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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        clmul_lhs = $clmul_lhs:literal,
21        clmul_rhs = $clmul_rhs:literal,
22        clmul_result = $clmul_result:literal,
23        swap_op = $swap_op:literal,
24        swapped = $swapped:literal,
25        reversed = $reversed:literal,
26        le_bytes = $le_bytes:literal,
27        be_bytes = $be_bytes:literal,
28        to_xe_bytes_doc = $to_xe_bytes_doc:expr,
29        from_xe_bytes_doc = $from_xe_bytes_doc:expr,
30        bound_condition = $bound_condition:literal,
31    ) => {
32        /// The smallest value that can be represented by this integer type.
33        ///
34        /// # Examples
35        ///
36        /// ```
37        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, 0);")]
38        /// ```
39        #[stable(feature = "assoc_int_consts", since = "1.43.0")]
40        pub const MIN: Self = 0;
41
42        /// The largest value that can be represented by this integer type
43        #[doc = concat!("(2<sup>", $BITS, "</sup> &minus; 1", $bound_condition, ").")]
44        ///
45        /// # Examples
46        ///
47        /// ```
48        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($MaxV), ");")]
49        /// ```
50        #[stable(feature = "assoc_int_consts", since = "1.43.0")]
51        pub const MAX: Self = !0;
52
53        /// The size of this integer type in bits.
54        ///
55        /// # Examples
56        ///
57        /// ```
58        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
59        /// ```
60        #[stable(feature = "int_bits_const", since = "1.53.0")]
61        pub const BITS: u32 = Self::MAX.count_ones();
62
63        /// Returns the number of ones in the binary representation of `self`.
64        ///
65        /// # Examples
66        ///
67        /// ```
68        #[doc = concat!("let n = 0b01001100", stringify!($SelfT), ";")]
69        /// assert_eq!(n.count_ones(), 3);
70        ///
71        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
72        #[doc = concat!("assert_eq!(max.count_ones(), ", stringify!($BITS), ");")]
73        ///
74        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
75        /// assert_eq!(zero.count_ones(), 0);
76        /// ```
77        #[stable(feature = "rust1", since = "1.0.0")]
78        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
79        #[doc(alias = "popcount")]
80        #[doc(alias = "popcnt")]
81        #[must_use = "this returns the result of the operation, \
82                      without modifying the original"]
83        #[inline(always)]
84        pub const fn count_ones(self) -> u32 {
85            return intrinsics::ctpop(self);
86        }
87
88        /// Returns the number of zeros in the binary representation of `self`.
89        ///
90        /// # Examples
91        ///
92        /// ```
93        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
94        #[doc = concat!("assert_eq!(zero.count_zeros(), ", stringify!($BITS), ");")]
95        ///
96        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
97        /// assert_eq!(max.count_zeros(), 0);
98        /// ```
99        ///
100        /// This is heavily dependent on the width of the type, and thus
101        /// might give surprising results depending on type inference:
102        /// ```
103        /// # fn foo(_: u8) {}
104        /// # fn bar(_: u16) {}
105        /// let lucky = 7;
106        /// foo(lucky);
107        /// assert_eq!(lucky.count_zeros(), 5);
108        /// assert_eq!(lucky.count_ones(), 3);
109        ///
110        /// let lucky = 7;
111        /// bar(lucky);
112        /// assert_eq!(lucky.count_zeros(), 13);
113        /// assert_eq!(lucky.count_ones(), 3);
114        /// ```
115        /// You might want to use [`Self::count_ones`] instead, or emphasize
116        /// the type you're using in the call rather than method syntax:
117        /// ```
118        /// let small = 1;
119        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::count_zeros(small), ", stringify!($BITS_MINUS_ONE) ,");")]
120        /// ```
121        #[stable(feature = "rust1", since = "1.0.0")]
122        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
123        #[must_use = "this returns the result of the operation, \
124                      without modifying the original"]
125        #[inline(always)]
126        pub const fn count_zeros(self) -> u32 {
127            (!self).count_ones()
128        }
129
130        /// Returns the number of leading zeros in the binary representation of `self`.
131        ///
132        /// Depending on what you're doing with the value, you might also be interested in the
133        /// [`ilog2`] function which returns a consistent number, even if the type widens.
134        ///
135        /// # Examples
136        ///
137        /// ```
138        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX >> 2;")]
139        /// assert_eq!(n.leading_zeros(), 2);
140        ///
141        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
142        #[doc = concat!("assert_eq!(zero.leading_zeros(), ", stringify!($BITS), ");")]
143        ///
144        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
145        /// assert_eq!(max.leading_zeros(), 0);
146        /// ```
147        #[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")]
148        #[stable(feature = "rust1", since = "1.0.0")]
149        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
150        #[must_use = "this returns the result of the operation, \
151                      without modifying the original"]
152        #[inline(always)]
153        pub const fn leading_zeros(self) -> u32 {
154            return intrinsics::ctlz(self as $ActualT);
155        }
156
157        /// Returns the number of trailing zeros in the binary representation
158        /// of `self`.
159        ///
160        /// # Examples
161        ///
162        /// ```
163        #[doc = concat!("let n = 0b0101000", stringify!($SelfT), ";")]
164        /// assert_eq!(n.trailing_zeros(), 3);
165        ///
166        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
167        #[doc = concat!("assert_eq!(zero.trailing_zeros(), ", stringify!($BITS), ");")]
168        ///
169        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
170        #[doc = concat!("assert_eq!(max.trailing_zeros(), 0);")]
171        /// ```
172        #[stable(feature = "rust1", since = "1.0.0")]
173        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
174        #[must_use = "this returns the result of the operation, \
175                      without modifying the original"]
176        #[inline(always)]
177        pub const fn trailing_zeros(self) -> u32 {
178            return intrinsics::cttz(self);
179        }
180
181        /// Returns the number of leading ones in the binary representation of `self`.
182        ///
183        /// # Examples
184        ///
185        /// ```
186        #[doc = concat!("let n = !(", stringify!($SelfT), "::MAX >> 2);")]
187        /// assert_eq!(n.leading_ones(), 2);
188        ///
189        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
190        /// assert_eq!(zero.leading_ones(), 0);
191        ///
192        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
193        #[doc = concat!("assert_eq!(max.leading_ones(), ", stringify!($BITS), ");")]
194        /// ```
195        #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
196        #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
197        #[must_use = "this returns the result of the operation, \
198                      without modifying the original"]
199        #[inline(always)]
200        pub const fn leading_ones(self) -> u32 {
201            (!self).leading_zeros()
202        }
203
204        /// Returns the number of trailing ones in the binary representation
205        /// of `self`.
206        ///
207        /// # Examples
208        ///
209        /// ```
210        #[doc = concat!("let n = 0b1010111", stringify!($SelfT), ";")]
211        /// assert_eq!(n.trailing_ones(), 3);
212        ///
213        #[doc = concat!("let zero = 0", stringify!($SelfT), ";")]
214        /// assert_eq!(zero.trailing_ones(), 0);
215        ///
216        #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")]
217        #[doc = concat!("assert_eq!(max.trailing_ones(), ", stringify!($BITS), ");")]
218        /// ```
219        #[stable(feature = "leading_trailing_ones", since = "1.46.0")]
220        #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
221        #[must_use = "this returns the result of the operation, \
222                      without modifying the original"]
223        #[inline(always)]
224        pub const fn trailing_ones(self) -> u32 {
225            (!self).trailing_zeros()
226        }
227
228        /// Returns the minimum number of bits required to represent `self`.
229        ///
230        /// This method returns zero if `self` is zero.
231        ///
232        /// # Examples
233        ///
234        /// ```
235        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".bit_width(), 0);")]
236        #[doc = concat!("assert_eq!(0b111_", stringify!($SelfT), ".bit_width(), 3);")]
237        #[doc = concat!("assert_eq!(0b1110_", stringify!($SelfT), ".bit_width(), 4);")]
238        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.bit_width(), ", stringify!($BITS), ");")]
239        /// ```
240        #[stable(feature = "uint_bit_width", since = "1.97.0")]
241        #[rustc_const_stable(feature = "uint_bit_width", since = "1.97.0")]
242        #[must_use = "this returns the result of the operation, \
243                      without modifying the original"]
244        #[inline(always)]
245        pub const fn bit_width(self) -> u32 {
246            Self::BITS - self.leading_zeros()
247        }
248
249        /// Returns `self` with only the most significant bit set, or `0` if
250        /// the input is `0`.
251        ///
252        /// # Examples
253        ///
254        /// ```
255        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
256        ///
257        /// assert_eq!(n.isolate_highest_one(), 0b_01000000);
258        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_highest_one(), 0);")]
259        /// ```
260        #[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
261        #[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
262        #[must_use = "this returns the result of the operation, \
263                      without modifying the original"]
264        #[inline(always)]
265        pub const fn isolate_highest_one(self) -> Self {
266            self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros()))
267        }
268
269        /// Returns `self` with only the least significant bit set, or `0` if
270        /// the input is `0`.
