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 $UnsignedT).trailing_ones()
168 }
169
170 /// Returns `self` with only the most significant bit set, or `0` if
171 /// the input is `0`.
172 ///
173 /// # Examples
174 ///
175 /// ```
176 #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
177 ///
178 /// assert_eq!(n.isolate_highest_one(), 0b_01000000);
179 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_highest_one(), 0);")]
180 /// ```
181 #[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
182 #[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
183 #[must_use = "this returns the result of the operation, \
184 without modifying the original"]
185 #[inline(always)]
186 pub const fn isolate_highest_one(self) -> Self {
187 self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros()))
188 }
189
190 /// Returns `self` with only the least significant bit set, or `0` if
191 /// the input is `0`.
192 ///
193 /// # Examples
194 ///
195 /// ```
196 #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
197 ///
198 /// assert_eq!(n.isolate_lowest_one(), 0b_00000100);
199 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_lowest_one(), 0);")]
200 /// ```
201 #[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
202 #[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
203 #[must_use = "this returns the result of the operation, \
204 without modifying the original"]
205 #[inline(always)]
206 pub const fn isolate_lowest_one(self) -> Self {
207 self & self.wrapping_neg()
208 }
209
210 /// Returns the index of the highest bit set to one in `self`, or `None`
211 /// if `self` is `0`.
212 ///
213 /// Note that for non-negative numbers, this is equivalent to
214 /// [`checked_ilog2`](Self::checked_ilog2).
215 ///
216 /// # Examples
217 ///
218 /// ```
219 #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".highest_one(), None);")]
220 #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".highest_one(), Some(0));")]
221 #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".highest_one(), Some(4));")]
222 #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".highest_one(), Some(4));")]
223 /// ```
224 #[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
225 #[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
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 $UnsignedT).highest_one()
231 }
232
233 /// Returns the index of the lowest bit set to one in `self`, or `None`
234 /// if `self` is `0`.
235 ///
236 /// # Examples
237 ///
238 /// ```
239 #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".lowest_one(), None);")]
240 #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".lowest_one(), Some(0));")]
241 #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".lowest_one(), Some(4));")]
242 #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".lowest_one(), Some(0));")]
243 /// ```
244 #[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
245 #[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
246 #[must_use = "this returns the result of the operation, \
247 without modifying the original"]
248 #[inline(always)]
249 pub const fn lowest_one(self) -> Option<u32> {
250 (self as $UnsignedT).lowest_one()
251 }
252
253 /// Returns the bit pattern of `self` reinterpreted as an unsigned integer of the same size.
254 ///
255 /// This produces the same result as an `as` cast, but ensures that the bit-width remains
256 /// the same.
257 ///
258 /// # Examples
259 ///
260 /// ```
261 #[doc = concat!("let n = -1", stringify!($SelfT), ";")]
262 ///
263 #[doc = concat!("assert_eq!(n.cast_unsigned(), ", stringify!($UnsignedT), "::MAX);")]
264 /// ```
265 #[stable(feature = "integer_sign_cast", since = "1.87.0")]
266 #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
267 #[must_use = "this returns the result of the operation, \
268 without modifying the original"]
269 #[inline(always)]
270 pub const fn cast_unsigned(self) -> $UnsignedT {
271 self as $UnsignedT
272 }
273
274 /// Saturating conversion of `self` to an unsigned integer of the same size.
275 ///
276 /// Negative values are clamped to `0`.
277 ///
278 /// For other kinds of unsigned integer casts, see
279 /// [`cast_unsigned`](Self::cast_unsigned),
280 /// [`checked_cast_unsigned`](Self::checked_cast_unsigned),
281 /// or [`strict_cast_unsigned`](Self::strict_cast_unsigned).
282 ///
283 /// # Examples
284 ///
285 /// ```
286 /// #![feature(integer_cast_extras)]
287 #[doc = concat!("let n = ", stringify!($SelfT), "::MIN;")]
288 ///
289 #[doc = concat!("assert_eq!(n.saturating_cast_unsigned(), 0", stringify!($UnsignedT), ");")]
290 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".saturating_cast_unsigned(), 64", stringify!($UnsignedT), ");")]
291 /// ```
292 #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
293 #[unstable(feature = "integer_cast_extras", issue = "154650")]
294 #[must_use = "this returns the result of the operation, \
295 without modifying the original"]
296 #[inline(always)]
297 pub const fn saturating_cast_unsigned(self) -> $UnsignedT {
298 if self >= 0 {
299 self.cast_unsigned()
300 } else {
301 0
302 }
303 }
304
305 /// Checked conversion of `self` to an unsigned integer of the same size,
306 /// returning `None` if `self` is negative.
307 ///
308 /// For other kinds of unsigned integer casts, see
309 /// [`cast_unsigned`](Self::cast_unsigned),
310 /// [`saturating_cast_unsigned`](Self::saturating_cast_unsigned),
311 /// or [`strict_cast_unsigned`](Self::strict_cast_unsigned).
312 ///
313 /// # Examples
314 ///
315 /// ```
316 /// #![feature(integer_cast_extras)]
317 #[doc = concat!("let n = ", stringify!($SelfT), "::MIN;")]
318 ///
319 #[doc = concat!("assert_eq!(n.checked_cast_unsigned(), None);")]
320 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_cast_unsigned(), Some(64", stringify!($UnsignedT), "));")]
321 /// ```
322 #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
323 #[unstable(feature = "integer_cast_extras", issue = "154650")]
324 #[must_use = "this returns the result of the operation, \
325 without modifying the original"]
326 #[inline(always)]
327 pub const fn checked_cast_unsigned(self) -> Option<$UnsignedT> {
328 if self >= 0 {
329 Some(self.cast_unsigned())
330 } else {
331 None
332 }
333 }
334
335 /// Strict conversion of `self` to an unsigned integer of the same size,
336 /// which panics if `self` is negative.
337 ///
338 /// For other kinds of unsigned integer casts, see
339 /// [`cast_unsigned`](Self::cast_unsigned),
340 /// [`checked_cast_unsigned`](Self::checked_cast_unsigned),
341 /// or [`saturating_cast_unsigned`](Self::saturating_cast_unsigned).
342 ///
343 /// # Examples
344 ///
345 /// ```should_panic
346 /// #![feature(integer_cast_extras)]
347 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_cast_unsigned();")]
348 /// ```
349 #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
350 #[unstable(feature = "integer_cast_extras", issue = "154650")]
351 #[must_use = "this returns the result of the operation, \
352 without modifying the original"]
353 #[inline]
354 #[track_caller]
355 pub const fn strict_cast_unsigned(self) -> $UnsignedT {
356 match self.checked_cast_unsigned() {
357 Some(n) => n,
358 None => imp::overflow_panic::cast_integer(),
359 }
360 }
361
362 /// Shifts the bits to the left by a specified amount, `n`,
363 /// wrapping the truncated bits to the end of the resulting integer.
364 ///
365 /// `rotate_left(n)` is equivalent to applying `rotate_left(1)` a total of `n` times. In
366 /// particular, a rotation by the number of bits in `self` returns the input value
367 /// unchanged.
368 ///
369 /// Please note this isn't the same operation as the `<<` shifting operator!
370 ///
371 /// # Examples
372 ///
373 /// ```
374 #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
375 #[doc = concat!("let m = ", $rot_result, ";")]
376 ///
377 #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
378 #[doc = concat!("assert_eq!(n.rotate_left(1024), n);")]
379 /// ```
380 #[stable(feature = "rust1", since = "1.0.0")]
381 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
382 #[must_use = "this returns the result of the operation, \
383 without modifying the original"]
384 #[inline(always)]
385 pub const fn rotate_left(self, n: u32) -> Self {
386 (self as $UnsignedT).rotate_left(n) as Self
387 }
388
389 /// Shifts the bits to the right by a specified amount, `n`,
390 /// wrapping the truncated bits to the beginning of the resulting
391 /// integer.
392 ///
393 /// `rotate_right(n)` is equivalent to applying `rotate_right(1)` a total of `n` times. In
394 /// particular, a rotation by the number of bits in `self` returns the input value
395 /// unchanged.
396 ///
397 /// Please note this isn't the same operation as the `>>` shifting operator!
398 ///
399 /// # Examples
400 ///
401 /// ```
402 #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
403 #[doc = concat!("let m = ", $rot_op, ";")]
404 ///
405 #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
406 #[doc = concat!("assert_eq!(n.rotate_right(1024), n);")]
407 /// ```
408 #[stable(feature = "rust1", since = "1.0.0")]
409 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
410 #[must_use = "this returns the result of the operation, \
411 without modifying the original"]
412 #[inline(always)]
413 pub const fn rotate_right(self, n: u32) -> Self {
414 (self as $UnsignedT).rotate_right(n) as Self
415 }
416
417 /// Reverses the byte order of the integer.
418 ///
419 /// # Examples
420 ///
421 /// ```
422 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
423 ///
424 /// let m = n.swap_bytes();
425 ///
426 #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
427 /// ```
428 #[stable(feature = "rust1", since = "1.0.0")]
429 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
430 #[must_use = "this returns the result of the operation, \
431 without modifying the original"]
432 #[inline(always)]
433 pub const fn swap_bytes(self) -> Self {
434 (self as $UnsignedT).swap_bytes() as Self
435 }
436
437 /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
438 /// second least-significant bit becomes second most-significant bit, etc.
439 ///
440 /// # Examples
441 ///
442 /// ```
443 #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
444 /// let m = n.reverse_bits();
445 ///
446 #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
447 #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
448 /// ```
449 #[stable(feature = "reverse_bits", since = "1.37.0")]
450 #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
451 #[must_use = "this returns the result of the operation, \
452 without modifying the original"]
453 #[inline(always)]
454 pub const fn reverse_bits(self) -> Self {
455 (self as $UnsignedT).reverse_bits() as Self
456 }
457
458 /// Converts an integer from big endian to the target's endianness.
459 ///
460 /// On big endian this is a no-op. On little endian the bytes are swapped.
461 ///
462 /// See also [from_be_bytes()](Self::from_be_bytes).
463 ///
464 /// # Examples
465 ///
466 /// ```
467 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
468 ///
469 /// if cfg!(target_endian = "big") {
470 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
471 /// } else {
472 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
473 /// }
474 /// ```
475 #[stable(feature = "rust1", since = "1.0.0")]
476 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
477 #[must_use]
478 #[inline]
479 pub const fn from_be(x: Self) -> Self {
480 cfg_select! {
481 target_endian = "big" => x,
482 _ => x.swap_bytes(),
483 }
484 }
485
486 /// Converts an integer from little endian to the target's endianness.
487 ///
488 /// On little endian this is a no-op. On big endian the bytes are swapped.
489 ///
490 /// See also [from_le_bytes()](Self::from_le_bytes).
491 ///
492 /// # Examples
493 ///
494 /// ```
495 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
496 ///
497 /// if cfg!(target_endian = "little") {
498 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
499 /// } else {
500 #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
501 /// }
502 /// ```
503 #[stable(feature = "rust1", since = "1.0.0")]
504 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
505 #[must_use]
506 #[inline]
507 pub const fn from_le(x: Self) -> Self {
508 cfg_select! {
509 target_endian = "little" => x,
510 _ => x.swap_bytes(),
511 }
512 }
513
514 /// Swaps bytes of `self` on little endian targets.
515 ///
516 /// On big endian this is a no-op.
517 ///
518 /// The returned value has the same type as `self`, and will be interpreted
519 /// as (a potentially different) value of a native-endian
520 #[doc = concat!("`", stringify!($SelfT), "`.")]
521 ///
522 /// See [`to_be_bytes()`](Self::to_be_bytes) for a type-safe alternative.
523 ///
524 /// # Examples
525 ///
526 /// ```
527 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
528 ///
529 /// if cfg!(target_endian = "big") {
530 /// assert_eq!(n.to_be(), n)
531 /// } else {
532 /// assert_eq!(n.to_be(), n.swap_bytes())
533 /// }
534 /// ```
535 #[stable(feature = "rust1", since = "1.0.0")]
536 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
537 #[must_use = "this returns the result of the operation, \
538 without modifying the original"]
539 #[inline]
540 pub const fn to_be(self) -> Self { // or not to be?
541 cfg_select! {
542 target_endian = "big" => self,
543 _ => self.swap_bytes(),
544 }
545 }
546
547 /// Swaps bytes of `self` on big endian targets.
548 ///
549 /// On little endian this is a no-op.
550 ///
551 /// The returned value has the same type as `self`, and will be interpreted
552 /// as (a potentially different) value of a native-endian
553 #[doc = concat!("`", stringify!($SelfT), "`.")]
554 ///
555 /// See [`to_le_bytes()`](Self::to_le_bytes) for a type-safe alternative.
556 ///
557 /// # Examples
558 ///
559 /// ```
560 #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
561 ///
562 /// if cfg!(target_endian = "little") {
563 /// assert_eq!(n.to_le(), n)
564 /// } else {
565 /// assert_eq!(n.to_le(), n.swap_bytes())
566 /// }
567 /// ```
568 #[stable(feature = "rust1", since = "1.0.0")]
569 #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
570 #[must_use = "this returns the result of the operation, \
571 without modifying the original"]
572 #[inline]
573 pub const fn to_le(self) -> Self {
574 cfg_select! {
575 target_endian = "little" => self,
576 _ => self.swap_bytes(),
577 }
578 }
579
580 /// Checked integer addition. Computes `self + rhs`, returning `None`
581 /// if overflow occurred.
582 ///
583 /// # Examples
584 ///
585 /// ```
586 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")]
587 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
588 /// ```
589 #[stable(feature = "rust1", since = "1.0.0")]
590 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
591 #[must_use = "this returns the result of the operation, \
592 without modifying the original"]
593 #[inline]
594 pub const fn checked_add(self, rhs: Self) -> Option<Self> {
595 let (a, b) = self.overflowing_add(rhs);
596 if intrinsics::unlikely(b) { None } else { Some(a) }
597 }
598
599 /// Strict integer addition. Computes `self + rhs`, panicking
600 /// if overflow occurred.
601 ///
602 /// # Panics
603 ///
604 /// ## Overflow behavior
605 ///
606 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
607 ///
608 /// # Examples
609 ///
610 /// ```
611 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
612 /// ```
613 ///
614 /// The following panics because of overflow:
615 ///
616 /// ```should_panic
617 #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
618 /// ```
619 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
620 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
621 #[must_use = "this returns the result of the operation, \
622 without modifying the original"]
623 #[inline]
624 #[track_caller]
625 pub const fn strict_add(self, rhs: Self) -> Self {
626 let (a, b) = self.overflowing_add(rhs);
627 if b { imp::overflow_panic::add() } else { a }
628 }
629
630 /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
631 /// cannot occur.
632 ///
633 /// Calling `x.unchecked_add(y)` is semantically equivalent to calling
634 /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
635 ///
636 /// If you're just trying to avoid the panic in debug mode, then **do not**
637 /// use this. Instead, you're looking for [`wrapping_add`].
638 ///
639 /// # Safety
640 ///
641 /// This results in undefined behavior when overflow occurs, i.e. when
642 /// [`checked_add`] would return `None`.
643 ///
644 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
645 #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
646 #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
647 #[stable(feature = "unchecked_math", since = "1.79.0")]
648 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
649 #[must_use = "this returns the result of the operation, \
650 without modifying the original"]
651 #[inline(always)]
652 #[track_caller]
653 pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
654 assert_unsafe_precondition!(
655 check_language_ub,
656 concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
657 (
658 lhs: $SelfT = self,
659 rhs: $SelfT = rhs,
660 ) => !lhs.overflowing_add(rhs).1,
661 );
662
663 // SAFETY: this is guaranteed to be safe by the caller.
664 unsafe {
665 intrinsics::unchecked_add(self, rhs)
666 }
667 }
668
669 /// Checked addition with an unsigned integer. Computes `self + rhs`,
670 /// returning `None` if overflow occurred.
671 ///
672 /// # Examples
673 ///
674 /// ```
675 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")]
676 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")]
677 /// ```
678 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
679 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
680 #[must_use = "this returns the result of the operation, \
681 without modifying the original"]
682 #[inline]
683 pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
684 let (a, b) = self.overflowing_add_unsigned(rhs);
685 if intrinsics::unlikely(b) { None } else { Some(a) }
686 }
687
688 /// Strict addition with an unsigned integer. Computes `self + rhs`,
689 /// panicking if overflow occurred.
