panics
1051 ///
1052 /// This function will panic if `rhs == 0`.
1053 ///
1054 /// ## Overflow behavior
1055 ///
1056 /// On overflow, this function will panic if overflow checks are enabled (default in debug
1057 /// mode) and wrap if overflow checks are disabled (default in release mode).
1058 ///
1059 /// # Examples
1060 ///
1061 /// ```
1062 /// #![feature(exact_div)]
1063 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(2), Some(32));")]
1064 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(32), Some(2));")]
1065 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).div_exact(-1), Some(", stringify!($Max), "));")]
1066 #[doc = concat!("assert_eq!(65", stringify!($SelfT), ".div_exact(2), None);")]
1067 /// ```
1068 /// ```should_panic
1069 /// #![feature(exact_div)]
1070 #[doc = concat!("let _ = 64", stringify!($SelfT),".div_exact(0);")]
1071 /// ```
1072 /// ```should_panic
1073 /// #![feature(exact_div)]
1074 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.div_exact(-1);")]
1075 /// ```
1076 #[unstable(
1077 feature = "exact_div",
1078 issue = "139911",
1079 )]
1080 #[must_use = "this returns the result of the operation, \
1081 without modifying the original"]
1082 #[inline]
1083 #[rustc_inherit_overflow_checks]
1084 pub const fn div_exact(self, rhs: Self) -> Option<Self> {
1085 if self % rhs != 0 {
1086 None
1087 } else {
1088 Some(self / rhs)
1089 }
1090 }
1091
1092 /// Unchecked integer division without remainder. Computes `self / rhs`.
1093 ///
1094 /// # Safety
1095 ///
1096 /// This results in undefined behavior when `rhs == 0`, `self % rhs != 0`, or
1097 #[doc = concat!("`self == ", stringify!($SelfT), "::MIN && rhs == -1`,")]
1098 /// i.e. when [`checked_div_exact`](Self::checked_div_exact) would return `None`.
1099 #[unstable(
1100 feature = "exact_div",
1101 issue = "139911",
1102 )]
1103 #[must_use = "this returns the result of the operation, \
1104 without modifying the original"]
1105 #[inline]
1106 pub const unsafe fn unchecked_div_exact(self, rhs: Self) -> Self {
1107 assert_unsafe_precondition!(
1108 check_language_ub,
1109 concat!(stringify!($SelfT), "::unchecked_div_exact cannot overflow, divide by zero, or leave a remainder"),
1110 (
1111 lhs: $SelfT = self,
1112 rhs: $SelfT = rhs,
1113 ) => rhs > 0 && lhs % rhs == 0 && (lhs != <$SelfT>::MIN || rhs != -1),
1114 );
1115 // SAFETY: Same precondition
1116 unsafe { intrinsics::exact_div(self, rhs) }
1117 }
1118
1119 /// Checked integer remainder. Computes `self % rhs`, returning `None` if
1120 /// `rhs == 0` or the division results in overflow.
1121 ///
1122 /// # Examples
1123 ///
1124 /// ```
1125 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
1126 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
1127 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")]
1128 /// ```
1129 #[stable(feature = "wrapping", since = "1.7.0")]
1130 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1131 #[must_use = "this returns the result of the operation, \
1132 without modifying the original"]
1133 #[inline]
1134 pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
1135 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
1136 None
1137 } else {
1138 // SAFETY: div by zero and by INT_MIN have been checked above
1139 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
1140 }
1141 }
1142
1143 /// Strict integer remainder. Computes `self % rhs`, panicking if
1144 /// the division results in overflow.
1145 ///
1146 /// # Panics
1147 ///
1148 /// This function will panic if `rhs` is zero.
1149 ///
1150 /// ## Overflow behavior
1151 ///
1152 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1153 ///
1154 /// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
1155 /// signed type (where `MIN` is the negative minimal value), which is invalid due to implementation artifacts.
1156 ///
1157 /// # Examples
1158 ///
1159 /// ```
1160 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem(2), 1);")]
1161 /// ```
1162 ///
1163 /// The following panics because of division by zero:
1164 ///
1165 /// ```should_panic
1166 #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
1167 /// ```
1168 ///
1169 /// The following panics because of overflow:
1170 ///
1171 /// ```should_panic
1172 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem(-1);")]
1173 /// ```
1174 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1175 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1176 #[must_use = "this returns the result of the operation, \
1177 without modifying the original"]
1178 #[inline]
1179 #[track_caller]
1180 pub const fn strict_rem(self, rhs: Self) -> Self {
1181 let (a, b) = self.overflowing_rem(rhs);
1182 if b { overflow_panic::rem() } else { a }
1183 }
1184
1185 /// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None`
1186 /// if `rhs == 0` or the division results in overflow.
1187 ///
1188 /// # Examples
1189 ///
1190 /// ```
1191 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
1192 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
1193 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")]
1194 /// ```
1195 #[stable(feature = "euclidean_division", since = "1.38.0")]
1196 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1197 #[must_use = "this returns the result of the operation, \
1198 without modifying the original"]
1199 #[inline]
1200 pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
1201 // Using `&` helps LLVM see that it is the same check made in division.
1202 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
1203 None
1204 } else {
1205 Some(self.rem_euclid(rhs))
1206 }
1207 }
1208
1209 /// Strict Euclidean remainder. Computes `self.rem_euclid(rhs)`, panicking if
1210 /// the division results in overflow.
1211 ///
1212 /// # Panics
1213 ///
1214 /// This function will panic if `rhs` is zero.
1215 ///
1216 /// ## Overflow behavior
1217 ///
1218 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1219 ///
1220 /// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
1221 /// signed type (where `MIN` is the negative minimal value), which is invalid due to implementation artifacts.
1222 ///
1223 /// # Examples
1224 ///
1225 /// ```
1226 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem_euclid(2), 1);")]
1227 /// ```
1228 ///
1229 /// The following panics because of division by zero:
1230 ///
1231 /// ```should_panic
1232 #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
1233 /// ```
1234 ///
1235 /// The following panics because of overflow:
1236 ///
1237 /// ```should_panic
1238 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem_euclid(-1);")]
1239 /// ```
1240 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1241 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1242 #[must_use = "this returns the result of the operation, \
1243 without modifying the original"]
1244 #[inline]
1245 #[track_caller]
1246 pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
1247 let (a, b) = self.overflowing_rem_euclid(rhs);
1248 if b { overflow_panic::rem() } else { a }
1249 }
1250
1251 /// Checked negation. Computes `-self`, returning `None` if `self == MIN`.
1252 ///
1253 /// # Examples
1254 ///
1255 /// ```
1256 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")]
1257 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")]
1258 /// ```
1259 #[stable(feature = "wrapping", since = "1.7.0")]
1260 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1261 #[must_use = "this returns the result of the operation, \
1262 without modifying the original"]
1263 #[inline]
1264 pub const fn checked_neg(self) -> Option<Self> {
1265 let (a, b) = self.overflowing_neg();
1266 if intrinsics::unlikely(b) { None } else { Some(a) }
1267 }
1268
1269 /// Unchecked negation. Computes `-self`, assuming overflow cannot occur.
1270 ///
1271 /// # Safety
1272 ///
1273 /// This results in undefined behavior when
1274 #[doc = concat!("`self == ", stringify!($SelfT), "::MIN`,")]
1275 /// i.e. when [`checked_neg`] would return `None`.
1276 ///
1277 #[doc = concat!("[`checked_neg`]: ", stringify!($SelfT), "::checked_neg")]
1278 #[stable(feature = "unchecked_neg", since = "1.93.0")]
1279 #[rustc_const_stable(feature = "unchecked_neg", since = "1.93.0")]
1280 #[must_use = "this returns the result of the operation, \
1281 without modifying the original"]
1282 #[inline(always)]
1283 #[track_caller]
1284 pub const unsafe fn unchecked_neg(self) -> Self {
1285 assert_unsafe_precondition!(
1286 check_language_ub,
1287 concat!(stringify!($SelfT), "::unchecked_neg cannot overflow"),
1288 (
1289 lhs: $SelfT = self,
1290 ) => !lhs.overflowing_neg().1,
1291 );
1292
1293 // SAFETY: this is guaranteed to be safe by the caller.
1294 unsafe {
1295 intrinsics::unchecked_sub(0, self)
1296 }
1297 }
1298
1299 /// Strict negation. Computes `-self`, panicking if `self == MIN`.
1300 ///
1301 /// # Panics
1302 ///
1303 /// ## Overflow behavior
1304 ///
1305 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1306 ///
1307 /// # Examples
1308 ///
1309 /// ```
1310 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_neg(), -5);")]
1311 /// ```
1312 ///
1313 /// The following panics because of overflow:
1314 ///
1315 /// ```should_panic
1316 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_neg();")]
1317 /// ```
1318 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1319 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1320 #[must_use = "this returns the result of the operation, \
1321 without modifying the original"]
1322 #[inline]
1323 #[track_caller]
1324 pub const fn strict_neg(self) -> Self {
1325 let (a, b) = self.overflowing_neg();
1326 if b { overflow_panic::neg() } else { a }
1327 }
1328
1329 /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger
1330 /// than or equal to the number of bits in `self`.
1331 ///
1332 /// # Examples
1333 ///
1334 /// ```
1335 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
1336 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")]
1337 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
1338 /// ```
1339 #[stable(feature = "wrapping", since = "1.7.0")]
1340 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1341 #[must_use = "this returns the result of the operation, \
1342 without modifying the original"]
1343 #[inline]
1344 pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
1345 // Not using overflowing_shl as that's a wrapping shift
1346 if rhs < Self::BITS {
1347 // SAFETY: just checked the RHS is in-range
1348 Some(unsafe { self.unchecked_shl(rhs) })
1349 } else {
1350 None
1351 }
1352 }
1353
1354 /// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
1355 /// than or equal to the number of bits in `self`.
1356 ///
1357 /// # Panics
1358 ///
1359 /// ## Overflow behavior
1360 ///
1361 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1362 ///
1363 /// # Examples
1364 ///
1365 /// ```
1366 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
1367 /// ```
1368 ///
1369 /// The following panics because of overflow:
1370 ///
1371 /// ```should_panic
1372 #[doc = concat!("let _ = 0x1", stringify!($SelfT), ".strict_shl(129);")]
1373 /// ```
1374 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1375 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1376 #[must_use = "this returns the result of the operation, \
1377 without modifying the original"]
1378 #[inline]
1379 #[track_caller]
1380 pub const fn strict_shl(self, rhs: u32) -> Self {
1381 let (a, b) = self.overflowing_shl(rhs);
1382 if b { overflow_panic::shl() } else { a }
1383 }
1384
1385 /// Unchecked shift left. Computes `self << rhs`, assuming that
1386 /// `rhs` is less than the number of bits in `self`.
1387 ///
1388 /// # Safety
1389 ///
1390 /// This results in undefined behavior if `rhs` is larger than
1391 /// or equal to the number of bits in `self`,
1392 /// i.e. when [`checked_shl`] would return `None`.
1393 ///
1394 #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
1395 #[stable(feature = "unchecked_shifts", since = "1.93.0")]
1396 #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
1397 #[must_use = "this returns the result of the operation, \
1398 without modifying the original"]
1399 #[inline(always)]
1400 #[track_caller]
1401 pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
1402 assert_unsafe_precondition!(
1403 check_language_ub,
1404 concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
1405 (
1406 rhs: u32 = rhs,
1407 ) => rhs < <$ActualT>::BITS,
1408 );
1409
1410 // SAFETY: this is guaranteed to be safe by the caller.
1411 unsafe {
1412 intrinsics::unchecked_shl(self, rhs)
1413 }
1414 }
1415
1416 /// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
1417 ///
1418 /// If `rhs` is larger or equal to the number of bits in `self`,
1419 /// the entire value is shifted out, and `0` is returned.
