core/num/
uint_macros.rs

1macro_rules! uint_impl {
2    (
3        Self = $SelfT:ty,
4        ActualT = $ActualT:ident,
5        SignedT = $SignedT:ident,
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        MAX = $MaxV:literal,
14        rot = $rot:literal,
15        rot_op = $rot_op:literal,
16        rot_result = $rot_result:literal,
17        fsh_op = $fsh_op:literal,
18        fshl_result = $fshl_result:literal,
19        fshr_result = $fshr_result:literal,
20        swap_op = $swap_op:literal,
21        swapped = $swapped:literal,
22        reversed = $reversed:literal,
23        le_bytes = $le_bytes:literal,
24        be_bytes = $be_bytes:literal,
25        to_xe_bytes_doc = $to_xe_bytes_doc:expr,
26        from_xe_bytes_doc = $from_xe_bytes_doc:expr,
27        bound_condition = $bound_condition:literal,
28    ) => {
29        /// The smallest value that can be represented by this integer type.
30        ///
31        /// # Examples
32        ///
33        /// ```
34        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, 0);")]
35        /// ```
36        #[stable(feature = "assoc_int_consts", since = "1.43.0")]
37        pub const MIN: Self = 0;
38
39        /// The largest value that can be represented by this integer type
40        #[doc = concat!("(2<sup>", $BITS, "</sup> &minus; 1", $bound_condition, ").")]
41        ///
42        /// # Examples
43        ///
44        /// ```
45        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($MaxV), ");")]
46        /// ```
47        #[stable(feature = "assoc_int_consts", since = "1.43.0")]
48        pub const MAX: Self = !0;
49
50        /// The size of this integer type in bits.
51        ///
52        /// # Examples
53        ///
54        /// ```
55        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
56        /// ```
57        #[stable(feature = "int_bits_const", since = "1.53.0")]
58        pub const BITS: u32 = Self::MAX.count_ones();
59
60        /// Returns the number of ones in the binary representation of `self`.
61        ///
62        /// # Examples
63        ///
64        /// ```
65        #[doc = concat!("let n = 0b01001100", stringify!($SelfT), ";")]
66        /// assert_eq!(n.count_ones(), 3);
67        ///
68        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
69        #[doc = concat!("assert_eq!(max.count_ones(), ", stringify!($BITS), ");")]
70        ///
71        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
72        /// assert_eq!(zero.count_ones(), 0);
73        /// ```
74        #[stable(feature = "rust1", since = "1.0.0")]
75        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
76        #[doc(alias = "popcount")]
77        #[doc(alias = "popcnt")]
78        #[must_use = "this returns the result of the operation, \
79                      without modifying the original"]
80        #[inline(always)]
81        pub const fn count_ones(self) -> u32 {
82            return intrinsics::ctpop(self);
83        }
84
85        /// Returns the number of zeros in the binary representation of `self`.
86        ///
87        /// # Examples
88        ///
89        /// ```
90        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
91        #[doc = concat!("assert_eq!(zero.count_zeros(), ", stringify!($BITS), ");")]
92        ///
93        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
94        /// assert_eq!(max.count_zeros(), 0);
95        /// ```
96        #[stable(feature = "rust1", since = "1.0.0")]
97        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
98        #[must_use = "this returns the result of the operation, \
99                      without modifying the original"]
100        #[inline(always)]
101        pub const fn count_zeros(self) -> u32 {
102            (!self).count_ones()
103        }
104
105        /// Returns the number of leading zeros in the binary representation of `self`.
106        ///
107        /// Depending on what you're doing with the value, you might also be interested in the
108        /// [`ilog2`] function which returns a consistent number, even if the type widens.
109        ///
110        /// # Examples
111        ///
112        /// ```
113        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX >> 2;")]
114        /// assert_eq!(n.leading_zeros(), 2);
115        ///
116        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
117        #[doc = concat!("assert_eq!(zero.leading_zeros(), ", stringify!($BITS), ");")]
118        ///
119        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
120        /// assert_eq!(max.leading_zeros(), 0);
121        /// ```
122        #[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")]
123        #[stable(feature = "rust1", since = "1.0.0")]
124        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
125        #[must_use = "this returns the result of the operation, \
126                      without modifying the original"]
127        #[inline(always)]
128        pub const fn leading_zeros(self) -> u32 {
129            return intrinsics::ctlz(self as $ActualT);
130        }
131
132        /// Returns the number of trailing zeros in the binary representation
133        /// of `self`.
134        ///
135        /// # Examples
136        ///
137        /// ```
138        #[doc = concat!("let n = 0b0101000", stringify!($SelfT), ";")]
139        /// assert_eq!(n.trailing_zeros(), 3);
140        ///
141        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
142        #[doc = concat!("assert_eq!(zero.trailing_zeros(), ", stringify!($BITS), ");")]
143        ///
144        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
145        #[doc = concat!("assert_eq!(max.trailing_zeros(), 0);")]
146        /// ```
147        #[stable(feature = "rust1", since = "1.0.0")]
148        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
149        #[must_use = "this returns the result of the operation, \
150                      without modifying the original"]
151        #[inline(always)]
152        pub const fn trailing_zeros(self) -> u32 {
153            return intrinsics::cttz(self);
154        }
155
156        /// Returns the number of leading ones in the binary representation of `self`.
157        ///
158        /// # Examples
159        ///
160        /// ```
161        #[doc = concat!("let n = !(", stringify!($SelfT), "::MAX >> 2);")]
162        /// assert_eq!(n.leading_ones(), 2);
163        ///
164        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
165        /// assert_eq!(zero.leading_ones(), 0);
166        ///
167        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
168        #[doc = concat!("assert_eq!(max.leading_ones(), ", stringify!($BITS), ");")]
169        /// ```
170        #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
171        #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
172        #[must_use = "this returns the result of the operation, \
173                      without modifying the original"]
174        #[inline(always)]
175        pub const fn leading_ones(self) -> u32 {
176            (!self).leading_zeros()
177        }
178
179        /// Returns the number of trailing ones in the binary representation
180        /// of `self`.
181        ///
182        /// # Examples
183        ///
184        /// ```
185        #[doc = concat!("let n = 0b1010111", stringify!($SelfT), ";")]
186        /// assert_eq!(n.trailing_ones(), 3);
187        ///
188        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
189        /// assert_eq!(zero.trailing_ones(), 0);
190        ///
191        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
192        #[doc = concat!("assert_eq!(max.trailing_ones(), ", stringify!($BITS), ");")]
193        /// ```
194        #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
195        #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
196        #[must_use = "this returns the result of the operation, \
197                      without modifying the original"]
198        #[inline(always)]
199        pub const fn trailing_ones(self) -> u32 {
200            (!self).trailing_zeros()
201        }
202
203        /// Returns the minimum number of bits required to represent `self`.
204        ///
205        /// This method returns zero if `self` is zero.
206        ///
207        /// # Examples
208        ///
209        /// ```
210        /// #![feature(uint_bit_width)]
211        ///
212        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".bit_width(), 0);")]
213        #[doc = concat!("assert_eq!(0b111_", stringify!($SelfT), ".bit_width(), 3);")]
214        #[doc = concat!("assert_eq!(0b1110_", stringify!($SelfT), ".bit_width(), 4);")]
215        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.bit_width(), ", stringify!($BITS), ");")]
216        /// ```
217        #[unstable(feature = "uint_bit_width", issue = "142326")]
218        #[must_use = "this returns the result of the operation, \
219                      without modifying the original"]
220        #[inline(always)]
221        pub const fn bit_width(self) -> u32 {
222            Self::BITS - self.leading_zeros()
223        }
224
225        /// Returns `self` with only the most significant bit set, or `0` if
226        /// the input is `0`.
227        ///
228        /// # Examples
229        ///
230        /// ```
231        /// #![feature(isolate_most_least_significant_one)]
232        ///
233        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
234        ///
235        /// assert_eq!(n.isolate_highest_one(), 0b_01000000);
236        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_highest_one(), 0);")]
237        /// ```
238        #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
239        #[must_use = "this returns the result of the operation, \
240                      without modifying the original"]
241        #[inline(always)]
242        pub const fn isolate_highest_one(self) -> Self {
243            self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros()))
244        }
245
246        /// Returns `self` with only the least significant bit set, or `0` if
247        /// the input is `0`.
248        ///
249        /// # Examples
250        ///
251        /// ```
252        /// #![feature(isolate_most_least_significant_one)]
253        ///
254        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
255        ///
256        /// assert_eq!(n.isolate_lowest_one(), 0b_00000100);
257        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_lowest_one(), 0);")]
258        /// ```
259        #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
260        #[must_use = "this returns the result of the operation, \
261                      without modifying the original"]
262        #[inline(always)]
263        pub const fn isolate_lowest_one(self) -> Self {
264            self & self.wrapping_neg()
265        }
266
267        /// Returns the index of the highest bit set to one in `self`, or `None`
268        /// if `self` is `0`.
269        ///
270        /// # Examples
271        ///
272        /// ```
273        /// #![feature(int_lowest_highest_one)]
274        ///
275        #[doc = concat!("assert_eq!(0x0_", stringify!($SelfT), ".highest_one(), None);")]
276        #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".highest_one(), Some(0));")]
277        #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".highest_one(), Some(4));")]
278        #[doc = concat!("assert_eq!(0x1f_", stringify!($SelfT), ".highest_one(), Some(4));")]
279        /// ```
280        #[unstable(feature = "int_lowest_highest_one", issue = "145203")]
281        #[must_use = "this returns the result of the operation, \
282                      without modifying the original"]
283        #[inline(always)]
284        pub const fn highest_one(self) -> Option<u32> {
285            match NonZero::new(self) {
286                Some(v) => Some(v.highest_one()),
287                None => None,
288            }
289        }
290
291        /// Returns the index of the lowest bit set to one in `self`, or `None`
292        /// if `self` is `0`.
293        ///
294        /// # Examples
295        ///
296        /// ```
297        /// #![feature(int_lowest_highest_one)]
298        ///
299        #[doc = concat!("assert_eq!(0x0_", stringify!($SelfT), ".lowest_one(), None);")]
300        #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".lowest_one(), Some(0));")]
301        #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".lowest_one(), Some(4));")]
302        #[doc = concat!("assert_eq!(0x1f_", stringify!($SelfT), ".lowest_one(), Some(0));")]
303        /// ```
304        #[unstable(feature = "int_lowest_highest_one", issue = "145203")]
305        #[must_use = "this returns the result of the operation, \
306                      without modifying the original"]
307        #[inline(always)]
308        pub const fn lowest_one(self) -> Option<u32> {
309            match NonZero::new(self) {
310                Some(v) => Some(v.lowest_one()),
311                None => None,
312            }
313        }
314
315        /// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size.
316        ///
317        /// This produces the same result as an `as` cast, but ensures that the bit-width remains
318        /// the same.
319        ///
320        /// # Examples
321        ///
322        /// ```
323        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")]
324        ///
325        #[doc = concat!("assert_eq!(n.cast_signed(), -1", stringify!($SignedT), ");")]
326        /// ```
327        #[stable(feature = "integer_sign_cast", since = "1.87.0")]
328        #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
329        #[must_use = "this returns the result of the operation, \
330                      without modifying the original"]
331        #[inline(always)]
332        pub const fn cast_signed(self) -> $SignedT {
333            self as $SignedT
334        }
335
336        /// Shifts the bits to the left by a specified amount, `n`,
337        /// wrapping the truncated bits to the end of the resulting integer.
338        ///
339        /// Please note this isn't the same operation as the `<<` shifting operator!
340        ///
341        /// # Examples
342        ///
343        /// ```
344        #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
345        #[doc = concat!("let m = ", $rot_result, ";")]
346        ///
347        #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
348        /// ```
349        #[stable(feature = "rust1", since = "1.0.0")]
350        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
351        #[must_use = "this returns the result of the operation, \
352                      without modifying the original"]
353        #[inline(always)]
354        pub const fn rotate_left(self, n: u32) -> Self {
355            return intrinsics::rotate_left(self, n);
356        }
357
358        /// Shifts the bits to the right by a specified amount, `n`,
359        /// wrapping the truncated bits to the beginning of the resulting
360        /// integer.
361        ///
362        /// Please note this isn't the same operation as the `>>` shifting operator!
363        ///
364        /// # Examples
365        ///
366        /// ```
367        #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
368        #[doc = concat!("let m = ", $rot_op, ";")]
369        ///
370        #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
371        /// ```
372        #[stable(feature = "rust1", since = "1.0.0")]
373        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
374        #[must_use = "this returns the result of the operation, \
375                      without modifying the original"]
376        #[inline(always)]
377        pub const fn rotate_right(self, n: u32) -> Self {
378            return intrinsics::rotate_right(self, n);
379        }
380
381        /// Performs a left funnel shift (concatenates `self` with `rhs`, with `self`
382        /// making up the most significant half, then shifts the combined value left
383        /// by `n`, and most significant half is extracted to produce the result).
384        ///
385        /// Please note this isn't the same operation as the `<<` shifting operator or
386        /// [`rotate_left`](Self::rotate_left), although `a.funnel_shl(a, n)` is *equivalent*
387        /// to `a.rotate_left(n)`.
388        ///
389        /// # Panics
390        ///
391        /// If `n` is greater than or equal to the number of bits in `self`
392        ///
393        /// # Examples
394        ///
395        /// Basic usage:
396        ///
397        /// ```
398        /// #![feature(funnel_shifts)]
399        #[doc = concat!("let a = ", $rot_op, stringify!($SelfT), ";")]
400        #[doc = concat!("let b = ", $fsh_op, stringify!($SelfT), ";")]
401        #[doc = concat!("let m = ", $fshl_result, ";")]
402        ///
403        #[doc = concat!("assert_eq!(a.funnel_shl(b, ", $rot, "), m);")]
404        /// ```
405        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
406        #[unstable(feature = "funnel_shifts", issue = "145686")]
407        #[must_use = "this returns the result of the operation, \
408                      without modifying the original"]
409        #[inline(always)]
410        pub const fn funnel_shl(self, rhs: Self, n: u32) -> Self {
411            assert!(n < Self::BITS, "attempt to funnel shift left with overflow");
412            // SAFETY: just checked that `shift` is in-range
413            unsafe { intrinsics::unchecked_funnel_shl(self, rhs, n) }
414        }
415
416        /// Performs a right funnel shift (concatenates `self` and `rhs`, with `self`
417        /// making up the most significant half, then shifts the combined value right
418        /// by `n`, and least significant half is extracted to produce the result).
419        ///
420        /// Please note this isn't the same operation as the `>>` shifting operator or
421        /// [`rotate_right`](Self::rotate_right), although `a.funnel_shr(a, n)` is *equivalent*
422        /// to `a.rotate_right(n)`.
423        ///
424        /// # Panics
425        ///
426        /// If `n` is greater than or equal to the number of bits in `self`
427        ///
428        /// # Examples
429        ///
430        /// Basic usage:
431        ///
432        /// ```
433        /// #![feature(funnel_shifts)]
434        #[doc = concat!("let a = ", $rot_op, stringify!($SelfT), ";")]
435        #[doc = concat!("let b = ", $fsh_op, stringify!($SelfT), ";")]
436        #[doc = concat!("let m = ", $fshr_result, ";")]
437        ///
438        #[doc = concat!("assert_eq!(a.funnel_shr(b, ", $rot, "), m);")]
439        /// ```
440        #[rustc_const_unstable(feature = "funnel_shifts", issue = "145686")]
441        #[unstable(feature = "funnel_shifts", issue = "145686")]
442        #[must_use = "this returns the result of the operation, \
443                      without modifying the original"]
444        #[inline(always)]
445        pub const fn funnel_shr(self, rhs: Self, n: u32) -> Self {
446            assert!(n < Self::BITS, "attempt to funnel shift right with overflow");
447            // SAFETY: just checked that `shift` is in-range
448            unsafe { intrinsics::unchecked_funnel_shr(self, rhs, n) }
449        }
450
451        /// Reverses the byte order of the integer.