271        ///
272        /// # Examples
273        ///
274        /// ```
275        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
276        ///
277        /// assert_eq!(n.isolate_lowest_one(), 0b_00000100);
278        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_lowest_one(), 0);")]
279        /// ```
280        #[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
281        #[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
282        #[must_use = "this returns the result of the operation, \
283                      without modifying the original"]
284        #[inline(always)]
285        pub const fn isolate_lowest_one(self) -> Self {
286            self & self.wrapping_neg()
287        }
288
289        /// Returns the index of the highest bit set to one in `self`, or `None`
290        /// if `self` is `0`.
291        ///
292        /// Note that this is equivalent to [`checked_ilog2`](Self::checked_ilog2).
293        ///
294        /// # Examples
295        ///
296        /// ```
297        #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".highest_one(), None);")]
298        #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".highest_one(), Some(0));")]
299        #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".highest_one(), Some(4));")]
300        #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".highest_one(), Some(4));")]
301        /// ```
302        #[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
303        #[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
304        #[must_use = "this returns the result of the operation, \
305                      without modifying the original"]
306        #[inline(always)]
307        pub const fn highest_one(self) -> Option<u32> {
308            match NonZero::new(self) {
309                Some(v) => Some(v.highest_one()),
310                None => None,
311            }
312        }
313
314        /// Returns the index of the lowest bit set to one in `self`, or `None`
315        /// if `self` is `0`.
316        ///
317        /// # Examples
318        ///
319        /// ```
320        #[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".lowest_one(), None);")]
321        #[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".lowest_one(), Some(0));")]
322        #[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".lowest_one(), Some(4));")]
323        #[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".lowest_one(), Some(0));")]
324        /// ```
325        #[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
326        #[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
327        #[must_use = "this returns the result of the operation, \
328                      without modifying the original"]
329        #[inline(always)]
330        pub const fn lowest_one(self) -> Option<u32> {
331            match NonZero::new(self) {
332                Some(v) => Some(v.lowest_one()),
333                None => None,
334            }
335        }
336
337        /// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size.
338        ///
339        /// This produces the same result as an `as` cast, but ensures that the bit-width remains
340        /// the same.
341        ///
342        /// # Examples
343        ///
344        /// ```
345        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")]
346        ///
347        #[doc = concat!("assert_eq!(n.cast_signed(), -1", stringify!($SignedT), ");")]
348        /// ```
349        #[stable(feature = "integer_sign_cast", since = "1.87.0")]
350        #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
351        #[must_use = "this returns the result of the operation, \
352                      without modifying the original"]
353        #[inline(always)]
354        pub const fn cast_signed(self) -> $SignedT {
355            self as $SignedT
356        }
357
358        /// Saturating conversion of `self` to a signed integer of the same size.
359        ///
360        /// The signed integer's maximum value is returned if `self` is larger
361        /// than the maximum positive value representable by the signed integer.
362        ///
363        /// For other kinds of signed integer casts, see
364        /// [`cast_signed`](Self::cast_signed),
365        /// [`checked_cast_signed`](Self::checked_cast_signed),
366        /// or [`strict_cast_signed`](Self::strict_cast_signed).
367        ///
368        /// # Examples
369        ///
370        /// ```
371        /// #![feature(integer_cast_extras)]
372        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")]
373        ///
374        #[doc = concat!("assert_eq!(n.saturating_cast_signed(), ", stringify!($SignedT), "::MAX);")]
375        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".saturating_cast_signed(), 64", stringify!($SignedT), ");")]
376        /// ```
377        #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
378        #[unstable(feature = "integer_cast_extras", issue = "154650")]
379        #[must_use = "this returns the result of the operation, \
380                      without modifying the original"]
381        #[inline(always)]
382        pub const fn saturating_cast_signed(self) -> $SignedT {
383            // Clamp to the signed integer max size, which is ActualT::MAX >> 1.
384            if self <= <$SignedT>::MAX.cast_unsigned() {
385                self.cast_signed()
386            } else {
387                <$SignedT>::MAX
388            }
389        }
390
391        /// Checked conversion of `self` to a signed integer of the same size,
392        /// returning `None` if `self` is larger than the signed integer's
393        /// maximum value.
394        ///
395        /// For other kinds of signed integer casts, see
396        /// [`cast_signed`](Self::cast_signed),
397        /// [`saturating_cast_signed`](Self::saturating_cast_signed),
398        /// or [`strict_cast_signed`](Self::strict_cast_signed).
399        ///
400        /// # Examples
401        ///
402        /// ```
403        /// #![feature(integer_cast_extras)]
404        #[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")]
405        ///
406        #[doc = concat!("assert_eq!(n.checked_cast_signed(), None);")]
407        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_cast_signed(), Some(64", stringify!($SignedT), "));")]
408        /// ```
409        #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
410        #[unstable(feature = "integer_cast_extras", issue = "154650")]
411        #[must_use = "this returns the result of the operation, \
412                      without modifying the original"]
413        #[inline(always)]
414        pub const fn checked_cast_signed(self) -> Option<$SignedT> {
415            if self <= <$SignedT>::MAX.cast_unsigned() {
416                Some(self.cast_signed())
417            } else {
418                None
419            }
420        }
421
422        /// Strict conversion of `self` to a signed integer of the same size,
423        /// which panics if `self` is larger than the signed integer's maximum
424        /// value.
425        ///
426        /// For other kinds of signed integer casts, see
427        /// [`cast_signed`](Self::cast_signed),
428        /// [`checked_cast_signed`](Self::checked_cast_signed),
429        /// or [`saturating_cast_signed`](Self::saturating_cast_signed).
430        ///
431        /// # Examples
432        ///
433        /// ```should_panic
434        /// #![feature(integer_cast_extras)]
435        #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_cast_signed();")]
436        /// ```
437        #[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
438        #[unstable(feature = "integer_cast_extras", issue = "154650")]
439        #[must_use = "this returns the result of the operation, \
440                      without modifying the original"]
441        #[inline]
442        #[track_caller]
443        pub const fn strict_cast_signed(self) -> $SignedT {
444            match self.checked_cast_signed() {
445                Some(n) => n,
446                None => imp::overflow_panic::cast_integer(),
447            }
448        }
449
450        /// Shifts the bits to the left by a specified amount, `n`,
451        /// wrapping the truncated bits to the end of the resulting integer.
452        ///
453        /// `rotate_left(n)` is equivalent to applying `rotate_left(1)` a total of `n` times. In
454        /// particular, a rotation by the number of bits in `self` returns the input value
455        /// unchanged.
456        ///
457        /// Please note this isn't the same operation as the `<<` shifting operator!
458        ///
459        /// # Examples
460        ///
461        /// ```
462        #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
463        #[doc = concat!("let m = ", $rot_result, ";")]
464        ///
465        #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
466        #[doc = concat!("assert_eq!(n.rotate_left(1024), n);")]
467        /// ```
468        #[stable(feature = "rust1", since = "1.0.0")]
469        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
470        #[must_use = "this returns the result of the operation, \
471                      without modifying the original"]
472        #[inline(always)]
473        #[rustc_allow_const_fn_unstable(const_trait_impl)] // for the intrinsic fallback
474        pub const fn rotate_left(self, n: u32) -> Self {
475            return intrinsics::rotate_left(self, n);
476        }
477
478        /// Shifts the bits to the right by a specified amount, `n`,
479        /// wrapping the truncated bits to the beginning of the resulting
480        /// integer.
481        ///
482        /// `rotate_right(n)` is equivalent to applying `rotate_right(1)` a total of `n` times. In
483        /// particular, a rotation by the number of bits in `self` returns the input value
484        /// unchanged.
485        ///
486        /// Please note this isn't the same operation as the `>>` shifting operator!
487        ///
488        /// # Examples
489        ///
490        /// ```
491        #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
492        #[doc = concat!("let m = ", $rot_op, ";")]
493        ///
494        #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
495        #[doc = concat!("assert_eq!(n.rotate_right(1024), n);")]
496        /// ```
497        #[stable(feature = "rust1", since = "1.0.0")]
498        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
499        #[must_use = "this returns the result of the operation, \
500                      without modifying the original"]
501        #[inline(always)]
502        #[rustc_allow_const_fn_unstable(const_trait_impl)] // for the intrinsic fallback
503        pub const fn rotate_right(self, n: u32) -> Self {
504            return intrinsics::rotate_right(self, n);
505        }
506
507        /// Performs a left funnel shift.
508        ///
509        /// This operation can be thought of as concatenating `self` and `right` into an
510        /// integer twice the size of
511        #[doc = concat!("`", stringify!($SelfT) , "`,")]
512        /// performing a left shift by `n`, and returning the **left half** of the result.
513        ///
514        /// The name comes from "funneling" a wider integer to a narrower integer.