1420 ///
1421 /// # Examples
1422 ///
1423 /// ```
1424 #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
1425 #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(129), 0);")]
1426 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(0), 0b101);")]
1427 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(1), 0b1010);")]
1428 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(2), 0b10100);")]
1429 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(", stringify!($BITS), "), 0);")]
1430 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
1431 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(", stringify!($BITS), "), 0);")]
1432 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
1433 /// ```
1434 #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1435 #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1436 #[must_use = "this returns the result of the operation, \
1437 without modifying the original"]
1438 #[inline]
1439 pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
1440 if rhs < Self::BITS {
1441 // SAFETY:
1442 // rhs is just checked to be in-range above
1443 unsafe { self.unchecked_shl(rhs) }
1444 } else {
1445 0
1446 }
1447 }
1448
1449 /// Exact shift left. Computes `self << rhs` as long as it can be reversed losslessly.
1450 ///
1451 /// Returns `None` if any bits that would be shifted out differ from the resulting sign bit
1452 /// or if `rhs` >=
1453 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1454 /// Otherwise, returns `Some(self << rhs)`.
1455 ///
1456 /// # Examples
1457 ///
1458 /// ```
1459 /// #![feature(exact_bitshifts)]
1460 ///
1461 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(4), Some(0x10));")]
1462 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 2), Some(1 << ", stringify!($SelfT), "::BITS - 2));")]
1463 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
1464 #[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 2), Some(-0x2 << ", stringify!($SelfT), "::BITS - 2));")]
1465 #[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
1466 /// ```
1467 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1468 #[must_use = "this returns the result of the operation, \
1469 without modifying the original"]
1470 #[inline]
1471 pub const fn shl_exact(self, rhs: u32) -> Option<$SelfT> {
1472 if rhs < self.leading_zeros() || rhs < self.leading_ones() {
1473 // SAFETY: rhs is checked above
1474 Some(unsafe { self.unchecked_shl(rhs) })
1475 } else {
1476 None
1477 }
1478 }
1479
1480 /// Unchecked exact shift left. Computes `self << rhs`, assuming the operation can be
1481 /// losslessly reversed and `rhs` cannot be larger than
1482 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1483 ///
1484 /// # Safety
1485 ///
1486 /// This results in undefined behavior when `rhs >= self.leading_zeros() && rhs >=
1487 /// self.leading_ones()` i.e. when
1488 #[doc = concat!("[`", stringify!($SelfT), "::shl_exact`]")]
1489 /// would return `None`.
1490 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1491 #[must_use = "this returns the result of the operation, \
1492 without modifying the original"]
1493 #[inline]
1494 pub const unsafe fn unchecked_shl_exact(self, rhs: u32) -> $SelfT {
1495 assert_unsafe_precondition!(
1496 check_library_ub,
1497 concat!(stringify!($SelfT), "::unchecked_shl_exact cannot shift out bits that would change the value of the first bit"),
1498 (
1499 zeros: u32 = self.leading_zeros(),
1500 ones: u32 = self.leading_ones(),
1501 rhs: u32 = rhs,
1502 ) => rhs < zeros || rhs < ones,
1503 );
1504
1505 // SAFETY: this is guaranteed to be safe by the caller
1506 unsafe { self.unchecked_shl(rhs) }
1507 }
1508
1509 /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is
1510 /// larger than or equal to the number of bits in `self`.
1511 ///
1512 /// # Examples
1513 ///
1514 /// ```
1515 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
1516 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")]
1517 /// ```
1518 #[stable(feature = "wrapping", since = "1.7.0")]
1519 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1520 #[must_use = "this returns the result of the operation, \
1521 without modifying the original"]
1522 #[inline]
1523 pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
1524 // Not using overflowing_shr as that's a wrapping shift
1525 if rhs < Self::BITS {
1526 // SAFETY: just checked the RHS is in-range
1527 Some(unsafe { self.unchecked_shr(rhs) })
1528 } else {
1529 None
1530 }
1531 }
1532
1533 /// Strict shift right. Computes `self >> rhs`, panicking if `rhs` is
1534 /// larger than or equal to the number of bits in `self`.
1535 ///
1536 /// # Panics
1537 ///
1538 /// ## Overflow behavior
1539 ///
1540 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1541 ///
1542 /// # Examples
1543 ///
1544 /// ```
1545 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
1546 /// ```
1547 ///
1548 /// The following panics because of overflow:
1549 ///
1550 /// ```should_panic
1551 #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(128);")]
1552 /// ```
1553 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1554 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1555 #[must_use = "this returns the result of the operation, \
1556 without modifying the original"]
1557 #[inline]
1558 #[track_caller]
1559 pub const fn strict_shr(self, rhs: u32) -> Self {
1560 let (a, b) = self.overflowing_shr(rhs);
1561 if b { overflow_panic::shr() } else { a }
1562 }
1563
1564 /// Unchecked shift right. Computes `self >> rhs`, assuming that
1565 /// `rhs` is less than the number of bits in `self`.
1566 ///
1567 /// # Safety
1568 ///
1569 /// This results in undefined behavior if `rhs` is larger than
1570 /// or equal to the number of bits in `self`,
1571 /// i.e. when [`checked_shr`] would return `None`.
1572 ///
1573 #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
1574 #[stable(feature = "unchecked_shifts", since = "1.93.0")]
1575 #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
1576 #[must_use = "this returns the result of the operation, \
1577 without modifying the original"]
1578 #[inline(always)]
1579 #[track_caller]
1580 pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
1581 assert_unsafe_precondition!(
1582 check_language_ub,
1583 concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
1584 (
1585 rhs: u32 = rhs,
1586 ) => rhs < <$ActualT>::BITS,
1587 );
1588
1589 // SAFETY: this is guaranteed to be safe by the caller.
1590 unsafe {
1591 intrinsics::unchecked_shr(self, rhs)
1592 }
1593 }
1594
1595 /// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
1596 ///
1597 /// If `rhs` is larger or equal to the number of bits in `self`,
1598 /// the entire value is shifted out, which yields `0` for a positive number,
1599 /// and `-1` for a negative number.
1600 ///
1601 /// # Examples
1602 ///
1603 /// ```
1604 #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
1605 #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(129), 0);")]
1606 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.unbounded_shr(129), -1);")]
1607 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(0), 0b1010);")]
1608 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(1), 0b101);")]
1609 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(2), 0b10);")]
1610 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(", stringify!($BITS), "), 0);")]
1611 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
1612 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(", stringify!($BITS), "), -1);")]
1613 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), -1);")]
1614 /// ```
1615 #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1616 #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1617 #[must_use = "this returns the result of the operation, \
1618 without modifying the original"]
1619 #[inline]
1620 pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
1621 if rhs < Self::BITS {
1622 // SAFETY:
1623 // rhs is just checked to be in-range above
1624 unsafe { self.unchecked_shr(rhs) }
1625 } else {
1626 // A shift by `Self::BITS-1` suffices for signed integers, because the sign bit is copied for each of the shifted bits.
1627
1628 // SAFETY:
1629 // `Self::BITS-1` is guaranteed to be less than `Self::BITS`
1630 unsafe { self.unchecked_shr(Self::BITS - 1) }
1631 }
1632 }
1633
1634 /// Exact shift right. Computes `self >> rhs` as long as it can be reversed losslessly.
1635 ///
1636 /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
1637 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1638 /// Otherwise, returns `Some(self >> rhs)`.
1639 ///
1640 /// # Examples
1641 ///
1642 /// ```
1643 /// #![feature(exact_bitshifts)]
1644 ///
1645 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(4), Some(0x1));")]
1646 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(5), None);")]
1647 /// ```
1648 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1649 #[must_use = "this returns the result of the operation, \
1650 without modifying the original"]
1651 #[inline]
1652 pub const fn shr_exact(self, rhs: u32) -> Option<$SelfT> {
1653 if rhs <= self.trailing_zeros() && rhs < <$SelfT>::BITS {
1654 // SAFETY: rhs is checked above
1655 Some(unsafe { self.unchecked_shr(rhs) })
1656 } else {
1657 None
1658 }
1659 }
1660
1661 /// Unchecked exact shift right. Computes `self >> rhs`, assuming the operation can be
1662 /// losslessly reversed and `rhs` cannot be larger than
1663 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1664 ///
1665 /// # Safety
1666 ///
1667 /// This results in undefined behavior when `rhs > self.trailing_zeros() || rhs >=
1668 #[doc = concat!(stringify!($SelfT), "::BITS`")]
1669 /// i.e. when
1670 #[doc = concat!("[`", stringify!($SelfT), "::shr_exact`]")]
1671 /// would return `None`.
1672 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1673 #[must_use = "this returns the result of the operation, \
1674 without modifying the original"]
1675 #[inline]
1676 pub const unsafe fn unchecked_shr_exact(self, rhs: u32) -> $SelfT {
1677 assert_unsafe_precondition!(
1678 check_library_ub,
1679 concat!(stringify!($SelfT), "::unchecked_shr_exact cannot shift out non-zero bits"),
1680 (
1681 zeros: u32 = self.trailing_zeros(),
1682 bits: u32 = <$SelfT>::BITS,
1683 rhs: u32 = rhs,
1684 ) => rhs <= zeros && rhs < bits,
1685 );
1686
1687 // SAFETY: this is guaranteed to be safe by the caller
1688 unsafe { self.unchecked_shr(rhs) }
1689 }
1690
1691 /// Checked absolute value. Computes `self.abs()`, returning `None` if
1692 /// `self == MIN`.
1693 ///
1694 /// # Examples
1695 ///
1696 /// ```
1697 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")]
1698 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")]
1699 /// ```
1700 #[stable(feature = "no_panic_abs", since = "1.13.0")]
1701 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1702 #[must_use = "this returns the result of the operation, \
1703 without modifying the original"]
1704 #[inline]
1705 pub const fn checked_abs(self) -> Option<Self> {
1706 if self.is_negative() {
1707 self.checked_neg()
1708 } else {
1709 Some(self)
1710 }
1711 }
1712
1713 /// Strict absolute value. Computes `self.abs()`, panicking if
1714 /// `self == MIN`.
1715 ///
1716 /// # Panics
1717 ///
1718 /// ## Overflow behavior
1719 ///
1720 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1721 ///
1722 /// # Examples
1723 ///
1724 /// ```
1725 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").strict_abs(), 5);")]
1726 /// ```
1727 ///
1728 /// The following panics because of overflow:
1729 ///
1730 /// ```should_panic
1731 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_abs();")]
1732 /// ```
1733 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1734 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1735 #[must_use = "this returns the result of the operation, \
1736 without modifying the original"]
1737 #[inline]
1738 #[track_caller]
1739 pub const fn strict_abs(self) -> Self {
1740 if self.is_negative() {
1741 self.strict_neg()
1742 } else {
1743 self
1744 }
1745 }
1746
1747 /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
1748 /// overflow occurred.
1749 ///
1750 /// # Examples
1751 ///
1752 /// ```
1753 #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")]
1754 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".checked_pow(0), Some(1));")]
1755 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
1756 /// ```
1757
1758 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1759 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1760 #[must_use = "this returns the result of the operation, \
1761 without modifying the original"]
1762 #[inline]
1763 pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
1764 if exp == 0 {
1765 return Some(1);
1766 }
1767 let mut base = self;
1768 let mut acc: Self = 1;
1769
1770 loop {
1771 if (exp & 1) == 1 {
1772 acc = try_opt!(acc.checked_mul(base));
1773 // since exp!=0, finally the exp must be 1.