690 ///
691 /// # Panics
692 ///
693 /// ## Overflow behavior
694 ///
695 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
696 ///
697 /// # Examples
698 ///
699 /// ```
700 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_unsigned(2), 3);")]
701 /// ```
702 ///
703 /// The following panics because of overflow:
704 ///
705 /// ```should_panic
706 #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_unsigned(3);")]
707 /// ```
708 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
709 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
710 #[must_use = "this returns the result of the operation, \
711 without modifying the original"]
712 #[inline]
713 #[track_caller]
714 pub const fn strict_add_unsigned(self, rhs: $UnsignedT) -> Self {
715 let (a, b) = self.overflowing_add_unsigned(rhs);
716 if b { imp::overflow_panic::add() } else { a }
717 }
718
719 /// Checked integer subtraction. Computes `self - rhs`, returning `None` if
720 /// overflow occurred.
721 ///
722 /// # Examples
723 ///
724 /// ```
725 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")]
726 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")]
727 /// ```
728 #[stable(feature = "rust1", since = "1.0.0")]
729 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
730 #[must_use = "this returns the result of the operation, \
731 without modifying the original"]
732 #[inline]
733 pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
734 let (a, b) = self.overflowing_sub(rhs);
735 if intrinsics::unlikely(b) { None } else { Some(a) }
736 }
737
738 /// Strict integer subtraction. Computes `self - rhs`, panicking if
739 /// overflow occurred.
740 ///
741 /// # Panics
742 ///
743 /// ## Overflow behavior
744 ///
745 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
746 ///
747 /// # Examples
748 ///
749 /// ```
750 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).strict_sub(1), ", stringify!($SelfT), "::MIN + 1);")]
751 /// ```
752 ///
753 /// The following panics because of overflow:
754 ///
755 /// ```should_panic
756 #[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub(3);")]
757 /// ```
758 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
759 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
760 #[must_use = "this returns the result of the operation, \
761 without modifying the original"]
762 #[inline]
763 #[track_caller]
764 pub const fn strict_sub(self, rhs: Self) -> Self {
765 let (a, b) = self.overflowing_sub(rhs);
766 if b { imp::overflow_panic::sub() } else { a }
767 }
768
769 /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
770 /// cannot occur.
771 ///
772 /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
773 /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
774 ///
775 /// If you're just trying to avoid the panic in debug mode, then **do not**
776 /// use this. Instead, you're looking for [`wrapping_sub`].
777 ///
778 /// # Safety
779 ///
780 /// This results in undefined behavior when overflow occurs, i.e. when
781 /// [`checked_sub`] would return `None`.
782 ///
783 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
784 #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
785 #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
786 #[stable(feature = "unchecked_math", since = "1.79.0")]
787 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
788 #[must_use = "this returns the result of the operation, \
789 without modifying the original"]
790 #[inline(always)]
791 #[track_caller]
792 pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
793 assert_unsafe_precondition!(
794 check_language_ub,
795 concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
796 (
797 lhs: $SelfT = self,
798 rhs: $SelfT = rhs,
799 ) => !lhs.overflowing_sub(rhs).1,
800 );
801
802 // SAFETY: this is guaranteed to be safe by the caller.
803 unsafe {
804 intrinsics::unchecked_sub(self, rhs)
805 }
806 }
807
808 /// Checked subtraction with an unsigned integer. Computes `self - rhs`,
809 /// returning `None` if overflow occurred.
810 ///
811 /// # Examples
812 ///
813 /// ```
814 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")]
815 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")]
816 /// ```
817 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
818 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
819 #[must_use = "this returns the result of the operation, \
820 without modifying the original"]
821 #[inline]
822 pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
823 let (a, b) = self.overflowing_sub_unsigned(rhs);
824 if intrinsics::unlikely(b) { None } else { Some(a) }
825 }
826
827 /// Strict subtraction with an unsigned integer. Computes `self - rhs`,
828 /// panicking if overflow occurred.
829 ///
830 /// # Panics
831 ///
832 /// ## Overflow behavior
833 ///
834 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
835 ///
836 /// # Examples
837 ///
838 /// ```
839 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub_unsigned(2), -1);")]
840 /// ```
841 ///
842 /// The following panics because of overflow:
843 ///
844 /// ```should_panic
845 #[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub_unsigned(3);")]
846 /// ```
847 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
848 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
849 #[must_use = "this returns the result of the operation, \
850 without modifying the original"]
851 #[inline]
852 #[track_caller]
853 pub const fn strict_sub_unsigned(self, rhs: $UnsignedT) -> Self {
854 let (a, b) = self.overflowing_sub_unsigned(rhs);
855 if b { imp::overflow_panic::sub() } else { a }
856 }
857
858 /// Checked integer multiplication. Computes `self * rhs`, returning `None` if
859 /// overflow occurred.
860 ///
861 /// # Examples
862 ///
863 /// ```
864 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")]
865 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
866 /// ```
867 #[stable(feature = "rust1", since = "1.0.0")]
868 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
869 #[must_use = "this returns the result of the operation, \
870 without modifying the original"]
871 #[inline]
872 pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
873 let (a, b) = self.overflowing_mul(rhs);
874 if intrinsics::unlikely(b) { None } else { Some(a) }
875 }
876
877 /// Strict integer multiplication. Computes `self * rhs`, panicking if
878 /// overflow occurred.
879 ///
880 /// # Panics
881 ///
882 /// ## Overflow behavior
883 ///
884 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
885 ///
886 /// # Examples
887 ///
888 /// ```
889 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.strict_mul(1), ", stringify!($SelfT), "::MAX);")]
890 /// ```
891 ///
892 /// The following panics because of overflow:
893 ///
894 /// ``` should_panic
895 #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
896 /// ```
897 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
898 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
899 #[must_use = "this returns the result of the operation, \
900 without modifying the original"]
901 #[inline]
902 #[track_caller]
903 pub const fn strict_mul(self, rhs: Self) -> Self {
904 let (a, b) = self.overflowing_mul(rhs);
905 if b { imp::overflow_panic::mul() } else { a }
906 }
907
908 /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
909 /// cannot occur.
910 ///
911 /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
912 /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
913 ///
914 /// If you're just trying to avoid the panic in debug mode, then **do not**
915 /// use this. Instead, you're looking for [`wrapping_mul`].
916 ///
917 /// # Safety
918 ///
919 /// This results in undefined behavior when overflow occurs, i.e. when
920 /// [`checked_mul`] would return `None`.
921 ///
922 /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
923 #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
924 #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
925 #[stable(feature = "unchecked_math", since = "1.79.0")]
926 #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
927 #[must_use = "this returns the result of the operation, \
928 without modifying the original"]
929 #[inline(always)]
930 #[track_caller]
931 pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
932 assert_unsafe_precondition!(
933 check_language_ub,
934 concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
935 (
936 lhs: $SelfT = self,
937 rhs: $SelfT = rhs,
938 ) => !lhs.overflowing_mul(rhs).1,
939 );
940
941 // SAFETY: this is guaranteed to be safe by the caller.
942 unsafe {
943 intrinsics::unchecked_mul(self, rhs)
944 }
945 }
946
947 /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
948 /// or the division results in overflow.
949 ///
950 /// # Examples
951 ///
952 /// ```
953 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")]
954 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")]
955 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")]
956 /// ```
957 #[stable(feature = "rust1", since = "1.0.0")]
958 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
959 #[must_use = "this returns the result of the operation, \
960 without modifying the original"]
961 #[inline]
962 pub const fn checked_div(self, rhs: Self) -> Option<Self> {
963 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
964 None
965 } else {
966 // SAFETY: div by zero and by INT_MIN have been checked above
967 Some(unsafe { intrinsics::unchecked_div(self, rhs) })
968 }
969 }
970
971 /// Strict integer division. Computes `self / rhs`, panicking
972 /// if overflow occurred.
973 ///
974 /// # Panics
975 ///
976 /// This function will panic if `rhs` is zero.
977 ///
978 /// ## Overflow behavior
979 ///
980 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
981 ///
982 /// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
983 /// [`MIN`](Self::MIN) is the negative minimal value for the type); the result of this is `-MIN`, a positive value
984 /// that is too large to represent in the type.
985 ///
986 /// Note that this is equivalent to normal division: `MIN / -1` will also panic both in
987 /// debug and release builds.
988 ///
989 /// # Examples
990 ///
991 /// ```
992 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div(-1), ", stringify!($Max), ");")]
993 /// ```
994 ///
995 /// The following panics because of overflow:
996 ///
997 /// ```should_panic
998 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div(-1);")]
999 /// ```
1000 ///
1001 /// The following panics because of division by zero:
1002 ///
1003 /// ```should_panic
1004 #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
1005 /// ```
1006 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1007 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1008 #[must_use = "this returns the result of the operation, \
1009 without modifying the original"]
1010 #[inline]
1011 #[track_caller]
1012 pub const fn strict_div(self, rhs: Self) -> Self {
1013 // Normal division already checks for "div-by-minus-1".
1014 self / rhs
1015 }
1016
1017 /// Checked Euclidean division. Computes `self.div_euclid(rhs)`,
1018 /// returning `None` if `rhs == 0` or the division results in overflow.
1019 ///
1020 /// # Examples
1021 ///
1022 /// ```
1023 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")]
1024 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")]
1025 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")]
1026 /// ```
1027 #[stable(feature = "euclidean_division", since = "1.38.0")]
1028 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1029 #[must_use = "this returns the result of the operation, \
1030 without modifying the original"]
1031 #[inline]
1032 pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
1033 // Using `&` helps LLVM see that it is the same check made in division.
1034 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
1035 None
1036 } else {
1037 Some(self.div_euclid(rhs))
1038 }
1039 }
1040
1041 /// Strict Euclidean division. Computes `self.div_euclid(rhs)`, panicking
1042 /// if overflow occurred.
1043 ///
1044 /// # Panics
1045 ///
1046 /// This function will panic if `rhs` is zero.
1047 ///
1048 /// ## Overflow behavior
1049 ///
1050 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1051 ///
1052 /// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
1053 /// [`MIN`](Self::MIN) is the negative minimal value for the type); the result of this is `-MIN`, a positive value
1054 /// that is too large to represent in the type.
1055 ///
1056 /// Note that this is equivalent to `div_euclid`: `MIN.div_euclid(-1)` will also panic both
1057 /// in debug and release builds.
1058 ///
1059 /// # Examples
1060 ///
1061 /// ```
1062 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div_euclid(-1), ", stringify!($Max), ");")]
1063 /// ```
1064 ///
1065 /// The following panics because of overflow:
1066 ///
1067 /// ```should_panic
1068 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div_euclid(-1);")]
1069 /// ```
1070 ///
1071 /// The following panics because of division by zero:
1072 ///
1073 /// ```should_panic
1074 #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
1075 /// ```
1076 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1077 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1078 #[must_use = "this returns the result of the operation, \
1079 without modifying the original"]
1080 #[inline]
1081 #[track_caller]
1082 pub const fn strict_div_euclid(self, rhs: Self) -> Self {
1083 // Normal `div_euclid` already checks for "div-by-minus-1".
1084 self.div_euclid(rhs)
1085 }
1086
1087 /// Checked integer division without remainder. Computes `self / rhs`,
1088 /// returning `None` if `rhs == 0`, the division results in overflow,
1089 /// or `self % rhs != 0`.
1090 ///
1091 /// # Examples
1092 ///
1093 /// ```
1094 /// #![feature(exact_div)]
1095 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_exact(-1), Some(", stringify!($Max), "));")]
1096 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_div_exact(2), None);")]
1097 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_exact(-1), None);")]
1098 #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_exact(0), None);")]
1099 /// ```
1100 #[unstable(
1101 feature = "exact_div",
1102 issue = "139911",
1103 )]
1104 #[must_use = "this returns the result of the operation, \
1105 without modifying the original"]
1106 #[inline]
1107 pub const fn checked_div_exact(self, rhs: Self) -> Option<Self> {
1108 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
1109 None
1110 } else {
1111 // SAFETY: division by zero and overflow are checked above
1112 unsafe {
1113 if intrinsics::unlikely(intrinsics::unchecked_rem(self, rhs) != 0) {
1114 None
1115 } else {
1116 Some(intrinsics::exact_div(self, rhs))
1117 }
1118 }
1119 }
1120 }
1121
1122 /// Integer division without remainder. Computes `self / rhs`, returning `None` if `self % rhs != 0`.
1123 ///
1124 /// # Panics
1125 ///
1126 /// This function will panic if `rhs == 0`.
1127 ///
1128 /// ## Overflow behavior
1129 ///
1130 /// On overflow, this function will panic if overflow checks are enabled (default in debug
1131 /// mode) and wrap if overflow checks are disabled (default in release mode).
1132 ///
1133 /// # Examples
1134 ///
1135 /// ```
1136 /// #![feature(exact_div)]
1137 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(2), Some(32));")]
1138 #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(32), Some(2));")]
1139 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).div_exact(-1), Some(", stringify!($Max), "));")]
1140 #[doc = concat!("assert_eq!(65", stringify!($SelfT), ".div_exact(2), None);")]
1141 /// ```
1142 /// ```should_panic
1143 /// #![feature(exact_div)]
1144 #[doc = concat!("let _ = 64", stringify!($SelfT),".div_exact(0);")]
1145 /// ```
1146 /// ```should_panic
1147 /// #![feature(exact_div)]
1148 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.div_exact(-1);")]
1149 /// ```
1150 #[unstable(
1151 feature = "exact_div",
1152 issue = "139911",
1153 )]
1154 #[must_use = "this returns the result of the operation, \
1155 without modifying the original"]
1156 #[inline]
1157 #[rustc_inherit_overflow_checks]
1158 pub const fn div_exact(self, rhs: Self) -> Option<Self> {
1159 if self % rhs != 0 {
1160 None
1161 } else {
1162 Some(self / rhs)
1163 }
1164 }
1165
1166 /// Unchecked integer division without remainder. Computes `self / rhs`.
1167 ///
1168 /// # Safety
1169 ///
1170 /// This results in undefined behavior when `rhs == 0`, `self % rhs != 0`, or
1171 #[doc = concat!("`self == ", stringify!($SelfT), "::MIN && rhs == -1`,")]
1172 /// i.e. when [`checked_div_exact`](Self::checked_div_exact) would return `None`.
1173 #[unstable(
1174 feature = "exact_div",
1175 issue = "139911",
1176 )]
1177 #[must_use = "this returns the result of the operation, \
1178 without modifying the original"]
1179 #[inline]
1180 pub const unsafe fn unchecked_div_exact(self, rhs: Self) -> Self {
1181 assert_unsafe_precondition!(
1182 check_language_ub,
1183 concat!(stringify!($SelfT), "::unchecked_div_exact cannot overflow, divide by zero, or leave a remainder"),
1184 (
1185 lhs: $SelfT = self,
1186 rhs: $SelfT = rhs,
1187 ) => rhs != 0 && lhs % rhs == 0 && (lhs != <$SelfT>::MIN || rhs != -1),
1188 );
1189 // SAFETY: Same precondition
1190 unsafe { intrinsics::exact_div(self, rhs) }
1191 }
1192
1193 /// Checked integer remainder. Computes `self % rhs`, returning `None` if
1194 /// `rhs == 0` or the division results in overflow.
1195 ///
1196 /// # Examples
1197 ///
1198 /// ```
1199 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
1200 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
1201 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")]
1202 /// ```
1203 #[stable(feature = "wrapping", since = "1.7.0")]
1204 #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1205 #[must_use = "this returns the result of the operation, \
1206 without modifying the original"]
1207 #[inline]
1208 pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
1209 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
1210 None
1211 } else {
1212 // SAFETY: div by zero and by INT_MIN have been checked above
1213 Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
1214 }
1215 }
1216
1217 /// Strict integer remainder. Computes `self % rhs`, panicking if
1218 /// the division results in overflow.
1219 ///
1220 /// # Panics
1221 ///
1222 /// This function will panic if `rhs` is zero.
1223 ///
1224 /// ## Overflow behavior
1225 ///
1226 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1227 ///
1228 /// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
1229 /// signed type (where [`MIN`](Self::MIN) is the negative minimal value), which is invalid due to implementation artifacts.
1230 ///
1231 /// # Examples
1232 ///
1233 /// ```
1234 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem(2), 1);")]
1235 /// ```
1236 ///
1237 /// The following panics because of division by zero:
1238 ///
1239 /// ```should_panic
1240 #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
1241 /// ```
1242 ///
1243 /// The following panics because of overflow:
1244 ///
1245 /// ```should_panic
1246 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem(-1);")]
1247 /// ```
1248 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1249 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1250 #[must_use = "this returns the result of the operation, \
1251 without modifying the original"]
1252 #[inline]
1253 #[track_caller]
1254 pub const fn strict_rem(self, rhs: Self) -> Self {
1255 let (a, b) = self.overflowing_rem(rhs);
1256 if b { imp::overflow_panic::rem() } else { a }
1257 }
1258
1259 /// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None`
1260 /// if `rhs == 0` or the division results in overflow.