452        ///
453        /// # Examples
454        ///
455        /// ```
456        #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
457        /// let m = n.swap_bytes();
458        ///
459        #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
460        /// ```
461        #[stable(feature = "rust1", since = "1.0.0")]
462        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
463        #[must_use = "this returns the result of the operation, \
464                      without modifying the original"]
465        #[inline(always)]
466        pub const fn swap_bytes(self) -> Self {
467            intrinsics::bswap(self as $ActualT) as Self
468        }
469
470        /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
471        ///                 second least-significant bit becomes second most-significant bit, etc.
472        ///
473        /// # Examples
474        ///
475        /// ```
476        #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
477        /// let m = n.reverse_bits();
478        ///
479        #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
480        #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
481        /// ```
482        #[stable(feature = "reverse_bits", since = "1.37.0")]
483        #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
484        #[must_use = "this returns the result of the operation, \
485                      without modifying the original"]
486        #[inline(always)]
487        pub const fn reverse_bits(self) -> Self {
488            intrinsics::bitreverse(self as $ActualT) as Self
489        }
490
491        /// Converts an integer from big endian to the target's endianness.
492        ///
493        /// On big endian this is a no-op. On little endian the bytes are
494        /// swapped.
495        ///
496        /// # Examples
497        ///
498        /// ```
499        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
500        ///
501        /// if cfg!(target_endian = "big") {
502        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
503        /// } else {
504        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
505        /// }
506        /// ```
507        #[stable(feature = "rust1", since = "1.0.0")]
508        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
509        #[must_use]
510        #[inline(always)]
511        pub const fn from_be(x: Self) -> Self {
512            #[cfg(target_endian = "big")]
513            {
514                x
515            }
516            #[cfg(not(target_endian = "big"))]
517            {
518                x.swap_bytes()
519            }
520        }
521
522        /// Converts an integer from little endian to the target's endianness.
523        ///
524        /// On little endian this is a no-op. On big endian the bytes are
525        /// swapped.
526        ///
527        /// # Examples
528        ///
529        /// ```
530        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
531        ///
532        /// if cfg!(target_endian = "little") {
533        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
534        /// } else {
535        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
536        /// }
537        /// ```
538        #[stable(feature = "rust1", since = "1.0.0")]
539        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
540        #[must_use]
541        #[inline(always)]
542        pub const fn from_le(x: Self) -> Self {
543            #[cfg(target_endian = "little")]
544            {
545                x
546            }
547            #[cfg(not(target_endian = "little"))]
548            {
549                x.swap_bytes()
550            }
551        }
552
553        /// Converts `self` to big endian from the target's endianness.
554        ///
555        /// On big endian this is a no-op. On little endian the bytes are
556        /// swapped.
557        ///
558        /// # Examples
559        ///
560        /// ```
561        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
562        ///
563        /// if cfg!(target_endian = "big") {
564        ///     assert_eq!(n.to_be(), n)
565        /// } else {
566        ///     assert_eq!(n.to_be(), n.swap_bytes())
567        /// }
568        /// ```
569        #[stable(feature = "rust1", since = "1.0.0")]
570        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
571        #[must_use = "this returns the result of the operation, \
572                      without modifying the original"]
573        #[inline(always)]
574        pub const fn to_be(self) -> Self { // or not to be?
575            #[cfg(target_endian = "big")]
576            {
577                self
578            }
579            #[cfg(not(target_endian = "big"))]
580            {
581                self.swap_bytes()
582            }
583        }
584
585        /// Converts `self` to little endian from the target's endianness.
586        ///
587        /// On little endian this is a no-op. On big endian the bytes are
588        /// swapped.
589        ///
590        /// # Examples
591        ///
592        /// ```
593        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
594        ///
595        /// if cfg!(target_endian = "little") {
596        ///     assert_eq!(n.to_le(), n)
597        /// } else {
598        ///     assert_eq!(n.to_le(), n.swap_bytes())
599        /// }
600        /// ```
601        #[stable(feature = "rust1", since = "1.0.0")]
602        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
603        #[must_use = "this returns the result of the operation, \
604                      without modifying the original"]
605        #[inline(always)]
606        pub const fn to_le(self) -> Self {
607            #[cfg(target_endian = "little")]
608            {
609                self
610            }
611            #[cfg(not(target_endian = "little"))]
612            {
613                self.swap_bytes()
614            }
615        }
616
617        /// Checked integer addition. Computes `self + rhs`, returning `None`
618        /// if overflow occurred.
619        ///
620        /// # Examples
621        ///
622        /// ```
623        #[doc = concat!(
624            "assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), ",
625            "Some(", stringify!($SelfT), "::MAX - 1));"
626        )]
627        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
628        /// ```
629        #[stable(feature = "rust1", since = "1.0.0")]
630        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
631        #[must_use = "this returns the result of the operation, \
632                      without modifying the original"]
633        #[inline]
634        pub const fn checked_add(self, rhs: Self) -> Option<Self> {
635            // This used to use `overflowing_add`, but that means it ends up being
636            // a `wrapping_add`, losing some optimization opportunities. Notably,
637            // phrasing it this way helps `.checked_add(1)` optimize to a check
638            // against `MAX` and a `add nuw`.
639            // Per <https://github.com/rust-lang/rust/pull/124114#issuecomment-2066173305>,
640            // LLVM is happy to re-form the intrinsic later if useful.
641
642            if intrinsics::unlikely(intrinsics::add_with_overflow(self, rhs).1) {
643                None
644            } else {
645                // SAFETY: Just checked it doesn't overflow
646                Some(unsafe { intrinsics::unchecked_add(self, rhs) })
647            }
648        }
649
650        /// Strict integer addition. Computes `self + rhs`, panicking
651        /// if overflow occurred.
652        ///
653        /// # Panics
654        ///
655        /// ## Overflow behavior
656        ///
657        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
658        ///
659        /// # Examples
660        ///
661        /// ```
662        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
663        /// ```
664        ///
665        /// The following panics because of overflow:
666        ///
667        /// ```should_panic
668        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
669        /// ```
670        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
671        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
672        #[must_use = "this returns the result of the operation, \
673                      without modifying the original"]
674        #[inline]
675        #[track_caller]
676        pub const fn strict_add(self, rhs: Self) -> Self {
677            let (a, b) = self.overflowing_add(rhs);
678            if b { overflow_panic::add() } else { a }
679        }
680
681        /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
682        /// cannot occur.
683        ///
684        /// Calling `x.unchecked_add(y)` is semantically equivalent to calling
685        /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
686        ///
687        /// If you're just trying to avoid the panic in debug mode, then **do not**
688        /// use this.  Instead, you're looking for [`wrapping_add`].
689        ///
690        /// # Safety
691        ///
692        /// This results in undefined behavior when
693        #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
694        /// i.e. when [`checked_add`] would return `None`.
695        ///
696        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
697        #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
698        #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
699        #[stable(feature = "unchecked_math", since = "1.79.0")]
700        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
701        #[must_use = "this returns the result of the operation, \
702                      without modifying the original"]
703        #[inline(always)]
704        #[track_caller]
705        pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
706            assert_unsafe_precondition!(
707                check_language_ub,
708                concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
709                (
710                    lhs: $SelfT = self,
711                    rhs: $SelfT = rhs,
712                ) => !lhs.overflowing_add(rhs).1,
713            );
714
715            // SAFETY: this is guaranteed to be safe by the caller.
716            unsafe {
717                intrinsics::unchecked_add(self, rhs)
718            }
719        }
720
721        /// Checked addition with a signed integer. Computes `self + rhs`,
722        /// returning `None` if overflow occurred.
723        ///
724        /// # Examples
725        ///
726        /// ```
727        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(2), Some(3));")]
728        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(-2), None);")]
729        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_signed(3), None);")]
730        /// ```
731        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
732        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
733        #[must_use = "this returns the result of the operation, \
734                      without modifying the original"]
735        #[inline]
736        pub const fn checked_add_signed(self, rhs: $SignedT) -> Option<Self> {
737            let (a, b) = self.overflowing_add_signed(rhs);
738            if intrinsics::unlikely(b) { None } else { Some(a) }
739        }
740
741        /// Strict addition with a signed integer. Computes `self + rhs`,
742        /// panicking if overflow occurred.
743        ///
744        /// # Panics
745        ///
746        /// ## Overflow behavior
747        ///
748        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
749        ///
750        /// # Examples
751        ///
752        /// ```
753        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_signed(2), 3);")]
754        /// ```
755        ///
756        /// The following panic because of overflow:
757        ///
758        /// ```should_panic
759        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_add_signed(-2);")]
760        /// ```
761        ///
762        /// ```should_panic
763        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_signed(3);")]
764        /// ```
765        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
766        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
767        #[must_use = "this returns the result of the operation, \
768                      without modifying the original"]
769        #[inline]
770        #[track_caller]
771        pub const fn strict_add_signed(self, rhs: $SignedT) -> Self {
772            let (a, b) = self.overflowing_add_signed(rhs);
773            if b { overflow_panic::add() } else { a }
774        }
775
776        /// Checked integer subtraction. Computes `self - rhs`, returning
777        /// `None` if overflow occurred.
778        ///
779        /// # Examples
780        ///
781        /// ```
782        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub(1), Some(0));")]
783        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);")]
784        /// ```
785        #[stable(feature = "rust1", since = "1.0.0")]
786        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
787        #[must_use = "this returns the result of the operation, \
788                      without modifying the original"]
789        #[inline]
790        pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
791            // Per PR#103299, there's no advantage to the `overflowing` intrinsic
792            // for *unsigned* subtraction and we just emit the manual check anyway.
793            // Thus, rather than using `overflowing_sub` that produces a wrapping
794            // subtraction, check it ourself so we can use an unchecked one.
795
796            if self < rhs {
797                None
798            } else {
799                // SAFETY: just checked this can't overflow
800                Some(unsafe { intrinsics::unchecked_sub(self, rhs) })
801            }
802        }
803
804        /// Strict integer subtraction. Computes `self - rhs`, panicking if
805        /// overflow occurred.
806        ///
807        /// # Panics
808        ///
809        /// ## Overflow behavior
810        ///
811        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
812        ///
813        /// # Examples
814        ///
815        /// ```
816        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub(1), 0);")]
817        /// ```
818        ///
819        /// The following panics because of overflow:
820        ///
821        /// ```should_panic
822        #[doc = concat!("let _ = 0", stringify!($SelfT), ".strict_sub(1);")]
823        /// ```
824        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
825        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
826        #[must_use = "this returns the result of the operation, \
827                      without modifying the original"]
828        #[inline]
829        #[track_caller]
830        pub const fn strict_sub(self, rhs: Self) -> Self {
831            let (a, b) = self.overflowing_sub(rhs);
832            if b { overflow_panic::sub() } else { a }
833        }
834
835        /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
836        /// cannot occur.
837        ///
838        /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
839        /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
840        ///
841        /// If you're just trying to avoid the panic in debug mode, then **do not**
842        /// use this.  Instead, you're looking for [`wrapping_sub`].
843        ///
844        /// If you find yourself writing code like this:
845        ///
846        /// ```
847        /// # let foo = 30_u32;
848        /// # let bar = 20;
849        /// if foo >= bar {
850        ///     // SAFETY: just checked it will not overflow
851        ///     let diff = unsafe { foo.unchecked_sub(bar) };
852        ///     // ... use diff ...
853        /// }
854        /// ```
855        ///
856        /// Consider changing it to
857        ///
858        /// ```
859        /// # let foo = 30_u32;
860        /// # let bar = 20;
861        /// if let Some(diff) = foo.checked_sub(bar) {
862        ///     // ... use diff ...
863        /// }
864        /// ```
865        ///
866        /// As that does exactly the same thing -- including telling the optimizer
867        /// that the subtraction cannot overflow -- but avoids needing `unsafe`.
868        ///
869        /// # Safety
870        ///
871        /// This results in undefined behavior when
872        #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
873        /// i.e. when [`checked_sub`] would return `None`.
874        ///
875        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
876        #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
877        #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
878        #[stable(feature = "unchecked_math", since = "1.79.0")]
879        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
880        #[must_use = "this returns the result of the operation, \
881                      without modifying the original"]
882        #[inline(always)]
883        #[track_caller]
884        pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
885            assert_unsafe_precondition!(
886                check_language_ub,
887                concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
888                (
889                    lhs: $SelfT = self,
890                    rhs: $SelfT = rhs,
891                ) => !lhs.overflowing_sub(rhs).1,
892            );
893
894            // SAFETY: this is guaranteed to be safe by the caller.
895            unsafe {
896                intrinsics::unchecked_sub(self, rhs)
897            }
898        }
899
900        /// Checked subtraction with a signed integer. Computes `self - rhs`,
901        /// returning `None` if overflow occurred.
902        ///
903        /// # Examples
904        ///
905        /// ```
906        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(2), None);")]
907        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(-2), Some(3));")]
908        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_sub_signed(-4), None);")]
909        /// ```
910        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
911        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
912        #[must_use = "this returns the result of the operation, \
913                      without modifying the original"]
914        #[inline]
915        pub const fn checked_sub_signed(self, rhs: $SignedT) -> Option<Self> {
916            let (res, overflow) = self.overflowing_sub_signed(rhs);
917
918            if !overflow {
919                Some(res)
920            } else {
921                None
922            }
923        }
924
925        /// Strict subtraction with a signed integer. Computes `self - rhs`,
926        /// panicking if overflow occurred.
927        ///
928        /// # Panics
929        ///
930        /// ## Overflow behavior
931        ///
932        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
933        ///
934        /// # Examples
935        ///
936        /// ```
937        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".strict_sub_signed(2), 1);")]
938        /// ```
939        ///
940        /// The following panic because of overflow:
941        ///
942        /// ```should_panic
943        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_sub_signed(2);")]
944        /// ```
945        ///
946        /// ```should_panic
947        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX).strict_sub_signed(-1);")]
948        /// ```
949        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
950        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
951        #[must_use = "this returns the result of the operation, \
952                      without modifying the original"]
953        #[inline]
954        #[track_caller]
955        pub const fn strict_sub_signed(self, rhs: $SignedT) -> Self {
956            let (a, b) = self.overflowing_sub_signed(rhs);
957            if b { overflow_panic::sub() } else { a }
958        }
959
960        #[doc = concat!(
961            "Checked integer subtraction. Computes `self - rhs` and checks if the result fits into an [`",
962            stringify!($SignedT), "`], returning `None` if overflow occurred."
963        )]
964        ///
965        /// # Examples
966        ///
967        /// ```
968        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_signed_diff(2), Some(8));")]
969        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_signed_diff(10), Some(-8));")]
970        #[doc = concat!(
971            "assert_eq!(",
972            stringify!($SelfT),
973            "::MAX.checked_signed_diff(",
974            stringify!($SignedT),
975            "::MAX as ",
976            stringify!($SelfT),
977            "), None);"
978        )]
979        #[doc = concat!(
980            "assert_eq!((",
981            stringify!($SignedT),
982            "::MAX as ",
983            stringify!($SelfT),
984            ").checked_signed_diff(",
985            stringify!($SelfT),
986            "::MAX), Some(",
987            stringify!($SignedT),
988            "::MIN));"
989        )]
990        #[doc = concat!(
991            "assert_eq!((",
992            stringify!($SignedT),
993            "::MAX as ",
994            stringify!($SelfT),
995            " + 1).checked_signed_diff(0), None);"
996        )]
997        #[doc = concat!(
998            "assert_eq!(",
999            stringify!($SelfT),
1000            "::MAX.checked_signed_diff(",
1001            stringify!($SelfT),
1002            "::MAX), Some(0));"
1003        )]
1004        /// ```
1005        #[stable(feature = "unsigned_signed_diff", since = "1.91.0")]
1006        #[rustc_const_stable(feature = "unsigned_signed_diff", since = "1.91.0")]
1007        #[inline]
1008        pub const fn checked_signed_diff(self, rhs: Self) -> Option<$SignedT> {
1009            let res = self.wrapping_sub(rhs) as $SignedT;
1010            let overflow = (self >= rhs) == (res < 0);
1011
1012            if !overflow {
1013                Some(res)
1014            } else {
1015                None
1016            }
1017        }
1018
1019        /// Checked integer multiplication. Computes `self * rhs`, returning
1020        /// `None` if overflow occurred.