1774 if exp == 1 {
1775 return Some(acc);
1776 }
1777 }
1778 exp /= 2;
1779 base = try_opt!(base.checked_mul(base));
1780 }
1781 }
1782
1783 /// Strict exponentiation. Computes `self.pow(exp)`, panicking if
1784 /// overflow occurred.
1785 ///
1786 /// # Panics
1787 ///
1788 /// ## Overflow behavior
1789 ///
1790 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1791 ///
1792 /// # Examples
1793 ///
1794 /// ```
1795 #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".strict_pow(2), 64);")]
1796 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".strict_pow(0), 1);")]
1797 /// ```
1798 ///
1799 /// The following panics because of overflow:
1800 ///
1801 /// ```should_panic
1802 #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
1803 /// ```
1804 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1805 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1806 #[must_use = "this returns the result of the operation, \
1807 without modifying the original"]
1808 #[inline]
1809 #[track_caller]
1810 pub const fn strict_pow(self, mut exp: u32) -> Self {
1811 if exp == 0 {
1812 return 1;
1813 }
1814 let mut base = self;
1815 let mut acc: Self = 1;
1816
1817 loop {
1818 if (exp & 1) == 1 {
1819 acc = acc.strict_mul(base);
1820 // since exp!=0, finally the exp must be 1.
1821 if exp == 1 {
1822 return acc;
1823 }
1824 }
1825 exp /= 2;
1826 base = base.strict_mul(base);
1827 }
1828 }
1829
1830 /// Returns the square root of the number, rounded down.
1831 ///
1832 /// Returns `None` if `self` is negative.
1833 ///
1834 /// # Examples
1835 ///
1836 /// ```
1837 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_isqrt(), Some(3));")]
1838 /// ```
1839 #[stable(feature = "isqrt", since = "1.84.0")]
1840 #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
1841 #[must_use = "this returns the result of the operation, \
1842 without modifying the original"]
1843 #[inline]
1844 pub const fn checked_isqrt(self) -> Option<Self> {
1845 if self < 0 {
1846 None
1847 } else {
1848 // SAFETY: Input is nonnegative in this `else` branch.
1849 let result = unsafe {
1850 crate::num::int_sqrt::$ActualT(self as $ActualT) as $SelfT
1851 };
1852
1853 // Inform the optimizer what the range of outputs is. If
1854 // testing `core` crashes with no panic message and a
1855 // `num::int_sqrt::i*` test failed, it's because your edits
1856 // caused these assertions to become false.
1857 //
1858 // SAFETY: Integer square root is a monotonically nondecreasing
1859 // function, which means that increasing the input will never
1860 // cause the output to decrease. Thus, since the input for
1861 // nonnegative signed integers is bounded by
1862 // `[0, <$ActualT>::MAX]`, sqrt(n) will be bounded by
1863 // `[sqrt(0), sqrt(<$ActualT>::MAX)]`.
1864 unsafe {
1865 // SAFETY: `<$ActualT>::MAX` is nonnegative.
1866 const MAX_RESULT: $SelfT = unsafe {
1867 crate::num::int_sqrt::$ActualT(<$ActualT>::MAX) as $SelfT
1868 };
1869
1870 crate::hint::assert_unchecked(result >= 0);
1871 crate::hint::assert_unchecked(result <= MAX_RESULT);
1872 }
1873
1874 Some(result)
1875 }
1876 }
1877
1878 /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric
1879 /// bounds instead of overflowing.
1880 ///
1881 /// # Examples
1882 ///
1883 /// ```
1884 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
1885 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")]
1886 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")]
1887 /// ```
1888
1889 #[stable(feature = "rust1", since = "1.0.0")]
1890 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1891 #[must_use = "this returns the result of the operation, \
1892 without modifying the original"]
1893 #[inline(always)]
1894 pub const fn saturating_add(self, rhs: Self) -> Self {
1895 intrinsics::saturating_add(self, rhs)
1896 }
1897
1898 /// Saturating addition with an unsigned integer. Computes `self + rhs`,
1899 /// saturating at the numeric bounds instead of overflowing.
1900 ///
1901 /// # Examples
1902 ///
1903 /// ```
1904 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")]
1905 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")]
1906 /// ```
1907 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
1908 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
1909 #[must_use = "this returns the result of the operation, \
1910 without modifying the original"]
1911 #[inline]
1912 pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self {
1913 // Overflow can only happen at the upper bound
1914 // We cannot use `unwrap_or` here because it is not `const`
1915 match self.checked_add_unsigned(rhs) {
1916 Some(x) => x,
1917 None => Self::MAX,
1918 }
1919 }
1920
1921 /// Saturating integer subtraction. Computes `self - rhs`, saturating at the
1922 /// numeric bounds instead of overflowing.
1923 ///
1924 /// # Examples
1925 ///
1926 /// ```
1927 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")]
1928 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")]
1929 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")]
1930 /// ```
1931 #[stable(feature = "rust1", since = "1.0.0")]
1932 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1933 #[must_use = "this returns the result of the operation, \
1934 without modifying the original"]
1935 #[inline(always)]
1936 pub const fn saturating_sub(self, rhs: Self) -> Self {
1937 intrinsics::saturating_sub(self, rhs)
1938 }
1939
1940 /// Saturating subtraction with an unsigned integer. Computes `self - rhs`,
1941 /// saturating at the numeric bounds instead of overflowing.
1942 ///
1943 /// # Examples
1944 ///
1945 /// ```
1946 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")]
1947 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")]
1948 /// ```
1949 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
1950 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
1951 #[must_use = "this returns the result of the operation, \
1952 without modifying the original"]
1953 #[inline]
1954 pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self {
1955 // Overflow can only happen at the lower bound
1956 // We cannot use `unwrap_or` here because it is not `const`
1957 match self.checked_sub_unsigned(rhs) {
1958 Some(x) => x,
1959 None => Self::MIN,
1960 }
1961 }
1962
1963 /// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN`
1964 /// instead of overflowing.
1965 ///
1966 /// # Examples
1967 ///
1968 /// ```
1969 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")]
1970 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")]
1971 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")]
1972 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")]
1973 /// ```
1974
1975 #[stable(feature = "saturating_neg", since = "1.45.0")]
1976 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1977 #[must_use = "this returns the result of the operation, \
1978 without modifying the original"]
1979 #[inline(always)]
1980 pub const fn saturating_neg(self) -> Self {
1981 intrinsics::saturating_sub(0, self)
1982 }
1983
1984 /// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self ==
1985 /// MIN` instead of overflowing.
1986 ///
1987 /// # Examples
1988 ///
1989 /// ```
1990 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")]
1991 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")]
1992 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")]
1993 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")]
1994 /// ```
1995
1996 #[stable(feature = "saturating_neg", since = "1.45.0")]
1997 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
1998 #[must_use = "this returns the result of the operation, \
1999 without modifying the original"]
2000 #[inline]
2001 pub const fn saturating_abs(self) -> Self {
2002 if self.is_negative() {
2003 self.saturating_neg()
2004 } else {
2005 self
2006 }
2007 }
2008
2009 /// Saturating integer multiplication. Computes `self * rhs`, saturating at the
2010 /// numeric bounds instead of overflowing.
2011 ///
2012 /// # Examples
2013 ///
2014 /// ```
2015 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")]
2016 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")]
2017 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")]
2018 /// ```
2019 #[stable(feature = "wrapping", since = "1.7.0")]
2020 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2021 #[must_use = "this returns the result of the operation, \
2022 without modifying the original"]
2023 #[inline]
2024 pub const fn saturating_mul(self, rhs: Self) -> Self {
2025 match self.checked_mul(rhs) {
2026 Some(x) => x,
2027 None => if (self < 0) == (rhs < 0) {
2028 Self::MAX
2029 } else {
2030 Self::MIN
2031 }
2032 }
2033 }
2034
2035 /// Saturating integer division. Computes `self / rhs`, saturating at the
2036 /// numeric bounds instead of overflowing.
2037 ///
2038 /// # Panics
2039 ///
2040 /// This function will panic if `rhs` is zero.
2041 ///
2042 /// # Examples
2043 ///
2044 /// ```
2045 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
2046 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")]
2047 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")]
2048 ///
2049 /// ```
2050 #[stable(feature = "saturating_div", since = "1.58.0")]
2051 #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
2052 #[must_use = "this returns the result of the operation, \
2053 without modifying the original"]
2054 #[inline]
2055 pub const fn saturating_div(self, rhs: Self) -> Self {
2056 match self.overflowing_div(rhs) {
2057 (result, false) => result,
2058 (_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow
2059 }
2060 }
2061
2062 /// Saturating integer exponentiation. Computes `self.pow(exp)`,
2063 /// saturating at the numeric bounds instead of overflowing.
2064 ///
2065 /// # Examples
2066 ///
2067 /// ```
2068 #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")]
2069 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".saturating_pow(0), 1);")]
2070 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
2071 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")]
2072 /// ```
2073 #[stable(feature = "no_panic_pow", since = "1.34.0")]
2074 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2075 #[must_use = "this returns the result of the operation, \
2076 without modifying the original"]
2077 #[inline]
2078 pub const fn saturating_pow(self, exp: u32) -> Self {
2079 match self.checked_pow(exp) {
2080 Some(x) => x,
2081 None if self < 0 && exp % 2 == 1 => Self::MIN,
2082 None => Self::MAX,
2083 }
2084 }
2085
2086 /// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the
2087 /// boundary of the type.
2088 ///
2089 /// # Examples
2090 ///
2091 /// ```
2092 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")]
2093 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")]
2094 /// ```
2095 #[stable(feature = "rust1", since = "1.0.0")]
2096 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2097 #[must_use = "this returns the result of the operation, \
2098 without modifying the original"]
2099 #[inline(always)]
2100 pub const fn wrapping_add(self, rhs: Self) -> Self {
2101 intrinsics::wrapping_add(self, rhs)
2102 }
2103
2104 /// Wrapping (modular) addition with an unsigned integer. Computes
2105 /// `self + rhs`, wrapping around at the boundary of the type.
2106 ///
2107 /// # Examples
2108 ///
2109 /// ```
2110 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")]
2111 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")]
2112 /// ```
2113 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2114 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2115 #[must_use = "this returns the result of the operation, \
2116 without modifying the original"]
2117 #[inline(always)]
2118 pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self {
2119 self.wrapping_add(rhs as Self)
2120 }
2121
2122 /// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the
2123 /// boundary of the type.
2124 ///
2125 /// # Examples
2126 ///
2127 /// ```
2128 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")]
2129 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")]
2130 /// ```
2131 #[stable(feature = "rust1", since = "1.0.0")]
2132 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2133 #[must_use = "this returns the result of the operation, \
2134 without modifying the original"]
2135 #[inline(always)]
2136 pub const fn wrapping_sub(self, rhs: Self) -> Self {
2137 intrinsics::wrapping_sub(self, rhs)
2138 }
2139
2140 /// Wrapping (modular) subtraction with an unsigned integer. Computes
2141 /// `self - rhs`, wrapping around at the boundary of the type.
2142 ///
2143 /// # Examples
2144 ///
2145 /// ```
2146 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")]
2147 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")]
2148 /// ```
2149 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2150 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2151 #[must_use = "this returns the result of the operation, \
2152 without modifying the original"]
2153 #[inline(always)]
2154 pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self {
2155 self.wrapping_sub(rhs as Self)
2156 }
2157
2158 /// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at
2159 /// the boundary of the type.
2160 ///
2161 /// # Examples
2162 ///
2163 /// ```
2164 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")]
2165 /// assert_eq!(11i8.wrapping_mul(12), -124);
2166 /// ```
2167 #[stable(feature = "rust1", since = "1.0.0")]
2168 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2169 #[must_use = "this returns the result of the operation, \
2170 without modifying the original"]
2171 #[inline(always)]
2172 pub const fn wrapping_mul(self, rhs: Self) -> Self {
2173 intrinsics::wrapping_mul(self, rhs)
2174 }
2175
2176 /// Wrapping (modular) division. Computes `self / rhs`, wrapping around at the
2177 /// boundary of the type.