1261 ///
1262 /// # Examples
1263 ///
1264 /// ```
1265 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
1266 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
1267 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")]
1268 /// ```
1269 #[stable(feature = "euclidean_division", since = "1.38.0")]
1270 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1271 #[must_use = "this returns the result of the operation, \
1272 without modifying the original"]
1273 #[inline]
1274 pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
1275 // Using `&` helps LLVM see that it is the same check made in division.
1276 if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
1277 None
1278 } else {
1279 Some(self.rem_euclid(rhs))
1280 }
1281 }
1282
1283 /// Strict Euclidean remainder. Computes `self.rem_euclid(rhs)`, panicking if
1284 /// the division results in overflow.
1285 ///
1286 /// # Panics
1287 ///
1288 /// This function will panic if `rhs` is zero.
1289 ///
1290 /// ## Overflow behavior
1291 ///
1292 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1293 ///
1294 /// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
1295 /// signed type (where [`MIN`](Self::MIN) is the negative minimal value), which is invalid due to implementation artifacts.
1296 ///
1297 /// # Examples
1298 ///
1299 /// ```
1300 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem_euclid(2), 1);")]
1301 /// ```
1302 ///
1303 /// The following panics because of division by zero:
1304 ///
1305 /// ```should_panic
1306 #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
1307 /// ```
1308 ///
1309 /// The following panics because of overflow:
1310 ///
1311 /// ```should_panic
1312 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem_euclid(-1);")]
1313 /// ```
1314 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1315 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1316 #[must_use = "this returns the result of the operation, \
1317 without modifying the original"]
1318 #[inline]
1319 #[track_caller]
1320 pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
1321 let (a, b) = self.overflowing_rem_euclid(rhs);
1322 if b { imp::overflow_panic::rem() } else { a }
1323 }
1324
1325 /// Disjoint, bitwise or. Computes `self | rhs`, assuming no overlapping one bits.
1326 ///
1327 /// Practically, this requires that `self | rhs`, `self ^ rhs`, and `self + rhs` all
1328 /// yield the same result, allowing for any of the three to be emitted in codegen --
1329 /// depending on whichever is cheapest.
1330 ///
1331 /// # Examples
1332 ///
1333 /// ```
1334 /// #![feature(disjoint_bitor)]
1335 ///
1336 /// assert_eq!(
1337 /// // SAFETY: `1` and `-2` have no ones in common.
1338 #[doc = concat!(" unsafe { 1_", stringify!($SelfT), ".unchecked_disjoint_bitor(-2) },")]
1339 /// -1,
1340 /// );
1341 /// ```
1342 ///
1343 /// # Safety
1344 ///
1345 /// This results in undefined behaviour if `self` and `rhs` have any overlapping one
1346 /// bits, i.e. `lhs & rhs` must be zero.
1347 ///
1348 /// Notably, this prevents both values from being negative.
1349 #[unstable(feature = "disjoint_bitor", issue = "135758")]
1350 #[rustc_const_unstable(feature = "disjoint_bitor", issue = "135758")]
1351 #[must_use = "this returns the result of the operation, \
1352 without modifying the original"]
1353 #[inline]
1354 pub const unsafe fn unchecked_disjoint_bitor(self, rhs: Self) -> Self {
1355 assert_unsafe_precondition!(
1356 check_language_ub,
1357 concat!(stringify!($SelfT), "::unchecked_disjoint_bitor cannot bitor overlapping ones"),
1358 (
1359 lhs: $SelfT = self,
1360 rhs: $SelfT = rhs,
1361 ) => (lhs & rhs) == 0,
1362 );
1363
1364 // SAFETY: Same precondition.
1365 unsafe { intrinsics::disjoint_bitor(self, rhs) }
1366 }
1367
1368 /// Checked negation. Computes `-self`, returning `None` if `self == MIN`.
1369 ///
1370 /// # Examples
1371 ///
1372 /// ```
1373 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")]
1374 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")]
1375 /// ```
1376 #[stable(feature = "wrapping", since = "1.7.0")]
1377 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1378 #[must_use = "this returns the result of the operation, \
1379 without modifying the original"]
1380 #[inline]
1381 pub const fn checked_neg(self) -> Option<Self> {
1382 let (a, b) = self.overflowing_neg();
1383 if intrinsics::unlikely(b) { None } else { Some(a) }
1384 }
1385
1386 /// Unchecked negation. Computes `-self`, assuming overflow cannot occur.
1387 ///
1388 /// # Safety
1389 ///
1390 /// This results in undefined behavior when
1391 #[doc = concat!("`self == ", stringify!($SelfT), "::MIN`,")]
1392 /// i.e. when [`checked_neg`] would return `None`.
1393 ///
1394 #[doc = concat!("[`checked_neg`]: ", stringify!($SelfT), "::checked_neg")]
1395 #[stable(feature = "unchecked_neg", since = "1.93.0")]
1396 #[rustc_const_stable(feature = "unchecked_neg", since = "1.93.0")]
1397 #[must_use = "this returns the result of the operation, \
1398 without modifying the original"]
1399 #[inline(always)]
1400 #[track_caller]
1401 pub const unsafe fn unchecked_neg(self) -> Self {
1402 assert_unsafe_precondition!(
1403 check_language_ub,
1404 concat!(stringify!($SelfT), "::unchecked_neg cannot overflow"),
1405 (
1406 lhs: $SelfT = self,
1407 ) => !lhs.overflowing_neg().1,
1408 );
1409
1410 // SAFETY: this is guaranteed to be safe by the caller.
1411 unsafe {
1412 intrinsics::unchecked_sub(0, self)
1413 }
1414 }
1415
1416 /// Strict negation. Computes `-self`, panicking if `self == MIN`.
1417 ///
1418 /// # Panics
1419 ///
1420 /// ## Overflow behavior
1421 ///
1422 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1423 ///
1424 /// # Examples
1425 ///
1426 /// ```
1427 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_neg(), -5);")]
1428 /// ```
1429 ///
1430 /// The following panics because of overflow:
1431 ///
1432 /// ```should_panic
1433 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_neg();")]
1434 /// ```
1435 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1436 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1437 #[must_use = "this returns the result of the operation, \
1438 without modifying the original"]
1439 #[inline]
1440 #[track_caller]
1441 pub const fn strict_neg(self) -> Self {
1442 let (a, b) = self.overflowing_neg();
1443 if b { imp::overflow_panic::neg() } else { a }
1444 }
1445
1446 /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger
1447 /// than or equal to the number of bits in `self`.
1448 ///
1449 /// # Examples
1450 ///
1451 /// ```
1452 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
1453 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")]
1454 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
1455 /// ```
1456 #[stable(feature = "wrapping", since = "1.7.0")]
1457 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1458 #[must_use = "this returns the result of the operation, \
1459 without modifying the original"]
1460 #[inline]
1461 pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
1462 // Not using overflowing_shl as that's a wrapping shift
1463 if rhs < Self::BITS {
1464 // SAFETY: just checked the RHS is in-range
1465 Some(unsafe { self.unchecked_shl(rhs) })
1466 } else {
1467 None
1468 }
1469 }
1470
1471 /// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
1472 /// than or equal to the number of bits in `self`.
1473 ///
1474 /// # Panics
1475 ///
1476 /// ## Overflow behavior
1477 ///
1478 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1479 ///
1480 /// # Examples
1481 ///
1482 /// ```
1483 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
1484 /// ```
1485 ///
1486 /// The following panics because of overflow:
1487 ///
1488 /// ```should_panic
1489 #[doc = concat!("let _ = 0x1", stringify!($SelfT), ".strict_shl(129);")]
1490 /// ```
1491 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1492 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1493 #[must_use = "this returns the result of the operation, \
1494 without modifying the original"]
1495 #[inline]
1496 #[track_caller]
1497 pub const fn strict_shl(self, rhs: u32) -> Self {
1498 let (a, b) = self.overflowing_shl(rhs);
1499 if b { imp::overflow_panic::shl() } else { a }
1500 }
1501
1502 /// Unchecked shift left. Computes `self << rhs`, assuming that
1503 /// `rhs` is less than the number of bits in `self`.
1504 ///
1505 /// # Safety
1506 ///
1507 /// This results in undefined behavior if `rhs` is larger than
1508 /// or equal to the number of bits in `self`,
1509 /// i.e. when [`checked_shl`] would return `None`.
1510 ///
1511 #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
1512 #[stable(feature = "unchecked_shifts", since = "1.93.0")]
1513 #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
1514 #[must_use = "this returns the result of the operation, \
1515 without modifying the original"]
1516 #[inline(always)]
1517 #[track_caller]
1518 pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
1519 assert_unsafe_precondition!(
1520 check_language_ub,
1521 concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
1522 (
1523 rhs: u32 = rhs,
1524 ) => rhs < <$ActualT>::BITS,
1525 );
1526
1527 // SAFETY: this is guaranteed to be safe by the caller.
1528 unsafe {
1529 intrinsics::unchecked_shl(self, rhs)
1530 }
1531 }
1532
1533 /// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
1534 ///
1535 /// If `rhs` is larger or equal to the number of bits in `self`,
1536 /// the entire value is shifted out, and `0` is returned.
1537 ///
1538 /// # Examples
1539 ///
1540 /// ```
1541 #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
1542 #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(129), 0);")]
1543 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(0), 0b101);")]
1544 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(1), 0b1010);")]
1545 #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(2), 0b10100);")]
1546 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(", stringify!($BITS), "), 0);")]
1547 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
1548 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(", stringify!($BITS), "), 0);")]
1549 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
1550 /// ```
1551 #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1552 #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1553 #[must_use = "this returns the result of the operation, \
1554 without modifying the original"]
1555 #[inline]
1556 pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
1557 if rhs < Self::BITS {
1558 // SAFETY:
1559 // rhs is just checked to be in-range above
1560 unsafe { self.unchecked_shl(rhs) }
1561 } else {
1562 0
1563 }
1564 }
1565
1566 /// Exact shift left. Computes `self << rhs` as long as it can be reversed losslessly.
1567 ///
1568 /// Returns `None` if any bits that would be shifted out differ from the resulting sign bit
1569 /// or if `rhs` >=
1570 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1571 /// Otherwise, returns `Some(self << rhs)`.
1572 ///
1573 /// # Examples
1574 ///
1575 /// ```
1576 /// #![feature(exact_bitshifts)]
1577 ///
1578 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(4), Some(0x10));")]
1579 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 2), Some(1 << ", stringify!($SelfT), "::BITS - 2));")]
1580 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
1581 #[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 2), Some(-0x2 << ", stringify!($SelfT), "::BITS - 2));")]
1582 #[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
1583 /// ```
1584 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1585 #[must_use = "this returns the result of the operation, \
1586 without modifying the original"]
1587 #[inline]
1588 pub const fn shl_exact(self, rhs: u32) -> Option<$SelfT> {
1589 if rhs < self.leading_zeros() || rhs < self.leading_ones() {
1590 // SAFETY: rhs is checked above
1591 Some(unsafe { self.unchecked_shl(rhs) })
1592 } else {
1593 None
1594 }
1595 }
1596
1597 /// Unchecked exact shift left. Computes `self << rhs`, assuming the operation can be
1598 /// losslessly reversed and `rhs` cannot be larger than
1599 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1600 ///
1601 /// # Safety
1602 ///
1603 /// This results in undefined behavior when `rhs >= self.leading_zeros() && rhs >=
1604 /// self.leading_ones()` i.e. when
1605 #[doc = concat!("[`", stringify!($SelfT), "::shl_exact`]")]
1606 /// would return `None`.
1607 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1608 #[must_use = "this returns the result of the operation, \
1609 without modifying the original"]
1610 #[inline]
1611 pub const unsafe fn unchecked_shl_exact(self, rhs: u32) -> $SelfT {
1612 assert_unsafe_precondition!(
1613 check_library_ub,
1614 concat!(stringify!($SelfT), "::unchecked_shl_exact cannot shift out bits that would change the value of the first bit"),
1615 (
1616 zeros: u32 = self.leading_zeros(),
1617 ones: u32 = self.leading_ones(),
1618 rhs: u32 = rhs,
1619 ) => rhs < zeros || rhs < ones,
1620 );
1621
1622 // SAFETY: this is guaranteed to be safe by the caller
1623 unsafe { self.unchecked_shl(rhs) }
1624 }
1625
1626 /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is
1627 /// larger than or equal to the number of bits in `self`.
1628 ///
1629 /// # Examples
1630 ///
1631 /// ```
1632 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
1633 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")]
1634 /// ```
1635 #[stable(feature = "wrapping", since = "1.7.0")]
1636 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1637 #[must_use = "this returns the result of the operation, \
1638 without modifying the original"]
1639 #[inline]
1640 pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
1641 // Not using overflowing_shr as that's a wrapping shift
1642 if rhs < Self::BITS {
1643 // SAFETY: just checked the RHS is in-range
1644 Some(unsafe { self.unchecked_shr(rhs) })
1645 } else {
1646 None
1647 }
1648 }
1649
1650 /// Strict shift right. Computes `self >> rhs`, panicking if `rhs` is
1651 /// larger than or equal to the number of bits in `self`.
1652 ///
1653 /// # Panics
1654 ///
1655 /// ## Overflow behavior
1656 ///
1657 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1658 ///
1659 /// # Examples
1660 ///
1661 /// ```
1662 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
1663 /// ```
1664 ///
1665 /// The following panics because of overflow:
1666 ///
1667 /// ```should_panic
1668 #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(128);")]
1669 /// ```
1670 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1671 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1672 #[must_use = "this returns the result of the operation, \
1673 without modifying the original"]
1674 #[inline]
1675 #[track_caller]
1676 pub const fn strict_shr(self, rhs: u32) -> Self {
1677 let (a, b) = self.overflowing_shr(rhs);
1678 if b { imp::overflow_panic::shr() } else { a }
1679 }
1680
1681 /// Unchecked shift right. Computes `self >> rhs`, assuming that
1682 /// `rhs` is less than the number of bits in `self`.
1683 ///
1684 /// # Safety
1685 ///
1686 /// This results in undefined behavior if `rhs` is larger than
1687 /// or equal to the number of bits in `self`,
1688 /// i.e. when [`checked_shr`] would return `None`.
1689 ///
1690 #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
1691 #[stable(feature = "unchecked_shifts", since = "1.93.0")]
1692 #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
1693 #[must_use = "this returns the result of the operation, \
1694 without modifying the original"]
1695 #[inline(always)]
1696 #[track_caller]
1697 pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
1698 assert_unsafe_precondition!(
1699 check_language_ub,
1700 concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
1701 (
1702 rhs: u32 = rhs,
1703 ) => rhs < <$ActualT>::BITS,
1704 );
1705
1706 // SAFETY: this is guaranteed to be safe by the caller.
1707 unsafe {
1708 intrinsics::unchecked_shr(self, rhs)
1709 }
1710 }
1711
1712 /// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
1713 ///
1714 /// If `rhs` is larger or equal to the number of bits in `self`,
1715 /// the entire value is shifted out, which yields `0` for a positive number,
1716 /// and `-1` for a negative number.
1717 ///
1718 /// # Examples
1719 ///
1720 /// ```
1721 #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
1722 #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(129), 0);")]
1723 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.unbounded_shr(129), -1);")]
1724 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(0), 0b1010);")]
1725 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(1), 0b101);")]
1726 #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(2), 0b10);")]
1727 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(", stringify!($BITS), "), 0);")]
1728 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
1729 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(", stringify!($BITS), "), -1);")]
1730 #[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), -1);")]
1731 /// ```
1732 #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1733 #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1734 #[must_use = "this returns the result of the operation, \
1735 without modifying the original"]
1736 #[inline]
1737 pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
1738 if rhs < Self::BITS {
1739 // SAFETY:
1740 // rhs is just checked to be in-range above
1741 unsafe { self.unchecked_shr(rhs) }
1742 } else {
1743 // A shift by `Self::BITS-1` suffices for signed integers, because the sign bit is copied for each of the shifted bits.
1744
1745 // SAFETY:
1746 // `Self::BITS-1` is guaranteed to be less than `Self::BITS`
1747 unsafe { self.unchecked_shr(Self::BITS - 1) }
1748 }
1749 }
1750
1751 /// Exact shift right. Computes `self >> rhs` as long as it can be reversed losslessly.