515        ///
516        /// # Panics
517        ///
518        /// ## Overflow behavior
519        ///
520        /// If overflow checks are enabled (default in debug mode), this function will panic if `n`
521        /// is greater than or equal to the number of bits in `self`. If overflow checks are
522        /// disabled (default in release mode), there is no panic; instead, the value is shifted
523        /// by `n % Self::BITS`.
524        // FIXME(wrapping_funnel_shifts): link to `wrapping_funnel_shl` when stable.
525        ///
526        /// # Examples
527        ///
528        /// ```
529        #[doc = concat!("let a = ", $rot_op, "_", stringify!($SelfT), ";")]
530        #[doc = concat!("let b = ", $fsh_op, "_", stringify!($SelfT), ";")]
531        ///
532        #[doc = concat!("assert_eq!(a.funnel_shl(b, ", $rot, "), ", $fshl_result, ");")]
533        ///
534        /// // Using zeros as the right operand acts as a normal shift left
535        #[doc = concat!("assert_eq!(a.funnel_shl(0, ", $rot, "), a << ", $rot, ");")]
536        ///
537        /// // Shifting by 0 returns `self` unchanged
538        #[doc = concat!("assert_eq!(a.funnel_shl(b, 0), a);")]
539        ///
540        /// // Using the same value as the right operand acts as a rotate
541        #[doc = concat!("assert_eq!(a.funnel_shl(a, ", $rot, "), a.rotate_left(", $rot, "));")]
542        /// ```
543        ///
544        /// Note that while `funnel_shl` can act as a rotate, it does not allow for
545        /// rotating by an unbounded amount like [`rotate_left`](Self::rotate_left) does:
546        ///
547        /// ```should_panic
548        /// # #![feature(cfg_overflow_checks)]
549        /// # #[cfg(overflow_checks)] {
550        #[doc = concat!("let a = ", stringify!($SelfT), "::MAX;")]
551        /// // Okay
552        #[doc = concat!("let _ = a.rotate_left(", stringify!($SelfT), "::BITS);")]
553        /// // Panics (only when overflow checks are enabled)
554        #[doc = concat!("let _ = a.funnel_shl(a, ", stringify!($SelfT), "::BITS);")]
555        /// # }
556        /// # #[cfg(not(overflow_checks))] panic!("fulfill should_panic");
557        /// ```
558        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
559        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
560        #[must_use = "this returns the result of the operation, without modifying the original"]
561        #[inline(always)]
562        #[rustc_inherit_overflow_checks]
563        pub const fn funnel_shl(self, right: Self, n: u32) -> Self {
564            if intrinsics::overflow_checks() {
565                assert!(n < Self::BITS, "attempt to funnel shift left with overflow");
566            }
567            // SAFETY: `n` is wrapped to within range
568            unsafe {
569                let n = n & (Self::BITS - 1);
570                self.unchecked_funnel_shl(right, n)
571            }
572        }
573
574        /// Performs a right funnel shift.
575        ///
576        /// This operation can be thought of as concatenating `self` and `right` into an
577        /// integer twice the size of
578        #[doc = concat!("`", stringify!($SelfT) , "`,")]
579        /// performing a right shift by `n`, and returning the **right half** of the result.
580        ///
581        /// The name comes from "funneling" a wider integer to a narrower integer.
582        ///
583        /// # Panics
584        ///
585        /// ## Overflow behavior
586        ///
587        /// If overflow checks are enabled (default in debug mode), this function will panic if `n`
588        /// is greater than or equal to the number of bits in `self`. If overflow checks are
589        /// disabled (default in release mode), there is no panic; instead, the value is shifted
590        /// by `n % Self::BITS`.
591        // FIXME(wrapping_funnel_shifts): link to `wrapping_funnel_shr` when stable.
592        ///
593        /// # Examples
594        ///
595        /// ```
596        #[doc = concat!("let a = ", $rot_op, "_", stringify!($SelfT), ";")]
597        #[doc = concat!("let b = ", $fsh_op, "_", stringify!($SelfT), ";")]
598        ///
599        #[doc = concat!("assert_eq!(a.funnel_shr(b, ", $rot, "), ", $fshr_result, ");")]
600        ///
601        /// // Using zeros as the left operand acts as a normal shift right
602        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".funnel_shr(a, ", $rot, "), a >> ", $rot, ");")]
603        ///
604        /// // Shifting by 0 returns `right` unchanged
605        #[doc = concat!("assert_eq!(b.funnel_shr(a, 0), a);")]
606        ///
607        /// // Using the same value as the right operand acts as a rotate
608        #[doc = concat!("assert_eq!(a.funnel_shr(a, ", $rot, "), a.rotate_right(", $rot, "));")]
609        /// ```
610        ///
611        /// Note that while `funnel_shr` can act as a rotate, it does not allow for
612        /// rotating by an unbounded amount like [`rotate_right`](Self::rotate_right) does:
613        ///
614        /// ```should_panic
615        /// # #![feature(cfg_overflow_checks)]
616        /// # #[cfg(overflow_checks)] {
617        #[doc = concat!("let a = ", stringify!($SelfT), "::MAX;")]
618        /// // Okay
619        #[doc = concat!("let _ = a.rotate_right(", stringify!($SelfT), "::BITS);")]
620        /// // Panics (only when overflow checks are enabled)
621        #[doc = concat!("let _ = a.funnel_shr(a, ", stringify!($SelfT), "::BITS);")]
622        /// # }
623        /// # #[cfg(not(overflow_checks))] panic!("fulfill should_panic");
624        /// ```
625        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
626        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
627        #[must_use = "this returns the result of the operation, without modifying the original"]
628        #[inline(always)]
629        #[rustc_inherit_overflow_checks]
630        pub const fn funnel_shr(self, right: Self, n: u32) -> Self {
631            if intrinsics::overflow_checks() {
632                assert!(n < Self::BITS, "attempt to funnel shift right with overflow");
633            }
634            // SAFETY: `n` is wrapped to within range
635            unsafe {
636                let n = n & (Self::BITS - 1);
637                self.unchecked_funnel_shr(right, n)
638            }
639        }
640
641        /// Unchecked funnel shift left.
642        ///
643        /// # Safety
644        ///
645        /// This results in undefined behavior if `n` is greater than or equal to
646        #[doc = concat!("`", stringify!($SelfT) , "::BITS`,")]
647        /// i.e. when [`funnel_shl`](Self::funnel_shl) would panic.
648        ///
649        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
650        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
651        #[rustc_allow_const_fn_unstable(const_trait_impl)]
652        #[must_use = "this returns the result of the operation, without modifying the original"]
653        #[inline(always)]
654        #[track_caller]
655        pub const unsafe fn unchecked_funnel_shl(self, right: Self, n: u32) -> Self {
656            assert_unsafe_precondition!(
657                check_language_ub,
658                concat!(stringify!($SelfT), "::unchecked_funnel_shl cannot overflow"),
659                (n: u32 = n) => n < <$ActualT>::BITS,
660            );
661
662            // SAFETY: this is guaranteed to be safe by the caller.
663            unsafe {
664                intrinsics::unchecked_funnel_shl(self, right, n)
665            }
666        }
667
668        /// Unchecked funnel shift right.
669        ///
670        /// # Safety
671        ///
672        /// This results in undefined behavior if `n` is greater than or equal to
673        #[doc = concat!("`", stringify!($SelfT) , "::BITS`,")]
674        /// i.e. when [`funnel_shr`](Self::funnel_shr) would panic.
675        ///
676        #[rustc_const_stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
677        #[stable(feature = "funnel_shifts", since = "CURRENT_RUSTC_VERSION")]
678        #[rustc_allow_const_fn_unstable(const_trait_impl)]
679        #[must_use = "this returns the result of the operation, without modifying the original"]
680        #[inline(always)]
681        #[track_caller]
682        pub const unsafe fn unchecked_funnel_shr(self, right: Self, n: u32) -> Self {
683            assert_unsafe_precondition!(
684                check_language_ub,
685                concat!(stringify!($SelfT), "::unchecked_funnel_shr cannot overflow"),
686                (n: u32 = n) => n < <$ActualT>::BITS,
687            );
688
689            // SAFETY: this is guaranteed to be safe by the caller.
690            unsafe {
691                intrinsics::unchecked_funnel_shr(self, right, n)
692            }
693        }
694
695        /// Performs a carry-less multiplication, returning the lower bits.
696        ///
697        /// This operation is similar to long multiplication in base 2, except that exclusive or is
698        /// used instead of addition. The implementation is equivalent to:
699        ///
700        /// ```no_run
701        #[doc = concat!("pub fn carryless_mul(lhs: ", stringify!($SelfT), ", rhs: ", stringify!($SelfT), ") -> ", stringify!($SelfT), "{")]
702        ///     let mut retval = 0;
703        #[doc = concat!("    for i in 0..",  stringify!($SelfT), "::BITS {")]
704        ///         if (rhs >> i) & 1 != 0 {
705        ///             // long multiplication would use +=
706        ///             retval ^= lhs << i;
707        ///         }
708        ///     }
709        ///     retval
710        /// }
711        /// ```
712        ///
713        /// The actual implementation is more efficient, and on some platforms lowers directly to a
714        /// dedicated instruction.