2178 ///
2179 /// The only case where such wrapping can occur is when one divides `MIN / -1` on a signed type (where
2180 /// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
2181 /// that is too large to represent in the type. In such a case, this function returns `MIN` itself.
2182 ///
2183 /// # Panics
2184 ///
2185 /// This function will panic if `rhs` is zero.
2186 ///
2187 /// # Examples
2188 ///
2189 /// ```
2190 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
2191 /// assert_eq!((-128i8).wrapping_div(-1), -128);
2192 /// ```
2193 #[stable(feature = "num_wrapping", since = "1.2.0")]
2194 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2195 #[must_use = "this returns the result of the operation, \
2196 without modifying the original"]
2197 #[inline]
2198 pub const fn wrapping_div(self, rhs: Self) -> Self {
2199 self.overflowing_div(rhs).0
2200 }
2201
2202 /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`,
2203 /// wrapping around at the boundary of the type.
2204 ///
2205 /// Wrapping will only occur in `MIN / -1` on a signed type (where `MIN` is the negative minimal value
2206 /// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the
2207 /// type. In this case, this method returns `MIN` itself.
2208 ///
2209 /// # Panics
2210 ///
2211 /// This function will panic if `rhs` is zero.
2212 ///
2213 /// # Examples
2214 ///
2215 /// ```
2216 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
2217 /// assert_eq!((-128i8).wrapping_div_euclid(-1), -128);
2218 /// ```
2219 #[stable(feature = "euclidean_division", since = "1.38.0")]
2220 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2221 #[must_use = "this returns the result of the operation, \
2222 without modifying the original"]
2223 #[inline]
2224 pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
2225 self.overflowing_div_euclid(rhs).0
2226 }
2227
2228 /// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the
2229 /// boundary of the type.
2230 ///
2231 /// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y`
2232 /// invalid for `MIN / -1` on a signed type (where `MIN` is the negative minimal value). In such a case,
2233 /// this function returns `0`.
2234 ///
2235 /// # Panics
2236 ///
2237 /// This function will panic if `rhs` is zero.
2238 ///
2239 /// # Examples
2240 ///
2241 /// ```
2242 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
2243 /// assert_eq!((-128i8).wrapping_rem(-1), 0);
2244 /// ```
2245 #[stable(feature = "num_wrapping", since = "1.2.0")]
2246 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2247 #[must_use = "this returns the result of the operation, \
2248 without modifying the original"]
2249 #[inline]
2250 pub const fn wrapping_rem(self, rhs: Self) -> Self {
2251 self.overflowing_rem(rhs).0
2252 }
2253
2254 /// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around
2255 /// at the boundary of the type.
2256 ///
2257 /// Wrapping will only occur in `MIN % -1` on a signed type (where `MIN` is the negative minimal value
2258 /// for the type). In this case, this method returns 0.
2259 ///
2260 /// # Panics
2261 ///
2262 /// This function will panic if `rhs` is zero.
2263 ///
2264 /// # Examples
2265 ///
2266 /// ```
2267 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
2268 /// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0);
2269 /// ```
2270 #[stable(feature = "euclidean_division", since = "1.38.0")]
2271 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2272 #[must_use = "this returns the result of the operation, \
2273 without modifying the original"]
2274 #[inline]
2275 pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
2276 self.overflowing_rem_euclid(rhs).0
2277 }
2278
2279 /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
2280 /// of the type.
2281 ///
2282 /// The only case where such wrapping can occur is when one negates `MIN` on a signed type (where `MIN`
2283 /// is the negative minimal value for the type); this is a positive value that is too large to represent
2284 /// in the type. In such a case, this function returns `MIN` itself.
2285 ///
2286 /// # Examples
2287 ///
2288 /// ```
2289 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")]
2290 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_neg(), 100);")]
2291 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")]
2292 /// ```
2293 #[stable(feature = "num_wrapping", since = "1.2.0")]
2294 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2295 #[must_use = "this returns the result of the operation, \
2296 without modifying the original"]
2297 #[inline(always)]
2298 pub const fn wrapping_neg(self) -> Self {
2299 (0 as $SelfT).wrapping_sub(self)
2300 }
2301
2302 /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes
2303 /// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
2304 ///
2305 /// Beware that, unlike most other `wrapping_*` methods on integers, this
2306 /// does *not* give the same result as doing the shift in infinite precision
2307 /// then truncating as needed. The behaviour matches what shift instructions
2308 /// do on many processors, and is what the `<<` operator does when overflow
2309 /// checks are disabled, but numerically it's weird. Consider, instead,
2310 /// using [`Self::unbounded_shl`] which has nicer behaviour.
2311 ///
2312 /// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to
2313 /// the range of the type, rather than the bits shifted out of the LHS being returned to the other end.
2314 /// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function,
2315 /// which may be what you want instead.
2316 ///
2317 /// # Examples
2318 ///
2319 /// ```
2320 #[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(7), -128);")]
2321 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(", stringify!($BITS), "), 42);")]
2322 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(1).wrapping_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
2323 #[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(128), -1);")]
2324 #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".wrapping_shl(1025), 10);")]
2325 /// ```
2326 #[stable(feature = "num_wrapping", since = "1.2.0")]
2327 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2328 #[must_use = "this returns the result of the operation, \
2329 without modifying the original"]
2330 #[inline(always)]
2331 pub const fn wrapping_shl(self, rhs: u32) -> Self {
2332 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2333 // out of bounds
2334 unsafe {
2335 self.unchecked_shl(rhs & (Self::BITS - 1))
2336 }
2337 }
2338
2339 /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask`
2340 /// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
2341 ///
2342 /// Beware that, unlike most other `wrapping_*` methods on integers, this
2343 /// does *not* give the same result as doing the shift in infinite precision
2344 /// then truncating as needed. The behaviour matches what shift instructions
2345 /// do on many processors, and is what the `>>` operator does when overflow
2346 /// checks are disabled, but numerically it's weird. Consider, instead,
2347 /// using [`Self::unbounded_shr`] which has nicer behaviour.
2348 ///
2349 /// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted
2350 /// to the range of the type, rather than the bits shifted out of the LHS being returned to the other
2351 /// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function,
2352 /// which may be what you want instead.
2353 ///
2354 /// # Examples
2355 ///
2356 /// ```
2357 #[doc = concat!("assert_eq!((-128_", stringify!($SelfT), ").wrapping_shr(7), -1);")]
2358 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(", stringify!($BITS), "), 42);")]
2359 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(1).wrapping_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
2360 /// assert_eq!((-128_i16).wrapping_shr(64), -128);
2361 #[doc = concat!("assert_eq!(10_", stringify!($SelfT), ".wrapping_shr(1025), 5);")]
2362 /// ```
2363 #[stable(feature = "num_wrapping", since = "1.2.0")]
2364 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2365 #[must_use = "this returns the result of the operation, \
2366 without modifying the original"]
2367 #[inline(always)]
2368 pub const fn wrapping_shr(self, rhs: u32) -> Self {
2369 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2370 // out of bounds
2371 unsafe {
2372 self.unchecked_shr(rhs & (Self::BITS - 1))
2373 }
2374 }
2375
2376 /// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at
2377 /// the boundary of the type.
2378 ///
2379 /// The only case where such wrapping can occur is when one takes the absolute value of the negative
2380 /// minimal value for the type; this is a positive value that is too large to represent in the type. In
2381 /// such a case, this function returns `MIN` itself.
2382 ///
2383 /// # Examples
2384 ///
2385 /// ```
2386 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")]
2387 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")]
2388 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")]
2389 /// assert_eq!((-128i8).wrapping_abs() as u8, 128);
2390 /// ```
2391 #[stable(feature = "no_panic_abs", since = "1.13.0")]
2392 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2393 #[must_use = "this returns the result of the operation, \
2394 without modifying the original"]
2395 #[allow(unused_attributes)]
2396 #[inline]
2397 pub const fn wrapping_abs(self) -> Self {
2398 if self.is_negative() {
2399 self.wrapping_neg()
2400 } else {
2401 self
2402 }
2403 }
2404
2405 /// Computes the absolute value of `self` without any wrapping
2406 /// or panicking.
2407 ///
2408 ///
2409 /// # Examples
2410 ///
2411 /// ```
2412 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")]
2413 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")]
2414 /// assert_eq!((-128i8).unsigned_abs(), 128u8);
2415 /// ```
2416 #[stable(feature = "unsigned_abs", since = "1.51.0")]
2417 #[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")]
2418 #[must_use = "this returns the result of the operation, \
2419 without modifying the original"]
2420 #[inline]
2421 pub const fn unsigned_abs(self) -> $UnsignedT {
2422 self.wrapping_abs() as $UnsignedT
2423 }
2424
2425 /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
2426 /// wrapping around at the boundary of the type.
2427 ///
2428 /// # Examples
2429 ///
2430 /// ```
2431 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")]
2432 /// assert_eq!(3i8.wrapping_pow(5), -13);
2433 /// assert_eq!(3i8.wrapping_pow(6), -39);
2434 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_pow(0), 1);")]
2435 /// ```
2436 #[stable(feature = "no_panic_pow", since = "1.34.0")]
2437 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2438 #[must_use = "this returns the result of the operation, \
2439 without modifying the original"]
2440 #[inline]
2441 pub const fn wrapping_pow(self, mut exp: u32) -> Self {
2442 if exp == 0 {
2443 return 1;
2444 }
2445 let mut base = self;
2446 let mut acc: Self = 1;
2447
2448 if intrinsics::is_val_statically_known(exp) {
2449 while exp > 1 {
2450 if (exp & 1) == 1 {
2451 acc = acc.wrapping_mul(base);
2452 }
2453 exp /= 2;
2454 base = base.wrapping_mul(base);
2455 }
2456
2457 // since exp!=0, finally the exp must be 1.
2458 // Deal with the final bit of the exponent separately, since
2459 // squaring the base afterwards is not necessary.
2460 acc.wrapping_mul(base)
2461 } else {
2462 // This is faster than the above when the exponent is not known
2463 // at compile time. We can't use the same code for the constant
2464 // exponent case because LLVM is currently unable to unroll
2465 // this loop.
2466 loop {
2467 if (exp & 1) == 1 {
2468 acc = acc.wrapping_mul(base);
2469 // since exp!=0, finally the exp must be 1.
2470 if exp == 1 {
2471 return acc;
2472 }
2473 }
2474 exp /= 2;
2475 base = base.wrapping_mul(base);
2476 }
2477 }
2478 }
2479
2480 /// Calculates `self` + `rhs`.
2481 ///
2482 /// Returns a tuple of the addition along with a boolean indicating
2483 /// whether an arithmetic overflow would occur. If an overflow would have
2484 /// occurred then the wrapped value is returned.
2485 ///
2486 /// # Examples
2487 ///
2488 /// ```
2489 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
2490 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")]
2491 /// ```
2492 #[stable(feature = "wrapping", since = "1.7.0")]
2493 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2494 #[must_use = "this returns the result of the operation, \
2495 without modifying the original"]
2496 #[inline(always)]
2497 pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
2498 let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
2499 (a as Self, b)
2500 }
2501
2502 /// Calculates `self` + `rhs` + `carry` and checks for overflow.
2503 ///
2504 /// Performs "ternary addition" of two integer operands and a carry-in
2505 /// bit, and returns a tuple of the sum along with a boolean indicating
2506 /// whether an arithmetic overflow would occur. On overflow, the wrapped
2507 /// value is returned.