1021        ///
1022        /// # Examples
1023        ///
1024        /// ```
1025        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_mul(1), Some(5));")]
1026        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
1027        /// ```
1028        #[stable(feature = "rust1", since = "1.0.0")]
1029        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1030        #[must_use = "this returns the result of the operation, \
1031                      without modifying the original"]
1032        #[inline]
1033        pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
1034            let (a, b) = self.overflowing_mul(rhs);
1035            if intrinsics::unlikely(b) { None } else { Some(a) }
1036        }
1037
1038        /// Strict integer multiplication. Computes `self * rhs`, panicking if
1039        /// overflow occurred.
1040        ///
1041        /// # Panics
1042        ///
1043        /// ## Overflow behavior
1044        ///
1045        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1046        ///
1047        /// # Examples
1048        ///
1049        /// ```
1050        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_mul(1), 5);")]
1051        /// ```
1052        ///
1053        /// The following panics because of overflow:
1054        ///
1055        /// ``` should_panic
1056        #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
1057        /// ```
1058        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1059        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1060        #[must_use = "this returns the result of the operation, \
1061                      without modifying the original"]
1062        #[inline]
1063        #[track_caller]
1064        pub const fn strict_mul(self, rhs: Self) -> Self {
1065            let (a, b) = self.overflowing_mul(rhs);
1066            if b { overflow_panic::mul() } else { a }
1067        }
1068
1069        /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
1070        /// cannot occur.
1071        ///
1072        /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
1073        /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
1074        ///
1075        /// If you're just trying to avoid the panic in debug mode, then **do not**
1076        /// use this.  Instead, you're looking for [`wrapping_mul`].
1077        ///
1078        /// # Safety
1079        ///
1080        /// This results in undefined behavior when
1081        #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
1082        /// i.e. when [`checked_mul`] would return `None`.
1083        ///
1084        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
1085        #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
1086        #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
1087        #[stable(feature = "unchecked_math", since = "1.79.0")]
1088        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
1089        #[must_use = "this returns the result of the operation, \
1090                      without modifying the original"]
1091        #[inline(always)]
1092        #[track_caller]
1093        pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
1094            assert_unsafe_precondition!(
1095                check_language_ub,
1096                concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
1097                (
1098                    lhs: $SelfT = self,
1099                    rhs: $SelfT = rhs,
1100                ) => !lhs.overflowing_mul(rhs).1,
1101            );
1102
1103            // SAFETY: this is guaranteed to be safe by the caller.
1104            unsafe {
1105                intrinsics::unchecked_mul(self, rhs)
1106            }
1107        }
1108
1109        /// Checked integer division. Computes `self / rhs`, returning `None`
1110        /// if `rhs == 0`.
1111        ///
1112        /// # Examples
1113        ///
1114        /// ```
1115        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div(2), Some(64));")]
1116        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div(0), None);")]
1117        /// ```
1118        #[stable(feature = "rust1", since = "1.0.0")]
1119        #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1120        #[must_use = "this returns the result of the operation, \
1121                      without modifying the original"]
1122        #[inline]
1123        pub const fn checked_div(self, rhs: Self) -> Option<Self> {
1124            if intrinsics::unlikely(rhs == 0) {
1125                None
1126            } else {
1127                // SAFETY: div by zero has been checked above and unsigned types have no other
1128                // failure modes for division
1129                Some(unsafe { intrinsics::unchecked_div(self, rhs) })
1130            }
1131        }
1132
1133        /// Strict integer division. Computes `self / rhs`.
1134        ///
1135        /// Strict division on unsigned types is just normal division. There's no
1136        /// way overflow could ever happen. This function exists so that all
1137        /// operations are accounted for in the strict operations.
1138        ///
1139        /// # Panics
1140        ///
1141        /// This function will panic if `rhs` is zero.
1142        ///
1143        /// # Examples
1144        ///
1145        /// ```
1146        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div(10), 10);")]
1147        /// ```
1148        ///
1149        /// The following panics because of division by zero:
1150        ///
1151        /// ```should_panic
1152        #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
1153        /// ```
1154        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1155        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1156        #[must_use = "this returns the result of the operation, \
1157                      without modifying the original"]
1158        #[inline(always)]
1159        #[track_caller]
1160        pub const fn strict_div(self, rhs: Self) -> Self {
1161            self / rhs
1162        }
1163
1164        /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, returning `None`
1165        /// if `rhs == 0`.
1166        ///
1167        /// # Examples
1168        ///
1169        /// ```
1170        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div_euclid(2), Some(64));")]
1171        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div_euclid(0), None);")]
1172        /// ```
1173        #[stable(feature = "euclidean_division", since = "1.38.0")]
1174        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1175        #[must_use = "this returns the result of the operation, \
1176                      without modifying the original"]
1177        #[inline]
1178        pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
1179            if intrinsics::unlikely(rhs == 0) {
1180                None
1181            } else {
1182                Some(self.div_euclid(rhs))
1183            }
1184        }
1185
1186        /// Strict Euclidean division. Computes `self.div_euclid(rhs)`.
1187        ///
1188        /// Strict division on unsigned types is just normal division. There's no
1189        /// way overflow could ever happen. This function exists so that all
1190        /// operations are accounted for in the strict operations. Since, for the
1191        /// positive integers, all common definitions of division are equal, this
1192        /// is exactly equal to `self.strict_div(rhs)`.
1193        ///
1194        /// # Panics
1195        ///
1196        /// This function will panic if `rhs` is zero.
1197        ///
1198        /// # Examples
1199        ///
1200        /// ```
1201        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div_euclid(10), 10);")]
1202        /// ```
1203        /// The following panics because of division by zero:
1204        ///
1205        /// ```should_panic
1206        #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
1207        /// ```
1208        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1209        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1210        #[must_use = "this returns the result of the operation, \
1211                      without modifying the original"]
1212        #[inline(always)]
1213        #[track_caller]
1214        pub const fn strict_div_euclid(self, rhs: Self) -> Self {
1215            self / rhs
1216        }
1217
1218        /// Checked integer division without remainder. Computes `self / rhs`,
1219        /// returning `None` if `rhs == 0` or if `self % rhs != 0`.
1220        ///
1221        /// # Examples
1222        ///
1223        /// ```
1224        /// #![feature(exact_div)]
1225        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_exact_div(2), Some(32));")]
1226        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_exact_div(32), Some(2));")]
1227        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_exact_div(0), None);")]
1228        #[doc = concat!("assert_eq!(65", stringify!($SelfT), ".checked_exact_div(2), None);")]
1229        /// ```
1230        #[unstable(
1231            feature = "exact_div",
1232            issue = "139911",
1233        )]
1234        #[must_use = "this returns the result of the operation, \
1235                      without modifying the original"]
1236        #[inline]
1237        pub const fn checked_exact_div(self, rhs: Self) -> Option<Self> {
1238            if intrinsics::unlikely(rhs == 0) {
1239                None
1240            } else {
1241                // SAFETY: division by zero is checked above
1242                unsafe {
1243                    if intrinsics::unlikely(intrinsics::unchecked_rem(self, rhs) != 0) {
1244                        None
1245                    } else {
1246                        Some(intrinsics::exact_div(self, rhs))
1247                    }
1248                }
1249            }
1250        }
1251
1252        /// Checked integer division without remainder. Computes `self / rhs`.
1253        ///
1254        /// # Panics
1255        ///
1256        /// This function will panic  if `rhs == 0` or `self % rhs != 0`.
1257        ///
1258        /// # Examples
1259        ///
1260        /// ```
1261        /// #![feature(exact_div)]
1262        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".exact_div(2), 32);")]
1263        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".exact_div(32), 2);")]
1264        /// ```
1265        ///
1266        /// ```should_panic
1267        /// #![feature(exact_div)]
1268        #[doc = concat!("let _ = 65", stringify!($SelfT), ".exact_div(2);")]
1269        /// ```
1270        #[unstable(
1271            feature = "exact_div",
1272            issue = "139911",
1273        )]
1274        #[must_use = "this returns the result of the operation, \
1275                      without modifying the original"]
1276        #[inline]
1277        pub const fn exact_div(self, rhs: Self) -> Self {
1278            match self.checked_exact_div(rhs) {
1279                Some(x) => x,
1280                None => panic!("Failed to divide without remainder"),
1281            }
1282        }
1283
1284        /// Unchecked integer division without remainder. Computes `self / rhs`.
1285        ///
1286        /// # Safety
1287        ///
1288        /// This results in undefined behavior when `rhs == 0` or `self % rhs != 0`,
1289        /// i.e. when [`checked_exact_div`](Self::checked_exact_div) would return `None`.
1290        #[unstable(
1291            feature = "exact_div",
1292            issue = "139911",
1293        )]
1294        #[must_use = "this returns the result of the operation, \
1295                      without modifying the original"]
1296        #[inline]
1297        pub const unsafe fn unchecked_exact_div(self, rhs: Self) -> Self {
1298            assert_unsafe_precondition!(
1299                check_language_ub,
1300                concat!(stringify!($SelfT), "::unchecked_exact_div divide by zero or leave a remainder"),
1301                (
1302                    lhs: $SelfT = self,
1303                    rhs: $SelfT = rhs,
1304                ) => rhs > 0 && lhs % rhs == 0,
1305            );
1306            // SAFETY: Same precondition
1307            unsafe { intrinsics::exact_div(self, rhs) }
1308        }
1309
1310        /// Checked integer remainder. Computes `self % rhs`, returning `None`
1311        /// if `rhs == 0`.
1312        ///
1313        /// # Examples
1314        ///
1315        /// ```
1316        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
1317        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
1318        /// ```
1319        #[stable(feature = "wrapping", since = "1.7.0")]
1320        #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1321        #[must_use = "this returns the result of the operation, \
1322                      without modifying the original"]
1323        #[inline]
1324        pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
1325            if intrinsics::unlikely(rhs == 0) {
1326                None
1327            } else {
1328                // SAFETY: div by zero has been checked above and unsigned types have no other
1329                // failure modes for division
1330                Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
1331            }
1332        }
1333
1334        /// Strict integer remainder. Computes `self % rhs`.
1335        ///
1336        /// Strict remainder calculation on unsigned types is just the regular
1337        /// remainder calculation. There's no way overflow could ever happen.
1338        /// This function exists so that all operations are accounted for in the
1339        /// strict operations.
1340        ///
1341        /// # Panics
1342        ///
1343        /// This function will panic if `rhs` is zero.
1344        ///
1345        /// # Examples
1346        ///
1347        /// ```
1348        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem(10), 0);")]
1349        /// ```
1350        ///
1351        /// The following panics because of division by zero:
1352        ///
1353        /// ```should_panic
1354        #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
1355        /// ```
1356        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1357        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1358        #[must_use = "this returns the result of the operation, \
1359                      without modifying the original"]
1360        #[inline(always)]
1361        #[track_caller]
1362        pub const fn strict_rem(self, rhs: Self) -> Self {
1363            self % rhs
1364        }
1365
1366        /// Checked Euclidean modulo. Computes `self.rem_euclid(rhs)`, returning `None`
1367        /// if `rhs == 0`.
1368        ///
1369        /// # Examples
1370        ///
1371        /// ```
1372        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
1373        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
1374        /// ```
1375        #[stable(feature = "euclidean_division", since = "1.38.0")]
1376        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1377        #[must_use = "this returns the result of the operation, \
1378                      without modifying the original"]
1379        #[inline]
1380        pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
1381            if intrinsics::unlikely(rhs == 0) {
1382                None
1383            } else {
1384                Some(self.rem_euclid(rhs))
1385            }
1386        }
1387
1388        /// Strict Euclidean modulo. Computes `self.rem_euclid(rhs)`.
1389        ///
1390        /// Strict modulo calculation on unsigned types is just the regular
1391        /// remainder calculation. There's no way overflow could ever happen.
1392        /// This function exists so that all operations are accounted for in the
1393        /// strict operations. Since, for the positive integers, all common
1394        /// definitions of division are equal, this is exactly equal to
1395        /// `self.strict_rem(rhs)`.
1396        ///
1397        /// # Panics
1398        ///
1399        /// This function will panic if `rhs` is zero.
1400        ///
1401        /// # Examples
1402        ///
1403        /// ```
1404        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem_euclid(10), 0);")]
1405        /// ```
1406        ///
1407        /// The following panics because of division by zero:
1408        ///
1409        /// ```should_panic
1410        #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
1411        /// ```
1412        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1413        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1414        #[must_use = "this returns the result of the operation, \
1415                      without modifying the original"]
1416        #[inline(always)]
1417        #[track_caller]
1418        pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
1419            self % rhs
1420        }
1421
1422        /// Same value as `self | other`, but UB if any bit position is set in both inputs.
1423        ///
1424        /// This is a situational micro-optimization for places where you'd rather
1425        /// use addition on some platforms and bitwise or on other platforms, based
1426        /// on exactly which instructions combine better with whatever else you're
1427        /// doing.  Note that there's no reason to bother using this for places
1428        /// where it's clear from the operations involved that they can't overlap.
1429        /// For example, if you're combining `u16`s into a `u32` with
1430        /// `((a as u32) << 16) | (b as u32)`, that's fine, as the backend will
1431        /// know those sides of the `|` are disjoint without needing help.
1432        ///
1433        /// # Examples
1434        ///
1435        /// ```
1436        /// #![feature(disjoint_bitor)]
1437        ///
1438        /// // SAFETY: `1` and `4` have no bits in common.
1439        /// unsafe {
1440        #[doc = concat!("    assert_eq!(1_", stringify!($SelfT), ".unchecked_disjoint_bitor(4), 5);")]
1441        /// }
1442        /// ```
1443        ///
1444        /// # Safety
1445        ///
1446        /// Requires that `(self & other) == 0`, otherwise it's immediate UB.
1447        ///
1448        /// Equivalently, requires that `(self | other) == (self + other)`.
1449        #[unstable(feature = "disjoint_bitor", issue = "135758")]
1450        #[rustc_const_unstable(feature = "disjoint_bitor", issue = "135758")]
1451        #[inline]
1452        pub const unsafe fn unchecked_disjoint_bitor(self, other: Self) -> Self {
1453            assert_unsafe_precondition!(
1454                check_language_ub,
1455                concat!(stringify!($SelfT), "::unchecked_disjoint_bitor cannot have overlapping bits"),
1456                (
1457                    lhs: $SelfT = self,
1458                    rhs: $SelfT = other,
1459                ) => (lhs & rhs) == 0,
1460            );
1461
1462            // SAFETY: Same precondition
1463            unsafe { intrinsics::disjoint_bitor(self, other) }
1464        }
1465
1466        /// Returns the logarithm of the number with respect to an arbitrary base,
1467        /// rounded down.
1468        ///
1469        /// This method might not be optimized owing to implementation details;
1470        /// `ilog2` can produce results more efficiently for base 2, and `ilog10`
1471        /// can produce results more efficiently for base 10.
1472        ///
1473        /// # Panics
1474        ///
1475        /// This function will panic if `self` is zero, or if `base` is less than 2.
1476        ///
1477        /// # Examples
1478        ///
1479        /// ```
1480        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
1481        /// ```
1482        #[stable(feature = "int_log", since = "1.67.0")]
1483        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1484        #[must_use = "this returns the result of the operation, \
1485                      without modifying the original"]
1486        #[inline]
1487        #[track_caller]
1488        pub const fn ilog(self, base: Self) -> u32 {
1489            assert!(base >= 2, "base of integer logarithm must be at least 2");
1490            if let Some(log) = self.checked_ilog(base) {
1491                log
1492            } else {
1493                int_log10::panic_for_nonpositive_argument()
1494            }
1495        }
1496
1497        /// Returns the base 2 logarithm of the number, rounded down.
1498        ///
1499        /// # Panics
1500        ///
1501        /// This function will panic if `self` is zero.
1502        ///
1503        /// # Examples
1504        ///
1505        /// ```
1506        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
1507        /// ```
1508        #[stable(feature = "int_log", since = "1.67.0")]
1509        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1510        #[must_use = "this returns the result of the operation, \
1511                      without modifying the original"]
1512        #[inline]
1513        #[track_caller]
1514        pub const fn ilog2(self) -> u32 {
1515            if let Some(log) = self.checked_ilog2() {
1516                log
1517            } else {
1518                int_log10::panic_for_nonpositive_argument()
1519            }
1520        }
1521
1522        /// Returns the base 10 logarithm of the number, rounded down.