715        ///
716        /// # Uses
717        ///
718        /// Carryless multiplication can be used to turn a bitmask of quote characters into a
719        /// bit mask of characters surrounded by quotes:
720        ///
721        /// ```no_run
722        /// r#"abc xxx "foobar" zzz "a"!"#; // input string
723        ///  0b0000000010000001000001010; // quote_mask
724        ///  0b0000000001111110000000100; // quote_mask.carryless_mul(!0) & !quote_mask
725        /// ```
726        ///
727        /// Another use is in cryptography, where carryless multiplication allows for efficient
728        /// implementations of polynomial multiplication in `GF(2)[X]`, the polynomial ring
729        /// over `GF(2)`.
730        ///
731        /// # Examples
732        ///
733        /// ```
734        /// #![feature(uint_carryless_mul)]
735        ///
736        #[doc = concat!("let a = ", $clmul_lhs, stringify!($SelfT), ";")]
737        #[doc = concat!("let b = ", $clmul_rhs, stringify!($SelfT), ";")]
738        ///
739        #[doc = concat!("assert_eq!(a.carryless_mul(b), ", $clmul_result, ");")]
740        /// ```
741        #[rustc_const_unstable(feature = "uint_carryless_mul", issue = "152080")]
742        #[doc(alias = "clmul")]
743        #[unstable(feature = "uint_carryless_mul", issue = "152080")]
744        #[must_use = "this returns the result of the operation, \
745                      without modifying the original"]
746        #[inline(always)]
747        pub const fn carryless_mul(self, rhs: Self) -> Self {
748            intrinsics::carryless_mul(self, rhs)
749        }
750
751        /// Reverses the byte order of the integer.
752        ///
753        /// # Examples
754        ///
755        /// ```
756        #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
757        /// let m = n.swap_bytes();
758        ///
759        #[doc = concat!("assert_eq!(m, ", $swapped, ");")]
760        /// ```
761        #[stable(feature = "rust1", since = "1.0.0")]
762        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
763        #[must_use = "this returns the result of the operation, \
764                      without modifying the original"]
765        #[inline(always)]
766        pub const fn swap_bytes(self) -> Self {
767            intrinsics::bswap(self as $ActualT) as Self
768        }
769
770        /// Returns an integer with the bit locations specified by `mask` packed
771        /// contiguously into the least significant bits of the result.
772        /// ```
773        /// #![feature(uint_gather_scatter_bits)]
774        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b1011_1100;")]
775        ///
776        /// assert_eq!(n.extract_bits(0b0010_0100), 0b0000_0011);
777        /// assert_eq!(n.extract_bits(0xF0), 0b0000_1011);
778        /// ```
779        #[doc(alias = "pext")]
780        #[unstable(feature = "uint_gather_scatter_bits", issue = "149069")]
781        #[must_use = "this returns the result of the operation, \
782                      without modifying the original"]
783        #[inline]
784        pub const fn extract_bits(self, mask: Self) -> Self {
785            imp::int_bits::$ActualT::extract_impl(self as $ActualT, mask as $ActualT) as $SelfT
786        }
787
788        /// Returns an integer with the least significant bits of `self`
789        /// distributed to the bit locations specified by `mask`.
790        /// ```
791        /// #![feature(uint_gather_scatter_bits)]
792        #[doc = concat!("let n: ", stringify!($SelfT), " = 0b1010_1101;")]
793        ///
794        /// assert_eq!(n.deposit_bits(0b0101_0101), 0b0101_0001);
795        /// assert_eq!(n.deposit_bits(0xF0), 0b1101_0000);
796        /// ```
797        #[doc(alias = "pdep")]
798        #[unstable(feature = "uint_gather_scatter_bits", issue = "149069")]
799        #[must_use = "this returns the result of the operation, \
800                      without modifying the original"]
801        #[inline]
802        pub const fn deposit_bits(self, mask: Self) -> Self {
803            imp::int_bits::$ActualT::deposit_impl(self as $ActualT, mask as $ActualT) as $SelfT
804        }
805
806        /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
807        ///                 second least-significant bit becomes second most-significant bit, etc.
808        ///
809        /// # Examples
810        ///
811        /// ```
812        #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
813        /// let m = n.reverse_bits();
814        ///
815        #[doc = concat!("assert_eq!(m, ", $reversed, ");")]
816        #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
817        /// ```
818        #[stable(feature = "reverse_bits", since = "1.37.0")]
819        #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")]
820        #[must_use = "this returns the result of the operation, \
821                      without modifying the original"]
822        #[inline(always)]
823        pub const fn reverse_bits(self) -> Self {
824            intrinsics::bitreverse(self as $ActualT) as Self
825        }
826
827        /// Converts an integer from big endian to the target's endianness.
828        ///
829        /// On big endian this is a no-op. On little endian the bytes are
830        /// swapped.
831        ///
832        /// # Examples
833        ///
834        /// ```
835        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
836        ///
837        /// if cfg!(target_endian = "big") {
838        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
839        /// } else {
840        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
841        /// }
842        /// ```
843        #[stable(feature = "rust1", since = "1.0.0")]
844        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
845        #[must_use]
846        #[inline(always)]
847        pub const fn from_be(x: Self) -> Self {
848            cfg_select! {
849                target_endian = "big" => x,
850                _ => x.swap_bytes(),
851            }
852        }
853
854        /// Converts an integer from little endian to the target's endianness.
855        ///
856        /// On little endian this is a no-op. On big endian the bytes are
857        /// swapped.
858        ///
859        /// # Examples
860        ///
861        /// ```
862        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
863        ///
864        /// if cfg!(target_endian = "little") {
865        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
866        /// } else {
867        #[doc = concat!("    assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
868        /// }
869        /// ```
870        #[stable(feature = "rust1", since = "1.0.0")]
871        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
872        #[must_use]
873        #[inline(always)]
874        pub const fn from_le(x: Self) -> Self {
875            cfg_select! {
876                target_endian = "little" => x,
877                _ => x.swap_bytes(),
878            }
879        }
880
881        /// Converts `self` to big endian from the target's endianness.
882        ///
883        /// On big endian this is a no-op. On little endian the bytes are
884        /// swapped.
885        ///
886        /// # Examples
887        ///
888        /// ```
889        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
890        ///
891        /// if cfg!(target_endian = "big") {
892        ///     assert_eq!(n.to_be(), n)
893        /// } else {
894        ///     assert_eq!(n.to_be(), n.swap_bytes())
895        /// }
896        /// ```
897        #[stable(feature = "rust1", since = "1.0.0")]
898        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
899        #[must_use = "this returns the result of the operation, \
900                      without modifying the original"]
901        #[inline(always)]
902        pub const fn to_be(self) -> Self { // or not to be?
903            cfg_select! {
904                target_endian = "big" => self,
905                _ => self.swap_bytes(),
906            }
907        }
908
909        /// Converts `self` to little endian from the target's endianness.
910        ///
911        /// On little endian this is a no-op. On big endian the bytes are
912        /// swapped.
913        ///
914        /// # Examples
915        ///
916        /// ```
917        #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
918        ///
919        /// if cfg!(target_endian = "little") {
920        ///     assert_eq!(n.to_le(), n)
921        /// } else {
922        ///     assert_eq!(n.to_le(), n.swap_bytes())
923        /// }
924        /// ```
925        #[stable(feature = "rust1", since = "1.0.0")]
926        #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
927        #[must_use = "this returns the result of the operation, \
928                      without modifying the original"]
929        #[inline(always)]
930        pub const fn to_le(self) -> Self {
931            cfg_select! {
932                target_endian = "little" => self,
933                _ => self.swap_bytes(),
934            }
935        }
936
937        /// Checked integer addition. Computes `self + rhs`, returning `None`
938        /// if overflow occurred.
939        ///
940        /// # Examples
941        ///
942        /// ```
943        #[doc = concat!(
944            "assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), ",
945            "Some(", stringify!($SelfT), "::MAX - 1));"
946        )]
947        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
948        /// ```
949        #[stable(feature = "rust1", since = "1.0.0")]
950        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
951        #[must_use = "this returns the result of the operation, \
952                      without modifying the original"]
953        #[inline]
954        pub const fn checked_add(self, rhs: Self) -> Option<Self> {
955            // This used to use `overflowing_add`, but that means it ends up being
956            // a `wrapping_add`, losing some optimization opportunities. Notably,
957            // phrasing it this way helps `.checked_add(1)` optimize to a check
958            // against `MAX` and a `add nuw`.
959            // Per <https://github.com/rust-lang/rust/pull/124114#issuecomment-2066173305>,
960            // LLVM is happy to re-form the intrinsic later if useful.