2508 ///
2509 /// This allows chaining together multiple additions to create a wider
2510 /// addition, and can be useful for bignum addition. This method should
2511 /// only be used for the most significant word; for the less significant
2512 /// words the unsigned method
2513 #[doc = concat!("[`", stringify!($UnsignedT), "::carrying_add`]")]
2514 /// should be used.
2515 ///
2516 /// The output boolean returned by this method is *not* a carry flag,
2517 /// and should *not* be added to a more significant word.
2518 ///
2519 /// If the input carry is false, this method is equivalent to
2520 /// [`overflowing_add`](Self::overflowing_add).
2521 ///
2522 /// # Examples
2523 ///
2524 /// ```
2525 /// #![feature(bigint_helper_methods)]
2526 /// // Only the most significant word is signed.
2527 /// //
2528 #[doc = concat!("// 10 MAX (a = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2529 #[doc = concat!("// + -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
2530 /// // ---------
2531 #[doc = concat!("// 6 8 (sum = 6 × 2^", stringify!($BITS), " + 8)")]
2532 ///
2533 #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (10, ", stringify!($UnsignedT), "::MAX);")]
2534 #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
2535 /// let carry0 = false;
2536 ///
2537 #[doc = concat!("// ", stringify!($UnsignedT), "::carrying_add for the less significant words")]
2538 /// let (sum0, carry1) = a0.carrying_add(b0, carry0);
2539 /// assert_eq!(carry1, true);
2540 ///
2541 #[doc = concat!("// ", stringify!($SelfT), "::carrying_add for the most significant word")]
2542 /// let (sum1, overflow) = a1.carrying_add(b1, carry1);
2543 /// assert_eq!(overflow, false);
2544 ///
2545 /// assert_eq!((sum1, sum0), (6, 8));
2546 /// ```
2547 #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2548 #[must_use = "this returns the result of the operation, \
2549 without modifying the original"]
2550 #[inline]
2551 pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
2552 // note: longer-term this should be done via an intrinsic.
2553 // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
2554 let (a, b) = self.overflowing_add(rhs);
2555 let (c, d) = a.overflowing_add(carry as $SelfT);
2556 (c, b != d)
2557 }
2558
2559 /// Calculates `self` + `rhs` with an unsigned `rhs`.
2560 ///
2561 /// Returns a tuple of the addition along with a boolean indicating
2562 /// whether an arithmetic overflow would occur. If an overflow would
2563 /// have occurred then the wrapped value is returned.
2564 ///
2565 /// # Examples
2566 ///
2567 /// ```
2568 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")]
2569 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")]
2570 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")]
2571 /// ```
2572 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2573 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2574 #[must_use = "this returns the result of the operation, \
2575 without modifying the original"]
2576 #[inline]
2577 pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
2578 let rhs = rhs as Self;
2579 let (res, overflowed) = self.overflowing_add(rhs);
2580 (res, overflowed ^ (rhs < 0))
2581 }
2582
2583 /// Calculates `self` - `rhs`.
2584 ///
2585 /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
2586 /// would occur. If an overflow would have occurred then the wrapped value is returned.
2587 ///
2588 /// # Examples
2589 ///
2590 /// ```
2591 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
2592 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
2593 /// ```
2594 #[stable(feature = "wrapping", since = "1.7.0")]
2595 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2596 #[must_use = "this returns the result of the operation, \
2597 without modifying the original"]
2598 #[inline(always)]
2599 pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
2600 let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
2601 (a as Self, b)
2602 }
2603
2604 /// Calculates `self` − `rhs` − `borrow` and checks for
2605 /// overflow.
2606 ///
2607 /// Performs "ternary subtraction" by subtracting both an integer
2608 /// operand and a borrow-in bit from `self`, and returns a tuple of the
2609 /// difference along with a boolean indicating whether an arithmetic
2610 /// overflow would occur. On overflow, the wrapped value is returned.
2611 ///
2612 /// This allows chaining together multiple subtractions to create a
2613 /// wider subtraction, and can be useful for bignum subtraction. This
2614 /// method should only be used for the most significant word; for the
2615 /// less significant words the unsigned method
2616 #[doc = concat!("[`", stringify!($UnsignedT), "::borrowing_sub`]")]
2617 /// should be used.
2618 ///
2619 /// The output boolean returned by this method is *not* a borrow flag,
2620 /// and should *not* be subtracted from a more significant word.
2621 ///
2622 /// If the input borrow is false, this method is equivalent to
2623 /// [`overflowing_sub`](Self::overflowing_sub).
2624 ///
2625 /// # Examples
2626 ///
2627 /// ```
2628 /// #![feature(bigint_helper_methods)]
2629 /// // Only the most significant word is signed.
2630 /// //
2631 #[doc = concat!("// 6 8 (a = 6 × 2^", stringify!($BITS), " + 8)")]
2632 #[doc = concat!("// - -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
2633 /// // ---------
2634 #[doc = concat!("// 10 MAX (diff = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2635 ///
2636 #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (6, 8);")]
2637 #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
2638 /// let borrow0 = false;
2639 ///
2640 #[doc = concat!("// ", stringify!($UnsignedT), "::borrowing_sub for the less significant words")]
2641 /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
2642 /// assert_eq!(borrow1, true);
2643 ///
2644 #[doc = concat!("// ", stringify!($SelfT), "::borrowing_sub for the most significant word")]
2645 /// let (diff1, overflow) = a1.borrowing_sub(b1, borrow1);
2646 /// assert_eq!(overflow, false);
2647 ///
2648 #[doc = concat!("assert_eq!((diff1, diff0), (10, ", stringify!($UnsignedT), "::MAX));")]
2649 /// ```
2650 #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2651 #[must_use = "this returns the result of the operation, \
2652 without modifying the original"]
2653 #[inline]
2654 pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
2655 // note: longer-term this should be done via an intrinsic.
2656 // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
2657 let (a, b) = self.overflowing_sub(rhs);
2658 let (c, d) = a.overflowing_sub(borrow as $SelfT);
2659 (c, b != d)
2660 }
2661
2662 /// Calculates `self` - `rhs` with an unsigned `rhs`.
2663 ///
2664 /// Returns a tuple of the subtraction along with a boolean indicating
2665 /// whether an arithmetic overflow would occur. If an overflow would
2666 /// have occurred then the wrapped value is returned.
2667 ///
2668 /// # Examples
2669 ///
2670 /// ```
2671 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")]
2672 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")]
2673 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")]
2674 /// ```
2675 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2676 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2677 #[must_use = "this returns the result of the operation, \
2678 without modifying the original"]
2679 #[inline]
2680 pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
2681 let rhs = rhs as Self;
2682 let (res, overflowed) = self.overflowing_sub(rhs);
2683 (res, overflowed ^ (rhs < 0))
2684 }
2685
2686 /// Calculates the multiplication of `self` and `rhs`.
2687 ///
2688 /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow
2689 /// would occur. If an overflow would have occurred then the wrapped value is returned.
2690 ///
2691 /// # Examples
2692 ///
2693 /// ```
2694 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")]
2695 /// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true));
2696 /// ```
2697 #[stable(feature = "wrapping", since = "1.7.0")]
2698 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2699 #[must_use = "this returns the result of the operation, \
2700 without modifying the original"]
2701 #[inline(always)]
2702 pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
2703 let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
2704 (a as Self, b)
2705 }
2706
2707 /// Calculates the complete product `self * rhs` without the possibility to overflow.
2708 ///
2709 /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2710 /// of the result as two separate values, in that order.
2711 ///
2712 /// If you also need to add a carry to the wide result, then you want
2713 /// [`Self::carrying_mul`] instead.
2714 ///
2715 /// # Examples
2716 ///
2717 /// Please note that this example is shared among integer types, which is why `i32` is used.
2718 ///
2719 /// ```
2720 /// #![feature(bigint_helper_methods)]
2721 /// assert_eq!(5i32.widening_mul(-2), (4294967286, -1));
2722 /// assert_eq!(1_000_000_000i32.widening_mul(-10), (2884901888, -3));
2723 /// ```
2724 #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2725 #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2726 #[must_use = "this returns the result of the operation, \
2727 without modifying the original"]
2728 #[inline]
2729 pub const fn widening_mul(self, rhs: Self) -> ($UnsignedT, Self) {
2730 Self::carrying_mul_add(self, rhs, 0, 0)
2731 }
2732
2733 /// Calculates the "full multiplication" `self * rhs + carry`
2734 /// without the possibility to overflow.
2735 ///
2736 /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2737 /// of the result as two separate values, in that order.
2738 ///
2739 /// Performs "long multiplication" which takes in an extra amount to add, and may return an
2740 /// additional amount of overflow. This allows for chaining together multiple
2741 /// multiplications to create "big integers" which represent larger values.
2742 ///
2743 /// If you don't need the `carry`, then you can use [`Self::widening_mul`] instead.
2744 ///
2745 /// # Examples
2746 ///
2747 /// Please note that this example is shared among integer types, which is why `i32` is used.
2748 ///
2749 /// ```
2750 /// #![feature(bigint_helper_methods)]
2751 /// assert_eq!(5i32.carrying_mul(-2, 0), (4294967286, -1));
2752 /// assert_eq!(5i32.carrying_mul(-2, 10), (0, 0));
2753 /// assert_eq!(1_000_000_000i32.carrying_mul(-10, 0), (2884901888, -3));
2754 /// assert_eq!(1_000_000_000i32.carrying_mul(-10, 10), (2884901898, -3));
2755 #[doc = concat!("assert_eq!(",
2756 stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
2757 "(", stringify!($SelfT), "::MAX.unsigned_abs() + 1, ", stringify!($SelfT), "::MAX / 2));"
2758 )]
2759 /// ```
2760 #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2761 #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2762 #[must_use = "this returns the result of the operation, \
2763 without modifying the original"]
2764 #[inline]
2765 pub const fn carrying_mul(self, rhs: Self, carry: Self) -> ($UnsignedT, Self) {
2766 Self::carrying_mul_add(self, rhs, carry, 0)
2767 }
2768
2769 /// Calculates the "full multiplication" `self * rhs + carry + add`
2770 /// without the possibility to overflow.
2771 ///
2772 /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2773 /// of the result as two separate values, in that order.
2774 ///
2775 /// Performs "long multiplication" which takes in an extra amount to add, and may return an
2776 /// additional amount of overflow. This allows for chaining together multiple
2777 /// multiplications to create "big integers" which represent larger values.
2778 ///
2779 /// If you don't need either `carry`, then you can use [`Self::widening_mul`] instead,
2780 /// and if you only need one `carry`, then you can use [`Self::carrying_mul`] instead.
2781 ///
2782 /// # Examples
2783 ///
2784 /// Please note that this example is shared among integer types, which is why `i32` is used.
2785 ///
2786 /// ```
2787 /// #![feature(bigint_helper_methods)]
2788 /// assert_eq!(5i32.carrying_mul_add(-2, 0, 0), (4294967286, -1));
2789 /// assert_eq!(5i32.carrying_mul_add(-2, 10, 10), (10, 0));
2790 /// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 0, 0), (2884901888, -3));
2791 /// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 10, 10), (2884901908, -3));
2792 #[doc = concat!("assert_eq!(",
2793 stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
2794 "(", stringify!($UnsignedT), "::MAX, ", stringify!($SelfT), "::MAX / 2));"
2795 )]
2796 /// ```
2797 #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2798 #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2799 #[must_use = "this returns the result of the operation, \
2800 without modifying the original"]
2801 #[inline]
2802 pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> ($UnsignedT, Self) {
2803 intrinsics::carrying_mul_add(self, rhs, carry, add)
2804 }
2805
2806 /// Calculates the divisor when `self` is divided by `rhs`.
2807 ///
2808 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
2809 /// occur. If an overflow would occur then self is returned.