1523        ///
1524        /// # Panics
1525        ///
1526        /// This function will panic if `self` is zero.
1527        ///
1528        /// # Example
1529        ///
1530        /// ```
1531        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
1532        /// ```
1533        #[stable(feature = "int_log", since = "1.67.0")]
1534        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1535        #[must_use = "this returns the result of the operation, \
1536                      without modifying the original"]
1537        #[inline]
1538        #[track_caller]
1539        pub const fn ilog10(self) -> u32 {
1540            if let Some(log) = self.checked_ilog10() {
1541                log
1542            } else {
1543                int_log10::panic_for_nonpositive_argument()
1544            }
1545        }
1546
1547        /// Returns the logarithm of the number with respect to an arbitrary base,
1548        /// rounded down.
1549        ///
1550        /// Returns `None` if the number is zero, or if the base is not at least 2.
1551        ///
1552        /// This method might not be optimized owing to implementation details;
1553        /// `checked_ilog2` can produce results more efficiently for base 2, and
1554        /// `checked_ilog10` can produce results more efficiently for base 10.
1555        ///
1556        /// # Examples
1557        ///
1558        /// ```
1559        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
1560        /// ```
1561        #[stable(feature = "int_log", since = "1.67.0")]
1562        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1563        #[must_use = "this returns the result of the operation, \
1564                      without modifying the original"]
1565        #[inline]
1566        pub const fn checked_ilog(self, base: Self) -> Option<u32> {
1567            // Inform compiler of optimizations when the base is known at
1568            // compile time and there's a cheaper method available.
1569            //
1570            // Note: Like all optimizations, this is not guaranteed to be
1571            // applied by the compiler. If you want those specific bases,
1572            // use `.checked_ilog2()` or `.checked_ilog10()` directly.
1573            if core::intrinsics::is_val_statically_known(base) {
1574                if base == 2 {
1575                    return self.checked_ilog2();
1576                } else if base == 10 {
1577                    return self.checked_ilog10();
1578                }
1579            }
1580
1581            if self <= 0 || base <= 1 {
1582                None
1583            } else if self < base {
1584                Some(0)
1585            } else {
1586                // Since base >= self, n >= 1
1587                let mut n = 1;
1588                let mut r = base;
1589
1590                // Optimization for 128 bit wide integers.
1591                if Self::BITS == 128 {
1592                    // The following is a correct lower bound for ⌊log(base,self)⌋ because
1593                    //
1594                    // log(base,self) = log(2,self) / log(2,base)
1595                    //                ≥ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1)
1596                    //
1597                    // hence
1598                    //
1599                    // ⌊log(base,self)⌋ ≥ ⌊ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1) ⌋ .
1600                    n = self.ilog2() / (base.ilog2() + 1);
1601                    r = base.pow(n);
1602                }
1603
1604                while r <= self / base {
1605                    n += 1;
1606                    r *= base;
1607                }
1608                Some(n)
1609            }
1610        }
1611
1612        /// Returns the base 2 logarithm of the number, rounded down.
1613        ///
1614        /// Returns `None` if the number is zero.
1615        ///
1616        /// # Examples
1617        ///
1618        /// ```
1619        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
1620        /// ```
1621        #[stable(feature = "int_log", since = "1.67.0")]
1622        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1623        #[must_use = "this returns the result of the operation, \
1624                      without modifying the original"]
1625        #[inline]
1626        pub const fn checked_ilog2(self) -> Option<u32> {
1627            match NonZero::new(self) {
1628                Some(x) => Some(x.ilog2()),
1629                None => None,
1630            }
1631        }
1632
1633        /// Returns the base 10 logarithm of the number, rounded down.
1634        ///
1635        /// Returns `None` if the number is zero.
1636        ///
1637        /// # Examples
1638        ///
1639        /// ```
1640        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
1641        /// ```
1642        #[stable(feature = "int_log", since = "1.67.0")]
1643        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1644        #[must_use = "this returns the result of the operation, \
1645                      without modifying the original"]
1646        #[inline]
1647        pub const fn checked_ilog10(self) -> Option<u32> {
1648            match NonZero::new(self) {
1649                Some(x) => Some(x.ilog10()),
1650                None => None,
1651            }
1652        }
1653
1654        /// Checked negation. Computes `-self`, returning `None` unless `self ==
1655        /// 0`.
1656        ///
1657        /// Note that negating any positive integer will overflow.
1658        ///
1659        /// # Examples
1660        ///
1661        /// ```
1662        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_neg(), Some(0));")]
1663        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_neg(), None);")]
1664        /// ```
1665        #[stable(feature = "wrapping", since = "1.7.0")]
1666        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1667        #[must_use = "this returns the result of the operation, \
1668                      without modifying the original"]
1669        #[inline]
1670        pub const fn checked_neg(self) -> Option<Self> {
1671            let (a, b) = self.overflowing_neg();
1672            if intrinsics::unlikely(b) { None } else { Some(a) }
1673        }
1674
1675        /// Strict negation. Computes `-self`, panicking unless `self ==
1676        /// 0`.
1677        ///
1678        /// Note that negating any positive integer will overflow.
1679        ///
1680        /// # Panics
1681        ///
1682        /// ## Overflow behavior
1683        ///
1684        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1685        ///
1686        /// # Examples
1687        ///
1688        /// ```
1689        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".strict_neg(), 0);")]
1690        /// ```
1691        ///
1692        /// The following panics because of overflow:
1693        ///
1694        /// ```should_panic
1695        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_neg();")]
1696        /// ```
1697        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1698        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1699        #[must_use = "this returns the result of the operation, \
1700                      without modifying the original"]
1701        #[inline]
1702        #[track_caller]
1703        pub const fn strict_neg(self) -> Self {
1704            let (a, b) = self.overflowing_neg();
1705            if b { overflow_panic::neg() } else { a }
1706        }
1707
1708        /// Checked shift left. Computes `self << rhs`, returning `None`
1709        /// if `rhs` is larger than or equal to the number of bits in `self`.
1710        ///
1711        /// # Examples
1712        ///
1713        /// ```
1714        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
1715        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(129), None);")]
1716        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
1717        /// ```
1718        #[stable(feature = "wrapping", since = "1.7.0")]
1719        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1720        #[must_use = "this returns the result of the operation, \
1721                      without modifying the original"]
1722        #[inline]
1723        pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
1724            // Not using overflowing_shl as that's a wrapping shift
1725            if rhs < Self::BITS {
1726                // SAFETY: just checked the RHS is in-range
1727                Some(unsafe { self.unchecked_shl(rhs) })
1728            } else {
1729                None
1730            }
1731        }
1732
1733        /// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
1734        /// than or equal to the number of bits in `self`.
1735        ///
1736        /// # Panics
1737        ///
1738        /// ## Overflow behavior
1739        ///
1740        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1741        ///
1742        /// # Examples
1743        ///
1744        /// ```
1745        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
1746        /// ```
1747        ///
1748        /// The following panics because of overflow:
1749        ///
1750        /// ```should_panic
1751        #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shl(129);")]
1752        /// ```
1753        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1754        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1755        #[must_use = "this returns the result of the operation, \
1756                      without modifying the original"]
1757        #[inline]
1758        #[track_caller]
1759        pub const fn strict_shl(self, rhs: u32) -> Self {
1760            let (a, b) = self.overflowing_shl(rhs);
1761            if b { overflow_panic::shl() } else { a }
1762        }
1763
1764        /// Unchecked shift left. Computes `self << rhs`, assuming that
1765        /// `rhs` is less than the number of bits in `self`.
1766        ///
1767        /// # Safety
1768        ///
1769        /// This results in undefined behavior if `rhs` is larger than
1770        /// or equal to the number of bits in `self`,
1771        /// i.e. when [`checked_shl`] would return `None`.
1772        ///
1773        #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
1774        #[unstable(
1775            feature = "unchecked_shifts",
1776            reason = "niche optimization path",
1777            issue = "85122",
1778        )]
1779        #[must_use = "this returns the result of the operation, \
1780                      without modifying the original"]
1781        #[inline(always)]
1782        #[track_caller]
1783        pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
1784            assert_unsafe_precondition!(
1785                check_language_ub,
1786                concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
1787                (
1788                    rhs: u32 = rhs,
1789                ) => rhs < <$ActualT>::BITS,
1790            );
1791
1792            // SAFETY: this is guaranteed to be safe by the caller.
1793            unsafe {
1794                intrinsics::unchecked_shl(self, rhs)
1795            }
1796        }
1797
1798        /// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
1799        ///
1800        /// If `rhs` is larger or equal to the number of bits in `self`,
1801        /// the entire value is shifted out, and `0` is returned.
1802        ///
1803        /// # Examples
1804        ///
1805        /// ```
1806        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
1807        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(129), 0);")]
1808        /// ```
1809        #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1810        #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1811        #[must_use = "this returns the result of the operation, \
1812                      without modifying the original"]
1813        #[inline]
1814        pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
1815            if rhs < Self::BITS {
1816                // SAFETY:
1817                // rhs is just checked to be in-range above
1818                unsafe { self.unchecked_shl(rhs) }
1819            } else {
1820                0
1821            }
1822        }
1823
1824        /// Exact shift left. Computes `self << rhs` as long as it can be reversed losslessly.
1825        ///
1826        /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
1827        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1828        /// Otherwise, returns `Some(self << rhs)`.
1829        ///
1830        /// # Examples
1831        ///
1832        /// ```
1833        /// #![feature(exact_bitshifts)]
1834        ///
1835        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".exact_shl(4), Some(0x10));")]
1836        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".exact_shl(129), None);")]
1837        /// ```
1838        #[unstable(feature = "exact_bitshifts", issue = "144336")]
1839        #[must_use = "this returns the result of the operation, \
1840                      without modifying the original"]
1841        #[inline]
1842        pub const fn exact_shl(self, rhs: u32) -> Option<$SelfT> {
1843            if rhs <= self.leading_zeros() && rhs < <$SelfT>::BITS {
1844                // SAFETY: rhs is checked above
1845                Some(unsafe { self.unchecked_shl(rhs) })
1846            } else {
1847                None
1848            }
1849        }
1850
1851        /// Unchecked exact shift left. Computes `self << rhs`, assuming the operation can be
1852        /// losslessly reversed `rhs` cannot be larger than
1853        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
1854        ///
1855        /// # Safety
1856        ///
1857        /// This results in undefined behavior when `rhs > self.leading_zeros() || rhs >=
1858        #[doc = concat!(stringify!($SelfT), "::BITS`")]
1859        /// i.e. when
1860        #[doc = concat!("[`", stringify!($SelfT), "::exact_shl`]")]
1861        /// would return `None`.
1862        #[unstable(feature = "exact_bitshifts", issue = "144336")]
1863        #[must_use = "this returns the result of the operation, \
1864                      without modifying the original"]
1865        #[inline]
1866        pub const unsafe fn unchecked_exact_shl(self, rhs: u32) -> $SelfT {
1867            assert_unsafe_precondition!(
1868                check_language_ub,
1869                concat!(stringify!($SelfT), "::exact_shl_unchecked cannot shift out non-zero bits"),
1870                (
1871                    zeros: u32 = self.leading_zeros(),
1872                    bits: u32 =  <$SelfT>::BITS,
1873                    rhs: u32 = rhs,
1874                ) => rhs <= zeros && rhs < bits,
1875            );
1876
1877            // SAFETY: this is guaranteed to be safe by the caller
1878            unsafe { self.unchecked_shl(rhs) }
1879        }
1880
1881        /// Checked shift right. Computes `self >> rhs`, returning `None`
1882        /// if `rhs` is larger than or equal to the number of bits in `self`.
1883        ///
1884        /// # Examples
1885        ///
1886        /// ```
1887        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
1888        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(129), None);")]
1889        /// ```
1890        #[stable(feature = "wrapping", since = "1.7.0")]
1891        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1892        #[must_use = "this returns the result of the operation, \
1893                      without modifying the original"]
1894        #[inline]
1895        pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
1896            // Not using overflowing_shr as that's a wrapping shift
1897            if rhs < Self::BITS {
1898                // SAFETY: just checked the RHS is in-range
1899                Some(unsafe { self.unchecked_shr(rhs) })
1900            } else {
1901                None
1902            }
1903        }
1904
1905        /// Strict shift right. Computes `self >> rhs`, panicking `rhs` is
1906        /// larger than or equal to the number of bits in `self`.
1907        ///
1908        /// # Panics
1909        ///
1910        /// ## Overflow behavior
1911        ///
1912        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1913        ///
1914        /// # Examples
1915        ///
1916        /// ```
1917        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
1918        /// ```
1919        ///
1920        /// The following panics because of overflow:
1921        ///
1922        /// ```should_panic
1923        #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(129);")]
1924        /// ```
1925        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1926        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1927        #[must_use = "this returns the result of the operation, \
1928                      without modifying the original"]
1929        #[inline]
1930        #[track_caller]
1931        pub const fn strict_shr(self, rhs: u32) -> Self {
1932            let (a, b) = self.overflowing_shr(rhs);
1933            if b { overflow_panic::shr() } else { a }
1934        }
1935
1936        /// Unchecked shift right. Computes `self >> rhs`, assuming that
1937        /// `rhs` is less than the number of bits in `self`.
1938        ///
1939        /// # Safety
1940        ///
1941        /// This results in undefined behavior if `rhs` is larger than
1942        /// or equal to the number of bits in `self`,
1943        /// i.e. when [`checked_shr`] would return `None`.
1944        ///
1945        #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
1946        #[unstable(
1947            feature = "unchecked_shifts",
1948            reason = "niche optimization path",
1949            issue = "85122",
1950        )]
1951        #[must_use = "this returns the result of the operation, \
1952                      without modifying the original"]
1953        #[inline(always)]
1954        #[track_caller]
1955        pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
1956            assert_unsafe_precondition!(
1957                check_language_ub,
1958                concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
1959                (
1960                    rhs: u32 = rhs,
1961                ) => rhs < <$ActualT>::BITS,
1962            );
1963
1964            // SAFETY: this is guaranteed to be safe by the caller.
1965            unsafe {
1966                intrinsics::unchecked_shr(self, rhs)
1967            }
1968        }
1969
1970        /// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
1971        ///
1972        /// If `rhs` is larger or equal to the number of bits in `self`,
1973        /// the entire value is shifted out, and `0` is returned.
1974        ///
1975        /// # Examples
1976        ///
1977        /// ```
1978        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
1979        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(129), 0);")]
1980        /// ```
1981        #[stable(feature = "unbounded_shifts", since = "1.87.0")]
1982        #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
1983        #[must_use = "this returns the result of the operation, \
1984                      without modifying the original"]
1985        #[inline]
1986        pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
1987            if rhs < Self::BITS {
1988                // SAFETY:
1989                // rhs is just checked to be in-range above
1990                unsafe { self.unchecked_shr(rhs) }
1991            } else {
1992                0
1993            }
1994        }
1995
1996        /// Exact shift right. Computes `self >> rhs` as long as it can be reversed losslessly.
1997        ///
1998        /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
1999        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2000        /// Otherwise, returns `Some(self >> rhs)`.
2001        ///
2002        /// # Examples
2003        ///
2004        /// ```
2005        /// #![feature(exact_bitshifts)]
2006        ///
2007        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".exact_shr(4), Some(0x1));")]
2008        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".exact_shr(5), None);")]
2009        /// ```
2010        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2011        #[must_use = "this returns the result of the operation, \
2012                      without modifying the original"]
2013        #[inline]
2014        pub const fn exact_shr(self, rhs: u32) -> Option<$SelfT> {
2015            if rhs <= self.trailing_zeros() && rhs < <$SelfT>::BITS {
2016                // SAFETY: rhs is checked above
2017                Some(unsafe { self.unchecked_shr(rhs) })
2018            } else {
2019                None
2020            }
2021        }
2022
2023        /// Unchecked exact shift right. Computes `self >> rhs`, assuming the operation can be
2024        /// losslessly reversed and `rhs` cannot be larger than
2025        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2026        ///
2027        /// # Safety
2028        ///
2029        /// This results in undefined behavior when `rhs > self.trailing_zeros() || rhs >=
2030        #[doc = concat!(stringify!($SelfT), "::BITS`")]
2031        /// i.e. when
2032        #[doc = concat!("[`", stringify!($SelfT), "::exact_shr`]")]
2033        /// would return `None`.