961
962            if intrinsics::unlikely(intrinsics::add_with_overflow(self, rhs).1) {
963                None
964            } else {
965                // SAFETY: Just checked it doesn't overflow
966                Some(unsafe { intrinsics::unchecked_add(self, rhs) })
967            }
968        }
969
970        /// Strict integer addition. Computes `self + rhs`, panicking
971        /// if overflow occurred.
972        ///
973        /// # Panics
974        ///
975        /// ## Overflow behavior
976        ///
977        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
978        ///
979        /// # Examples
980        ///
981        /// ```
982        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
983        /// ```
984        ///
985        /// The following panics because of overflow:
986        ///
987        /// ```should_panic
988        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
989        /// ```
990        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
991        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
992        #[must_use = "this returns the result of the operation, \
993                      without modifying the original"]
994        #[inline]
995        #[track_caller]
996        pub const fn strict_add(self, rhs: Self) -> Self {
997            let (a, b) = self.overflowing_add(rhs);
998            if b { imp::overflow_panic::add() } else { a }
999        }
1000
1001        /// Unchecked integer addition. Computes `self + rhs`, assuming overflow
1002        /// cannot occur.
1003        ///
1004        /// Calling `x.unchecked_add(y)` is semantically equivalent to calling
1005        /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
1006        ///
1007        /// If you're just trying to avoid the panic in debug mode, then **do not**
1008        /// use this.  Instead, you're looking for [`wrapping_add`].
1009        ///
1010        /// # Safety
1011        ///
1012        /// This results in undefined behavior when
1013        #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX`,")]
1014        /// i.e. when [`checked_add`] would return `None`.
1015        ///
1016        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
1017        #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
1018        #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
1019        #[stable(feature = "unchecked_math", since = "1.79.0")]
1020        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
1021        #[must_use = "this returns the result of the operation, \
1022                      without modifying the original"]
1023        #[inline(always)]
1024        #[track_caller]
1025        pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
1026            assert_unsafe_precondition!(
1027                check_language_ub,
1028                concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
1029                (
1030                    lhs: $SelfT = self,
1031                    rhs: $SelfT = rhs,
1032                ) => !lhs.overflowing_add(rhs).1,
1033            );
1034
1035            // SAFETY: this is guaranteed to be safe by the caller.
1036            unsafe {
1037                intrinsics::unchecked_add(self, rhs)
1038            }
1039        }
1040
1041        /// Checked addition with a signed integer. Computes `self + rhs`,
1042        /// returning `None` if overflow occurred.
1043        ///
1044        /// # Examples
1045        ///
1046        /// ```
1047        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(2), Some(3));")]
1048        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(-2), None);")]
1049        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_signed(3), None);")]
1050        /// ```
1051        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
1052        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
1053        #[must_use = "this returns the result of the operation, \
1054                      without modifying the original"]
1055        #[inline]
1056        pub const fn checked_add_signed(self, rhs: $SignedT) -> Option<Self> {
1057            let (a, b) = self.overflowing_add_signed(rhs);
1058            if intrinsics::unlikely(b) { None } else { Some(a) }
1059        }
1060
1061        /// Strict addition with a signed integer. Computes `self + rhs`,
1062        /// panicking if overflow occurred.
1063        ///
1064        /// # Panics
1065        ///
1066        /// ## Overflow behavior
1067        ///
1068        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1069        ///
1070        /// # Examples
1071        ///
1072        /// ```
1073        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_signed(2), 3);")]
1074        /// ```
1075        ///
1076        /// The following panic because of overflow:
1077        ///
1078        /// ```should_panic
1079        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_add_signed(-2);")]
1080        /// ```
1081        ///
1082        /// ```should_panic
1083        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_signed(3);")]
1084        /// ```
1085        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1086        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1087        #[must_use = "this returns the result of the operation, \
1088                      without modifying the original"]
1089        #[inline]
1090        #[track_caller]
1091        pub const fn strict_add_signed(self, rhs: $SignedT) -> Self {
1092            let (a, b) = self.overflowing_add_signed(rhs);
1093            if b { imp::overflow_panic::add() } else { a }
1094        }
1095
1096        /// Checked integer subtraction. Computes `self - rhs`, returning
1097        /// `None` if overflow occurred.
1098        ///
1099        /// # Examples
1100        ///
1101        /// ```
1102        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub(1), Some(0));")]
1103        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);")]
1104        /// ```
1105        #[stable(feature = "rust1", since = "1.0.0")]
1106        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1107        #[must_use = "this returns the result of the operation, \
1108                      without modifying the original"]
1109        #[inline]
1110        pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
1111            // Per PR#103299, there's no advantage to the `overflowing` intrinsic
1112            // for *unsigned* subtraction and we just emit the manual check anyway.
1113            // Thus, rather than using `overflowing_sub` that produces a wrapping
1114            // subtraction, check it ourself so we can use an unchecked one.
1115
1116            if self < rhs {
1117                None
1118            } else {
1119                // SAFETY: just checked this can't overflow
1120                Some(unsafe { intrinsics::unchecked_sub(self, rhs) })
1121            }
1122        }
1123
1124        /// Strict integer subtraction. Computes `self - rhs`, panicking if
1125        /// overflow occurred.
1126        ///
1127        /// # Panics
1128        ///
1129        /// ## Overflow behavior
1130        ///
1131        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1132        ///
1133        /// # Examples
1134        ///
1135        /// ```
1136        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub(1), 0);")]
1137        /// ```
1138        ///
1139        /// The following panics because of overflow:
1140        ///
1141        /// ```should_panic
1142        #[doc = concat!("let _ = 0", stringify!($SelfT), ".strict_sub(1);")]
1143        /// ```
1144        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1145        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1146        #[must_use = "this returns the result of the operation, \
1147                      without modifying the original"]
1148        #[inline]
1149        #[track_caller]
1150        pub const fn strict_sub(self, rhs: Self) -> Self {
1151            let (a, b) = self.overflowing_sub(rhs);
1152            if b { imp::overflow_panic::sub() } else { a }
1153        }
1154
1155        /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
1156        /// cannot occur.
1157        ///
1158        /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
1159        /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
1160        ///
1161        /// If you're just trying to avoid the panic in debug mode, then **do not**
1162        /// use this.  Instead, you're looking for [`wrapping_sub`].
1163        ///
1164        /// If you find yourself writing code like this:
1165        ///
1166        /// ```
1167        /// # let foo = 30_u32;
1168        /// # let bar = 20;
1169        /// if foo >= bar {
1170        ///     // SAFETY: just checked it will not overflow
1171        ///     let diff = unsafe { foo.unchecked_sub(bar) };
1172        ///     // ... use diff ...
1173        /// }
1174        /// ```
1175        ///
1176        /// Consider changing it to
1177        ///
1178        /// ```
1179        /// # let foo = 30_u32;
1180        /// # let bar = 20;
1181        /// if let Some(diff) = foo.checked_sub(bar) {
1182        ///     // ... use diff ...
1183        /// }
1184        /// ```
1185        ///
1186        /// As that does exactly the same thing -- including telling the optimizer
1187        /// that the subtraction cannot overflow -- but avoids needing `unsafe`.
1188        ///
1189        /// # Safety
1190        ///
1191        /// This results in undefined behavior when
1192        #[doc = concat!("`self - rhs < ", stringify!($SelfT), "::MIN`,")]
1193        /// i.e. when [`checked_sub`] would return `None`.
1194        ///
1195        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
1196        #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
1197        #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
1198        #[stable(feature = "unchecked_math", since = "1.79.0")]
1199        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
1200        #[must_use = "this returns the result of the operation, \
1201                      without modifying the original"]
1202        #[inline(always)]
1203        #[track_caller]
1204        pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
1205            assert_unsafe_precondition!(
1206                check_language_ub,
1207                concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
1208                (
1209                    lhs: $SelfT = self,
1210                    rhs: $SelfT = rhs,
1211                ) => !lhs.overflowing_sub(rhs).1,
1212            );
1213
1214            // SAFETY: this is guaranteed to be safe by the caller.
1215            unsafe {
1216                intrinsics::unchecked_sub(self, rhs)
1217            }
1218        }
1219
1220        /// Checked subtraction with a signed integer. Computes `self - rhs`,
1221        /// returning `None` if overflow occurred.
1222        ///
1223        /// # Examples
1224        ///
1225        /// ```
1226        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(2), None);")]
1227        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(-2), Some(3));")]
1228        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_sub_signed(-4), None);")]
1229        /// ```
1230        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
1231        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
1232        #[must_use = "this returns the result of the operation, \
1233                      without modifying the original"]
1234        #[inline]
1235        pub const fn checked_sub_signed(self, rhs: $SignedT) -> Option<Self> {
1236            let (res, overflow) = self.overflowing_sub_signed(rhs);
1237
1238            if !overflow {
1239                Some(res)
1240            } else {
1241                None
1242            }
1243        }
1244
1245        /// Strict subtraction with a signed integer. Computes `self - rhs`,
1246        /// panicking if overflow occurred.