1752 ///
1753 /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
1754 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1755 /// Otherwise, returns `Some(self >> rhs)`.
1756 ///
1757 /// # Examples
1758 ///
1759 /// ```
1760 /// #![feature(exact_bitshifts)]
1761 ///
1762 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(4), Some(0x1));")]
1763 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(5), None);")]
1764 /// ```
1765 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1766 #[must_use = "this returns the result of the operation, \
1767 without modifying the original"]
1768 #[inline]
1769 pub const fn shr_exact(self, rhs: u32) -> Option<$SelfT> {
1770 if rhs <= self.trailing_zeros() && rhs < <$SelfT>::BITS {
1771 // SAFETY: rhs is checked above
1772 Some(unsafe { self.unchecked_shr(rhs) })
1773 } else {
1774 None
1775 }
1776 }
1777
1778 /// Unchecked exact shift right. Computes `self >> rhs`, assuming the operation can be
1779 /// losslessly reversed and `rhs` cannot be larger than
1780 #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1781 ///
1782 /// # Safety
1783 ///
1784 /// This results in undefined behavior when `rhs > self.trailing_zeros() || rhs >=
1785 #[doc = concat!(stringify!($SelfT), "::BITS`")]
1786 /// i.e. when
1787 #[doc = concat!("[`", stringify!($SelfT), "::shr_exact`]")]
1788 /// would return `None`.
1789 #[unstable(feature = "exact_bitshifts", issue = "144336")]
1790 #[must_use = "this returns the result of the operation, \
1791 without modifying the original"]
1792 #[inline]
1793 pub const unsafe fn unchecked_shr_exact(self, rhs: u32) -> $SelfT {
1794 assert_unsafe_precondition!(
1795 check_library_ub,
1796 concat!(stringify!($SelfT), "::unchecked_shr_exact cannot shift out non-zero bits"),
1797 (
1798 zeros: u32 = self.trailing_zeros(),
1799 bits: u32 = <$SelfT>::BITS,
1800 rhs: u32 = rhs,
1801 ) => rhs <= zeros && rhs < bits,
1802 );
1803
1804 // SAFETY: this is guaranteed to be safe by the caller
1805 unsafe { self.unchecked_shr(rhs) }
1806 }
1807
1808 /// Checked absolute value. Computes `self.abs()`, returning `None` if
1809 /// `self == MIN`.
1810 ///
1811 /// # Examples
1812 ///
1813 /// ```
1814 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")]
1815 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")]
1816 /// ```
1817 #[stable(feature = "no_panic_abs", since = "1.13.0")]
1818 #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1819 #[must_use = "this returns the result of the operation, \
1820 without modifying the original"]
1821 #[inline]
1822 pub const fn checked_abs(self) -> Option<Self> {
1823 if self.is_negative() {
1824 self.checked_neg()
1825 } else {
1826 Some(self)
1827 }
1828 }
1829
1830 /// Strict absolute value. Computes `self.abs()`, panicking if
1831 /// `self == MIN`.
1832 ///
1833 /// # Panics
1834 ///
1835 /// ## Overflow behavior
1836 ///
1837 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1838 ///
1839 /// # Examples
1840 ///
1841 /// ```
1842 #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").strict_abs(), 5);")]
1843 /// ```
1844 ///
1845 /// The following panics because of overflow:
1846 ///
1847 /// ```should_panic
1848 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_abs();")]
1849 /// ```
1850 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1851 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1852 #[must_use = "this returns the result of the operation, \
1853 without modifying the original"]
1854 #[inline]
1855 #[track_caller]
1856 pub const fn strict_abs(self) -> Self {
1857 if self.is_negative() {
1858 self.strict_neg()
1859 } else {
1860 self
1861 }
1862 }
1863
1864 /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
1865 /// overflow occurred.
1866 ///
1867 /// # Examples
1868 ///
1869 /// ```
1870 #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")]
1871 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".checked_pow(0), Some(1));")]
1872 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
1873 /// ```
1874
1875 #[stable(feature = "no_panic_pow", since = "1.34.0")]
1876 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
1877 #[must_use = "this returns the result of the operation, \
1878 without modifying the original"]
1879 #[inline]
1880 pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
1881 let mut base = self;
1882 let mut acc: Self = 1;
1883
1884 if intrinsics::is_val_statically_known(base) && base.unsigned_abs().is_power_of_two() {
1885 let k = base.unsigned_abs().ilog2();
1886 let shift = try_opt!(k.checked_mul(exp));
1887 return if base < 0 && (exp % 2) == 1 {
1888 (-1 as Self).shl_exact(shift)
1889 } else {
1890 (1 as Self).shl_exact(shift)
1891 }
1892 }
1893
1894 if exp == 0 {
1895 return Some(1);
1896 }
1897
1898 if intrinsics::is_val_statically_known(exp) {
1899 while exp > 1 {
1900 if (exp & 1) == 1 {
1901 acc = try_opt!(acc.checked_mul(base));
1902 }
1903 exp /= 2;
1904 base = try_opt!(base.checked_mul(base));
1905 }
1906
1907 // since exp!=0, finally the exp must be 1.
1908 // Deal with the final bit of the exponent separately, since
1909 // squaring the base afterwards is not necessary and may cause a
1910 // needless overflow.
1911 return acc.checked_mul(base);
1912 }
1913
1914 loop {
1915 if (exp & 1) == 1 {
1916 acc = try_opt!(acc.checked_mul(base));
1917 // since exp!=0, finally the exp must be 1.
1918 if exp == 1 {
1919 return Some(acc);
1920 }
1921 }
1922 exp /= 2;
1923 base = try_opt!(base.checked_mul(base));
1924 }
1925 }
1926
1927 /// Strict exponentiation. Computes `self.pow(exp)`, panicking if
1928 /// overflow occurred.
1929 ///
1930 /// # Panics
1931 ///
1932 /// ## Overflow behavior
1933 ///
1934 /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1935 ///
1936 /// # Examples
1937 ///
1938 /// ```
1939 #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".strict_pow(2), 64);")]
1940 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".strict_pow(0), 1);")]
1941 /// ```
1942 ///
1943 /// The following panics because of overflow:
1944 ///
1945 /// ```should_panic
1946 #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
1947 /// ```
1948 #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1949 #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1950 #[must_use = "this returns the result of the operation, \
1951 without modifying the original"]
1952 #[inline]
1953 #[track_caller]
1954 pub const fn strict_pow(self, exp: u32) -> Self {
1955 match self.checked_pow(exp) {
1956 Some(x) => x,
1957 None => imp::overflow_panic::pow(),
1958 }
1959 }
1960
1961 /// Returns the integer square root of the number, rounded down.
1962 ///
1963 /// This function returns the **principal (non-negative) square root**.
1964 /// For a given number `n`, although both `x` and `-x` satisfy x<sup>2</sup> = n,
1965 /// this function always returns the non-negative value.
1966 ///
1967 /// Returns `None` if `self` is negative.
1968 ///
1969 /// # Examples
1970 ///
1971 /// ```
1972 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_isqrt(), Some(3));")]
1973 /// ```
1974 #[stable(feature = "isqrt", since = "1.84.0")]
1975 #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
1976 #[must_use = "this returns the result of the operation, \
1977 without modifying the original"]
1978 #[inline]
1979 pub const fn checked_isqrt(self) -> Option<Self> {
1980 if self < 0 {
1981 None
1982 } else {
1983 // The upper bound of `$UnsignedT::MAX.isqrt()` told to the compiler
1984 // in the unsigned function also tells it that `result >= 0`
1985 let result = self.cast_unsigned().isqrt().cast_signed();
1986
1987 // Inform the optimizer what the range of outputs is. If
1988 // testing `core` crashes with no panic message and a
1989 // `num::int_sqrt::i*` test failed, it's because your edits
1990 // caused these assertions to become false.
1991 //
1992 // SAFETY: Integer square root is a monotonically nondecreasing
1993 // function, which means that increasing the input will never
1994 // cause the output to decrease. Thus, since the input for
1995 // nonnegative signed integers is bounded by
1996 // `[0, <$ActualT>::MAX]`, sqrt(n) will be bounded by
1997 // `[sqrt(0), sqrt(<$ActualT>::MAX)]`.
1998 unsafe {
1999 const MAX_RESULT: $SelfT = <$SelfT>::MAX.cast_unsigned().isqrt().cast_signed();
2000 crate::hint::assert_unchecked(result <= MAX_RESULT);
2001 }
2002 Some(result)
2003 }
2004 }
2005
2006 /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric
2007 /// bounds instead of overflowing.
2008 ///
2009 /// # Examples
2010 ///
2011 /// ```
2012 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
2013 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")]
2014 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")]
2015 /// ```
2016
2017 #[stable(feature = "rust1", since = "1.0.0")]
2018 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2019 #[must_use = "this returns the result of the operation, \
2020 without modifying the original"]
2021 #[inline(always)]
2022 pub const fn saturating_add(self, rhs: Self) -> Self {
2023 intrinsics::saturating_add(self, rhs)
2024 }
2025
2026 /// Saturating addition with an unsigned integer. Computes `self + rhs`,
2027 /// saturating at the numeric bounds instead of overflowing.
2028 ///
2029 /// # Examples
2030 ///
2031 /// ```
2032 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")]
2033 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")]
2034 /// ```
2035 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2036 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2037 #[must_use = "this returns the result of the operation, \
2038 without modifying the original"]
2039 #[inline]
2040 pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self {
2041 // Overflow can only happen at the upper bound
2042 // We cannot use `unwrap_or` here because it is not `const`
2043 match self.checked_add_unsigned(rhs) {
2044 Some(x) => x,
2045 None => Self::MAX,
2046 }
2047 }
2048
2049 /// Saturating integer subtraction. Computes `self - rhs`, saturating at the
2050 /// numeric bounds instead of overflowing.
2051 ///
2052 /// # Examples
2053 ///
2054 /// ```
2055 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")]
2056 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")]
2057 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")]
2058 /// ```
2059 #[stable(feature = "rust1", since = "1.0.0")]
2060 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2061 #[must_use = "this returns the result of the operation, \
2062 without modifying the original"]
2063 #[inline(always)]
2064 pub const fn saturating_sub(self, rhs: Self) -> Self {
2065 intrinsics::saturating_sub(self, rhs)
2066 }
2067
2068 /// Saturating subtraction with an unsigned integer. Computes `self - rhs`,
2069 /// saturating at the numeric bounds instead of overflowing.
2070 ///
2071 /// # Examples
2072 ///
2073 /// ```
2074 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")]
2075 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")]
2076 /// ```
2077 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2078 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2079 #[must_use = "this returns the result of the operation, \
2080 without modifying the original"]
2081 #[inline]
2082 pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self {
2083 // Overflow can only happen at the lower bound
2084 // We cannot use `unwrap_or` here because it is not `const`
2085 match self.checked_sub_unsigned(rhs) {
2086 Some(x) => x,
2087 None => Self::MIN,
2088 }
2089 }
2090
2091 /// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN`
2092 /// instead of overflowing.
2093 ///
2094 /// # Examples
2095 ///
2096 /// ```
2097 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")]
2098 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")]
2099 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")]
2100 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")]
2101 /// ```
2102
2103 #[stable(feature = "saturating_neg", since = "1.45.0")]
2104 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2105 #[must_use = "this returns the result of the operation, \
2106 without modifying the original"]
2107 #[inline(always)]
2108 pub const fn saturating_neg(self) -> Self {
2109 intrinsics::saturating_sub(0, self)
2110 }
2111
2112 /// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self ==
2113 /// MIN` instead of overflowing.
2114 ///
2115 /// # Examples
2116 ///
2117 /// ```
2118 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")]
2119 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")]
2120 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")]
2121 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")]
2122 /// ```
2123
2124 #[stable(feature = "saturating_neg", since = "1.45.0")]
2125 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2126 #[must_use = "this returns the result of the operation, \
2127 without modifying the original"]
2128 #[inline]
2129 pub const fn saturating_abs(self) -> Self {
2130 if self.is_negative() {
2131 self.saturating_neg()
2132 } else {
2133 self
2134 }
2135 }
2136
2137 /// Saturating integer multiplication. Computes `self * rhs`, saturating at the
2138 /// numeric bounds instead of overflowing.
2139 ///
2140 /// # Examples
2141 ///
2142 /// ```
2143 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")]
2144 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")]
2145 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")]
2146 /// ```
2147 #[stable(feature = "wrapping", since = "1.7.0")]
2148 #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2149 #[must_use = "this returns the result of the operation, \
2150 without modifying the original"]
2151 #[inline]
2152 pub const fn saturating_mul(self, rhs: Self) -> Self {
2153 match self.checked_mul(rhs) {
2154 Some(x) => x,
2155 None => if (self < 0) == (rhs < 0) {
2156 Self::MAX
2157 } else {
2158 Self::MIN
2159 }
2160 }
2161 }
2162
2163 /// Saturating integer division. Computes `self / rhs`, saturating at the
2164 /// numeric bounds instead of overflowing.
2165 ///
2166 /// # Panics
2167 ///
2168 /// This function will panic if `rhs` is zero.
2169 ///
2170 /// # Examples
2171 ///
2172 /// ```
2173 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
2174 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")]
2175 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")]
2176 ///
2177 /// ```
2178 #[stable(feature = "saturating_div", since = "1.58.0")]
2179 #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
2180 #[must_use = "this returns the result of the operation, \
2181 without modifying the original"]
2182 #[inline]
2183 #[track_caller]
2184 pub const fn saturating_div(self, rhs: Self) -> Self {
2185 match self.overflowing_div(rhs) {
2186 (result, false) => result,
2187 (_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow
2188 }
2189 }
2190
2191 /// Saturating integer exponentiation. Computes `self.pow(exp)`,
2192 /// saturating at the numeric bounds instead of overflowing.
2193 ///
2194 /// # Examples
2195 ///
2196 /// ```
2197 #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")]
2198 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".saturating_pow(0), 1);")]
2199 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
2200 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")]
2201 /// ```
2202 #[stable(feature = "no_panic_pow", since = "1.34.0")]
2203 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2204 #[must_use = "this returns the result of the operation, \
2205 without modifying the original"]
2206 #[inline]
2207 pub const fn saturating_pow(self, exp: u32) -> Self {
2208 match self.checked_pow(exp) {
2209 Some(x) => x,
2210 None if self < 0 && exp % 2 == 1 => Self::MIN,
2211 None => Self::MAX,
2212 }
2213 }
2214
2215 /// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the
2216 /// boundary of the type.
2217 ///
2218 /// # Examples
2219 ///
2220 /// ```
2221 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")]
2222 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")]
2223 /// ```
2224 #[stable(feature = "rust1", since = "1.0.0")]
2225 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2226 #[must_use = "this returns the result of the operation, \
2227 without modifying the original"]
2228 #[inline(always)]
2229 pub const fn wrapping_add(self, rhs: Self) -> Self {
2230 intrinsics::wrapping_add(self, rhs)
2231 }
2232
2233 /// Wrapping (modular) addition with an unsigned integer. Computes
2234 /// `self + rhs`, wrapping around at the boundary of the type.
2235 ///
2236 /// # Examples
2237 ///
2238 /// ```
2239 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")]
2240 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")]
2241 /// ```
2242 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2243 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2244 #[must_use = "this returns the result of the operation, \
2245 without modifying the original"]
2246 #[inline(always)]
2247 pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self {
2248 self.wrapping_add(rhs as Self)
2249 }
2250
2251 /// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the
2252 /// boundary of the type.
2253 ///
2254 /// # Examples
2255 ///
2256 /// ```
2257 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")]
2258 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")]
2259 /// ```
2260 #[stable(feature = "rust1", since = "1.0.0")]
2261 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2262 #[must_use = "this returns the result of the operation, \
2263 without modifying the original"]
2264 #[inline(always)]
2265 pub const fn wrapping_sub(self, rhs: Self) -> Self {
2266 intrinsics::wrapping_sub(self, rhs)
2267 }
2268
2269 /// Wrapping (modular) subtraction with an unsigned integer. Computes
2270 /// `self - rhs`, wrapping around at the boundary of the type.
2271 ///
2272 /// # Examples
2273 ///
2274 /// ```
2275 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")]
2276 #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")]
2277 /// ```
2278 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2279 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2280 #[must_use = "this returns the result of the operation, \
2281 without modifying the original"]
2282 #[inline(always)]
2283 pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self {
2284 self.wrapping_sub(rhs as Self)
2285 }
2286
2287 /// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at
2288 /// the boundary of the type.