2810 ///
2811 /// # Panics
2812 ///
2813 /// This function will panic if `rhs` is zero.
2814 ///
2815 /// # Examples
2816 ///
2817 /// ```
2818 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
2819 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")]
2820 /// ```
2821 #[inline]
2822 #[stable(feature = "wrapping", since = "1.7.0")]
2823 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
2824 #[must_use = "this returns the result of the operation, \
2825 without modifying the original"]
2826 pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
2827 // Using `&` helps LLVM see that it is the same check made in division.
2828 if intrinsics::unlikely((self == Self::MIN) & (rhs == -1)) {
2829 (self, true)
2830 } else {
2831 (self / rhs, false)
2832 }
2833 }
2834
2835 /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
2836 ///
2837 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
2838 /// occur. If an overflow would occur then `self` is returned.
2839 ///
2840 /// # Panics
2841 ///
2842 /// This function will panic if `rhs` is zero.
2843 ///
2844 /// # Examples
2845 ///
2846 /// ```
2847 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
2848 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")]
2849 /// ```
2850 #[inline]
2851 #[stable(feature = "euclidean_division", since = "1.38.0")]
2852 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2853 #[must_use = "this returns the result of the operation, \
2854 without modifying the original"]
2855 pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
2856 // Using `&` helps LLVM see that it is the same check made in division.
2857 if intrinsics::unlikely((self == Self::MIN) & (rhs == -1)) {
2858 (self, true)
2859 } else {
2860 (self.div_euclid(rhs), false)
2861 }
2862 }
2863
2864 /// Calculates the remainder when `self` is divided by `rhs`.
2865 ///
2866 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
2867 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
2868 ///
2869 /// # Panics
2870 ///
2871 /// This function will panic if `rhs` is zero.
2872 ///
2873 /// # Examples
2874 ///
2875 /// ```
2876 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
2877 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")]
2878 /// ```
2879 #[inline]
2880 #[stable(feature = "wrapping", since = "1.7.0")]
2881 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
2882 #[must_use = "this returns the result of the operation, \
2883 without modifying the original"]
2884 pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
2885 if intrinsics::unlikely(rhs == -1) {
2886 (0, self == Self::MIN)
2887 } else {
2888 (self % rhs, false)
2889 }
2890 }
2891
2892
2893 /// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`.
2894 ///
2895 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
2896 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
2897 ///
2898 /// # Panics
2899 ///
2900 /// This function will panic if `rhs` is zero.
2901 ///
2902 /// # Examples
2903 ///
2904 /// ```
2905 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
2906 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")]
2907 /// ```
2908 #[stable(feature = "euclidean_division", since = "1.38.0")]
2909 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2910 #[must_use = "this returns the result of the operation, \
2911 without modifying the original"]
2912 #[inline]
2913 #[track_caller]
2914 pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
2915 if intrinsics::unlikely(rhs == -1) {
2916 (0, self == Self::MIN)
2917 } else {
2918 (self.rem_euclid(rhs), false)
2919 }
2920 }
2921
2922
2923 /// Negates self, overflowing if this is equal to the minimum value.
2924 ///
2925 /// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow
2926 /// happened. If `self` is the minimum value (e.g., `i32::MIN` for values of type `i32`), then the
2927 /// minimum value will be returned again and `true` will be returned for an overflow happening.
2928 ///
2929 /// # Examples
2930 ///
2931 /// ```
2932 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")]
2933 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")]
2934 /// ```
2935 #[inline]
2936 #[stable(feature = "wrapping", since = "1.7.0")]
2937 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2938 #[must_use = "this returns the result of the operation, \
2939 without modifying the original"]
2940 #[allow(unused_attributes)]
2941 pub const fn overflowing_neg(self) -> (Self, bool) {
2942 if intrinsics::unlikely(self == Self::MIN) {
2943 (Self::MIN, true)
2944 } else {
2945 (-self, false)
2946 }
2947 }
2948
2949 /// Shifts self left by `rhs` bits.
2950 ///
2951 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
2952 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
2953 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
2954 ///
2955 /// # Examples
2956 ///
2957 /// ```
2958 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")]
2959 /// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));
2960 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
2961 /// ```
2962 #[stable(feature = "wrapping", since = "1.7.0")]
2963 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2964 #[must_use = "this returns the result of the operation, \
2965 without modifying the original"]
2966 #[inline]
2967 pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
2968 (self.wrapping_shl(rhs), rhs >= Self::BITS)
2969 }
2970
2971 /// Shifts self right by `rhs` bits.
2972 ///
2973 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
2974 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
2975 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
2976 ///
2977 /// # Examples
2978 ///
2979 /// ```
2980 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
2981 /// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
2982 /// ```
2983 #[stable(feature = "wrapping", since = "1.7.0")]
2984 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2985 #[must_use = "this returns the result of the operation, \
2986 without modifying the original"]
2987 #[inline]
2988 pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
2989 (self.wrapping_shr(rhs), rhs >= Self::BITS)
2990 }
2991
2992 /// Computes the absolute value of `self`.
2993 ///
2994 /// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow
2995 /// happened. If self is the minimum value
2996 #[doc = concat!("(e.g., ", stringify!($SelfT), "::MIN for values of type ", stringify!($SelfT), "),")]
2997 /// then the minimum value will be returned again and true will be returned
2998 /// for an overflow happening.
2999 ///
3000 /// # Examples
3001 ///
3002 /// ```
3003 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")]
3004 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")]
3005 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")]
3006 /// ```
3007 #[stable(feature = "no_panic_abs", since = "1.13.0")]
3008 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3009 #[must_use = "this returns the result of the operation, \
3010 without modifying the original"]
3011 #[inline]
3012 pub const fn overflowing_abs(self) -> (Self, bool) {
3013 (self.wrapping_abs(), self == Self::MIN)
3014 }
3015
3016 /// Raises self to the power of `exp`, using exponentiation by squaring.
3017 ///
3018 /// Returns a tuple of the exponentiation along with a bool indicating
3019 /// whether an overflow happened.
3020 ///
3021 /// # Examples
3022 ///
3023 /// ```
3024 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")]
3025 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".overflowing_pow(0), (1, false));")]
3026 /// assert_eq!(3i8.overflowing_pow(5), (-13, true));
3027 /// ```
3028 #[stable(feature = "no_panic_pow", since = "1.34.0")]
3029 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3030 #[must_use = "this returns the result of the operation, \
3031 without modifying the original"]
3032 #[inline]
3033 pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
3034 if exp == 0 {
3035 return (1,false);
3036 }
3037 let mut base = self;
3038 let mut acc: Self = 1;
3039 let mut overflown = false;
3040 // Scratch space for storing results of overflowing_mul.
3041 let mut r;
3042
3043 loop {
3044 if (exp & 1) == 1 {
3045 r = acc.overflowing_mul(base);
3046 // since exp!=0, finally the exp must be 1.
3047 if exp == 1 {
3048 r.1 |= overflown;
3049 return r;
3050 }
3051 acc = r.0;
3052 overflown |= r.1;
3053 }
3054 exp /= 2;
3055 r = base.overflowing_mul(base);
3056 base = r.0;
3057 overflown |= r.1;
3058 }
3059 }
3060
3061 /// Raises self to the power of `exp`, using exponentiation by squaring.
3062 ///
3063 /// # Examples
3064 ///
3065 /// ```
3066 #[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")]
3067 ///
3068 /// assert_eq!(x.pow(5), 32);
3069 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".pow(0), 1);")]
3070 /// ```
3071 #[stable(feature = "rust1", since = "1.0.0")]
3072 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3073 #[must_use = "this returns the result of the operation, \
3074 without modifying the original"]
3075 #[inline]
3076 #[rustc_inherit_overflow_checks]
3077 pub const fn pow(self, mut exp: u32) -> Self {
3078 if exp == 0 {
3079 return 1;
3080 }
3081 let mut base = self;
3082 let mut acc = 1;
3083
3084 if intrinsics::is_val_statically_known(exp) {
3085 while exp > 1 {
3086 if (exp & 1) == 1 {
3087 acc = acc * base;
3088 }
3089 exp /= 2;
3090 base = base * base;
3091 }
3092
3093 // since exp!=0, finally the exp must be 1.
3094 // Deal with the final bit of the exponent separately, since
3095 // squaring the base afterwards is not necessary and may cause a
3096 // needless overflow.
3097 acc * base
3098 } else {
3099 // This is faster than the above when the exponent is not known
3100 // at compile time. We can't use the same code for the constant
3101 // exponent case because LLVM is currently unable to unroll
3102 // this loop.
3103 loop {
3104 if (exp & 1) == 1 {
3105 acc = acc * base;
3106 // since exp!=0, finally the exp must be 1.
3107 if exp == 1 {
3108 return acc;
3109 }
3110 }
3111 exp /= 2;
3112 base = base * base;
3113 }
3114 }
3115 }
3116
3117 /// Returns the square root of the number, rounded down.
3118 ///
3119 /// # Panics
3120 ///
3121 /// This function will panic if `self` is negative.
3122 ///
3123 /// # Examples
3124 ///
3125 /// ```
3126 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
3127 /// ```
3128 #[stable(feature = "isqrt", since = "1.84.0")]
3129 #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
3130 #[must_use = "this returns the result of the operation, \
3131 without modifying the original"]
3132 #[inline]
3133 #[track_caller]
3134 pub const fn isqrt(self) -> Self {
3135 match self.checked_isqrt() {
3136 Some(sqrt) => sqrt,
3137 None => crate::num::int_sqrt::panic_for_negative_argument(),
3138 }
3139 }
3140
3141 /// Calculates the quotient of Euclidean division of `self` by `rhs`.
3142 ///
3143 /// This computes the integer `q` such that `self = q * rhs + r`, with
3144 /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`.
3145 ///
3146 /// In other words, the result is `self / rhs` rounded to the integer `q`
3147 /// such that `self >= q * rhs`.
3148 /// If `self > 0`, this is equal to rounding towards zero (the default in Rust);
3149 /// if `self < 0`, this is equal to rounding away from zero (towards +/- infinity).
3150 /// If `rhs > 0`, this is equal to rounding towards -infinity;
3151 /// if `rhs < 0`, this is equal to rounding towards +infinity.
3152 ///
3153 /// # Panics
3154 ///
3155 /// This function will panic if `rhs` is zero or if `self` is `Self::MIN`
3156 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3157 ///
3158 /// # Examples
3159 ///
3160 /// ```
3161 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
3162 /// let b = 4;
3163 ///
3164 /// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
3165 /// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
3166 /// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
3167 /// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
3168 /// ```
3169 #[stable(feature = "euclidean_division", since = "1.38.0")]
3170 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3171 #[must_use = "this returns the result of the operation, \
3172 without modifying the original"]
3173 #[inline]
3174 #[track_caller]
3175 pub const fn div_euclid(self, rhs: Self) -> Self {
3176 let q = self / rhs;
3177 if self % rhs < 0 {
3178 return if rhs > 0 { q - 1 } else { q + 1 }
3179 }
3180 q
3181 }
3182
3183
3184 /// Calculates the least nonnegative remainder of `self` when
3185 /// divided by `rhs`.
3186 ///
3187 /// This is done as if by the Euclidean division algorithm -- given
3188 /// `r = self.rem_euclid(rhs)`, the result satisfies
3189 /// `self = rhs * self.div_euclid(rhs) + r` and `0 <= r < abs(rhs)`.