2034        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2035        #[must_use = "this returns the result of the operation, \
2036                      without modifying the original"]
2037        #[inline]
2038        pub const unsafe fn unchecked_exact_shr(self, rhs: u32) -> $SelfT {
2039            assert_unsafe_precondition!(
2040                check_language_ub,
2041                concat!(stringify!($SelfT), "::exact_shr_unchecked cannot shift out non-zero bits"),
2042                (
2043                    zeros: u32 = self.trailing_zeros(),
2044                    bits: u32 =  <$SelfT>::BITS,
2045                    rhs: u32 = rhs,
2046                ) => rhs <= zeros && rhs < bits,
2047            );
2048
2049            // SAFETY: this is guaranteed to be safe by the caller
2050            unsafe { self.unchecked_shr(rhs) }
2051        }
2052
2053        /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
2054        /// overflow occurred.
2055        ///
2056        /// # Examples
2057        ///
2058        /// ```
2059        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_pow(5), Some(32));")]
2060        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
2061        /// ```
2062        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2063        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2064        #[must_use = "this returns the result of the operation, \
2065                      without modifying the original"]
2066        #[inline]
2067        pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
2068            if exp == 0 {
2069                return Some(1);
2070            }
2071            let mut base = self;
2072            let mut acc: Self = 1;
2073
2074            loop {
2075                if (exp & 1) == 1 {
2076                    acc = try_opt!(acc.checked_mul(base));
2077                    // since exp!=0, finally the exp must be 1.
2078                    if exp == 1 {
2079                        return Some(acc);
2080                    }
2081                }
2082                exp /= 2;
2083                base = try_opt!(base.checked_mul(base));
2084            }
2085        }
2086
2087        /// Strict exponentiation. Computes `self.pow(exp)`, panicking if
2088        /// overflow occurred.
2089        ///
2090        /// # Panics
2091        ///
2092        /// ## Overflow behavior
2093        ///
2094        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
2095        ///
2096        /// # Examples
2097        ///
2098        /// ```
2099        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".strict_pow(5), 32);")]
2100        /// ```
2101        ///
2102        /// The following panics because of overflow:
2103        ///
2104        /// ```should_panic
2105        #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
2106        /// ```
2107        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
2108        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
2109        #[must_use = "this returns the result of the operation, \
2110                      without modifying the original"]
2111        #[inline]
2112        #[track_caller]
2113        pub const fn strict_pow(self, mut exp: u32) -> Self {
2114            if exp == 0 {
2115                return 1;
2116            }
2117            let mut base = self;
2118            let mut acc: Self = 1;
2119
2120            loop {
2121                if (exp & 1) == 1 {
2122                    acc = acc.strict_mul(base);
2123                    // since exp!=0, finally the exp must be 1.
2124                    if exp == 1 {
2125                        return acc;
2126                    }
2127                }
2128                exp /= 2;
2129                base = base.strict_mul(base);
2130            }
2131        }
2132
2133        /// Saturating integer addition. Computes `self + rhs`, saturating at
2134        /// the numeric bounds instead of overflowing.
2135        ///
2136        /// # Examples
2137        ///
2138        /// ```
2139        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
2140        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(127), ", stringify!($SelfT), "::MAX);")]
2141        /// ```
2142        #[stable(feature = "rust1", since = "1.0.0")]
2143        #[must_use = "this returns the result of the operation, \
2144                      without modifying the original"]
2145        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2146        #[inline(always)]
2147        pub const fn saturating_add(self, rhs: Self) -> Self {
2148            intrinsics::saturating_add(self, rhs)
2149        }
2150
2151        /// Saturating addition with a signed integer. Computes `self + rhs`,
2152        /// saturating at the numeric bounds instead of overflowing.
2153        ///
2154        /// # Examples
2155        ///
2156        /// ```
2157        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(2), 3);")]
2158        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(-2), 0);")]
2159        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_add_signed(4), ", stringify!($SelfT), "::MAX);")]
2160        /// ```
2161        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2162        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2163        #[must_use = "this returns the result of the operation, \
2164                      without modifying the original"]
2165        #[inline]
2166        pub const fn saturating_add_signed(self, rhs: $SignedT) -> Self {
2167            let (res, overflow) = self.overflowing_add(rhs as Self);
2168            if overflow == (rhs < 0) {
2169                res
2170            } else if overflow {
2171                Self::MAX
2172            } else {
2173                0
2174            }
2175        }
2176
2177        /// Saturating integer subtraction. Computes `self - rhs`, saturating
2178        /// at the numeric bounds instead of overflowing.
2179        ///
2180        /// # Examples
2181        ///
2182        /// ```
2183        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(27), 73);")]
2184        #[doc = concat!("assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);")]
2185        /// ```
2186        #[stable(feature = "rust1", since = "1.0.0")]
2187        #[must_use = "this returns the result of the operation, \
2188                      without modifying the original"]
2189        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2190        #[inline(always)]
2191        pub const fn saturating_sub(self, rhs: Self) -> Self {
2192            intrinsics::saturating_sub(self, rhs)
2193        }
2194
2195        /// Saturating integer subtraction. Computes `self` - `rhs`, saturating at
2196        /// the numeric bounds instead of overflowing.
2197        ///
2198        /// # Examples
2199        ///
2200        /// ```
2201        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(2), 0);")]
2202        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(-2), 3);")]
2203        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_sub_signed(-4), ", stringify!($SelfT), "::MAX);")]
2204        /// ```
2205        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2206        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2207        #[must_use = "this returns the result of the operation, \
2208                      without modifying the original"]
2209        #[inline]
2210        pub const fn saturating_sub_signed(self, rhs: $SignedT) -> Self {
2211            let (res, overflow) = self.overflowing_sub_signed(rhs);
2212
2213            if !overflow {
2214                res
2215            } else if rhs < 0 {
2216                Self::MAX
2217            } else {
2218                0
2219            }
2220        }
2221
2222        /// Saturating integer multiplication. Computes `self * rhs`,
2223        /// saturating at the numeric bounds instead of overflowing.
2224        ///
2225        /// # Examples
2226        ///
2227        /// ```
2228        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".saturating_mul(10), 20);")]
2229        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).saturating_mul(10), ", stringify!($SelfT),"::MAX);")]
2230        /// ```
2231        #[stable(feature = "wrapping", since = "1.7.0")]
2232        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2233        #[must_use = "this returns the result of the operation, \
2234                      without modifying the original"]
2235        #[inline]
2236        pub const fn saturating_mul(self, rhs: Self) -> Self {
2237            match self.checked_mul(rhs) {
2238                Some(x) => x,
2239                None => Self::MAX,
2240            }
2241        }
2242
2243        /// Saturating integer division. Computes `self / rhs`, saturating at the
2244        /// numeric bounds instead of overflowing.
2245        ///
2246        /// # Panics
2247        ///
2248        /// This function will panic if `rhs` is zero.
2249        ///
2250        /// # Examples
2251        ///
2252        /// ```
2253        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
2254        ///
2255        /// ```
2256        #[stable(feature = "saturating_div", since = "1.58.0")]
2257        #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
2258        #[must_use = "this returns the result of the operation, \
2259                      without modifying the original"]
2260        #[inline]
2261        #[track_caller]
2262        pub const fn saturating_div(self, rhs: Self) -> Self {
2263            // on unsigned types, there is no overflow in integer division
2264            self.wrapping_div(rhs)
2265        }
2266
2267        /// Saturating integer exponentiation. Computes `self.pow(exp)`,
2268        /// saturating at the numeric bounds instead of overflowing.
2269        ///
2270        /// # Examples
2271        ///
2272        /// ```
2273        #[doc = concat!("assert_eq!(4", stringify!($SelfT), ".saturating_pow(3), 64);")]
2274        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
2275        /// ```
2276        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2277        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2278        #[must_use = "this returns the result of the operation, \
2279                      without modifying the original"]
2280        #[inline]
2281        pub const fn saturating_pow(self, exp: u32) -> Self {
2282            match self.checked_pow(exp) {
2283                Some(x) => x,
2284                None => Self::MAX,
2285            }
2286        }
2287
2288        /// Wrapping (modular) addition. Computes `self + rhs`,
2289        /// wrapping around at the boundary of the type.
2290        ///
2291        /// # Examples
2292        ///
2293        /// ```
2294        #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(55), 255);")]
2295        #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::MAX), 199);")]
2296        /// ```
2297        #[stable(feature = "rust1", since = "1.0.0")]
2298        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2299        #[must_use = "this returns the result of the operation, \
2300                      without modifying the original"]
2301        #[inline(always)]
2302        pub const fn wrapping_add(self, rhs: Self) -> Self {
2303            intrinsics::wrapping_add(self, rhs)
2304        }
2305
2306        /// Wrapping (modular) addition with a signed integer. Computes
2307        /// `self + rhs`, wrapping around at the boundary of the type.
2308        ///
2309        /// # Examples
2310        ///
2311        /// ```
2312        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(2), 3);")]
2313        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(-2), ", stringify!($SelfT), "::MAX);")]
2314        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_add_signed(4), 1);")]
2315        /// ```
2316        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2317        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2318        #[must_use = "this returns the result of the operation, \
2319                      without modifying the original"]
2320        #[inline]
2321        pub const fn wrapping_add_signed(self, rhs: $SignedT) -> Self {
2322            self.wrapping_add(rhs as Self)
2323        }
2324
2325        /// Wrapping (modular) subtraction. Computes `self - rhs`,
2326        /// wrapping around at the boundary of the type.
2327        ///
2328        /// # Examples
2329        ///
2330        /// ```
2331        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(100), 0);")]
2332        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::MAX), 101);")]
2333        /// ```
2334        #[stable(feature = "rust1", since = "1.0.0")]
2335        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2336        #[must_use = "this returns the result of the operation, \
2337                      without modifying the original"]
2338        #[inline(always)]
2339        pub const fn wrapping_sub(self, rhs: Self) -> Self {
2340            intrinsics::wrapping_sub(self, rhs)
2341        }
2342
2343        /// Wrapping (modular) subtraction with a signed integer. Computes
2344        /// `self - rhs`, wrapping around at the boundary of the type.
2345        ///
2346        /// # Examples
2347        ///
2348        /// ```
2349        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(2), ", stringify!($SelfT), "::MAX);")]
2350        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(-2), 3);")]
2351        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_sub_signed(-4), 1);")]
2352        /// ```
2353        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2354        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2355        #[must_use = "this returns the result of the operation, \
2356                      without modifying the original"]
2357        #[inline]
2358        pub const fn wrapping_sub_signed(self, rhs: $SignedT) -> Self {
2359            self.wrapping_sub(rhs as Self)
2360        }
2361
2362        /// Wrapping (modular) multiplication. Computes `self *
2363        /// rhs`, wrapping around at the boundary of the type.
2364        ///
2365        /// # Examples
2366        ///
2367        /// Please note that this example is shared among integer types, which is why `u8` is used.
2368        ///
2369        /// ```
2370        /// assert_eq!(10u8.wrapping_mul(12), 120);
2371        /// assert_eq!(25u8.wrapping_mul(12), 44);
2372        /// ```
2373        #[stable(feature = "rust1", since = "1.0.0")]
2374        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2375        #[must_use = "this returns the result of the operation, \
2376                      without modifying the original"]
2377        #[inline(always)]
2378        pub const fn wrapping_mul(self, rhs: Self) -> Self {
2379            intrinsics::wrapping_mul(self, rhs)
2380        }
2381
2382        /// Wrapping (modular) division. Computes `self / rhs`.
2383        ///
2384        /// Wrapped division on unsigned types is just normal division. There's
2385        /// no way wrapping could ever happen. This function exists so that all
2386        /// operations are accounted for in the wrapping operations.
2387        ///
2388        /// # Panics
2389        ///
2390        /// This function will panic if `rhs` is zero.
2391        ///
2392        /// # Examples
2393        ///
2394        /// ```
2395        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
2396        /// ```
2397        #[stable(feature = "num_wrapping", since = "1.2.0")]
2398        #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2399        #[must_use = "this returns the result of the operation, \
2400                      without modifying the original"]
2401        #[inline(always)]
2402        #[track_caller]
2403        pub const fn wrapping_div(self, rhs: Self) -> Self {
2404            self / rhs
2405        }
2406
2407        /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`.
2408        ///
2409        /// Wrapped division on unsigned types is just normal division. There's
2410        /// no way wrapping could ever happen. This function exists so that all
2411        /// operations are accounted for in the wrapping operations. Since, for
2412        /// the positive integers, all common definitions of division are equal,
2413        /// this is exactly equal to `self.wrapping_div(rhs)`.
2414        ///
2415        /// # Panics
2416        ///
2417        /// This function will panic if `rhs` is zero.
2418        ///
2419        /// # Examples
2420        ///
2421        /// ```
2422        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
2423        /// ```
2424        #[stable(feature = "euclidean_division", since = "1.38.0")]
2425        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2426        #[must_use = "this returns the result of the operation, \
2427                      without modifying the original"]
2428        #[inline(always)]
2429        #[track_caller]
2430        pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
2431            self / rhs
2432        }
2433
2434        /// Wrapping (modular) remainder. Computes `self % rhs`.
2435        ///
2436        /// Wrapped remainder calculation on unsigned types is just the regular
2437        /// remainder calculation. There's no way wrapping could ever happen.
2438        /// This function exists so that all operations are accounted for in the
2439        /// wrapping operations.
2440        ///
2441        /// # Panics
2442        ///
2443        /// This function will panic if `rhs` is zero.
2444        ///
2445        /// # Examples
2446        ///
2447        /// ```
2448        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
2449        /// ```
2450        #[stable(feature = "num_wrapping", since = "1.2.0")]
2451        #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2452        #[must_use = "this returns the result of the operation, \
2453                      without modifying the original"]
2454        #[inline(always)]
2455        #[track_caller]
2456        pub const fn wrapping_rem(self, rhs: Self) -> Self {
2457            self % rhs
2458        }
2459
2460        /// Wrapping Euclidean modulo. Computes `self.rem_euclid(rhs)`.
2461        ///
2462        /// Wrapped modulo calculation on unsigned types is just the regular
2463        /// remainder calculation. There's no way wrapping could ever happen.
2464        /// This function exists so that all operations are accounted for in the
2465        /// wrapping operations. Since, for the positive integers, all common
2466        /// definitions of division are equal, this is exactly equal to
2467        /// `self.wrapping_rem(rhs)`.
2468        ///
2469        /// # Panics
2470        ///
2471        /// This function will panic if `rhs` is zero.
2472        ///
2473        /// # Examples
2474        ///
2475        /// ```
2476        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
2477        /// ```
2478        #[stable(feature = "euclidean_division", since = "1.38.0")]
2479        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2480        #[must_use = "this returns the result of the operation, \
2481                      without modifying the original"]
2482        #[inline(always)]
2483        #[track_caller]
2484        pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
2485            self % rhs
2486        }
2487
2488        /// Wrapping (modular) negation. Computes `-self`,
2489        /// wrapping around at the boundary of the type.
2490        ///
2491        /// Since unsigned types do not have negative equivalents
2492        /// all applications of this function will wrap (except for `-0`).
2493        /// For values smaller than the corresponding signed type's maximum
2494        /// the result is the same as casting the corresponding signed value.
2495        /// Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)` where
2496        /// `MAX` is the corresponding signed type's maximum.
2497        ///
2498        /// # Examples
2499        ///
2500        /// ```
2501        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_neg(), 0);")]
2502        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_neg(), 1);")]
2503        #[doc = concat!("assert_eq!(13_", stringify!($SelfT), ".wrapping_neg(), (!13) + 1);")]
2504        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_neg(), !(42 - 1));")]
2505        /// ```
2506        #[stable(feature = "num_wrapping", since = "1.2.0")]
2507        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2508        #[must_use = "this returns the result of the operation, \
2509                      without modifying the original"]
2510        #[inline(always)]
2511        pub const fn wrapping_neg(self) -> Self {
2512            (0 as $SelfT).wrapping_sub(self)
2513        }
2514
2515        /// Panic-free bitwise shift-left; yields `self << mask(rhs)`,
2516        /// where `mask` removes any high-order bits of `rhs` that
2517        /// would cause the shift to exceed the bitwidth of the type.