2289 ///
2290 /// # Examples
2291 ///
2292 /// ```
2293 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")]
2294 /// assert_eq!(11i8.wrapping_mul(12), -124);
2295 /// ```
2296 #[stable(feature = "rust1", since = "1.0.0")]
2297 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2298 #[must_use = "this returns the result of the operation, \
2299 without modifying the original"]
2300 #[inline(always)]
2301 pub const fn wrapping_mul(self, rhs: Self) -> Self {
2302 intrinsics::wrapping_mul(self, rhs)
2303 }
2304
2305 /// Wrapping (modular) division. Computes `self / rhs`, wrapping around at the
2306 /// boundary of the type.
2307 ///
2308 /// The only case where such wrapping can occur is when one divides `MIN / -1` on a signed type (where
2309 /// [`MIN`](Self::MIN) is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
2310 /// that is too large to represent in the type. In such a case, this function returns [`MIN`](Self::MIN) itself.
2311 ///
2312 /// # Panics
2313 ///
2314 /// This function will panic if `rhs` is zero.
2315 ///
2316 /// # Examples
2317 ///
2318 /// ```
2319 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
2320 /// assert_eq!((-128i8).wrapping_div(-1), -128);
2321 /// ```
2322 #[stable(feature = "num_wrapping", since = "1.2.0")]
2323 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2324 #[must_use = "this returns the result of the operation, \
2325 without modifying the original"]
2326 #[inline]
2327 #[track_caller]
2328 pub const fn wrapping_div(self, rhs: Self) -> Self {
2329 self.overflowing_div(rhs).0
2330 }
2331
2332 /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`,
2333 /// wrapping around at the boundary of the type.
2334 ///
2335 /// Wrapping will only occur in `MIN / -1` on a signed type (where [`MIN`](Self::MIN) is the negative minimal value
2336 /// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the
2337 /// type. In this case, this method returns [`MIN`](Self::MIN) itself.
2338 ///
2339 /// # Panics
2340 ///
2341 /// This function will panic if `rhs` is zero.
2342 ///
2343 /// # Examples
2344 ///
2345 /// ```
2346 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
2347 /// assert_eq!((-128i8).wrapping_div_euclid(-1), -128);
2348 /// ```
2349 #[stable(feature = "euclidean_division", since = "1.38.0")]
2350 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2351 #[must_use = "this returns the result of the operation, \
2352 without modifying the original"]
2353 #[inline]
2354 #[track_caller]
2355 pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
2356 self.overflowing_div_euclid(rhs).0
2357 }
2358
2359 /// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the
2360 /// boundary of the type.
2361 ///
2362 /// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y`
2363 /// invalid for `MIN / -1` on a signed type (where [`MIN`](Self::MIN) is the negative minimal value). In such a case,
2364 /// this function returns `0`.
2365 ///
2366 /// # Panics
2367 ///
2368 /// This function will panic if `rhs` is zero.
2369 ///
2370 /// # Examples
2371 ///
2372 /// ```
2373 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
2374 /// assert_eq!((-128i8).wrapping_rem(-1), 0);
2375 /// ```
2376 #[stable(feature = "num_wrapping", since = "1.2.0")]
2377 #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2378 #[must_use = "this returns the result of the operation, \
2379 without modifying the original"]
2380 #[inline]
2381 #[track_caller]
2382 pub const fn wrapping_rem(self, rhs: Self) -> Self {
2383 self.overflowing_rem(rhs).0
2384 }
2385
2386 /// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around
2387 /// at the boundary of the type.
2388 ///
2389 /// Wrapping will only occur in `MIN % -1` on a signed type (where [`MIN`](Self::MIN) is
2390 /// the negative minimal value for the type). In this case, this method returns 0.
2391 ///
2392 /// # Panics
2393 ///
2394 /// This function will panic if `rhs` is zero.
2395 ///
2396 /// # Examples
2397 ///
2398 /// ```
2399 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
2400 /// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0);
2401 /// ```
2402 #[stable(feature = "euclidean_division", since = "1.38.0")]
2403 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2404 #[must_use = "this returns the result of the operation, \
2405 without modifying the original"]
2406 #[inline]
2407 #[track_caller]
2408 pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
2409 self.overflowing_rem_euclid(rhs).0
2410 }
2411
2412 /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
2413 /// of the type.
2414 ///
2415 /// The only case where such wrapping can occur is when one negates [`MIN`](Self::MIN) on a signed type (where [`MIN`](Self::MIN)
2416 /// is the negative minimal value for the type); this is a positive value that is too large to represent
2417 /// in the type. In such a case, this function returns [`MIN`](Self::MIN) itself.
2418 ///
2419 /// # Examples
2420 ///
2421 /// ```
2422 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")]
2423 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_neg(), 100);")]
2424 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")]
2425 /// ```
2426 #[stable(feature = "num_wrapping", since = "1.2.0")]
2427 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2428 #[must_use = "this returns the result of the operation, \
2429 without modifying the original"]
2430 #[inline(always)]
2431 pub const fn wrapping_neg(self) -> Self {
2432 (0 as $SelfT).wrapping_sub(self)
2433 }
2434
2435 /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes
2436 /// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
2437 ///
2438 /// Beware that, unlike most other `wrapping_*` methods on integers, this
2439 /// does *not* give the same result as doing the shift in infinite precision
2440 /// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
2441 /// do on many processors, and is what the `<<` operator does when overflow
2442 /// checks are disabled, but numerically it's weird. Consider, instead,
2443 /// using [`Self::unbounded_shl`] which has nicer behaviour.
2444 ///
2445 /// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to
2446 /// the range of the type, rather than the bits shifted out of the LHS being returned to the other end.
2447 /// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function,
2448 /// which may be what you want instead.
2449 ///
2450 /// # Examples
2451 ///
2452 /// ```
2453 #[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(7), -128);")]
2454 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(", stringify!($BITS), "), 42);")]
2455 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(1).wrapping_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
2456 #[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(128), -1);")]
2457 #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".wrapping_shl(1025), 10);")]
2458 /// ```
2459 #[stable(feature = "num_wrapping", since = "1.2.0")]
2460 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2461 #[must_use = "this returns the result of the operation, \
2462 without modifying the original"]
2463 #[inline(always)]
2464 pub const fn wrapping_shl(self, rhs: u32) -> Self {
2465 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2466 // out of bounds
2467 unsafe {
2468 self.unchecked_shl(rhs & (Self::BITS - 1))
2469 }
2470 }
2471
2472 /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask`
2473 /// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
2474 ///
2475 /// Beware that, unlike most other `wrapping_*` methods on integers, this
2476 /// does *not* give the same result as doing the shift in infinite precision
2477 /// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
2478 /// do on many processors, and is what the `>>` operator does when overflow
2479 /// checks are disabled, but numerically it's weird. Consider, instead,
2480 /// using [`Self::unbounded_shr`] which has nicer behaviour.
2481 ///
2482 /// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted
2483 /// to the range of the type, rather than the bits shifted out of the LHS being returned to the other
2484 /// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function,
2485 /// which may be what you want instead.
2486 ///
2487 /// # Examples
2488 ///
2489 /// ```
2490 #[doc = concat!("assert_eq!((-128_", stringify!($SelfT), ").wrapping_shr(7), -1);")]
2491 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(", stringify!($BITS), "), 42);")]
2492 #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(1).wrapping_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
2493 /// assert_eq!((-128_i16).wrapping_shr(64), -128);
2494 #[doc = concat!("assert_eq!(10_", stringify!($SelfT), ".wrapping_shr(1025), 5);")]
2495 /// ```
2496 #[stable(feature = "num_wrapping", since = "1.2.0")]
2497 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2498 #[must_use = "this returns the result of the operation, \
2499 without modifying the original"]
2500 #[inline(always)]
2501 pub const fn wrapping_shr(self, rhs: u32) -> Self {
2502 // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2503 // out of bounds
2504 unsafe {
2505 self.unchecked_shr(rhs & (Self::BITS - 1))
2506 }
2507 }
2508
2509 /// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at
2510 /// the boundary of the type.
2511 ///
2512 /// The only case where such wrapping can occur is when one takes the absolute value of the negative
2513 /// minimal value for the type; this is a positive value that is too large to represent in the type. In
2514 /// such a case, this function returns [`MIN`](Self::MIN) itself.
2515 ///
2516 /// # Examples
2517 ///
2518 /// ```
2519 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")]
2520 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")]
2521 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")]
2522 /// assert_eq!((-128i8).wrapping_abs() as u8, 128);
2523 /// ```
2524 #[stable(feature = "no_panic_abs", since = "1.13.0")]
2525 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2526 #[must_use = "this returns the result of the operation, \
2527 without modifying the original"]
2528 #[inline]
2529 pub const fn wrapping_abs(self) -> Self {
2530 if self.is_negative() {
2531 self.wrapping_neg()
2532 } else {
2533 self
2534 }
2535 }
2536
2537 /// Computes the absolute value of `self` without any wrapping
2538 /// or panicking.
2539 ///
2540 ///
2541 /// # Examples
2542 ///
2543 /// ```
2544 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")]
2545 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")]
2546 /// assert_eq!((-128i8).unsigned_abs(), 128u8);
2547 /// ```
2548 #[stable(feature = "unsigned_abs", since = "1.51.0")]
2549 #[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")]
2550 #[must_use = "this returns the result of the operation, \
2551 without modifying the original"]
2552 #[inline]
2553 pub const fn unsigned_abs(self) -> $UnsignedT {
2554 self.wrapping_abs() as $UnsignedT
2555 }
2556
2557 /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
2558 /// wrapping around at the boundary of the type.
2559 ///
2560 /// # Examples
2561 ///
2562 /// ```
2563 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")]
2564 /// assert_eq!(3i8.wrapping_pow(5), -13);
2565 /// assert_eq!(3i8.wrapping_pow(6), -39);
2566 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_pow(0), 1);")]
2567 /// ```
2568 #[stable(feature = "no_panic_pow", since = "1.34.0")]
2569 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2570 #[must_use = "this returns the result of the operation, \
2571 without modifying the original"]
2572 #[inline]
2573 pub const fn wrapping_pow(self, exp: u32) -> Self {
2574 let (a, _) = self.overflowing_pow(exp);
2575 a
2576 }
2577
2578 /// Calculates `self` + `rhs`.
2579 ///
2580 /// Returns a tuple of the addition along with a boolean indicating
2581 /// whether an arithmetic overflow would occur. If an overflow would have
2582 /// occurred then the wrapped value is returned (negative if overflowed
2583 /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
2584 ///
2585 /// # Examples
2586 ///
2587 /// ```
2588 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
2589 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")]
2590 /// ```
2591 #[stable(feature = "wrapping", since = "1.7.0")]
2592 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2593 #[must_use = "this returns the result of the operation, \
2594 without modifying the original"]
2595 #[inline(always)]
2596 pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
2597 let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
2598 (a as Self, b)
2599 }
2600
2601 /// Calculates `self` + `rhs` + `carry` and checks for overflow.
2602 ///
2603 /// Performs "ternary addition" of two integer operands and a carry-in
2604 /// bit, and returns a tuple of the sum along with a boolean indicating
2605 /// whether an arithmetic overflow would occur. On overflow, the wrapped
2606 /// value is returned.
2607 ///
2608 /// This allows chaining together multiple additions to create a wider
2609 /// addition, and can be useful for bignum addition. This method should
2610 /// only be used for the most significant word; for the less significant
2611 /// words the unsigned method
2612 #[doc = concat!("[`", stringify!($UnsignedT), "::carrying_add`]")]
2613 /// should be used.
2614 ///
2615 /// The output boolean returned by this method is *not* a carry flag,
2616 /// and should *not* be added to a more significant word.
2617 ///
2618 /// If overflow occurred, the wrapped value is returned (negative if overflowed
2619 /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
2620 ///
2621 /// If the input carry is false, this method is equivalent to
2622 /// [`overflowing_add`](Self::overflowing_add).
2623 ///
2624 /// # Examples
2625 ///
2626 /// ```
2627 /// #![feature(signed_bigint_helpers)]
2628 /// // Only the most significant word is signed.
2629 /// //
2630 #[doc = concat!("// 10 MAX (a = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2631 #[doc = concat!("// + -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
2632 /// // ---------
2633 #[doc = concat!("// 6 8 (sum = 6 × 2^", stringify!($BITS), " + 8)")]
2634 ///
2635 #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (10, ", stringify!($UnsignedT), "::MAX);")]
2636 #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
2637 /// let carry0 = false;
2638 ///
2639 #[doc = concat!("// ", stringify!($UnsignedT), "::carrying_add for the less significant words")]
2640 /// let (sum0, carry1) = a0.carrying_add(b0, carry0);
2641 /// assert_eq!(carry1, true);
2642 ///
2643 #[doc = concat!("// ", stringify!($SelfT), "::carrying_add for the most significant word")]
2644 /// let (sum1, overflow) = a1.carrying_add(b1, carry1);
2645 /// assert_eq!(overflow, false);
2646 ///
2647 /// assert_eq!((sum1, sum0), (6, 8));
2648 /// ```
2649 #[unstable(feature = "signed_bigint_helpers", issue = "151989")]
2650 #[must_use = "this returns the result of the operation, \
2651 without modifying the original"]
2652 #[inline]
2653 pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
2654 // note: longer-term this should be done via an intrinsic.
2655 // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
2656 let (a, b) = self.overflowing_add(rhs);
2657 let (c, d) = a.overflowing_add(carry as $SelfT);
2658 (c, b != d)
2659 }
2660
2661 /// Calculates `self` + `rhs` with an unsigned `rhs`.
2662 ///
2663 /// Returns a tuple of the addition along with a boolean indicating
2664 /// whether an arithmetic overflow would occur. If an overflow would
2665 /// have occurred then the wrapped value is returned.
2666 ///
2667 /// # Examples
2668 ///
2669 /// ```
2670 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")]
2671 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")]
2672 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")]
2673 /// ```
2674 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2675 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2676 #[must_use = "this returns the result of the operation, \
2677 without modifying the original"]
2678 #[inline]
2679 pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
2680 let rhs = rhs as Self;
2681 let (res, overflowed) = self.overflowing_add(rhs);
2682 (res, overflowed ^ (rhs < 0))
2683 }
2684
2685 /// Calculates `self` - `rhs`.
2686 ///
2687 /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
2688 /// would occur. If an overflow would have occurred then the wrapped value is returned
2689 /// (negative if overflowed above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
2690 ///
2691 /// # Examples
2692 ///
2693 /// ```
2694 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
2695 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, 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_sub(self, rhs: Self) -> (Self, bool) {
2703 let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
2704 (a as Self, b)
2705 }
2706
2707 /// Calculates `self` − `rhs` − `borrow` and checks for
2708 /// overflow.
2709 ///
2710 /// Performs "ternary subtraction" by subtracting both an integer
2711 /// operand and a borrow-in bit from `self`, and returns a tuple of the
2712 /// difference along with a boolean indicating whether an arithmetic
2713 /// overflow would occur. On overflow, the wrapped value is returned.
2714 ///
2715 /// This allows chaining together multiple subtractions to create a
2716 /// wider subtraction, and can be useful for bignum subtraction. This
2717 /// method should only be used for the most significant word; for the
2718 /// less significant words the unsigned method
2719 #[doc = concat!("[`", stringify!($UnsignedT), "::borrowing_sub`]")]
2720 /// should be used.
2721 ///
2722 /// The output boolean returned by this method is *not* a borrow flag,
2723 /// and should *not* be subtracted from a more significant word.
2724 ///
2725 /// If overflow occurred, the wrapped value is returned (negative if overflowed
2726 /// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
2727 ///
2728 /// If the input borrow is false, this method is equivalent to
2729 /// [`overflowing_sub`](Self::overflowing_sub).
2730 ///
2731 /// # Examples
2732 ///
2733 /// ```
2734 /// #![feature(signed_bigint_helpers)]
2735 /// // Only the most significant word is signed.