3190 ///
3191 /// # Panics
3192 ///
3193 /// This function will panic if `rhs` is zero or if `self` is `Self::MIN` and
3194 /// `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3195 ///
3196 /// # Examples
3197 ///
3198 /// ```
3199 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
3200 /// let b = 4;
3201 ///
3202 /// assert_eq!(a.rem_euclid(b), 3);
3203 /// assert_eq!((-a).rem_euclid(b), 1);
3204 /// assert_eq!(a.rem_euclid(-b), 3);
3205 /// assert_eq!((-a).rem_euclid(-b), 1);
3206 /// ```
3207 ///
3208 /// This will panic:
3209 /// ```should_panic
3210 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.rem_euclid(-1);")]
3211 /// ```
3212 #[doc(alias = "modulo", alias = "mod")]
3213 #[stable(feature = "euclidean_division", since = "1.38.0")]
3214 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3215 #[must_use = "this returns the result of the operation, \
3216 without modifying the original"]
3217 #[inline]
3218 #[track_caller]
3219 pub const fn rem_euclid(self, rhs: Self) -> Self {
3220 let r = self % rhs;
3221 if r < 0 {
3222 // Semantically equivalent to `if rhs < 0 { r - rhs } else { r + rhs }`.
3223 // If `rhs` is not `Self::MIN`, then `r + abs(rhs)` will not overflow
3224 // and is clearly equivalent, because `r` is negative.
3225 // Otherwise, `rhs` is `Self::MIN`, then we have
3226 // `r.wrapping_add(Self::MIN.wrapping_abs())`, which evaluates
3227 // to `r.wrapping_add(Self::MIN)`, which is equivalent to
3228 // `r - Self::MIN`, which is what we wanted (and will not overflow
3229 // for negative `r`).
3230 r.wrapping_add(rhs.wrapping_abs())
3231 } else {
3232 r
3233 }
3234 }
3235
3236 /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
3237 ///
3238 /// # Panics
3239 ///
3240 /// This function will panic if `rhs` is zero or if `self` is `Self::MIN`
3241 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3242 ///
3243 /// # Examples
3244 ///
3245 /// ```
3246 /// #![feature(int_roundings)]
3247 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
3248 /// let b = 3;
3249 ///
3250 /// assert_eq!(a.div_floor(b), 2);
3251 /// assert_eq!(a.div_floor(-b), -3);
3252 /// assert_eq!((-a).div_floor(b), -3);
3253 /// assert_eq!((-a).div_floor(-b), 2);
3254 /// ```
3255 #[unstable(feature = "int_roundings", issue = "88581")]
3256 #[must_use = "this returns the result of the operation, \
3257 without modifying the original"]
3258 #[inline]
3259 #[track_caller]
3260 pub const fn div_floor(self, rhs: Self) -> Self {
3261 let d = self / rhs;
3262 let r = self % rhs;
3263
3264 // If the remainder is non-zero, we need to subtract one if the
3265 // signs of self and rhs differ, as this means we rounded upwards
3266 // instead of downwards. We do this branchlessly by creating a mask
3267 // which is all-ones iff the signs differ, and 0 otherwise. Then by
3268 // adding this mask (which corresponds to the signed value -1), we
3269 // get our correction.
3270 let correction = (self ^ rhs) >> (Self::BITS - 1);
3271 if r != 0 {
3272 d + correction
3273 } else {
3274 d
3275 }
3276 }
3277
3278 /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
3279 ///
3280 /// # Panics
3281 ///
3282 /// This function will panic if `rhs` is zero or if `self` is `Self::MIN`
3283 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3284 ///
3285 /// # Examples
3286 ///
3287 /// ```
3288 /// #![feature(int_roundings)]
3289 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
3290 /// let b = 3;
3291 ///
3292 /// assert_eq!(a.div_ceil(b), 3);
3293 /// assert_eq!(a.div_ceil(-b), -2);
3294 /// assert_eq!((-a).div_ceil(b), -2);
3295 /// assert_eq!((-a).div_ceil(-b), 3);
3296 /// ```
3297 #[unstable(feature = "int_roundings", issue = "88581")]
3298 #[must_use = "this returns the result of the operation, \
3299 without modifying the original"]
3300 #[inline]
3301 #[track_caller]
3302 pub const fn div_ceil(self, rhs: Self) -> Self {
3303 let d = self / rhs;
3304 let r = self % rhs;
3305
3306 // When remainder is non-zero we have a.div_ceil(b) == 1 + a.div_floor(b),
3307 // so we can re-use the algorithm from div_floor, just adding 1.
3308 let correction = 1 + ((self ^ rhs) >> (Self::BITS - 1));
3309 if r != 0 {
3310 d + correction
3311 } else {
3312 d
3313 }
3314 }
3315
3316 /// If `rhs` is positive, calculates the smallest value greater than or
3317 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
3318 /// calculates the largest value less than or equal to `self` that is a
3319 /// multiple of `rhs`.
3320 ///
3321 /// # Panics
3322 ///
3323 /// This function will panic if `rhs` is zero.
3324 ///
3325 /// ## Overflow behavior
3326 ///
3327 /// On overflow, this function will panic if overflow checks are enabled (default in debug
3328 /// mode) and wrap if overflow checks are disabled (default in release mode).
3329 ///
3330 /// # Examples
3331 ///
3332 /// ```
3333 /// #![feature(int_roundings)]
3334 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
3335 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
3336 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
3337 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
3338 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
3339 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
3340 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")]
3341 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")]
3342 /// ```
3343 #[unstable(feature = "int_roundings", issue = "88581")]
3344 #[must_use = "this returns the result of the operation, \
3345 without modifying the original"]
3346 #[inline]
3347 #[rustc_inherit_overflow_checks]
3348 pub const fn next_multiple_of(self, rhs: Self) -> Self {
3349 // This would otherwise fail when calculating `r` when self == T::MIN.
3350 if rhs == -1 {
3351 return self;
3352 }
3353
3354 let r = self % rhs;
3355 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
3356 r + rhs
3357 } else {
3358 r
3359 };
3360
3361 if m == 0 {
3362 self
3363 } else {
3364 self + (rhs - m)
3365 }
3366 }
3367
3368 /// If `rhs` is positive, calculates the smallest value greater than or
3369 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
3370 /// calculates the largest value less than or equal to `self` that is a
3371 /// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
3372 /// would result in overflow.
3373 ///
3374 /// # Examples
3375 ///
3376 /// ```
3377 /// #![feature(int_roundings)]
3378 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
3379 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
3380 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
3381 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
3382 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
3383 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
3384 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")]
3385 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")]
3386 #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
3387 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
3388 /// ```
3389 #[unstable(feature = "int_roundings", issue = "88581")]
3390 #[must_use = "this returns the result of the operation, \
3391 without modifying the original"]
3392 #[inline]
3393 pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
3394 // This would otherwise fail when calculating `r` when self == T::MIN.
3395 if rhs == -1 {
3396 return Some(self);
3397 }
3398
3399 let r = try_opt!(self.checked_rem(rhs));
3400 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
3401 // r + rhs cannot overflow because they have opposite signs
3402 r + rhs
3403 } else {
3404 r
3405 };
3406
3407 if m == 0 {
3408 Some(self)
3409 } else {
3410 // rhs - m cannot overflow because m has the same sign as rhs
3411 self.checked_add(rhs - m)
3412 }
3413 }
3414
3415 /// Returns the logarithm of the number with respect to an arbitrary base,
3416 /// rounded down.
3417 ///
3418 /// This method might not be optimized owing to implementation details;
3419 /// `ilog2` can produce results more efficiently for base 2, and `ilog10`
3420 /// can produce results more efficiently for base 10.
3421 ///
3422 /// # Panics
3423 ///
3424 /// This function will panic if `self` is less than or equal to zero,
3425 /// or if `base` is less than 2.
3426 ///
3427 /// # Examples
3428 ///
3429 /// ```
3430 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
3431 /// ```
3432 #[stable(feature = "int_log", since = "1.67.0")]
3433 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3434 #[must_use = "this returns the result of the operation, \
3435 without modifying the original"]
3436 #[inline]
3437 #[track_caller]
3438 pub const fn ilog(self, base: Self) -> u32 {
3439 assert!(base >= 2, "base of integer logarithm must be at least 2");
3440 if let Some(log) = self.checked_ilog(base) {
3441 log
3442 } else {
3443 int_log10::panic_for_nonpositive_argument()
3444 }
3445 }
3446
3447 /// Returns the base 2 logarithm of the number, rounded down.
3448 ///
3449 /// # Panics
3450 ///
3451 /// This function will panic if `self` is less than or equal to zero.
3452 ///
3453 /// # Examples
3454 ///
3455 /// ```
3456 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
3457 /// ```
3458 #[stable(feature = "int_log", since = "1.67.0")]
3459 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3460 #[must_use = "this returns the result of the operation, \
3461 without modifying the original"]
3462 #[inline]
3463 #[track_caller]
3464 pub const fn ilog2(self) -> u32 {
3465 if let Some(log) = self.checked_ilog2() {
3466 log
3467 } else {
3468 int_log10::panic_for_nonpositive_argument()
3469 }
3470 }
3471
3472 /// Returns the base 10 logarithm of the number, rounded down.
3473 ///
3474 /// # Panics
3475 ///
3476 /// This function will panic if `self` is less than or equal to zero.
3477 ///
3478 /// # Example
3479 ///
3480 /// ```
3481 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
3482 /// ```
3483 #[stable(feature = "int_log", since = "1.67.0")]
3484 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3485 #[must_use = "this returns the result of the operation, \
3486 without modifying the original"]
3487 #[inline]
3488 #[track_caller]
3489 pub const fn ilog10(self) -> u32 {
3490 if let Some(log) = self.checked_ilog10() {
3491 log
3492 } else {
3493 int_log10::panic_for_nonpositive_argument()
3494 }
3495 }
3496
3497 /// Returns the logarithm of the number with respect to an arbitrary base,
3498 /// rounded down.
3499 ///
3500 /// Returns `None` if the number is negative or zero, or if the base is not at least 2.
3501 ///
3502 /// This method might not be optimized owing to implementation details;
3503 /// `checked_ilog2` can produce results more efficiently for base 2, and
3504 /// `checked_ilog10` can produce results more efficiently for base 10.
3505 ///
3506 /// # Examples
3507 ///
3508 /// ```
3509 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
3510 /// ```
3511 #[stable(feature = "int_log", since = "1.67.0")]
3512 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3513 #[must_use = "this returns the result of the operation, \
3514 without modifying the original"]
3515 #[inline]
3516 pub const fn checked_ilog(self, base: Self) -> Option<u32> {
3517 if self <= 0 || base <= 1 {
3518 None
3519 } else {
3520 // Delegate to the unsigned implementation.
3521 // The condition makes sure that both casts are exact.
3522 (self as $UnsignedT).checked_ilog(base as $UnsignedT)
3523 }
3524 }
3525
3526 /// Returns the base 2 logarithm of the number, rounded down.
3527 ///
3528 /// Returns `None` if the number is negative or zero.
3529 ///
3530 /// # Examples
3531 ///
3532 /// ```
3533 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
3534 /// ```
3535 #[stable(feature = "int_log", since = "1.67.0")]
3536 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3537 #[must_use = "this returns the result of the operation, \
3538 without modifying the original"]
3539 #[inline]
3540 pub const fn checked_ilog2(self) -> Option<u32> {
3541 if self <= 0 {
3542 None
3543 } else {
3544 // SAFETY: We just checked that this number is positive
3545 let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 };
3546 Some(log)
3547 }
3548 }
3549
3550 /// Returns the base 10 logarithm of the number, rounded down.
3551 ///
3552 /// Returns `None` if the number is negative or zero.
3553 ///
3554 /// # Example
3555 ///
3556 /// ```
3557 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
3558 /// ```
3559 #[stable(feature = "int_log", since = "1.67.0")]
3560 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3561 #[must_use = "this returns the result of the operation, \
3562 without modifying the original"]
3563 #[inline]
3564 pub const fn checked_ilog10(self) -> Option<u32> {
3565 int_log10::$ActualT(self as $ActualT)
3566 }
3567
3568 /// Computes the absolute value of `self`.