1247        ///
1248        /// # Panics
1249        ///
1250        /// ## Overflow behavior
1251        ///
1252        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1253        ///
1254        /// # Examples
1255        ///
1256        /// ```
1257        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".strict_sub_signed(2), 1);")]
1258        /// ```
1259        ///
1260        /// The following panic because of overflow:
1261        ///
1262        /// ```should_panic
1263        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_sub_signed(2);")]
1264        /// ```
1265        ///
1266        /// ```should_panic
1267        #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX).strict_sub_signed(-1);")]
1268        /// ```
1269        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1270        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1271        #[must_use = "this returns the result of the operation, \
1272                      without modifying the original"]
1273        #[inline]
1274        #[track_caller]
1275        pub const fn strict_sub_signed(self, rhs: $SignedT) -> Self {
1276            let (a, b) = self.overflowing_sub_signed(rhs);
1277            if b { imp::overflow_panic::sub() } else { a }
1278        }
1279
1280        #[doc = concat!(
1281            "Checked integer subtraction. Computes `self - rhs` and checks if the result fits into an [`",
1282            stringify!($SignedT), "`], returning `None` if overflow occurred."
1283        )]
1284        ///
1285        /// # Examples
1286        ///
1287        /// ```
1288        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_signed_diff(2), Some(8));")]
1289        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_signed_diff(10), Some(-8));")]
1290        #[doc = concat!(
1291            "assert_eq!(",
1292            stringify!($SelfT),
1293            "::MAX.checked_signed_diff(",
1294            stringify!($SignedT),
1295            "::MAX as ",
1296            stringify!($SelfT),
1297            "), None);"
1298        )]
1299        #[doc = concat!(
1300            "assert_eq!((",
1301            stringify!($SignedT),
1302            "::MAX as ",
1303            stringify!($SelfT),
1304            ").checked_signed_diff(",
1305            stringify!($SelfT),
1306            "::MAX), Some(",
1307            stringify!($SignedT),
1308            "::MIN));"
1309        )]
1310        #[doc = concat!(
1311            "assert_eq!((",
1312            stringify!($SignedT),
1313            "::MAX as ",
1314            stringify!($SelfT),
1315            " + 1).checked_signed_diff(0), None);"
1316        )]
1317        #[doc = concat!(
1318            "assert_eq!(",
1319            stringify!($SelfT),
1320            "::MAX.checked_signed_diff(",
1321            stringify!($SelfT),
1322            "::MAX), Some(0));"
1323        )]
1324        /// ```
1325        #[stable(feature = "unsigned_signed_diff", since = "1.91.0")]
1326        #[rustc_const_stable(feature = "unsigned_signed_diff", since = "1.91.0")]
1327        #[inline]
1328        pub const fn checked_signed_diff(self, rhs: Self) -> Option<$SignedT> {
1329            let res = self.wrapping_sub(rhs) as $SignedT;
1330            let overflow = (self >= rhs) == (res < 0);
1331
1332            if !overflow {
1333                Some(res)
1334            } else {
1335                None
1336            }
1337        }
1338
1339        /// Checked integer multiplication. Computes `self * rhs`, returning
1340        /// `None` if overflow occurred.
1341        ///
1342        /// # Examples
1343        ///
1344        /// ```
1345        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_mul(1), Some(5));")]
1346        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
1347        /// ```
1348        #[stable(feature = "rust1", since = "1.0.0")]
1349        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1350        #[must_use = "this returns the result of the operation, \
1351                      without modifying the original"]
1352        #[inline]
1353        pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
1354            let (a, b) = self.overflowing_mul(rhs);
1355            if intrinsics::unlikely(b) { None } else { Some(a) }
1356        }
1357
1358        /// Strict integer multiplication. Computes `self * rhs`, panicking if
1359        /// overflow occurred.
1360        ///
1361        /// # Panics
1362        ///
1363        /// ## Overflow behavior
1364        ///
1365        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
1366        ///
1367        /// # Examples
1368        ///
1369        /// ```
1370        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_mul(1), 5);")]
1371        /// ```
1372        ///
1373        /// The following panics because of overflow:
1374        ///
1375        /// ``` should_panic
1376        #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
1377        /// ```
1378        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1379        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1380        #[must_use = "this returns the result of the operation, \
1381                      without modifying the original"]
1382        #[inline]
1383        #[track_caller]
1384        pub const fn strict_mul(self, rhs: Self) -> Self {
1385            let (a, b) = self.overflowing_mul(rhs);
1386            if b { imp::overflow_panic::mul() } else { a }
1387        }
1388
1389        /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
1390        /// cannot occur.
1391        ///
1392        /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
1393        /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
1394        ///
1395        /// If you're just trying to avoid the panic in debug mode, then **do not**
1396        /// use this.  Instead, you're looking for [`wrapping_mul`].
1397        ///
1398        /// # Safety
1399        ///
1400        /// This results in undefined behavior when
1401        #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX`,")]
1402        /// i.e. when [`checked_mul`] would return `None`.
1403        ///
1404        /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
1405        #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
1406        #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
1407        #[stable(feature = "unchecked_math", since = "1.79.0")]
1408        #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
1409        #[must_use = "this returns the result of the operation, \
1410                      without modifying the original"]
1411        #[inline(always)]
1412        #[track_caller]
1413        pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
1414            assert_unsafe_precondition!(
1415                check_language_ub,
1416                concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
1417                (
1418                    lhs: $SelfT = self,
1419                    rhs: $SelfT = rhs,
1420                ) => !lhs.overflowing_mul(rhs).1,
1421            );
1422
1423            // SAFETY: this is guaranteed to be safe by the caller.
1424            unsafe {
1425                intrinsics::unchecked_mul(self, rhs)
1426            }
1427        }
1428
1429        /// Checked integer division. Computes `self / rhs`, returning `None`
1430        /// if `rhs == 0`.
1431        ///
1432        /// # Examples
1433        ///
1434        /// ```
1435        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div(2), Some(64));")]
1436        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div(0), None);")]
1437        /// ```
1438        #[stable(feature = "rust1", since = "1.0.0")]
1439        #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1440        #[must_use = "this returns the result of the operation, \
1441                      without modifying the original"]
1442        #[inline]
1443        pub const fn checked_div(self, rhs: Self) -> Option<Self> {
1444            if intrinsics::unlikely(rhs == 0) {
1445                None
1446            } else {
1447                // SAFETY: div by zero has been checked above and unsigned types have no other
1448                // failure modes for division
1449                Some(unsafe { intrinsics::unchecked_div(self, rhs) })
1450            }
1451        }
1452
1453        /// Strict integer division. Computes `self / rhs`.
1454        ///
1455        /// Strict division on unsigned types is just normal division. There's no
1456        /// way overflow could ever happen. This function exists so that all
1457        /// operations are accounted for in the strict operations.
1458        ///
1459        /// # Panics
1460        ///
1461        /// This function will panic if `rhs` is zero.
1462        ///
1463        /// # Examples
1464        ///
1465        /// ```
1466        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div(10), 10);")]
1467        /// ```
1468        ///
1469        /// The following panics because of division by zero:
1470        ///
1471        /// ```should_panic
1472        #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
1473        /// ```
1474        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1475        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1476        #[must_use = "this returns the result of the operation, \
1477                      without modifying the original"]
1478        #[inline(always)]
1479        #[track_caller]
1480        pub const fn strict_div(self, rhs: Self) -> Self {
1481            self / rhs
1482        }
1483
1484        /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, returning `None`
1485        /// if `rhs == 0`.
1486        ///
1487        /// # Examples
1488        ///
1489        /// ```
1490        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div_euclid(2), Some(64));")]
1491        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div_euclid(0), None);")]
1492        /// ```
1493        #[stable(feature = "euclidean_division", since = "1.38.0")]
1494        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1495        #[must_use = "this returns the result of the operation, \
1496                      without modifying the original"]
1497        #[inline]
1498        pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
1499            if intrinsics::unlikely(rhs == 0) {
1500                None
1501            } else {
1502                Some(self.div_euclid(rhs))
1503            }
1504        }
1505
1506        /// Strict Euclidean division. Computes `self.div_euclid(rhs)`.
1507        ///
1508        /// Strict division on unsigned types is just normal division. There's no
1509        /// way overflow could ever happen. This function exists so that all
1510        /// operations are accounted for in the strict operations. Since, for the
1511        /// positive integers, all common definitions of division are equal, this
1512        /// is exactly equal to `self.strict_div(rhs)`.
1513        ///
1514        /// # Panics
1515        ///
1516        /// This function will panic if `rhs` is zero.