2518        ///
2519        /// Note that this is *not* the same as a rotate-left; the
2520        /// RHS of a wrapping shift-left is restricted to the range
2521        /// of the type, rather than the bits shifted out of the LHS
2522        /// being returned to the other end. The primitive integer
2523        /// types all implement a [`rotate_left`](Self::rotate_left) function,
2524        /// which may be what you want instead.
2525        ///
2526        /// # Examples
2527        ///
2528        /// ```
2529        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(7), 128);")]
2530        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_shl(128), 1);")]
2531        /// ```
2532        #[stable(feature = "num_wrapping", since = "1.2.0")]
2533        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2534        #[must_use = "this returns the result of the operation, \
2535                      without modifying the original"]
2536        #[inline(always)]
2537        pub const fn wrapping_shl(self, rhs: u32) -> Self {
2538            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2539            // out of bounds
2540            unsafe {
2541                self.unchecked_shl(rhs & (Self::BITS - 1))
2542            }
2543        }
2544
2545        /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`,
2546        /// where `mask` removes any high-order bits of `rhs` that
2547        /// would cause the shift to exceed the bitwidth of the type.
2548        ///
2549        /// Note that this is *not* the same as a rotate-right; the
2550        /// RHS of a wrapping shift-right is restricted to the range
2551        /// of the type, rather than the bits shifted out of the LHS
2552        /// being returned to the other end. The primitive integer
2553        /// types all implement a [`rotate_right`](Self::rotate_right) function,
2554        /// which may be what you want instead.
2555        ///
2556        /// # Examples
2557        ///
2558        /// ```
2559        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(7), 1);")]
2560        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(128), 128);")]
2561        /// ```
2562        #[stable(feature = "num_wrapping", since = "1.2.0")]
2563        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2564        #[must_use = "this returns the result of the operation, \
2565                      without modifying the original"]
2566        #[inline(always)]
2567        pub const fn wrapping_shr(self, rhs: u32) -> Self {
2568            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2569            // out of bounds
2570            unsafe {
2571                self.unchecked_shr(rhs & (Self::BITS - 1))
2572            }
2573        }
2574
2575        /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
2576        /// wrapping around at the boundary of the type.
2577        ///
2578        /// # Examples
2579        ///
2580        /// ```
2581        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(5), 243);")]
2582        /// assert_eq!(3u8.wrapping_pow(6), 217);
2583        /// ```
2584        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2585        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2586        #[must_use = "this returns the result of the operation, \
2587                      without modifying the original"]
2588        #[inline]
2589        pub const fn wrapping_pow(self, mut exp: u32) -> Self {
2590            if exp == 0 {
2591                return 1;
2592            }
2593            let mut base = self;
2594            let mut acc: Self = 1;
2595
2596            if intrinsics::is_val_statically_known(exp) {
2597                while exp > 1 {
2598                    if (exp & 1) == 1 {
2599                        acc = acc.wrapping_mul(base);
2600                    }
2601                    exp /= 2;
2602                    base = base.wrapping_mul(base);
2603                }
2604
2605                // since exp!=0, finally the exp must be 1.
2606                // Deal with the final bit of the exponent separately, since
2607                // squaring the base afterwards is not necessary.
2608                acc.wrapping_mul(base)
2609            } else {
2610                // This is faster than the above when the exponent is not known
2611                // at compile time. We can't use the same code for the constant
2612                // exponent case because LLVM is currently unable to unroll
2613                // this loop.
2614                loop {
2615                    if (exp & 1) == 1 {
2616                        acc = acc.wrapping_mul(base);
2617                        // since exp!=0, finally the exp must be 1.
2618                        if exp == 1 {
2619                            return acc;
2620                        }
2621                    }
2622                    exp /= 2;
2623                    base = base.wrapping_mul(base);
2624                }
2625            }
2626        }
2627
2628        /// Calculates `self` + `rhs`.
2629        ///
2630        /// Returns a tuple of the addition along with a boolean indicating
2631        /// whether an arithmetic overflow would occur. If an overflow would
2632        /// have occurred then the wrapped value is returned.
2633        ///
2634        /// # Examples
2635        ///
2636        /// ```
2637        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
2638        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));")]
2639        /// ```
2640        #[stable(feature = "wrapping", since = "1.7.0")]
2641        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2642        #[must_use = "this returns the result of the operation, \
2643                      without modifying the original"]
2644        #[inline(always)]
2645        pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
2646            let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
2647            (a as Self, b)
2648        }
2649
2650        /// Calculates `self` + `rhs` + `carry` and returns a tuple containing
2651        /// the sum and the output carry (in that order).
2652        ///
2653        /// Performs "ternary addition" of two integer operands and a carry-in
2654        /// bit, and returns an output integer and a carry-out bit. This allows
2655        /// chaining together multiple additions to create a wider addition, and
2656        /// can be useful for bignum addition.
2657        ///
2658        #[doc = concat!("This can be thought of as a ", stringify!($BITS), "-bit \"full adder\", in the electronics sense.")]
2659        ///
2660        /// If the input carry is false, this method is equivalent to
2661        /// [`overflowing_add`](Self::overflowing_add), and the output carry is
2662        /// equal to the overflow flag. Note that although carry and overflow
2663        /// flags are similar for unsigned integers, they are different for
2664        /// signed integers.
2665        ///
2666        /// # Examples
2667        ///
2668        /// ```
2669        #[doc = concat!("//    3  MAX    (a = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2670        #[doc = concat!("// +  5    7    (b = 5 × 2^", stringify!($BITS), " + 7)")]
2671        /// // ---------
2672        #[doc = concat!("//    9    6    (sum = 9 × 2^", stringify!($BITS), " + 6)")]
2673        ///
2674        #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (3, ", stringify!($SelfT), "::MAX);")]
2675        #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
2676        /// let carry0 = false;
2677        ///
2678        /// let (sum0, carry1) = a0.carrying_add(b0, carry0);
2679        /// assert_eq!(carry1, true);
2680        /// let (sum1, carry2) = a1.carrying_add(b1, carry1);
2681        /// assert_eq!(carry2, false);
2682        ///
2683        /// assert_eq!((sum1, sum0), (9, 6));
2684        /// ```
2685        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
2686        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2687        #[must_use = "this returns the result of the operation, \
2688                      without modifying the original"]
2689        #[inline]
2690        pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
2691            // note: longer-term this should be done via an intrinsic, but this has been shown
2692            //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
2693            let (a, c1) = self.overflowing_add(rhs);
2694            let (b, c2) = a.overflowing_add(carry as $SelfT);
2695            // Ideally LLVM would know this is disjoint without us telling them,
2696            // but it doesn't <https://github.com/llvm/llvm-project/issues/118162>
2697            // SAFETY: Only one of `c1` and `c2` can be set.
2698            // For c1 to be set we need to have overflowed, but if we did then
2699            // `a` is at most `MAX-1`, which means that `c2` cannot possibly
2700            // overflow because it's adding at most `1` (since it came from `bool`)
2701            (b, unsafe { intrinsics::disjoint_bitor(c1, c2) })
2702        }
2703
2704        /// Calculates `self` + `rhs` with a signed `rhs`.
2705        ///
2706        /// Returns a tuple of the addition along with a boolean indicating
2707        /// whether an arithmetic overflow would occur. If an overflow would
2708        /// have occurred then the wrapped value is returned.
2709        ///
2710        /// # Examples
2711        ///
2712        /// ```
2713        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(2), (3, false));")]
2714        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(-2), (", stringify!($SelfT), "::MAX, true));")]
2715        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_signed(4), (1, true));")]
2716        /// ```
2717        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2718        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2719        #[must_use = "this returns the result of the operation, \
2720                      without modifying the original"]
2721        #[inline]
2722        pub const fn overflowing_add_signed(self, rhs: $SignedT) -> (Self, bool) {
2723            let (res, overflowed) = self.overflowing_add(rhs as Self);
2724            (res, overflowed ^ (rhs < 0))
2725        }
2726
2727        /// Calculates `self` - `rhs`.
2728        ///
2729        /// Returns a tuple of the subtraction along with a boolean indicating
2730        /// whether an arithmetic overflow would occur. If an overflow would
2731        /// have occurred then the wrapped value is returned.
2732        ///
2733        /// # Examples
2734        ///
2735        /// ```
2736        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
2737        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
2738        /// ```
2739        #[stable(feature = "wrapping", since = "1.7.0")]
2740        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2741        #[must_use = "this returns the result of the operation, \
2742                      without modifying the original"]
2743        #[inline(always)]
2744        pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
2745            let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
2746            (a as Self, b)
2747        }
2748
2749        /// Calculates `self` &minus; `rhs` &minus; `borrow` and returns a tuple
2750        /// containing the difference and the output borrow.
2751        ///
2752        /// Performs "ternary subtraction" by subtracting both an integer
2753        /// operand and a borrow-in bit from `self`, and returns an output
2754        /// integer and a borrow-out bit. This allows chaining together multiple
2755        /// subtractions to create a wider subtraction, and can be useful for
2756        /// bignum subtraction.
2757        ///
2758        /// # Examples
2759        ///
2760        /// ```
2761        #[doc = concat!("//    9    6    (a = 9 × 2^", stringify!($BITS), " + 6)")]
2762        #[doc = concat!("// -  5    7    (b = 5 × 2^", stringify!($BITS), " + 7)")]
2763        /// // ---------
2764        #[doc = concat!("//    3  MAX    (diff = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
2765        ///
2766        #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (9, 6);")]
2767        #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
2768        /// let borrow0 = false;
2769        ///
2770        /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
2771        /// assert_eq!(borrow1, true);
2772        /// let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1);
2773        /// assert_eq!(borrow2, false);
2774        ///
2775        #[doc = concat!("assert_eq!((diff1, diff0), (3, ", stringify!($SelfT), "::MAX));")]
2776        /// ```
2777        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
2778        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2779        #[must_use = "this returns the result of the operation, \
2780                      without modifying the original"]
2781        #[inline]
2782        pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
2783            // note: longer-term this should be done via an intrinsic, but this has been shown
2784            //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
2785            let (a, c1) = self.overflowing_sub(rhs);
2786            let (b, c2) = a.overflowing_sub(borrow as $SelfT);
2787            // SAFETY: Only one of `c1` and `c2` can be set.
2788            // For c1 to be set we need to have underflowed, but if we did then
2789            // `a` is nonzero, which means that `c2` cannot possibly
2790            // underflow because it's subtracting at most `1` (since it came from `bool`)
2791            (b, unsafe { intrinsics::disjoint_bitor(c1, c2) })
2792        }
2793
2794        /// Calculates `self` - `rhs` with a signed `rhs`
2795        ///
2796        /// Returns a tuple of the subtraction along with a boolean indicating
2797        /// whether an arithmetic overflow would occur. If an overflow would
2798        /// have occurred then the wrapped value is returned.
2799        ///
2800        /// # Examples
2801        ///
2802        /// ```
2803        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(2), (", stringify!($SelfT), "::MAX, true));")]
2804        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(-2), (3, false));")]
2805        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_sub_signed(-4), (1, true));")]
2806        /// ```
2807        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2808        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2809        #[must_use = "this returns the result of the operation, \
2810                      without modifying the original"]
2811        #[inline]
2812        pub const fn overflowing_sub_signed(self, rhs: $SignedT) -> (Self, bool) {
2813            let (res, overflow) = self.overflowing_sub(rhs as Self);
2814
2815            (res, overflow ^ (rhs < 0))
2816        }
2817
2818        /// Computes the absolute difference between `self` and `other`.
2819        ///
2820        /// # Examples
2821        ///
2822        /// ```
2823        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($SelfT), ");")]
2824        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($SelfT), ");")]
2825        /// ```
2826        #[stable(feature = "int_abs_diff", since = "1.60.0")]
2827        #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
2828        #[must_use = "this returns the result of the operation, \
2829                      without modifying the original"]
2830        #[inline]
2831        pub const fn abs_diff(self, other: Self) -> Self {
2832            if size_of::<Self>() == 1 {
2833                // Trick LLVM into generating the psadbw instruction when SSE2
2834                // is available and this function is autovectorized for u8's.
2835                (self as i32).wrapping_sub(other as i32).unsigned_abs() as Self
2836            } else {
2837                if self < other {
2838                    other - self
2839                } else {
2840                    self - other
2841                }
2842            }
2843        }
2844
2845        /// Calculates the multiplication of `self` and `rhs`.
2846        ///
2847        /// Returns a tuple of the multiplication along with a boolean
2848        /// indicating whether an arithmetic overflow would occur. If an
2849        /// overflow would have occurred then the wrapped value is returned.
2850        ///
2851        /// If you want the *value* of the overflow, rather than just *whether*
2852        /// an overflow occurred, see [`Self::carrying_mul`].
2853        ///
2854        /// # Examples
2855        ///
2856        /// Please note that this example is shared among integer types, which is why `u32` is used.
2857        ///
2858        /// ```
2859        /// assert_eq!(5u32.overflowing_mul(2), (10, false));
2860        /// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
2861        /// ```
2862        #[stable(feature = "wrapping", since = "1.7.0")]
2863        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2864        #[must_use = "this returns the result of the operation, \
2865                          without modifying the original"]
2866        #[inline(always)]
2867        pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
2868            let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
2869            (a as Self, b)
2870        }
2871
2872        /// Calculates the complete double-width product `self * rhs`.
2873        ///
2874        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2875        /// of the result as two separate values, in that order. As such,
2876        /// `a.widening_mul(b).0` produces the same result as `a.wrapping_mul(b)`.
2877        ///
2878        /// If you also need to add a value and carry to the wide result, then you want
2879        /// [`Self::carrying_mul_add`] instead.
2880        ///
2881        /// If you also need to add a carry to the wide result, then you want
2882        /// [`Self::carrying_mul`] instead.
2883        ///
2884        /// If you just want to know *whether* the multiplication overflowed, then you
2885        /// want [`Self::overflowing_mul`] instead.
2886        ///
2887        /// # Examples
2888        ///
2889        /// ```
2890        /// #![feature(bigint_helper_methods)]
2891        #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".widening_mul(7), (35, 0));")]
2892        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.widening_mul(", stringify!($SelfT), "::MAX), (1, ", stringify!($SelfT), "::MAX - 1));")]
2893        /// ```
2894        ///
2895        /// Compared to other `*_mul` methods:
2896        /// ```
2897        /// #![feature(bigint_helper_methods)]
2898        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::widening_mul(1 << ", stringify!($BITS_MINUS_ONE), ", 6), (0, 3));")]
2899        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::overflowing_mul(1 << ", stringify!($BITS_MINUS_ONE), ", 6), (0, true));")]
2900        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::wrapping_mul(1 << ", stringify!($BITS_MINUS_ONE), ", 6), 0);")]
2901        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::checked_mul(1 << ", stringify!($BITS_MINUS_ONE), ", 6), None);")]
2902        /// ```
2903        ///
2904        /// Please note that this example is shared among integer types, which is why `u32` is used.
2905        ///
2906        /// ```
2907        /// #![feature(bigint_helper_methods)]
2908        /// assert_eq!(5u32.widening_mul(2), (10, 0));
2909        /// assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2));
2910        /// ```
2911        #[unstable(feature = "bigint_helper_methods", issue = "85532")]
2912        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2913        #[must_use = "this returns the result of the operation, \
2914                      without modifying the original"]
2915        #[inline]
2916        pub const fn widening_mul(self, rhs: Self) -> (Self, Self) {
2917            Self::carrying_mul_add(self, rhs, 0, 0)
2918        }
2919
2920        /// Calculates the "full multiplication" `self * rhs + carry`
2921        /// without the possibility to overflow.
2922        ///
2923        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
2924        /// of the result as two separate values, in that order.
2925        ///
2926        /// Performs "long multiplication" which takes in an extra amount to add, and may return an
2927        /// additional amount of overflow. This allows for chaining together multiple
2928        /// multiplications to create "big integers" which represent larger values.