2736 /// //
2737 #[doc = concat!("// 6 8 (a = 6 × 2^", stringify!($BITS), " + 8)")]
2738 #[doc = concat!("// - -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
2739 /// // ---------
2740 #[doc = concat!("// 10 MAX (diff = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2741 ///
2742 #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (6, 8);")]
2743 #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
2744 /// let borrow0 = false;
2745 ///
2746 #[doc = concat!("// ", stringify!($UnsignedT), "::borrowing_sub for the less significant words")]
2747 /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
2748 /// assert_eq!(borrow1, true);
2749 ///
2750 #[doc = concat!("// ", stringify!($SelfT), "::borrowing_sub for the most significant word")]
2751 /// let (diff1, overflow) = a1.borrowing_sub(b1, borrow1);
2752 /// assert_eq!(overflow, false);
2753 ///
2754 #[doc = concat!("assert_eq!((diff1, diff0), (10, ", stringify!($UnsignedT), "::MAX));")]
2755 /// ```
2756 #[unstable(feature = "signed_bigint_helpers", issue = "151989")]
2757 #[must_use = "this returns the result of the operation, \
2758 without modifying the original"]
2759 #[inline]
2760 pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
2761 // note: longer-term this should be done via an intrinsic.
2762 // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
2763 let (a, b) = self.overflowing_sub(rhs);
2764 let (c, d) = a.overflowing_sub(borrow as $SelfT);
2765 (c, b != d)
2766 }
2767
2768 /// Calculates `self` - `rhs` with an unsigned `rhs`.
2769 ///
2770 /// Returns a tuple of the subtraction along with a boolean indicating
2771 /// whether an arithmetic overflow would occur. If an overflow would
2772 /// have occurred then the wrapped value is returned.
2773 ///
2774 /// # Examples
2775 ///
2776 /// ```
2777 #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")]
2778 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")]
2779 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")]
2780 /// ```
2781 #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2782 #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2783 #[must_use = "this returns the result of the operation, \
2784 without modifying the original"]
2785 #[inline]
2786 pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
2787 let rhs = rhs as Self;
2788 let (res, overflowed) = self.overflowing_sub(rhs);
2789 (res, overflowed ^ (rhs < 0))
2790 }
2791
2792 /// Calculates the multiplication of `self` and `rhs`.
2793 ///
2794 /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow
2795 /// would occur. If an overflow would have occurred then the wrapped value is returned.
2796 ///
2797 /// # Examples
2798 ///
2799 /// ```
2800 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")]
2801 /// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true));
2802 /// ```
2803 #[stable(feature = "wrapping", since = "1.7.0")]
2804 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
2805 #[must_use = "this returns the result of the operation, \
2806 without modifying the original"]
2807 #[inline(always)]
2808 pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
2809 let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
2810 (a as Self, b)
2811 }
2812
2813 /// Calculates the "full multiplication" `self * rhs + carry`
2814 /// without the possibility to overflow.
2815 ///
2816 /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2817 /// of the result as two separate values, in that order.
2818 ///
2819 /// Performs "long multiplication" which takes in an extra amount to add, and may return an
2820 /// additional amount of overflow. This allows for chaining together multiple
2821 /// multiplications to create "big integers" which represent larger values.
2822 ///
2823 /// # Examples
2824 ///
2825 /// Please note that this example is shared among integer types, which is why [`i32`] is used.
2826 ///
2827 /// ```
2828 /// #![feature(signed_bigint_helpers)]
2829 /// assert_eq!(5i32.carrying_mul(-2, 0), (4294967286, -1));
2830 /// assert_eq!(5i32.carrying_mul(-2, 10), (0, 0));
2831 /// assert_eq!(1_000_000_000i32.carrying_mul(-10, 0), (2884901888, -3));
2832 /// assert_eq!(1_000_000_000i32.carrying_mul(-10, 10), (2884901898, -3));
2833 #[doc = concat!("assert_eq!(",
2834 stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
2835 "(", stringify!($SelfT), "::MAX.unsigned_abs() + 1, ", stringify!($SelfT), "::MAX / 2));"
2836 )]
2837 /// ```
2838 #[unstable(feature = "signed_bigint_helpers", issue = "151989")]
2839 #[rustc_const_unstable(feature = "signed_bigint_helpers", issue = "151989")]
2840 #[must_use = "this returns the result of the operation, \
2841 without modifying the original"]
2842 #[inline]
2843 pub const fn carrying_mul(self, rhs: Self, carry: Self) -> ($UnsignedT, Self) {
2844 Self::carrying_mul_add(self, rhs, carry, 0)
2845 }
2846
2847 /// Calculates the "full multiplication" `self * rhs + carry + add`
2848 /// without the possibility to overflow.
2849 ///
2850 /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2851 /// of the result as two separate values, in that order.
2852 ///
2853 /// Performs "long multiplication" which takes in an extra amount to add, and may return an
2854 /// additional amount of overflow. This allows for chaining together multiple
2855 /// multiplications to create "big integers" which represent larger values.
2856 ///
2857 /// If you only need one `carry`, then you can use [`Self::carrying_mul`] instead.
2858 ///
2859 /// # Examples
2860 ///
2861 /// Please note that this example is shared among integer types, which is why `i32` is used.
2862 ///
2863 /// ```
2864 /// #![feature(signed_bigint_helpers)]
2865 /// assert_eq!(5i32.carrying_mul_add(-2, 0, 0), (4294967286, -1));
2866 /// assert_eq!(5i32.carrying_mul_add(-2, 10, 10), (10, 0));
2867 /// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 0, 0), (2884901888, -3));
2868 /// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 10, 10), (2884901908, -3));
2869 #[doc = concat!("assert_eq!(",
2870 stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
2871 "(", stringify!($UnsignedT), "::MAX, ", stringify!($SelfT), "::MAX / 2));"
2872 )]
2873 /// ```
2874 #[unstable(feature = "signed_bigint_helpers", issue = "151989")]
2875 #[rustc_const_unstable(feature = "signed_bigint_helpers", issue = "151989")]
2876 #[must_use = "this returns the result of the operation, \
2877 without modifying the original"]
2878 #[inline]
2879 pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> ($UnsignedT, Self) {
2880 intrinsics::carrying_mul_add(self, rhs, carry, add)
2881 }
2882
2883 /// Calculates the divisor when `self` is divided by `rhs`.
2884 ///
2885 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
2886 /// occur. If an overflow would occur then self is returned.
2887 ///
2888 /// # Panics
2889 ///
2890 /// This function will panic if `rhs` is zero.
2891 ///
2892 /// # Examples
2893 ///
2894 /// ```
2895 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
2896 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")]
2897 /// ```
2898 #[inline]
2899 #[stable(feature = "wrapping", since = "1.7.0")]
2900 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
2901 #[must_use = "this returns the result of the operation, \
2902 without modifying the original"]
2903 #[track_caller]
2904 pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
2905 // Using `&` helps LLVM see that it is the same check made in division.
2906 if intrinsics::unlikely((self == Self::MIN) & (rhs == -1)) {
2907 (self, true)
2908 } else {
2909 (self / rhs, false)
2910 }
2911 }
2912
2913 /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
2914 ///
2915 /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
2916 /// occur. If an overflow would occur then `self` is returned.
2917 ///
2918 /// # Panics
2919 ///
2920 /// This function will panic if `rhs` is zero.
2921 ///
2922 /// # Examples
2923 ///
2924 /// ```
2925 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
2926 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")]
2927 /// ```
2928 #[inline]
2929 #[stable(feature = "euclidean_division", since = "1.38.0")]
2930 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2931 #[must_use = "this returns the result of the operation, \
2932 without modifying the original"]
2933 #[track_caller]
2934 pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
2935 // Using `&` helps LLVM see that it is the same check made in division.
2936 if intrinsics::unlikely((self == Self::MIN) & (rhs == -1)) {
2937 (self, true)
2938 } else {
2939 (self.div_euclid(rhs), false)
2940 }
2941 }
2942
2943 /// Calculates the remainder when `self` is divided by `rhs`.
2944 ///
2945 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
2946 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
2947 ///
2948 /// # Panics
2949 ///
2950 /// This function will panic if `rhs` is zero.
2951 ///
2952 /// # Examples
2953 ///
2954 /// ```
2955 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
2956 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")]
2957 /// ```
2958 #[inline]
2959 #[stable(feature = "wrapping", since = "1.7.0")]
2960 #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
2961 #[must_use = "this returns the result of the operation, \
2962 without modifying the original"]
2963 #[track_caller]
2964 pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
2965 if intrinsics::unlikely(rhs == -1) {
2966 (0, self == Self::MIN)
2967 } else {
2968 (self % rhs, false)
2969 }
2970 }
2971
2972 /// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`.
2973 ///
2974 /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
2975 /// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
2976 ///
2977 /// # Panics
2978 ///
2979 /// This function will panic if `rhs` is zero.
2980 ///
2981 /// # Examples
2982 ///
2983 /// ```
2984 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
2985 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")]
2986 /// ```
2987 #[stable(feature = "euclidean_division", since = "1.38.0")]
2988 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2989 #[must_use = "this returns the result of the operation, \
2990 without modifying the original"]
2991 #[inline]
2992 #[track_caller]
2993 pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
2994 if intrinsics::unlikely(rhs == -1) {
2995 (0, self == Self::MIN)
2996 } else {
2997 (self.rem_euclid(rhs), false)
2998 }
2999 }
3000
3001 /// Negates self, overflowing if this is equal to the minimum value.
3002 ///
3003 /// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow
3004 /// happened. If `self` is the minimum value (e.g., [`i32::MIN`] for values of type [`i32`]), then the
3005 /// minimum value will be returned again and `true` will be returned for an overflow happening.
3006 ///
3007 /// # Examples
3008 ///
3009 /// ```
3010 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")]
3011 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")]
3012 /// ```
3013 #[inline]
3014 #[stable(feature = "wrapping", since = "1.7.0")]
3015 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3016 #[must_use = "this returns the result of the operation, \
3017 without modifying the original"]
3018 pub const fn overflowing_neg(self) -> (Self, bool) {
3019 if intrinsics::unlikely(self == Self::MIN) {
3020 (Self::MIN, true)
3021 } else {
3022 (-self, false)
3023 }
3024 }
3025
3026 /// Shifts self left by `rhs` bits.
3027 ///
3028 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
3029 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
3030 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
3031 ///
3032 /// # Examples
3033 ///
3034 /// ```
3035 #[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")]
3036 /// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));
3037 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
3038 /// ```
3039 #[stable(feature = "wrapping", since = "1.7.0")]
3040 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3041 #[must_use = "this returns the result of the operation, \
3042 without modifying the original"]
3043 #[inline]
3044 pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
3045 (self.wrapping_shl(rhs), rhs >= Self::BITS)
3046 }
3047
3048 /// Shifts self right by `rhs` bits.
3049 ///
3050 /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
3051 /// value was larger than or equal to the number of bits. If the shift value is too large, then value is
3052 /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
3053 ///
3054 /// # Examples
3055 ///
3056 /// ```
3057 #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
3058 /// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
3059 /// ```
3060 #[stable(feature = "wrapping", since = "1.7.0")]
3061 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3062 #[must_use = "this returns the result of the operation, \
3063 without modifying the original"]
3064 #[inline]
3065 pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
3066 (self.wrapping_shr(rhs), rhs >= Self::BITS)
3067 }
3068
3069 /// Computes the absolute value of `self`.
3070 ///
3071 /// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow
3072 /// happened. If self is the minimum value
3073 #[doc = concat!("(e.g., [`", stringify!($SelfT), "::MIN`] for values of type [`", stringify!($SelfT), "`]),")]
3074 /// then the minimum value will be returned again and true will be returned
3075 /// for an overflow happening.
3076 ///
3077 /// # Examples
3078 ///
3079 /// ```
3080 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")]
3081 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")]
3082 #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")]
3083 /// ```
3084 #[stable(feature = "no_panic_abs", since = "1.13.0")]
3085 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3086 #[must_use = "this returns the result of the operation, \
3087 without modifying the original"]
3088 #[inline]
3089 pub const fn overflowing_abs(self) -> (Self, bool) {
3090 (self.wrapping_abs(), self == Self::MIN)
3091 }
3092
3093 /// Raises self to the power of `exp`, using exponentiation by squaring.
3094 ///
3095 /// Returns a tuple of the exponentiation along with a bool indicating
3096 /// whether an overflow happened.
3097 ///
3098 /// # Examples
3099 ///
3100 /// ```
3101 #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")]
3102 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".overflowing_pow(0), (1, false));")]
3103 /// assert_eq!(3i8.overflowing_pow(5), (-13, true));
3104 /// ```
3105 #[stable(feature = "no_panic_pow", since = "1.34.0")]
3106 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3107 #[must_use = "this returns the result of the operation, \
3108 without modifying the original"]
3109 #[inline]
3110 pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
3111 let mut base = self;
3112 let mut acc: Self = 1;
3113 let mut overflow = false;
3114 let mut tmp_overflow;
3115
3116 if intrinsics::is_val_statically_known(base) && base.unsigned_abs().is_power_of_two() {
3117 let k = base.unsigned_abs().ilog2();
3118 let Some(shift) = k.checked_mul(exp) else {
3119 return (0, true)
3120 };
3121 let base: Self = if base < 0 && (exp % 2) != 0 { -1 } else { 1 };
3122 return (base.unbounded_shl(shift), base.shl_exact(shift).is_none());
3123 }
3124
3125 if exp == 0 {
3126 return (1, false);
3127 }
3128
3129 if intrinsics::is_val_statically_known(exp) {
3130 while exp > 1 {
3131 if (exp & 1) == 1 {
3132 (acc, tmp_overflow) = acc.overflowing_mul(base);
3133 overflow |= tmp_overflow;
3134 }
3135 exp /= 2;
3136 (base, tmp_overflow) = base.overflowing_mul(base);
3137 overflow |= tmp_overflow;
3138 }
3139
3140 // since exp!=0, finally the exp must be 1.
3141 // Deal with the final bit of the exponent separately, since
3142 // squaring the base afterwards is not necessary and may cause a
3143 // needless overflow.
3144 (acc, tmp_overflow) = acc.overflowing_mul(base);
3145 overflow |= tmp_overflow;
3146 return (acc, overflow);
3147 }
3148
3149 loop {
3150 if (exp & 1) == 1 {
3151 (acc, tmp_overflow) = acc.overflowing_mul(base);
3152 overflow |= tmp_overflow;
3153 // since exp!=0, finally the exp must be 1.
3154 if exp == 1 {
3155 return (acc, overflow);
3156 }
3157 }
3158 exp /= 2;
3159 (base, tmp_overflow) = base.overflowing_mul(base);
3160 overflow |= tmp_overflow;
3161 }
3162 }
3163
3164 /// Raises self to the power of `exp`, using exponentiation by squaring.
3165 ///
3166 /// # Examples
3167 ///
3168 /// ```
3169 #[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")]
3170 ///
3171 /// assert_eq!(x.pow(5), 32);
3172 #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".pow(0), 1);")]
3173 /// ```
3174 #[stable(feature = "rust1", since = "1.0.0")]
3175 #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3176 #[must_use = "this returns the result of the operation, \
3177 without modifying the original"]
3178 #[inline]
3179 #[rustc_inherit_overflow_checks]
3180 pub const fn pow(self, exp: u32) -> Self {
3181 if intrinsics::overflow_checks() {
3182 self.strict_pow(exp)
3183 } else {
3184 self.wrapping_pow(exp)
3185 }
3186 }
3187
3188 /// Returns the integer square root of the number, rounded down.
3189 ///
3190 /// This function returns the **principal (non-negative) square root**.
3191 /// For a given number `n`, although both `x` and `-x` satisfy x<sup>2</sup> = n,
3192 /// this function always returns the non-negative value.
3193 ///
3194 /// # Panics
3195 ///
3196 /// This function will panic if `self` is negative.
3197 ///
3198 /// # Examples
3199 ///
3200 /// ```
3201 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
3202 /// ```
3203 #[stable(feature = "isqrt", since = "1.84.0")]
3204 #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
3205 #[must_use = "this returns the result of the operation, \
3206 without modifying the original"]
3207 #[inline]
3208 #[track_caller]
3209 pub const fn isqrt(self) -> Self {
3210 match self.checked_isqrt() {
3211 Some(sqrt) => sqrt,
3212 None => imp::int_sqrt::panic_for_negative_argument(),
3213 }
3214 }
3215
3216 /// Calculates the quotient of Euclidean division of `self` by `rhs`.
3217 ///
3218 /// This computes the integer `q` such that `self = q * rhs + r`, with
3219 /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`.
3220 ///
3221 /// In other words, the result is `self / rhs` rounded to the integer `q`
3222 /// such that `self >= q * rhs`.
3223 /// If `self > 0`, this is equal to rounding towards zero (the default in Rust);
3224 /// if `self < 0`, this is equal to rounding away from zero (towards +/- infinity).
3225 /// If `rhs > 0`, this is equal to rounding towards -infinity;
3226 /// if `rhs < 0`, this is equal to rounding towards +infinity.