1517        ///
1518        /// # Examples
1519        ///
1520        /// ```
1521        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div_euclid(10), 10);")]
1522        /// ```
1523        /// The following panics because of division by zero:
1524        ///
1525        /// ```should_panic
1526        #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
1527        /// ```
1528        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1529        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1530        #[must_use = "this returns the result of the operation, \
1531                      without modifying the original"]
1532        #[inline(always)]
1533        #[track_caller]
1534        pub const fn strict_div_euclid(self, rhs: Self) -> Self {
1535            self / rhs
1536        }
1537
1538        /// Checked integer division without remainder. Computes `self / rhs`,
1539        /// returning `None` if `rhs == 0` or if `self % rhs != 0`.
1540        ///
1541        /// # Examples
1542        ///
1543        /// ```
1544        /// #![feature(exact_div)]
1545        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_div_exact(2), Some(32));")]
1546        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_div_exact(32), Some(2));")]
1547        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_div_exact(0), None);")]
1548        #[doc = concat!("assert_eq!(65", stringify!($SelfT), ".checked_div_exact(2), None);")]
1549        /// ```
1550        #[unstable(
1551            feature = "exact_div",
1552            issue = "139911",
1553        )]
1554        #[must_use = "this returns the result of the operation, \
1555                      without modifying the original"]
1556        #[inline]
1557        pub const fn checked_div_exact(self, rhs: Self) -> Option<Self> {
1558            if intrinsics::unlikely(rhs == 0) {
1559                None
1560            } else {
1561                // SAFETY: division by zero is checked above
1562                unsafe {
1563                    if intrinsics::unlikely(intrinsics::unchecked_rem(self, rhs) != 0) {
1564                        None
1565                    } else {
1566                        Some(intrinsics::exact_div(self, rhs))
1567                    }
1568                }
1569            }
1570        }
1571
1572        /// Integer division without remainder. Computes `self / rhs`, returning `None` if `self % rhs != 0`.
1573        ///
1574        /// # Panics
1575        ///
1576        /// This function will panic  if `rhs == 0`.
1577        ///
1578        /// # Examples
1579        ///
1580        /// ```
1581        /// #![feature(exact_div)]
1582        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(2), Some(32));")]
1583        #[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(32), Some(2));")]
1584        #[doc = concat!("assert_eq!(65", stringify!($SelfT), ".div_exact(2), None);")]
1585        /// ```
1586        #[unstable(
1587            feature = "exact_div",
1588            issue = "139911",
1589        )]
1590        #[must_use = "this returns the result of the operation, \
1591                      without modifying the original"]
1592        #[inline]
1593        #[rustc_inherit_overflow_checks]
1594        pub const fn div_exact(self, rhs: Self) -> Option<Self> {
1595            if self % rhs != 0 {
1596                None
1597            } else {
1598                Some(self / rhs)
1599            }
1600        }
1601
1602        /// Unchecked integer division without remainder. Computes `self / rhs`.
1603        ///
1604        /// # Safety
1605        ///
1606        /// This results in undefined behavior when `rhs == 0` or `self % rhs != 0`,
1607        /// i.e. when [`checked_div_exact`](Self::checked_div_exact) would return `None`.
1608        #[unstable(
1609            feature = "exact_div",
1610            issue = "139911",
1611        )]
1612        #[must_use = "this returns the result of the operation, \
1613                      without modifying the original"]
1614        #[inline]
1615        pub const unsafe fn unchecked_div_exact(self, rhs: Self) -> Self {
1616            assert_unsafe_precondition!(
1617                check_language_ub,
1618                concat!(stringify!($SelfT), "::unchecked_div_exact divide by zero or leave a remainder"),
1619                (
1620                    lhs: $SelfT = self,
1621                    rhs: $SelfT = rhs,
1622                ) => rhs > 0 && lhs % rhs == 0,
1623            );
1624            // SAFETY: Same precondition
1625            unsafe { intrinsics::exact_div(self, rhs) }
1626        }
1627
1628        /// Checked integer remainder. Computes `self % rhs`, returning `None`
1629        /// if `rhs == 0`.
1630        ///
1631        /// # Examples
1632        ///
1633        /// ```
1634        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
1635        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
1636        /// ```
1637        #[stable(feature = "wrapping", since = "1.7.0")]
1638        #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
1639        #[must_use = "this returns the result of the operation, \
1640                      without modifying the original"]
1641        #[inline]
1642        pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
1643            if intrinsics::unlikely(rhs == 0) {
1644                None
1645            } else {
1646                // SAFETY: div by zero has been checked above and unsigned types have no other
1647                // failure modes for division
1648                Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
1649            }
1650        }
1651
1652        /// Strict integer remainder. Computes `self % rhs`.
1653        ///
1654        /// Strict remainder calculation on unsigned types is just the regular
1655        /// remainder calculation. There's no way overflow could ever happen.
1656        /// This function exists so that all operations are accounted for in the
1657        /// strict operations.
1658        ///
1659        /// # Panics
1660        ///
1661        /// This function will panic if `rhs` is zero.
1662        ///
1663        /// # Examples
1664        ///
1665        /// ```
1666        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem(10), 0);")]
1667        /// ```
1668        ///
1669        /// The following panics because of division by zero:
1670        ///
1671        /// ```should_panic
1672        #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
1673        /// ```
1674        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1675        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1676        #[must_use = "this returns the result of the operation, \
1677                      without modifying the original"]
1678        #[inline(always)]
1679        #[track_caller]
1680        pub const fn strict_rem(self, rhs: Self) -> Self {
1681            self % rhs
1682        }
1683
1684        /// Checked Euclidean modulo. Computes `self.rem_euclid(rhs)`, returning `None`
1685        /// if `rhs == 0`.
1686        ///
1687        /// # Examples
1688        ///
1689        /// ```
1690        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
1691        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
1692        /// ```
1693        #[stable(feature = "euclidean_division", since = "1.38.0")]
1694        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
1695        #[must_use = "this returns the result of the operation, \
1696                      without modifying the original"]
1697        #[inline]
1698        pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
1699            if intrinsics::unlikely(rhs == 0) {
1700                None
1701            } else {
1702                Some(self.rem_euclid(rhs))
1703            }
1704        }
1705
1706        /// Strict Euclidean modulo. Computes `self.rem_euclid(rhs)`.
1707        ///
1708        /// Strict modulo calculation on unsigned types is just the regular
1709        /// remainder calculation. There's no way overflow could ever happen.
1710        /// This function exists so that all operations are accounted for in the
1711        /// strict operations. Since, for the positive integers, all common
1712        /// definitions of division are equal, this is exactly equal to
1713        /// `self.strict_rem(rhs)`.
1714        ///
1715        /// # Panics
1716        ///
1717        /// This function will panic if `rhs` is zero.
1718        ///
1719        /// # Examples
1720        ///
1721        /// ```
1722        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem_euclid(10), 0);")]
1723        /// ```
1724        ///
1725        /// The following panics because of division by zero:
1726        ///
1727        /// ```should_panic
1728        #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
1729        /// ```
1730        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
1731        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
1732        #[must_use = "this returns the result of the operation, \
1733                      without modifying the original"]
1734        #[inline(always)]
1735        #[track_caller]
1736        pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
1737            self % rhs
1738        }
1739
1740        /// Same value as `self | other`, but UB if any bit position is set in both inputs.
1741        ///
1742        /// This is a situational micro-optimization for places where you'd rather
1743        /// use addition on some platforms and bitwise or on other platforms, based
1744        /// on exactly which instructions combine better with whatever else you're
1745        /// doing.  Note that there's no reason to bother using this for places
1746        /// where it's clear from the operations involved that they can't overlap.
1747        /// For example, if you're combining `u16`s into a `u32` with
1748        /// `((a as u32) << 16) | (b as u32)`, that's fine, as the backend will
1749        /// know those sides of the `|` are disjoint without needing help.
1750        ///
1751        /// # Examples
1752        ///
1753        /// ```
1754        /// #![feature(disjoint_bitor)]
1755        ///
1756        /// // SAFETY: `1` and `4` have no bits in common.
1757        /// unsafe {
1758        #[doc = concat!("    assert_eq!(1_", stringify!($SelfT), ".unchecked_disjoint_bitor(4), 5);")]
1759        /// }
1760        /// ```
1761        ///
1762        /// # Safety
1763        ///
1764        /// Requires that `(self & other) == 0`, otherwise it's immediate UB.
1765        ///
1766        /// Equivalently, requires that `(self | other) == (self + other)`.
1767        #[unstable(feature = "disjoint_bitor", issue = "135758")]
1768        #[rustc_const_unstable(feature = "disjoint_bitor", issue = "135758")]
1769        #[inline]
1770        pub const unsafe fn unchecked_disjoint_bitor(self, other: Self) -> Self {
1771            assert_unsafe_precondition!(
1772                check_language_ub,
1773                concat!(stringify!($SelfT), "::unchecked_disjoint_bitor cannot have overlapping bits"),
1774                (
1775                    lhs: $SelfT = self,
1776                    rhs: $SelfT = other,
1777                ) => (lhs & rhs) == 0,
1778            );
1779
1780            // SAFETY: Same precondition
1781            unsafe { intrinsics::disjoint_bitor(self, other) }
1782        }
1783
1784        /// Returns the logarithm of the number with respect to an arbitrary base,
1785        /// rounded down.