2929        ///
2930        /// If you also need to add a value, then use [`Self::carrying_mul_add`].
2931        ///
2932        /// # Examples
2933        ///
2934        /// Please note that this example is shared among integer types, which is why `u32` is used.
2935        ///
2936        /// ```
2937        /// assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
2938        /// assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
2939        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
2940        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
2941        #[doc = concat!("assert_eq!(",
2942            stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
2943            "(0, ", stringify!($SelfT), "::MAX));"
2944        )]
2945        /// ```
2946        ///
2947        /// This is the core operation needed for scalar multiplication when
2948        /// implementing it for wider-than-native types.
2949        ///
2950        /// ```
2951        /// #![feature(bigint_helper_methods)]
2952        /// fn scalar_mul_eq(little_endian_digits: &mut Vec<u16>, multiplicand: u16) {
2953        ///     let mut carry = 0;
2954        ///     for d in little_endian_digits.iter_mut() {
2955        ///         (*d, carry) = d.carrying_mul(multiplicand, carry);
2956        ///     }
2957        ///     if carry != 0 {
2958        ///         little_endian_digits.push(carry);
2959        ///     }
2960        /// }
2961        ///
2962        /// let mut v = vec![10, 20];
2963        /// scalar_mul_eq(&mut v, 3);
2964        /// assert_eq!(v, [30, 60]);
2965        ///
2966        /// assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D);
2967        /// let mut v = vec![0x4321, 0x8765];
2968        /// scalar_mul_eq(&mut v, 0xFEED);
2969        /// assert_eq!(v, [0xE38D, 0xD159, 0x86D3]);
2970        /// ```
2971        ///
2972        /// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul),
2973        /// except that it gives the value of the overflow instead of just whether one happened:
2974        ///
2975        /// ```
2976        /// #![feature(bigint_helper_methods)]
2977        /// let r = u8::carrying_mul(7, 13, 0);
2978        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
2979        /// let r = u8::carrying_mul(13, 42, 0);
2980        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
2981        /// ```
2982        ///
2983        /// The value of the first field in the returned tuple matches what you'd get
2984        /// by combining the [`wrapping_mul`](Self::wrapping_mul) and
2985        /// [`wrapping_add`](Self::wrapping_add) methods:
2986        ///
2987        /// ```
2988        /// #![feature(bigint_helper_methods)]
2989        /// assert_eq!(
2990        ///     789_u16.carrying_mul(456, 123).0,
2991        ///     789_u16.wrapping_mul(456).wrapping_add(123),
2992        /// );
2993        /// ```
2994        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
2995        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
2996        #[must_use = "this returns the result of the operation, \
2997                      without modifying the original"]
2998        #[inline]
2999        pub const fn carrying_mul(self, rhs: Self, carry: Self) -> (Self, Self) {
3000            Self::carrying_mul_add(self, rhs, carry, 0)
3001        }
3002
3003        /// Calculates the "full multiplication" `self * rhs + carry1 + carry2`.
3004        ///
3005        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
3006        /// of the result as two separate values, in that order.
3007        ///
3008        /// This cannot overflow, as the double-width result has exactly enough
3009        /// space for the largest possible result. This is equivalent to how, in
3010        /// decimal, 9 × 9 + 9 + 9 = 81 + 18 = 99 = 9×10⁰ + 9×10¹ = 10² - 1.
3011        ///
3012        /// Performs "long multiplication" which takes in an extra amount to add, and may return an
3013        /// additional amount of overflow. This allows for chaining together multiple
3014        /// multiplications to create "big integers" which represent larger values.
3015        ///
3016        /// If you don't need the `add` part, then you can use [`Self::carrying_mul`] instead.
3017        ///
3018        /// # Examples
3019        ///
3020        /// Please note that this example is shared between integer types,
3021        /// which explains why `u32` is used here.
3022        ///
3023        /// ```
3024        /// assert_eq!(5u32.carrying_mul_add(2, 0, 0), (10, 0));
3025        /// assert_eq!(5u32.carrying_mul_add(2, 10, 10), (30, 0));
3026        /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 0, 0), (1410065408, 2));
3027        /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 10, 10), (1410065428, 2));
3028        #[doc = concat!("assert_eq!(",
3029            stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
3030            "(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX));"
3031        )]
3032        /// ```
3033        ///
3034        /// This is the core per-digit operation for "grade school" O(n²) multiplication.
3035        ///
3036        /// Please note that this example is shared between integer types,
3037        /// using `u8` for simplicity of the demonstration.
3038        ///
3039        /// ```
3040        /// fn quadratic_mul<const N: usize>(a: [u8; N], b: [u8; N]) -> [u8; N] {
3041        ///     let mut out = [0; N];
3042        ///     for j in 0..N {
3043        ///         let mut carry = 0;
3044        ///         for i in 0..(N - j) {
3045        ///             (out[j + i], carry) = u8::carrying_mul_add(a[i], b[j], out[j + i], carry);
3046        ///         }
3047        ///     }
3048        ///     out
3049        /// }
3050        ///
3051        /// // -1 * -1 == 1
3052        /// assert_eq!(quadratic_mul([0xFF; 3], [0xFF; 3]), [1, 0, 0]);
3053        ///
3054        /// assert_eq!(u32::wrapping_mul(0x9e3779b9, 0x7f4a7c15), 0xcffc982d);
3055        /// assert_eq!(
3056        ///     quadratic_mul(u32::to_le_bytes(0x9e3779b9), u32::to_le_bytes(0x7f4a7c15)),
3057        ///     u32::to_le_bytes(0xcffc982d)
3058        /// );
3059        /// ```
3060        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
3061        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
3062        #[must_use = "this returns the result of the operation, \
3063                      without modifying the original"]
3064        #[inline]
3065        pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> (Self, Self) {
3066            intrinsics::carrying_mul_add(self, rhs, carry, add)
3067        }
3068
3069        /// Calculates the divisor when `self` is divided by `rhs`.
3070        ///
3071        /// Returns a tuple of the divisor along with a boolean indicating
3072        /// whether an arithmetic overflow would occur. Note that for unsigned
3073        /// integers overflow never occurs, so the second value is always
3074        /// `false`.
3075        ///
3076        /// # Panics
3077        ///
3078        /// This function will panic if `rhs` is zero.
3079        ///
3080        /// # Examples
3081        ///
3082        /// ```
3083        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
3084        /// ```
3085        #[inline(always)]
3086        #[stable(feature = "wrapping", since = "1.7.0")]
3087        #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
3088        #[must_use = "this returns the result of the operation, \
3089                      without modifying the original"]
3090        #[track_caller]
3091        pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
3092            (self / rhs, false)
3093        }
3094
3095        /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
3096        ///
3097        /// Returns a tuple of the divisor along with a boolean indicating
3098        /// whether an arithmetic overflow would occur. Note that for unsigned
3099        /// integers overflow never occurs, so the second value is always
3100        /// `false`.
3101        /// Since, for the positive integers, all common
3102        /// definitions of division are equal, this
3103        /// is exactly equal to `self.overflowing_div(rhs)`.
3104        ///
3105        /// # Panics
3106        ///
3107        /// This function will panic if `rhs` is zero.
3108        ///
3109        /// # Examples
3110        ///
3111        /// ```
3112        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
3113        /// ```
3114        #[inline(always)]
3115        #[stable(feature = "euclidean_division", since = "1.38.0")]
3116        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3117        #[must_use = "this returns the result of the operation, \
3118                      without modifying the original"]
3119        #[track_caller]
3120        pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
3121            (self / rhs, false)
3122        }
3123
3124        /// Calculates the remainder when `self` is divided by `rhs`.
3125        ///
3126        /// Returns a tuple of the remainder after dividing along with a boolean
3127        /// indicating whether an arithmetic overflow would occur. Note that for
3128        /// unsigned integers overflow never occurs, so the second value is
3129        /// always `false`.
3130        ///
3131        /// # Panics
3132        ///
3133        /// This function will panic if `rhs` is zero.
3134        ///
3135        /// # Examples
3136        ///
3137        /// ```
3138        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
3139        /// ```
3140        #[inline(always)]
3141        #[stable(feature = "wrapping", since = "1.7.0")]
3142        #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
3143        #[must_use = "this returns the result of the operation, \
3144                      without modifying the original"]
3145        #[track_caller]
3146        pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
3147            (self % rhs, false)
3148        }
3149
3150        /// Calculates the remainder `self.rem_euclid(rhs)` as if by Euclidean division.
3151        ///
3152        /// Returns a tuple of the modulo after dividing along with a boolean
3153        /// indicating whether an arithmetic overflow would occur. Note that for
3154        /// unsigned integers overflow never occurs, so the second value is
3155        /// always `false`.
3156        /// Since, for the positive integers, all common
3157        /// definitions of division are equal, this operation
3158        /// is exactly equal to `self.overflowing_rem(rhs)`.
3159        ///
3160        /// # Panics
3161        ///
3162        /// This function will panic if `rhs` is zero.
3163        ///
3164        /// # Examples
3165        ///
3166        /// ```
3167        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
3168        /// ```
3169        #[inline(always)]
3170        #[stable(feature = "euclidean_division", since = "1.38.0")]
3171        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3172        #[must_use = "this returns the result of the operation, \
3173                      without modifying the original"]
3174        #[track_caller]
3175        pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
3176            (self % rhs, false)
3177        }
3178
3179        /// Negates self in an overflowing fashion.
3180        ///
3181        /// Returns `!self + 1` using wrapping operations to return the value
3182        /// that represents the negation of this unsigned value. Note that for
3183        /// positive unsigned values overflow always occurs, but negating 0 does
3184        /// not overflow.
3185        ///
3186        /// # Examples
3187        ///
3188        /// ```
3189        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_neg(), (0, false));")]
3190        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!($SelfT), ", true));")]
3191        /// ```
3192        #[inline(always)]
3193        #[stable(feature = "wrapping", since = "1.7.0")]
3194        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3195        #[must_use = "this returns the result of the operation, \
3196                      without modifying the original"]
3197        pub const fn overflowing_neg(self) -> (Self, bool) {
3198            ((!self).wrapping_add(1), self != 0)
3199        }
3200
3201        /// Shifts self left by `rhs` bits.
3202        ///
3203        /// Returns a tuple of the shifted version of self along with a boolean
3204        /// indicating whether the shift value was larger than or equal to the
3205        /// number of bits. If the shift value is too large, then value is
3206        /// masked (N-1) where N is the number of bits, and this value is then
3207        /// used to perform the shift.
3208        ///
3209        /// # Examples
3210        ///
3211        /// ```
3212        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(4), (0x10, false));")]
3213        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));")]
3214        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
3215        /// ```
3216        #[stable(feature = "wrapping", since = "1.7.0")]
3217        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3218        #[must_use = "this returns the result of the operation, \
3219                      without modifying the original"]
3220        #[inline(always)]
3221        pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
3222            (self.wrapping_shl(rhs), rhs >= Self::BITS)
3223        }
3224
3225        /// Shifts self right by `rhs` bits.
3226        ///
3227        /// Returns a tuple of the shifted version of self along with a boolean
3228        /// indicating whether the shift value was larger than or equal to the
3229        /// number of bits. If the shift value is too large, then value is
3230        /// masked (N-1) where N is the number of bits, and this value is then
3231        /// used to perform the shift.
3232        ///
3233        /// # Examples
3234        ///
3235        /// ```
3236        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
3237        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));")]
3238        /// ```
3239        #[stable(feature = "wrapping", since = "1.7.0")]
3240        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3241        #[must_use = "this returns the result of the operation, \
3242                      without modifying the original"]
3243        #[inline(always)]
3244        pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
3245            (self.wrapping_shr(rhs), rhs >= Self::BITS)
3246        }
3247
3248        /// Raises self to the power of `exp`, using exponentiation by squaring.
3249        ///
3250        /// Returns a tuple of the exponentiation along with a bool indicating
3251        /// whether an overflow happened.
3252        ///
3253        /// # Examples
3254        ///
3255        /// ```
3256        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(5), (243, false));")]
3257        /// assert_eq!(3u8.overflowing_pow(6), (217, true));
3258        /// ```
3259        #[stable(feature = "no_panic_pow", since = "1.34.0")]
3260        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3261        #[must_use = "this returns the result of the operation, \
3262                      without modifying the original"]
3263        #[inline]
3264        pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
3265            if exp == 0{
3266                return (1,false);
3267            }
3268            let mut base = self;
3269            let mut acc: Self = 1;
3270            let mut overflown = false;
3271            // Scratch space for storing results of overflowing_mul.
3272            let mut r;
3273
3274            loop {
3275                if (exp & 1) == 1 {
3276                    r = acc.overflowing_mul(base);
3277                    // since exp!=0, finally the exp must be 1.
3278                    if exp == 1 {
3279                        r.1 |= overflown;
3280                        return r;
3281                    }
3282                    acc = r.0;
3283                    overflown |= r.1;
3284                }
3285                exp /= 2;
3286                r = base.overflowing_mul(base);
3287                base = r.0;
3288                overflown |= r.1;
3289            }
3290        }
3291
3292        /// Raises self to the power of `exp`, using exponentiation by squaring.
3293        ///
3294        /// # Examples
3295        ///
3296        /// ```
3297        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".pow(5), 32);")]
3298        /// ```
3299        #[stable(feature = "rust1", since = "1.0.0")]
3300        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3301        #[must_use = "this returns the result of the operation, \
3302                      without modifying the original"]
3303        #[inline]
3304        #[rustc_inherit_overflow_checks]
3305        pub const fn pow(self, mut exp: u32) -> Self {
3306            if exp == 0 {
3307                return 1;
3308            }
3309            let mut base = self;
3310            let mut acc = 1;
3311
3312            if intrinsics::is_val_statically_known(exp) {
3313                while exp > 1 {
3314                    if (exp & 1) == 1 {
3315                        acc = acc * base;
3316                    }
3317                    exp /= 2;
3318                    base = base * base;
3319                }
3320
3321                // since exp!=0, finally the exp must be 1.
3322                // Deal with the final bit of the exponent separately, since
3323                // squaring the base afterwards is not necessary and may cause a
3324                // needless overflow.
3325                acc * base
3326            } else {
3327                // This is faster than the above when the exponent is not known
3328                // at compile time. We can't use the same code for the constant
3329                // exponent case because LLVM is currently unable to unroll
3330                // this loop.
3331                loop {
3332                    if (exp & 1) == 1 {
3333                        acc = acc * base;
3334                        // since exp!=0, finally the exp must be 1.
3335                        if exp == 1 {
3336                            return acc;
3337                        }
3338                    }
3339                    exp /= 2;
3340                    base = base * base;
3341                }
3342            }
3343        }
3344
3345        /// Returns the square root of the number, rounded down.
3346        ///
3347        /// # Examples
3348        ///
3349        /// ```
3350        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
3351        /// ```
3352        #[stable(feature = "isqrt", since = "1.84.0")]
3353        #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
3354        #[must_use = "this returns the result of the operation, \
3355                      without modifying the original"]
3356        #[inline]
3357        pub const fn isqrt(self) -> Self {
3358            let result = crate::num::int_sqrt::$ActualT(self as $ActualT) as $SelfT;
3359
3360            // Inform the optimizer what the range of outputs is. If testing
3361            // `core` crashes with no panic message and a `num::int_sqrt::u*`
3362            // test failed, it's because your edits caused these assertions or
3363            // the assertions in `fn isqrt` of `nonzero.rs` to become false.
3364            //
3365            // SAFETY: Integer square root is a monotonically nondecreasing
3366            // function, which means that increasing the input will never
3367            // cause the output to decrease. Thus, since the input for unsigned
3368            // integers is bounded by `[0, <$ActualT>::MAX]`, sqrt(n) will be
3369            // bounded by `[sqrt(0), sqrt(<$ActualT>::MAX)]`.
3370            unsafe {
3371                const MAX_RESULT: $SelfT = crate::num::int_sqrt::$ActualT(<$ActualT>::MAX) as $SelfT;
3372                crate::hint::assert_unchecked(result <= MAX_RESULT);
3373            }
3374
3375            result
3376        }
3377
3378        /// Performs Euclidean division.