3227 ///
3228 /// # Panics
3229 ///
3230 /// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
3231 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3232 ///
3233 /// # Examples
3234 ///
3235 /// ```
3236 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
3237 /// let b = 4;
3238 ///
3239 /// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
3240 /// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
3241 /// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
3242 /// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
3243 /// ```
3244 #[stable(feature = "euclidean_division", since = "1.38.0")]
3245 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3246 #[must_use = "this returns the result of the operation, \
3247 without modifying the original"]
3248 #[inline]
3249 #[track_caller]
3250 pub const fn div_euclid(self, rhs: Self) -> Self {
3251 let q = self / rhs;
3252 if self % rhs < 0 {
3253 return if rhs > 0 { q - 1 } else { q + 1 }
3254 }
3255 q
3256 }
3257
3258 /// Calculates the least nonnegative remainder of `self` when
3259 /// divided by `rhs`.
3260 ///
3261 /// This is done as if by the Euclidean division algorithm -- given
3262 /// `r = self.rem_euclid(rhs)`, the result satisfies
3263 /// `self = rhs * self.div_euclid(rhs) + r` and `0 <= r < abs(rhs)`.
3264 ///
3265 /// # Panics
3266 ///
3267 /// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`] and
3268 /// `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3269 ///
3270 /// # Examples
3271 ///
3272 /// ```
3273 #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
3274 /// let b = 4;
3275 ///
3276 /// assert_eq!(a.rem_euclid(b), 3);
3277 /// assert_eq!((-a).rem_euclid(b), 1);
3278 /// assert_eq!(a.rem_euclid(-b), 3);
3279 /// assert_eq!((-a).rem_euclid(-b), 1);
3280 /// ```
3281 ///
3282 /// This will panic:
3283 /// ```should_panic
3284 #[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.rem_euclid(-1);")]
3285 /// ```
3286 #[doc(alias = "modulo", alias = "mod")]
3287 #[stable(feature = "euclidean_division", since = "1.38.0")]
3288 #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3289 #[must_use = "this returns the result of the operation, \
3290 without modifying the original"]
3291 #[inline]
3292 #[track_caller]
3293 pub const fn rem_euclid(self, rhs: Self) -> Self {
3294 let r = self % rhs;
3295 if r < 0 {
3296 // Semantically equivalent to `if rhs < 0 { r - rhs } else { r + rhs }`.
3297 // If `rhs` is not `Self::MIN`, then `r + abs(rhs)` will not overflow
3298 // and is clearly equivalent, because `r` is negative.
3299 // Otherwise, `rhs` is `Self::MIN`, then we have
3300 // `r.wrapping_add(Self::MIN.wrapping_abs())`, which evaluates
3301 // to `r.wrapping_add(Self::MIN)`, which is equivalent to
3302 // `r - Self::MIN`, which is what we wanted (and will not overflow
3303 // for negative `r`).
3304 r.wrapping_add(rhs.wrapping_abs())
3305 } else {
3306 r
3307 }
3308 }
3309
3310 /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
3311 ///
3312 /// # Panics
3313 ///
3314 /// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
3315 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3316 ///
3317 /// # Examples
3318 ///
3319 /// ```
3320 /// #![feature(int_roundings)]
3321 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
3322 /// let b = 3;
3323 ///
3324 /// assert_eq!(a.div_floor(b), 2);
3325 /// assert_eq!(a.div_floor(-b), -3);
3326 /// assert_eq!((-a).div_floor(b), -3);
3327 /// assert_eq!((-a).div_floor(-b), 2);
3328 /// ```
3329 #[unstable(feature = "int_roundings", issue = "88581")]
3330 #[must_use = "this returns the result of the operation, \
3331 without modifying the original"]
3332 #[inline]
3333 #[track_caller]
3334 pub const fn div_floor(self, rhs: Self) -> Self {
3335 let d = self / rhs;
3336 let r = self % rhs;
3337
3338 // If the remainder is non-zero, we need to subtract one if the
3339 // signs of self and rhs differ, as this means we rounded upwards
3340 // instead of downwards. We do this branchlessly by creating a mask
3341 // which is all-ones iff the signs differ, and 0 otherwise. Then by
3342 // adding this mask (which corresponds to the signed value -1), we
3343 // get our correction.
3344 let correction = (self ^ rhs) >> (Self::BITS - 1);
3345 if r != 0 {
3346 d + correction
3347 } else {
3348 d
3349 }
3350 }
3351
3352 /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
3353 ///
3354 /// # Panics
3355 ///
3356 /// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
3357 /// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
3358 ///
3359 /// # Examples
3360 ///
3361 /// ```
3362 /// #![feature(int_roundings)]
3363 #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
3364 /// let b = 3;
3365 ///
3366 /// assert_eq!(a.div_ceil(b), 3);
3367 /// assert_eq!(a.div_ceil(-b), -2);
3368 /// assert_eq!((-a).div_ceil(b), -2);
3369 /// assert_eq!((-a).div_ceil(-b), 3);
3370 /// ```
3371 #[unstable(feature = "int_roundings", issue = "88581")]
3372 #[must_use = "this returns the result of the operation, \
3373 without modifying the original"]
3374 #[inline]
3375 #[track_caller]
3376 pub const fn div_ceil(self, rhs: Self) -> Self {
3377 let d = self / rhs;
3378 let r = self % rhs;
3379
3380 // When remainder is non-zero we have a.div_ceil(b) == 1 + a.div_floor(b),
3381 // so we can re-use the algorithm from div_floor, just adding 1.
3382 let correction = 1 + ((self ^ rhs) >> (Self::BITS - 1));
3383 if r != 0 {
3384 d + correction
3385 } else {
3386 d
3387 }
3388 }
3389
3390 /// If `rhs` is positive, calculates the smallest value greater than or
3391 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
3392 /// calculates the largest value less than or equal to `self` that is a
3393 /// multiple of `rhs`.
3394 ///
3395 /// # Panics
3396 ///
3397 /// This function will panic if `rhs` is zero.
3398 ///
3399 /// ## Overflow behavior
3400 ///
3401 /// On overflow, this function will panic if overflow checks are enabled (default in debug
3402 /// mode) and wrap if overflow checks are disabled (default in release mode).
3403 ///
3404 /// # Examples
3405 ///
3406 /// ```
3407 /// #![feature(int_roundings)]
3408 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
3409 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
3410 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
3411 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
3412 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
3413 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
3414 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")]
3415 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")]
3416 /// ```
3417 #[unstable(feature = "int_roundings", issue = "88581")]
3418 #[must_use = "this returns the result of the operation, \
3419 without modifying the original"]
3420 #[inline]
3421 #[rustc_inherit_overflow_checks]
3422 pub const fn next_multiple_of(self, rhs: Self) -> Self {
3423 // This would otherwise fail when calculating `r` when self == T::MIN.
3424 if rhs == -1 {
3425 return self;
3426 }
3427
3428 let r = self % rhs;
3429 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
3430 r + rhs
3431 } else {
3432 r
3433 };
3434
3435 if m == 0 {
3436 self
3437 } else {
3438 self + (rhs - m)
3439 }
3440 }
3441
3442 /// If `rhs` is positive, calculates the smallest value greater than or
3443 /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
3444 /// calculates the largest value less than or equal to `self` that is a
3445 /// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
3446 /// would result in overflow.
3447 ///
3448 /// # Examples
3449 ///
3450 /// ```
3451 /// #![feature(int_roundings)]
3452 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
3453 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
3454 #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
3455 #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
3456 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
3457 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
3458 #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")]
3459 #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")]
3460 #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
3461 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
3462 /// ```
3463 #[unstable(feature = "int_roundings", issue = "88581")]
3464 #[must_use = "this returns the result of the operation, \
3465 without modifying the original"]
3466 #[inline]
3467 pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
3468 // This would otherwise fail when calculating `r` when self == T::MIN.
3469 if rhs == -1 {
3470 return Some(self);
3471 }
3472
3473 let r = try_opt!(self.checked_rem(rhs));
3474 let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
3475 // r + rhs cannot overflow because they have opposite signs
3476 r + rhs
3477 } else {
3478 r
3479 };
3480
3481 if m == 0 {
3482 Some(self)
3483 } else {
3484 // rhs - m cannot overflow because m has the same sign as rhs
3485 self.checked_add(rhs - m)
3486 }
3487 }
3488
3489 /// Returns the logarithm of the number with respect to an arbitrary base,
3490 /// rounded down.
3491 ///
3492 /// This method might not be optimized owing to implementation details;
3493 /// [`ilog2`][Self::ilog2] can produce results more efficiently for base 2,
3494 /// and [`ilog10`](Self::ilog10) can produce results more efficiently for base 10.
3495 ///
3496 /// # Panics
3497 ///
3498 /// This function will panic if `self` is less than or equal to zero,
3499 /// or if `base` is less than 2.
3500 ///
3501 /// # Examples
3502 ///
3503 /// ```
3504 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
3505 /// ```
3506 #[stable(feature = "int_log", since = "1.67.0")]
3507 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3508 #[must_use = "this returns the result of the operation, \
3509 without modifying the original"]
3510 #[inline]
3511 #[track_caller]
3512 pub const fn ilog(self, base: Self) -> u32 {
3513 assert!(base >= 2, "base of integer logarithm must be at least 2");
3514 if let Some(log) = self.checked_ilog(base) {
3515 log
3516 } else {
3517 imp::int_log10::panic_for_nonpositive_argument()
3518 }
3519 }
3520
3521 /// Returns the base 2 logarithm of the number, rounded down.
3522 ///
3523 /// # Panics
3524 ///
3525 /// This function will panic if `self` is less than or equal to zero.
3526 ///
3527 /// # Examples
3528 ///
3529 /// ```
3530 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
3531 /// ```
3532 #[stable(feature = "int_log", since = "1.67.0")]
3533 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3534 #[must_use = "this returns the result of the operation, \
3535 without modifying the original"]
3536 #[inline]
3537 #[track_caller]
3538 pub const fn ilog2(self) -> u32 {
3539 if let Some(log) = self.checked_ilog2() {
3540 log
3541 } else {
3542 imp::int_log10::panic_for_nonpositive_argument()
3543 }
3544 }
3545
3546 /// Returns the base 10 logarithm of the number, rounded down.
3547 ///
3548 /// # Panics
3549 ///
3550 /// This function will panic if `self` is less than or equal to zero.
3551 ///
3552 /// # Example
3553 ///
3554 /// ```
3555 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
3556 /// ```
3557 #[stable(feature = "int_log", since = "1.67.0")]
3558 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3559 #[must_use = "this returns the result of the operation, \
3560 without modifying the original"]
3561 #[inline]
3562 #[track_caller]
3563 pub const fn ilog10(self) -> u32 {
3564 if let Some(log) = self.checked_ilog10() {
3565 log
3566 } else {
3567 imp::int_log10::panic_for_nonpositive_argument()
3568 }
3569 }
3570
3571 /// Returns the logarithm of the number with respect to an arbitrary base,
3572 /// rounded down.
3573 ///
3574 /// Returns `None` if the number is negative or zero, or if the base is not at least 2.
3575 ///
3576 /// This method might not be optimized owing to implementation details;
3577 /// `checked_ilog2` can produce results more efficiently for base 2, and
3578 /// `checked_ilog10` can produce results more efficiently for base 10.
3579 ///
3580 /// # Examples
3581 ///
3582 /// ```
3583 #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
3584 /// ```
3585 #[stable(feature = "int_log", since = "1.67.0")]
3586 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3587 #[must_use = "this returns the result of the operation, \
3588 without modifying the original"]
3589 #[inline]
3590 pub const fn checked_ilog(self, base: Self) -> Option<u32> {
3591 if self <= 0 || base <= 1 {
3592 None
3593 } else {
3594 // Delegate to the unsigned implementation.
3595 // The condition makes sure that both casts are exact.
3596 (self as $UnsignedT).checked_ilog(base as $UnsignedT)
3597 }
3598 }
3599
3600 /// Returns the base 2 logarithm of the number, rounded down.
3601 ///
3602 /// Returns `None` if the number is negative or zero.
3603 ///
3604 /// Note that for non-negative numbers, this is equivalent to
3605 /// [`highest_one`](Self::highest_one).
3606 ///
3607 /// # Examples
3608 ///
3609 /// ```
3610 #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
3611 /// ```
3612 #[stable(feature = "int_log", since = "1.67.0")]
3613 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3614 #[must_use = "this returns the result of the operation, \
3615 without modifying the original"]
3616 #[inline]
3617 pub const fn checked_ilog2(self) -> Option<u32> {
3618 if self <= 0 {
3619 None
3620 } else {
3621 // SAFETY: We just checked that this number is positive
3622 let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 };
3623 Some(log)
3624 }
3625 }
3626
3627 /// Returns the base 10 logarithm of the number, rounded down.
3628 ///
3629 /// Returns `None` if the number is negative or zero.
3630 ///
3631 /// # Example
3632 ///
3633 /// ```
3634 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
3635 /// ```
3636 #[stable(feature = "int_log", since = "1.67.0")]
3637 #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
3638 #[must_use = "this returns the result of the operation, \
3639 without modifying the original"]
3640 #[inline]
3641 pub const fn checked_ilog10(self) -> Option<u32> {
3642 imp::int_log10::$ActualT(self as $ActualT)
3643 }
3644
3645 /// Computes the absolute value of `self`.
3646 ///
3647 /// # Overflow behavior
3648 ///
3649 /// The absolute value of
3650 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
3651 /// cannot be represented as an
3652 #[doc = concat!("`", stringify!($SelfT), "`,")]
3653 /// and attempting to calculate it will cause an overflow. This means
3654 /// that code in debug mode will trigger a panic on this case and
3655 /// optimized code will return
3656 #[doc = concat!("`", stringify!($SelfT), "::MIN`")]
3657 /// without a panic. If you do not want this behavior, consider
3658 /// using [`unsigned_abs`](Self::unsigned_abs) instead.
3659 ///
3660 /// # Examples
3661 ///
3662 /// ```
3663 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")]
3664 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")]
3665 /// ```
3666 #[stable(feature = "rust1", since = "1.0.0")]
3667 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3668 #[must_use = "this returns the result of the operation, \
3669 without modifying the original"]
3670 #[inline]
3671 #[rustc_inherit_overflow_checks]
3672 pub const fn abs(self) -> Self {
3673 // Note that the #[rustc_inherit_overflow_checks] and #[inline]
3674 // above mean that the overflow semantics of the subtraction
3675 // depend on the crate we're being called from.
3676 if self.is_negative() {
3677 -self
3678 } else {
3679 self
3680 }
3681 }
3682
3683 /// Computes the absolute difference between `self` and `other`.
3684 ///
3685 /// This function always returns the correct answer without overflow or
3686 /// panics by returning an unsigned integer.
3687 ///
3688 /// # Examples
3689 ///
3690 /// ```
3691 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")]
3692 #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")]
3693 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")]
3694 #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")]
3695 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")]
3696 /// ```
3697 #[stable(feature = "int_abs_diff", since = "1.60.0")]
3698 #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
3699 #[must_use = "this returns the result of the operation, \
3700 without modifying the original"]
3701 #[inline]
3702 pub const fn abs_diff(self, other: Self) -> $UnsignedT {
3703 if self < other {
3704 // Converting a non-negative x from signed to unsigned by using
3705 // `x as U` is left unchanged, but a negative x is converted
3706 // to value x + 2^N. Thus if `s` and `o` are binary variables
3707 // respectively indicating whether `self` and `other` are
3708 // negative, we are computing the mathematical value:
3709 //
3710 // (other + o*2^N) - (self + s*2^N) mod 2^N
3711 // other - self + (o-s)*2^N mod 2^N
3712 // other - self mod 2^N
3713 //
3714 // Finally, taking the mod 2^N of the mathematical value of
3715 // `other - self` does not change it as it already is
3716 // in the range [0, 2^N).
3717 (other as $UnsignedT).wrapping_sub(self as $UnsignedT)
3718 } else {
3719 (self as $UnsignedT).wrapping_sub(other as $UnsignedT)
3720 }
3721 }
3722
3723 /// Returns a number representing sign of `self`.
3724 ///
3725 /// - `0` if the number is zero
3726 /// - `1` if the number is positive
3727 /// - `-1` if the number is negative
3728 ///
3729 /// # Examples
3730 ///
3731 /// ```
3732 #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")]
3733 #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")]
3734 #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")]
3735 /// ```
3736 #[stable(feature = "rust1", since = "1.0.0")]
3737 #[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")]
3738 #[must_use = "this returns the result of the operation, \
3739 without modifying the original"]
3740 #[inline(always)]
3741 pub const fn signum(self) -> Self {
3742 // Picking the right way to phrase this is complicated
3743 // (<https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>)
3744 // so delegate it to `Ord` which is already producing -1/0/+1
3745 // exactly like we need and can be the place to deal with the complexity.