3569 ///
3570 /// # Overflow behavior
3571 ///
3572 /// The absolute value of
3573 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
3574 /// cannot be represented as an
3575 #[doc = concat!("`", stringify!($SelfT), "`,")]
3576 /// and attempting to calculate it will cause an overflow. This means
3577 /// that code in debug mode will trigger a panic on this case and
3578 /// optimized code will return
3579 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
3580 /// without a panic. If you do not want this behavior, consider
3581 /// using [`unsigned_abs`](Self::unsigned_abs) instead.
3582 ///
3583 /// # Examples
3584 ///
3585 /// ```
3586 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")]
3587 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")]
3588 /// ```
3589 #[stable(feature = "rust1", since = "1.0.0")]
3590 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3591 #[allow(unused_attributes)]
3592 #[must_use = "this returns the result of the operation, \
3593 without modifying the original"]
3594 #[inline]
3595 #[rustc_inherit_overflow_checks]
3596 pub const fn abs(self) -> Self {
3597 // Note that the #[rustc_inherit_overflow_checks] and #[inline]
3598 // above mean that the overflow semantics of the subtraction
3599 // depend on the crate we're being called from.
3600 if self.is_negative() {
3601 -self
3602 } else {
3603 self
3604 }
3605 }
3606
3607 /// Computes the absolute difference between `self` and `other`.
3608 ///
3609 /// This function always returns the correct answer without overflow or
3610 /// panics by returning an unsigned integer.
3611 ///
3612 /// # Examples
3613 ///
3614 /// ```
3615 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")]
3616 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")]
3617 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")]
3618 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")]
3619 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")]
3620 /// ```
3621 #[stable(feature = "int_abs_diff", since = "1.60.0")]
3622 #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
3623 #[must_use = "this returns the result of the operation, \
3624 without modifying the original"]
3625 #[inline]
3626 pub const fn abs_diff(self, other: Self) -> $UnsignedT {
3627 if self < other {
3628 // Converting a non-negative x from signed to unsigned by using
3629 // `x as U` is left unchanged, but a negative x is converted
3630 // to value x + 2^N. Thus if `s` and `o` are binary variables
3631 // respectively indicating whether `self` and `other` are
3632 // negative, we are computing the mathematical value:
3633 //
3634 // (other + o*2^N) - (self + s*2^N) mod 2^N
3635 // other - self + (o-s)*2^N mod 2^N
3636 // other - self mod 2^N
3637 //
3638 // Finally, taking the mod 2^N of the mathematical value of
3639 // `other - self` does not change it as it already is
3640 // in the range [0, 2^N).
3641 (other as $UnsignedT).wrapping_sub(self as $UnsignedT)
3642 } else {
3643 (self as $UnsignedT).wrapping_sub(other as $UnsignedT)
3644 }
3645 }
3646
3647 /// Returns a number representing sign of `self`.
3648 ///
3649 /// - `0` if the number is zero
3650 /// - `1` if the number is positive
3651 /// - `-1` if the number is negative
3652 ///
3653 /// # Examples
3654 ///
3655 /// ```
3656 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")]
3657 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")]
3658 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")]
3659 /// ```
3660 #[stable(feature = "rust1", since = "1.0.0")]
3661 #[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")]
3662 #[must_use = "this returns the result of the operation, \
3663 without modifying the original"]
3664 #[inline(always)]
3665 pub const fn signum(self) -> Self {
3666 // Picking the right way to phrase this is complicated
3667 // (<https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>)
3668 // so delegate it to `Ord` which is already producing -1/0/+1
3669 // exactly like we need and can be the place to deal with the complexity.
3670
3671 crate::intrinsics::three_way_compare(self, 0) as Self
3672 }
3673
3674 /// Returns `true` if `self` is positive and `false` if the number is zero or
3675 /// negative.
3676 ///
3677 /// # Examples
3678 ///
3679 /// ```
3680 #[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")]
3681 #[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")]
3682 /// ```
3683 #[must_use]
3684 #[stable(feature = "rust1", since = "1.0.0")]
3685 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3686 #[inline(always)]
3687 pub const fn is_positive(self) -> bool { self > 0 }
3688
3689 /// Returns `true` if `self` is negative and `false` if the number is zero or
3690 /// positive.
3691 ///
3692 /// # Examples
3693 ///
3694 /// ```
3695 #[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")]
3696 #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")]
3697 /// ```
3698 #[must_use]
3699 #[stable(feature = "rust1", since = "1.0.0")]
3700 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3701 #[inline(always)]
3702 pub const fn is_negative(self) -> bool { self < 0 }
3703
3704 /// Returns the memory representation of this integer as a byte array in
3705 /// big-endian (network) byte order.
3706 ///
3707 #[doc = $to_xe_bytes_doc]
3708 ///
3709 /// # Examples
3710 ///
3711 /// ```
3712 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
3713 #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
3714 /// ```
3715 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3716 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3717 #[must_use = "this returns the result of the operation, \
3718 without modifying the original"]
3719 #[inline]
3720 pub const fn to_be_bytes(self) -> [u8; size_of::<Self>()] {
3721 self.to_be().to_ne_bytes()
3722 }
3723
3724 /// Returns the memory representation of this integer as a byte array in
3725 /// little-endian byte order.
3726 ///
3727 #[doc = $to_xe_bytes_doc]
3728 ///
3729 /// # Examples
3730 ///
3731 /// ```
3732 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
3733 #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
3734 /// ```
3735 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3736 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3737 #[must_use = "this returns the result of the operation, \
3738 without modifying the original"]
3739 #[inline]
3740 pub const fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
3741 self.to_le().to_ne_bytes()
3742 }
3743
3744 /// Returns the memory representation of this integer as a byte array in
3745 /// native byte order.
3746 ///
3747 /// As the target platform's native endianness is used, portable code
3748 /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
3749 /// instead.
3750 ///
3751 #[doc = $to_xe_bytes_doc]
3752 ///
3753 /// [`to_be_bytes`]: Self::to_be_bytes
3754 /// [`to_le_bytes`]: Self::to_le_bytes
3755 ///
3756 /// # Examples
3757 ///
3758 /// ```
3759 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
3760 /// assert_eq!(
3761 /// bytes,
3762 /// if cfg!(target_endian = "big") {
3763 #[doc = concat!(" ", $be_bytes)]
3764 /// } else {
3765 #[doc = concat!(" ", $le_bytes)]
3766 /// }
3767 /// );
3768 /// ```
3769 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3770 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3771 #[allow(unnecessary_transmutes)]
3772 // SAFETY: const sound because integers are plain old datatypes so we can always
3773 // transmute them to arrays of bytes
3774 #[must_use = "this returns the result of the operation, \
3775 without modifying the original"]
3776 #[inline]
3777 pub const fn to_ne_bytes(self) -> [u8; size_of::<Self>()] {
3778 // SAFETY: integers are plain old datatypes so we can always transmute them to
3779 // arrays of bytes
3780 unsafe { mem::transmute(self) }
3781 }
3782
3783 /// Creates an integer value from its representation as a byte array in
3784 /// big endian.
3785 ///
3786 #[doc = $from_xe_bytes_doc]
3787 ///
3788 /// # Examples
3789 ///
3790 /// ```
3791 #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
3792 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3793 /// ```
3794 ///
3795 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3796 ///
3797 /// ```
3798 #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3799 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3800 /// *input = rest;
3801 #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
3802 /// }
3803 /// ```
3804 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3805 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3806 #[must_use]
3807 #[inline]
3808 pub const fn from_be_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3809 Self::from_be(Self::from_ne_bytes(bytes))
3810 }
3811
3812 /// Creates an integer value from its representation as a byte array in
3813 /// little endian.
3814 ///
3815 #[doc = $from_xe_bytes_doc]
3816 ///
3817 /// # Examples
3818 ///
3819 /// ```
3820 #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
3821 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3822 /// ```
3823 ///
3824 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3825 ///
3826 /// ```
3827 #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3828 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3829 /// *input = rest;
3830 #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
3831 /// }
3832 /// ```
3833 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3834 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3835 #[must_use]
3836 #[inline]
3837 pub const fn from_le_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3838 Self::from_le(Self::from_ne_bytes(bytes))
3839 }
3840
3841 /// Creates an integer value from its memory representation as a byte
3842 /// array in native endianness.
3843 ///
3844 /// As the target platform's native endianness is used, portable code
3845 /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
3846 /// appropriate instead.
3847 ///
3848 /// [`from_be_bytes`]: Self::from_be_bytes
3849 /// [`from_le_bytes`]: Self::from_le_bytes
3850 ///
3851 #[doc = $from_xe_bytes_doc]
3852 ///
3853 /// # Examples
3854 ///
3855 /// ```
3856 #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
3857 #[doc = concat!(" ", $be_bytes)]
3858 /// } else {
3859 #[doc = concat!(" ", $le_bytes)]
3860 /// });
3861 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3862 /// ```
3863 ///
3864 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3865 ///
3866 /// ```
3867 #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3868 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3869 /// *input = rest;
3870 #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
3871 /// }
3872 /// ```
3873 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3874 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3875 #[allow(unnecessary_transmutes)]
3876 #[must_use]
3877 // SAFETY: const sound because integers are plain old datatypes so we can always
3878 // transmute to them
3879 #[inline]
3880 pub const fn from_ne_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3881 // SAFETY: integers are plain old datatypes so we can always transmute to them
3882 unsafe { mem::transmute(bytes) }
3883 }
3884
3885 /// New code should prefer to use
3886 #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
3887 ///
3888 /// Returns the smallest value that can be represented by this integer type.
3889 #[stable(feature = "rust1", since = "1.0.0")]
3890 #[inline(always)]
3891 #[rustc_promotable]
3892 #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
3893 #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")]
3894 #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
3895 pub const fn min_value() -> Self {
3896 Self::MIN
3897 }
3898
3899 /// New code should prefer to use
3900 #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
3901 ///
3902 /// Returns the largest value that can be represented by this integer type.
3903 #[stable(feature = "rust1", since = "1.0.0")]
3904 #[inline(always)]
3905 #[rustc_promotable]
3906 #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
3907 #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")]
3908 #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
3909 pub const fn max_value() -> Self {
3910 Self::MAX
3911 }
3912
3913 /// Clamps this number to a symmetric range centred around zero.
3914 ///
3915 /// The method clamps the number's magnitude (absolute value) to be at most `limit`.
3916 ///
3917 /// This is functionally equivalent to `self.clamp(-limit, limit)`, but is more
3918 /// explicit about the intent.
3919 ///
3920 /// # Examples
3921 ///
3922 /// ```
3923 /// #![feature(clamp_magnitude)]
3924 #[doc = concat!("assert_eq!(120", stringify!($SelfT), ".clamp_magnitude(100), 100);")]
3925 #[doc = concat!("assert_eq!(-120", stringify!($SelfT), ".clamp_magnitude(100), -100);")]
3926 #[doc = concat!("assert_eq!(80", stringify!($SelfT), ".clamp_magnitude(100), 80);")]
3927 #[doc = concat!("assert_eq!(-80", stringify!($SelfT), ".clamp_magnitude(100), -80);")]
3928 /// ```
3929 #[must_use = "this returns the clamped value and does not modify the original"]
3930 #[unstable(feature = "clamp_magnitude", issue = "148519")]
3931 #[inline]
3932 pub fn clamp_magnitude(self, limit: $UnsignedT) -> Self {
3933 if let Ok(limit) = core::convert::TryInto::<$SelfT>::try_into(limit) {
3934 self.clamp(-limit, limit)
3935 } else {
3936 self
3937 }
3938 }
3939 }
3940}