3379        ///
3380        /// Since, for the positive integers, all common
3381        /// definitions of division are equal, this
3382        /// is exactly equal to `self / rhs`.
3383        ///
3384        /// # Panics
3385        ///
3386        /// This function will panic if `rhs` is zero.
3387        ///
3388        /// # Examples
3389        ///
3390        /// ```
3391        #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".div_euclid(4), 1); // or any other integer type")]
3392        /// ```
3393        #[stable(feature = "euclidean_division", since = "1.38.0")]
3394        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3395        #[must_use = "this returns the result of the operation, \
3396                      without modifying the original"]
3397        #[inline(always)]
3398        #[track_caller]
3399        pub const fn div_euclid(self, rhs: Self) -> Self {
3400            self / rhs
3401        }
3402
3403
3404        /// Calculates the least remainder of `self (mod rhs)`.
3405        ///
3406        /// Since, for the positive integers, all common
3407        /// definitions of division are equal, this
3408        /// is exactly equal to `self % rhs`.
3409        ///
3410        /// # Panics
3411        ///
3412        /// This function will panic if `rhs` is zero.
3413        ///
3414        /// # Examples
3415        ///
3416        /// ```
3417        #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".rem_euclid(4), 3); // or any other integer type")]
3418        /// ```
3419        #[doc(alias = "modulo", alias = "mod")]
3420        #[stable(feature = "euclidean_division", since = "1.38.0")]
3421        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3422        #[must_use = "this returns the result of the operation, \
3423                      without modifying the original"]
3424        #[inline(always)]
3425        #[track_caller]
3426        pub const fn rem_euclid(self, rhs: Self) -> Self {
3427            self % rhs
3428        }
3429
3430        /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
3431        ///
3432        /// This is the same as performing `self / rhs` for all unsigned integers.
3433        ///
3434        /// # Panics
3435        ///
3436        /// This function will panic if `rhs` is zero.
3437        ///
3438        /// # Examples
3439        ///
3440        /// ```
3441        /// #![feature(int_roundings)]
3442        #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_floor(4), 1);")]
3443        /// ```
3444        #[unstable(feature = "int_roundings", issue = "88581")]
3445        #[must_use = "this returns the result of the operation, \
3446                      without modifying the original"]
3447        #[inline(always)]
3448        #[track_caller]
3449        pub const fn div_floor(self, rhs: Self) -> Self {
3450            self / rhs
3451        }
3452
3453        /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
3454        ///
3455        /// # Panics
3456        ///
3457        /// This function will panic if `rhs` is zero.
3458        ///
3459        /// # Examples
3460        ///
3461        /// ```
3462        #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_ceil(4), 2);")]
3463        /// ```
3464        #[stable(feature = "int_roundings1", since = "1.73.0")]
3465        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3466        #[must_use = "this returns the result of the operation, \
3467                      without modifying the original"]
3468        #[inline]
3469        #[track_caller]
3470        pub const fn div_ceil(self, rhs: Self) -> Self {
3471            let d = self / rhs;
3472            let r = self % rhs;
3473            if r > 0 {
3474                d + 1
3475            } else {
3476                d
3477            }
3478        }
3479
3480        /// Calculates the smallest value greater than or equal to `self` that
3481        /// is a multiple of `rhs`.
3482        ///
3483        /// # Panics
3484        ///
3485        /// This function will panic if `rhs` is zero.
3486        ///
3487        /// ## Overflow behavior
3488        ///
3489        /// On overflow, this function will panic if overflow checks are enabled (default in debug
3490        /// mode) and wrap if overflow checks are disabled (default in release mode).
3491        ///
3492        /// # Examples
3493        ///
3494        /// ```
3495        #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
3496        #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
3497        /// ```
3498        #[stable(feature = "int_roundings1", since = "1.73.0")]
3499        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3500        #[must_use = "this returns the result of the operation, \
3501                      without modifying the original"]
3502        #[inline]
3503        #[rustc_inherit_overflow_checks]
3504        pub const fn next_multiple_of(self, rhs: Self) -> Self {
3505            match self % rhs {
3506                0 => self,
3507                r => self + (rhs - r)
3508            }
3509        }
3510
3511        /// Calculates the smallest value greater than or equal to `self` that
3512        /// is a multiple of `rhs`. Returns `None` if `rhs` is zero or the
3513        /// operation would result in overflow.
3514        ///
3515        /// # Examples
3516        ///
3517        /// ```
3518        #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
3519        #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
3520        #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
3521        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
3522        /// ```
3523        #[stable(feature = "int_roundings1", since = "1.73.0")]
3524        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3525        #[must_use = "this returns the result of the operation, \
3526                      without modifying the original"]
3527        #[inline]
3528        pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
3529            match try_opt!(self.checked_rem(rhs)) {
3530                0 => Some(self),
3531                // rhs - r cannot overflow because r is smaller than rhs
3532                r => self.checked_add(rhs - r)
3533            }
3534        }
3535
3536        /// Returns `true` if `self` is an integer multiple of `rhs`, and false otherwise.
3537        ///
3538        /// This function is equivalent to `self % rhs == 0`, except that it will not panic
3539        /// for `rhs == 0`. Instead, `0.is_multiple_of(0) == true`, and for any non-zero `n`,
3540        /// `n.is_multiple_of(0) == false`.
3541        ///
3542        /// # Examples
3543        ///
3544        /// ```
3545        #[doc = concat!("assert!(6_", stringify!($SelfT), ".is_multiple_of(2));")]
3546        #[doc = concat!("assert!(!5_", stringify!($SelfT), ".is_multiple_of(2));")]
3547        ///
3548        #[doc = concat!("assert!(0_", stringify!($SelfT), ".is_multiple_of(0));")]
3549        #[doc = concat!("assert!(!6_", stringify!($SelfT), ".is_multiple_of(0));")]
3550        /// ```
3551        #[stable(feature = "unsigned_is_multiple_of", since = "1.87.0")]
3552        #[rustc_const_stable(feature = "unsigned_is_multiple_of", since = "1.87.0")]
3553        #[must_use]
3554        #[inline]
3555        #[rustc_inherit_overflow_checks]
3556        pub const fn is_multiple_of(self, rhs: Self) -> bool {
3557            match rhs {
3558                0 => self == 0,
3559                _ => self % rhs == 0,
3560            }
3561        }
3562
3563        /// Returns `true` if and only if `self == 2^k` for some unsigned integer `k`.
3564        ///
3565        /// # Examples
3566        ///
3567        /// ```
3568        #[doc = concat!("assert!(16", stringify!($SelfT), ".is_power_of_two());")]
3569        #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_power_of_two());")]
3570        /// ```
3571        #[must_use]
3572        #[stable(feature = "rust1", since = "1.0.0")]
3573        #[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")]
3574        #[inline(always)]
3575        pub const fn is_power_of_two(self) -> bool {
3576            self.count_ones() == 1
3577        }
3578
3579        // Returns one less than next power of two.
3580        // (For 8u8 next power of two is 8u8 and for 6u8 it is 8u8)
3581        //
3582        // 8u8.one_less_than_next_power_of_two() == 7
3583        // 6u8.one_less_than_next_power_of_two() == 7
3584        //
3585        // This method cannot overflow, as in the `next_power_of_two`
3586        // overflow cases it instead ends up returning the maximum value
3587        // of the type, and can return 0 for 0.
3588        #[inline]
3589        const fn one_less_than_next_power_of_two(self) -> Self {
3590            if self <= 1 { return 0; }
3591
3592            let p = self - 1;
3593            // SAFETY: Because `p > 0`, it cannot consist entirely of leading zeros.
3594            // That means the shift is always in-bounds, and some processors
3595            // (such as intel pre-haswell) have more efficient ctlz
3596            // intrinsics when the argument is non-zero.
3597            let z = unsafe { intrinsics::ctlz_nonzero(p) };
3598            <$SelfT>::MAX >> z
3599        }
3600
3601        /// Returns the smallest power of two greater than or equal to `self`.
3602        ///
3603        /// When return value overflows (i.e., `self > (1 << (N-1))` for type
3604        /// `uN`), it panics in debug mode and the return value is wrapped to 0 in
3605        /// release mode (the only situation in which this method can return 0).
3606        ///
3607        /// # Examples
3608        ///
3609        /// ```
3610        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".next_power_of_two(), 2);")]
3611        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);")]
3612        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".next_power_of_two(), 1);")]
3613        /// ```
3614        #[stable(feature = "rust1", since = "1.0.0")]
3615        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3616        #[must_use = "this returns the result of the operation, \
3617                      without modifying the original"]
3618        #[inline]
3619        #[rustc_inherit_overflow_checks]
3620        pub const fn next_power_of_two(self) -> Self {
3621            self.one_less_than_next_power_of_two() + 1
3622        }
3623
3624        /// Returns the smallest power of two greater than or equal to `self`. If
3625        /// the next power of two is greater than the type's maximum value,
3626        /// `None` is returned, otherwise the power of two is wrapped in `Some`.
3627        ///
3628        /// # Examples
3629        ///
3630        /// ```
3631        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_next_power_of_two(), Some(2));")]
3632        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));")]
3633        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_power_of_two(), None);")]
3634        /// ```
3635        #[inline]
3636        #[stable(feature = "rust1", since = "1.0.0")]
3637        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3638        #[must_use = "this returns the result of the operation, \
3639                      without modifying the original"]
3640        pub const fn checked_next_power_of_two(self) -> Option<Self> {
3641            self.one_less_than_next_power_of_two().checked_add(1)
3642        }
3643
3644        /// Returns the smallest power of two greater than or equal to `n`. If
3645        /// the next power of two is greater than the type's maximum value,
3646        /// the return value is wrapped to `0`.
3647        ///
3648        /// # Examples
3649        ///
3650        /// ```
3651        /// #![feature(wrapping_next_power_of_two)]
3652        ///
3653        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".wrapping_next_power_of_two(), 2);")]
3654        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_next_power_of_two(), 4);")]
3655        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_next_power_of_two(), 0);")]
3656        /// ```
3657        #[inline]
3658        #[unstable(feature = "wrapping_next_power_of_two", issue = "32463",
3659                   reason = "needs decision on wrapping behavior")]
3660        #[must_use = "this returns the result of the operation, \
3661                      without modifying the original"]
3662        pub const fn wrapping_next_power_of_two(self) -> Self {
3663            self.one_less_than_next_power_of_two().wrapping_add(1)
3664        }
3665
3666        /// Returns the memory representation of this integer as a byte array in
3667        /// big-endian (network) byte order.
3668        ///
3669        #[doc = $to_xe_bytes_doc]
3670        ///
3671        /// # Examples
3672        ///
3673        /// ```
3674        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
3675        #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
3676        /// ```
3677        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3678        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3679        #[must_use = "this returns the result of the operation, \
3680                      without modifying the original"]
3681        #[inline]
3682        pub const fn to_be_bytes(self) -> [u8; size_of::<Self>()] {
3683            self.to_be().to_ne_bytes()
3684        }
3685
3686        /// Returns the memory representation of this integer as a byte array in
3687        /// little-endian byte order.
3688        ///
3689        #[doc = $to_xe_bytes_doc]
3690        ///
3691        /// # Examples
3692        ///
3693        /// ```
3694        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
3695        #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
3696        /// ```
3697        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3698        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3699        #[must_use = "this returns the result of the operation, \
3700                      without modifying the original"]
3701        #[inline]
3702        pub const fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
3703            self.to_le().to_ne_bytes()
3704        }
3705
3706        /// Returns the memory representation of this integer as a byte array in
3707        /// native byte order.
3708        ///
3709        /// As the target platform's native endianness is used, portable code
3710        /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
3711        /// instead.
3712        ///
3713        #[doc = $to_xe_bytes_doc]
3714        ///
3715        /// [`to_be_bytes`]: Self::to_be_bytes
3716        /// [`to_le_bytes`]: Self::to_le_bytes
3717        ///
3718        /// # Examples
3719        ///
3720        /// ```
3721        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
3722        /// assert_eq!(
3723        ///     bytes,
3724        ///     if cfg!(target_endian = "big") {
3725        #[doc = concat!("        ", $be_bytes)]
3726        ///     } else {
3727        #[doc = concat!("        ", $le_bytes)]
3728        ///     }
3729        /// );
3730        /// ```
3731        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3732        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3733        #[must_use = "this returns the result of the operation, \
3734                      without modifying the original"]
3735        #[allow(unnecessary_transmutes)]
3736        // SAFETY: const sound because integers are plain old datatypes so we can always
3737        // transmute them to arrays of bytes
3738        #[inline]
3739        pub const fn to_ne_bytes(self) -> [u8; size_of::<Self>()] {
3740            // SAFETY: integers are plain old datatypes so we can always transmute them to
3741            // arrays of bytes
3742            unsafe { mem::transmute(self) }
3743        }
3744
3745        /// Creates a native endian integer value from its representation
3746        /// as a byte array in big endian.
3747        ///
3748        #[doc = $from_xe_bytes_doc]
3749        ///
3750        /// # Examples
3751        ///
3752        /// ```
3753        #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
3754        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3755        /// ```
3756        ///
3757        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3758        ///
3759        /// ```
3760        #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3761        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3762        ///     *input = rest;
3763        #[doc = concat!("    ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
3764        /// }
3765        /// ```
3766        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3767        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3768        #[must_use]
3769        #[inline]
3770        pub const fn from_be_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3771            Self::from_be(Self::from_ne_bytes(bytes))
3772        }
3773
3774        /// Creates a native endian integer value from its representation
3775        /// as a byte array in little endian.
3776        ///
3777        #[doc = $from_xe_bytes_doc]
3778        ///
3779        /// # Examples
3780        ///
3781        /// ```
3782        #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
3783        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3784        /// ```
3785        ///
3786        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3787        ///
3788        /// ```
3789        #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3790        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3791        ///     *input = rest;
3792        #[doc = concat!("    ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
3793        /// }
3794        /// ```
3795        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3796        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3797        #[must_use]
3798        #[inline]
3799        pub const fn from_le_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3800            Self::from_le(Self::from_ne_bytes(bytes))
3801        }
3802
3803        /// Creates a native endian integer value from its memory representation
3804        /// as a byte array in native endianness.
3805        ///
3806        /// As the target platform's native endianness is used, portable code
3807        /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
3808        /// appropriate instead.
3809        ///
3810        /// [`from_be_bytes`]: Self::from_be_bytes
3811        /// [`from_le_bytes`]: Self::from_le_bytes
3812        ///
3813        #[doc = $from_xe_bytes_doc]
3814        ///
3815        /// # Examples
3816        ///
3817        /// ```
3818        #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
3819        #[doc = concat!("    ", $be_bytes, "")]
3820        /// } else {
3821        #[doc = concat!("    ", $le_bytes, "")]
3822        /// });
3823        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
3824        /// ```
3825        ///
3826        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
3827        ///
3828        /// ```
3829        #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
3830        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
3831        ///     *input = rest;
3832        #[doc = concat!("    ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
3833        /// }
3834        /// ```
3835        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
3836        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
3837        #[allow(unnecessary_transmutes)]
3838        #[must_use]
3839        // SAFETY: const sound because integers are plain old datatypes so we can always
3840        // transmute to them
3841        #[inline]
3842        pub const fn from_ne_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
3843            // SAFETY: integers are plain old datatypes so we can always transmute to them
3844            unsafe { mem::transmute(bytes) }
3845        }
3846
3847        /// New code should prefer to use
3848        #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
3849        ///
3850        /// Returns the smallest value that can be represented by this integer type.
3851        #[stable(feature = "rust1", since = "1.0.0")]
3852        #[rustc_promotable]
3853        #[inline(always)]
3854        #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
3855        #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")]
3856        #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
3857        pub const fn min_value() -> Self { Self::MIN }
3858
3859        /// New code should prefer to use
3860        #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
3861        ///
3862        /// Returns the largest value that can be represented by this integer type.
3863        #[stable(feature = "rust1", since = "1.0.0")]
3864        #[rustc_promotable]
3865        #[inline(always)]
3866        #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
3867        #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")]
3868        #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
3869        pub const fn max_value() -> Self { Self::MAX }
3870    }
3871}