3746
3747 crate::intrinsics::three_way_compare(self, 0) as Self
3748 }
3749
3750 /// Returns `true` if `self` is positive and `false` if the number is zero or
3751 /// negative.
3752 ///
3753 /// # Examples
3754 ///
3755 /// ```
3756 #[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")]
3757 #[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")]
3758 /// ```
3759 #[must_use]
3760 #[stable(feature = "rust1", since = "1.0.0")]
3761 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3762 #[inline(always)]
3763 pub const fn is_positive(self) -> bool { self > 0 }
3764
3765 /// Returns `true` if `self` is negative and `false` if the number is zero or
3766 /// positive.
3767 ///
3768 /// # Examples
3769 ///
3770 /// ```
3771 #[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")]
3772 #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")]
3773 /// ```
3774 #[must_use]
3775 #[stable(feature = "rust1", since = "1.0.0")]
3776 #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
3777 #[inline(always)]
3778 pub const fn is_negative(self) -> bool { self < 0 }
3779
3780 /// Returns the memory representation of this integer as a byte array in
3781 /// big-endian (network) byte order.
3782 ///
3783 #[doc = $to_xe_bytes_doc]
3784 ///
3785 /// # Examples
3786 ///
3787 /// ```
3788 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
3789 #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
3790 /// ```
3791 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3792 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3793 #[must_use = "this returns the result of the operation, \
3794 without modifying the original"]
3795 #[inline]
3796 pub const fn to_be_bytes(self) -> [u8; size_of::<Self>()] {
3797 self.to_be().to_ne_bytes()
3798 }
3799
3800 /// Returns the memory representation of this integer as a byte array in
3801 /// little-endian byte order.
3802 ///
3803 #[doc = $to_xe_bytes_doc]
3804 ///
3805 /// # Examples
3806 ///
3807 /// ```
3808 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
3809 #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
3810 /// ```
3811 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3812 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3813 #[must_use = "this returns the result of the operation, \
3814 without modifying the original"]
3815 #[inline]
3816 pub const fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
3817 self.to_le().to_ne_bytes()
3818 }
3819
3820 /// Returns the memory representation of this integer as a byte array in
3821 /// native byte order.
3822 ///
3823 /// As the target platform's native endianness is used, portable code
3824 /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
3825 /// instead.
3826 ///
3827 #[doc = $to_xe_bytes_doc]
3828 ///
3829 /// [`to_be_bytes`]: Self::to_be_bytes
3830 /// [`to_le_bytes`]: Self::to_le_bytes
3831 ///
3832 /// # Examples
3833 ///
3834 /// ```
3835 #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
3836 /// assert_eq!(
3837 /// bytes,
3838 /// if cfg!(target_endian = "big") {
3839 #[doc = concat!(" ", $be_bytes)]
3840 /// } else {
3841 #[doc = concat!(" ", $le_bytes)]
3842 /// }
3843 /// );
3844 /// ```
3845 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3846 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3847 #[allow(unnecessary_transmutes)]
3848 // SAFETY: const sound because integers are plain old datatypes so we can always
3849 // transmute them to arrays of bytes
3850 #[must_use = "this returns the result of the operation, \
3851 without modifying the original"]
3852 #[inline]
3853 pub const fn to_ne_bytes(self) -> [u8; size_of::<Self>()] {
3854 // SAFETY: integers are plain old datatypes so we can always transmute them to
3855 // arrays of bytes
3856 unsafe { mem::transmute(self) }
3857 }
3858
3859 /// Creates an integer value from its representation as a byte array in
3860 /// big endian.
3861 ///
3862 #[doc = $from_xe_bytes_doc]
3863 ///
3864 /// # Examples
3865 ///
3866 /// ```
3867 #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
3868 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3869 /// ```
3870 ///
3871 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3872 ///
3873 /// ```
3874 #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3875 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3876 /// *input = rest;
3877 #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
3878 /// }
3879 /// ```
3880 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3881 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3882 #[must_use]
3883 #[inline]
3884 pub const fn from_be_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3885 Self::from_be(Self::from_ne_bytes(bytes))
3886 }
3887
3888 /// Creates an integer value from its representation as a byte array in
3889 /// little endian.
3890 ///
3891 #[doc = $from_xe_bytes_doc]
3892 ///
3893 /// # Examples
3894 ///
3895 /// ```
3896 #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
3897 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3898 /// ```
3899 ///
3900 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3901 ///
3902 /// ```
3903 #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3904 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3905 /// *input = rest;
3906 #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
3907 /// }
3908 /// ```
3909 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3910 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3911 #[must_use]
3912 #[inline]
3913 pub const fn from_le_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3914 Self::from_le(Self::from_ne_bytes(bytes))
3915 }
3916
3917 /// Creates an integer value from its memory representation as a byte
3918 /// array in native endianness.
3919 ///
3920 /// As the target platform's native endianness is used, portable code
3921 /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
3922 /// appropriate instead.
3923 ///
3924 /// [`from_be_bytes`]: Self::from_be_bytes
3925 /// [`from_le_bytes`]: Self::from_le_bytes
3926 ///
3927 #[doc = $from_xe_bytes_doc]
3928 ///
3929 /// # Examples
3930 ///
3931 /// ```
3932 #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
3933 #[doc = concat!(" ", $be_bytes)]
3934 /// } else {
3935 #[doc = concat!(" ", $le_bytes)]
3936 /// });
3937 #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3938 /// ```
3939 ///
3940 /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3941 ///
3942 /// ```
3943 #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3944 #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3945 /// *input = rest;
3946 #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
3947 /// }
3948 /// ```
3949 #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3950 #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3951 #[allow(unnecessary_transmutes)]
3952 #[must_use]
3953 // SAFETY: const sound because integers are plain old datatypes so we can always
3954 // transmute to them
3955 #[inline]
3956 pub const fn from_ne_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3957 // SAFETY: integers are plain old datatypes so we can always transmute to them
3958 unsafe { mem::transmute(bytes) }
3959 }
3960
3961 /// New code should prefer to use
3962 #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
3963 ///
3964 /// Returns the smallest value that can be represented by this integer type.
3965 #[stable(feature = "rust1", since = "1.0.0")]
3966 #[inline(always)]
3967 #[rustc_promotable]
3968 #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
3969 #[deprecated(since = "1.99.0", note = "replaced by the `MIN` associated constant on this type")]
3970 #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
3971 pub const fn min_value() -> Self {
3972 Self::MIN
3973 }
3974
3975 /// New code should prefer to use
3976 #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
3977 ///
3978 /// Returns the largest value that can be represented by this integer type.
3979 #[stable(feature = "rust1", since = "1.0.0")]
3980 #[inline(always)]
3981 #[rustc_promotable]
3982 #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
3983 #[deprecated(since = "1.99.0", note = "replaced by the `MAX` associated constant on this type")]
3984 #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
3985 pub const fn max_value() -> Self {
3986 Self::MAX
3987 }
3988
3989 /// Clamps this number to a symmetric range centred around zero.
3990 ///
3991 /// The method clamps the number's magnitude (absolute value) to be at most `limit`.
3992 ///
3993 /// This is functionally equivalent to `self.clamp(-limit, limit)`, but is more
3994 /// explicit about the intent.
3995 ///
3996 /// # Examples
3997 ///
3998 /// ```
3999 /// #![feature(clamp_magnitude)]
4000 #[doc = concat!("assert_eq!(120", stringify!($SelfT), ".clamp_magnitude(100), 100);")]
4001 #[doc = concat!("assert_eq!((-120", stringify!($SelfT), ").clamp_magnitude(100), -100);")]
4002 #[doc = concat!("assert_eq!(80", stringify!($SelfT), ".clamp_magnitude(100), 80);")]
4003 #[doc = concat!("assert_eq!((-80", stringify!($SelfT), ").clamp_magnitude(100), -80);")]
4004 /// ```
4005 #[inline]
4006 #[must_use = "method returns a new number and does not mutate the original value"]
4007 #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
4008 #[unstable(feature = "clamp_magnitude", issue = "148519")]
4009 pub const fn clamp_magnitude(self, limit: $UnsignedT) -> Self {
4010 if let Ok(limit) = core::convert::TryInto::<$SelfT>::try_into(limit) {
4011 self.clamp(-limit, limit)
4012 } else {
4013 self
4014 }
4015 }
4016
4017 /// Truncate an integer to an integer of the same size or smaller, preserving the least
4018 /// significant bits.
4019 ///
4020 /// # Examples
4021 ///
4022 /// ```
4023 /// #![feature(integer_widen_truncate)]
4024 #[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".truncate());")]
4025 #[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").truncate());")]
4026 /// assert_eq!(120i8, 376i32.truncate());
4027 /// ```
4028 #[must_use = "this returns the truncated value and does not modify the original"]
4029 #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4030 #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4031 #[inline]
4032 pub const fn truncate<Target>(self) -> Target
4033 where Self: [const] traits::TruncateTarget<Target>
4034 {
4035 traits::TruncateTarget::internal_truncate(self)
4036 }
4037
4038 /// Truncate an integer to an integer of the same size or smaller, saturating at numeric bounds
4039 /// instead of truncating.
4040 ///
4041 /// # Examples
4042 ///
4043 /// ```
4044 /// #![feature(integer_widen_truncate)]
4045 #[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".saturating_truncate());")]
4046 #[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").saturating_truncate());")]
4047 /// assert_eq!(127i8, 376i32.saturating_truncate());
4048 /// assert_eq!(-128i8, (-1000i32).saturating_truncate());
4049 /// ```
4050 #[must_use = "this returns the truncated value and does not modify the original"]
4051 #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4052 #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4053 #[inline]
4054 pub const fn saturating_truncate<Target>(self) -> Target
4055 where Self: [const] traits::TruncateTarget<Target>
4056 {
4057 traits::TruncateTarget::internal_saturating_truncate(self)
4058 }
4059
4060 /// Truncate an integer to an integer of the same size or smaller, returning `None` if the value
4061 /// is outside the bounds of the smaller type.
4062 ///
4063 /// # Examples
4064 ///
4065 /// ```
4066 /// #![feature(integer_widen_truncate)]
4067 #[doc = concat!("assert_eq!(Some(120i8), 120", stringify!($SelfT), ".checked_truncate());")]
4068 #[doc = concat!("assert_eq!(Some(-120i8), (-120", stringify!($SelfT), ").checked_truncate());")]
4069 /// assert_eq!(None, 376i32.checked_truncate::<i8>());
4070 /// assert_eq!(None, (-1000i32).checked_truncate::<i8>());
4071 /// ```
4072 #[must_use = "this returns the truncated value and does not modify the original"]
4073 #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4074 #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4075 #[inline]
4076 pub const fn checked_truncate<Target>(self) -> Option<Target>
4077 where Self: [const] traits::TruncateTarget<Target>
4078 {
4079 traits::TruncateTarget::internal_checked_truncate(self)
4080 }
4081
4082 /// Widen to an integer of the same size or larger, preserving its value.
4083 ///
4084 /// # Examples
4085 ///
4086 /// ```
4087 /// #![feature(integer_widen_truncate)]
4088 #[doc = concat!("assert_eq!(120i128, 120i8.widen());")]
4089 #[doc = concat!("assert_eq!(-120i128, (-120i8).widen());")]
4090 /// ```
4091 #[must_use = "this returns the widened value and does not modify the original"]
4092 #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4093 #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4094 #[inline]
4095 pub const fn widen<Target>(self) -> Target
4096 where Self: [const] traits::WidenTarget<Target>
4097 {
4098 traits::WidenTarget::internal_widen(self)
4099 }
4100
4101 /// Converts `self` to the target integer type, saturating at the numeric
4102 /// bounds instead of overflowing.
4103 ///
4104 /// # Examples
4105 ///
4106 /// ```
4107 /// #![feature(integer_casts)]
4108 #[doc = concat!("assert_eq!(i8::MAX, ", stringify!($SelfT), "::MAX.saturating_cast());")]
4109 #[doc = concat!("assert_eq!(i8::MIN, ", stringify!($SelfT), "::MIN.saturating_cast());")]
4110 #[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".saturating_cast());")]
4111 #[doc = concat!("assert_eq!(0u8, (-42", stringify!($SelfT), ").saturating_cast());")]
4112 /// ```
4113 #[must_use = "this returns the cast result and does not modify the original"]
4114 #[unstable(feature = "integer_casts", issue = "157388")]
4115 #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4116 #[inline(always)]
4117 pub const fn saturating_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
4118 T::saturating_cast_from(self)
4119 }
4120
4121 /// Converts `self` to the target integer type, wrapping around at the
4122 /// boundary of the target type.
4123 ///
4124 /// # Examples
4125 ///
4126 /// ```
4127 /// #![feature(integer_casts)]
4128 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX as i8, ", stringify!($SelfT), "::MAX.wrapping_cast());")]
4129 #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN as i8, ", stringify!($SelfT), "::MIN.wrapping_cast());")]
4130 #[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".wrapping_cast());")]
4131 #[doc = concat!("assert_eq!(u8::MAX - 41, (-42", stringify!($SelfT), ").wrapping_cast());")]
4132 /// ```
4133 #[must_use = "this returns the cast result and does not modify the original"]
4134 #[unstable(feature = "integer_casts", issue = "157388")]
4135 #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4136 #[inline(always)]
4137 pub const fn wrapping_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
4138 T::wrapping_cast_from(self)
4139 }
4140
4141 /// Converts `self` to the target integer type, returning `None` if the value
4142 /// is not representable by the target type.
4143 ///
4144 /// # Examples
4145 ///
4146 /// ```
4147 /// #![feature(integer_casts)]
4148 #[doc = concat!("assert_eq!(Some(42u8), 42", stringify!($SelfT), ".checked_cast());")]
4149 #[doc = concat!("assert_eq!((-42", stringify!($SelfT), ").checked_cast::<u8>(), None);")]
4150 /// ```
4151 #[must_use = "this returns the cast result and does not modify the original"]
4152 #[unstable(feature = "integer_casts", issue = "157388")]
4153 #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4154 #[inline(always)]
4155 pub const fn checked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> Option<T> {
4156 T::checked_cast_from(self)
4157 }
4158
4159 /// Converts `self` to the target integer type, panicking if the value
4160 /// is not representable by the target type.
4161 ///
4162 /// # Panics
4163 ///
4164 /// This function will panic if the value is not representable by the target type.
4165 ///
4166 /// # Examples
4167 ///
4168 /// ```
4169 /// #![feature(integer_casts)]
4170 #[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".strict_cast());")]
4171 /// ```
4172 ///
4173 /// The following will panic:
4174 ///
4175 /// ```should_panic
4176 /// #![feature(integer_casts)]
4177 #[doc = concat!("let _ = (-42", stringify!($SelfT), ").strict_cast::<u8>();")]
4178 /// ```
4179 #[must_use = "this returns the cast result and does not modify the original"]
4180 #[unstable(feature = "integer_casts", issue = "157388")]
4181 #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4182 #[inline(always)]
4183 #[track_caller]
4184 pub const fn strict_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
4185 T::strict_cast_from(self)
4186 }
4187
4188 /// Converts `self` to the target integer type, assuming the value is
4189 /// representable by the target type.
4190 ///
4191 /// # Safety
4192 ///
4193 /// This results in undefined behavior if the integer value of `self` is bigger than `T::MAX`,
4194 /// or smaller than `T::MIN`, where `T` is the target type.
4195 #[must_use = "this returns the cast result and does not modify the original"]
4196 #[unstable(feature = "integer_casts", issue = "157388")]
4197 #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4198 #[inline(always)]
4199 pub const unsafe fn unchecked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
4200 assert_unsafe_precondition!(
4201 check_language_ub,
4202 concat!(stringify!($SelfT), "::unchecked_cast must fit in the target type"),
4203 (
4204 // Check has to be performed up-front because it depends on generic T.
4205 in_bounds: bool = {
4206 let cast_val = self.checked_cast::<T>();
4207 let ret = cast_val.is_some();
4208 core::mem::forget(cast_val); // We don't have const Drop, but we know it's an int.
4209 ret
4210 },
4211 ) => in_bounds,
4212 );
4213
4214 // SAFETY: this is guaranteed to be safe by the caller.
4215 unsafe { T::unchecked_cast_from(self) }
4216 }
4217 }
4218}