1786        ///
1787        /// This method might not be optimized owing to implementation details;
1788        /// [`ilog2`](Self::ilog2) can produce results more efficiently for base 2,
1789        /// and [`ilog10`](Self::ilog10) can produce results more efficiently for base 10.
1790        ///
1791        /// # Panics
1792        ///
1793        /// This function will panic if `self` is zero, or if `base` is less than 2.
1794        ///
1795        /// # Examples
1796        ///
1797        /// ```
1798        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
1799        /// ```
1800        #[stable(feature = "int_log", since = "1.67.0")]
1801        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1802        #[must_use = "this returns the result of the operation, \
1803                      without modifying the original"]
1804        #[inline]
1805        #[track_caller]
1806        pub const fn ilog(self, base: Self) -> u32 {
1807            assert!(base >= 2, "base of integer logarithm must be at least 2");
1808            if let Some(log) = self.checked_ilog(base) {
1809                log
1810            } else {
1811                imp::int_log10::panic_for_nonpositive_argument()
1812            }
1813        }
1814
1815        /// Returns the base 2 logarithm of the number, rounded down.
1816        ///
1817        /// # Panics
1818        ///
1819        /// This function will panic if `self` is zero.
1820        ///
1821        /// # Examples
1822        ///
1823        /// ```
1824        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
1825        /// ```
1826        #[stable(feature = "int_log", since = "1.67.0")]
1827        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1828        #[must_use = "this returns the result of the operation, \
1829                      without modifying the original"]
1830        #[inline]
1831        #[track_caller]
1832        pub const fn ilog2(self) -> u32 {
1833            if let Some(log) = self.checked_ilog2() {
1834                log
1835            } else {
1836                imp::int_log10::panic_for_nonpositive_argument()
1837            }
1838        }
1839
1840        /// Returns the base 10 logarithm of the number, rounded down.
1841        ///
1842        /// # Panics
1843        ///
1844        /// This function will panic if `self` is zero.
1845        ///
1846        /// # Example
1847        ///
1848        /// ```
1849        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
1850        /// ```
1851        #[stable(feature = "int_log", since = "1.67.0")]
1852        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1853        #[must_use = "this returns the result of the operation, \
1854                      without modifying the original"]
1855        #[inline]
1856        #[track_caller]
1857        pub const fn ilog10(self) -> u32 {
1858            if let Some(log) = self.checked_ilog10() {
1859                log
1860            } else {
1861                imp::int_log10::panic_for_nonpositive_argument()
1862            }
1863        }
1864
1865        /// Returns the logarithm of the number with respect to an arbitrary base,
1866        /// rounded down.
1867        ///
1868        /// Returns `None` if the number is zero, or if the base is not at least 2.
1869        ///
1870        /// This method might not be optimized owing to implementation details;
1871        /// `checked_ilog2` can produce results more efficiently for base 2, and
1872        /// `checked_ilog10` can produce results more efficiently for base 10.
1873        ///
1874        /// # Examples
1875        ///
1876        /// ```
1877        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
1878        #[doc = concat!("assert_eq!(4", stringify!($SelfT), ".checked_ilog(5), Some(0));")]
1879        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(0), None);")]
1880        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(1), None);")]
1881        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_ilog(1), None);")]
1882        /// ```
1883        #[stable(feature = "int_log", since = "1.67.0")]
1884        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1885        #[must_use = "this returns the result of the operation, \
1886                      without modifying the original"]
1887        #[inline]
1888        pub const fn checked_ilog(self, base: Self) -> Option<u32> {
1889            // Inform compiler of optimizations when the base is known at
1890            // compile time and there's a cheaper method available.
1891            //
1892            // Note: Like all optimizations, this is not guaranteed to be
1893            // applied by the compiler. If you want those specific bases,
1894            // use `.checked_ilog2()` or `.checked_ilog10()` directly.
1895            if core::intrinsics::is_val_statically_known(base) {
1896                // change of base:
1897                // if base == 2 ** k, then
1898                // log(base, n) == log(2, n) / k
1899                if base.is_power_of_two() && base > 1 {
1900                    let k = base.ilog2();
1901                    return Some(try_opt!(self.checked_ilog2()) / k);
1902                }
1903                if base == 10 {
1904                    return self.checked_ilog10();
1905                }
1906            }
1907
1908            if self <= 0 || base <= 1 {
1909                None
1910            } else if self < base {
1911                Some(0)
1912            } else {
1913                // Since base >= self, n >= 1
1914                let mut n = 1;
1915                let mut r = base;
1916
1917                // Optimization for 128 bit wide integers.
1918                if Self::BITS == 128 {
1919                    // The following is a correct lower bound for ⌊log(base,self)⌋ because
1920                    //
1921                    // log(base,self) = log(2,self) / log(2,base)
1922                    //                ≥ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1)
1923                    //
1924                    // hence
1925                    //
1926                    // ⌊log(base,self)⌋ ≥ ⌊ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1) ⌋ .
1927                    n = self.ilog2() / (base.ilog2() + 1);
1928                    r = base.pow(n);
1929                }
1930
1931                while r <= self / base {
1932                    n += 1;
1933                    r *= base;
1934                }
1935                Some(n)
1936            }
1937        }
1938
1939        /// Returns the base 2 logarithm of the number, rounded down.
1940        ///
1941        /// Returns `None` if the number is zero.
1942        ///
1943        /// Note that this is equivalent to [`highest_one`](Self::highest_one).
1944        ///
1945        /// # Examples
1946        ///
1947        /// ```
1948        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
1949        /// ```
1950        #[stable(feature = "int_log", since = "1.67.0")]
1951        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1952        #[must_use = "this returns the result of the operation, \
1953                      without modifying the original"]
1954        #[inline]
1955        pub const fn checked_ilog2(self) -> Option<u32> {
1956            match NonZero::new(self) {
1957                Some(x) => Some(x.ilog2()),
1958                None => None,
1959            }
1960        }
1961
1962        /// Returns the base 10 logarithm of the number, rounded down.
1963        ///
1964        /// Returns `None` if the number is zero.
1965        ///
1966        /// # Examples
1967        ///
1968        /// ```
1969        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
1970        /// ```
1971        #[stable(feature = "int_log", since = "1.67.0")]
1972        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1973        #[must_use = "this returns the result of the operation, \
1974                      without modifying the original"]
1975        #[inline]
1976        pub const fn checked_ilog10(self) -> Option<u32> {
1977            match NonZero::new(self) {
1978                Some(x) => Some(x.ilog10()),
1979                None => None,
1980            }
1981        }
1982
1983        /// Checked negation. Computes `-self`, returning `None` unless `self ==
1984        /// 0`.
1985        ///
1986        /// Note that negating any positive integer will overflow.
1987        ///
1988        /// # Examples
1989        ///
1990        /// ```
1991        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_neg(), Some(0));")]
1992        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_neg(), None);")]
1993        /// ```
1994        #[stable(feature = "wrapping", since = "1.7.0")]
1995        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
1996        #[must_use = "this returns the result of the operation, \
1997                      without modifying the original"]
1998        #[inline]
1999        pub const fn checked_neg(self) -> Option<Self> {
2000            let (a, b) = self.overflowing_neg();
2001            if intrinsics::unlikely(b) { None } else { Some(a) }
2002        }
2003
2004        /// Strict negation. Computes `-self`, panicking unless `self ==
2005        /// 0`.
2006        ///
2007        /// Note that negating any positive integer will overflow.
2008        ///
2009        /// # Panics
2010        ///
2011        /// ## Overflow behavior
2012        ///
2013        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
2014        ///
2015        /// # Examples
2016        ///
2017        /// ```
2018        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".strict_neg(), 0);")]
2019        /// ```
2020        ///
2021        /// The following panics because of overflow:
2022        ///
2023        /// ```should_panic
2024        #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_neg();")]
2025        /// ```
2026        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
2027        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
2028        #[must_use = "this returns the result of the operation, \
2029                      without modifying the original"]
2030        #[inline]
2031        #[track_caller]
2032        pub const fn strict_neg(self) -> Self {
2033            let (a, b) = self.overflowing_neg();
2034            if b { imp::overflow_panic::neg() } else { a }
2035        }
2036
2037        /// Checked shift left. Computes `self << rhs`, returning `None`
2038        /// if `rhs` is larger than or equal to the number of bits in `self`.
2039        ///
2040        /// # Examples
2041        ///
2042        /// ```
2043        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
2044        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(129), None);")]
2045        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
2046        /// ```
2047        #[stable(feature = "wrapping", since = "1.7.0")]
2048        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
2049        #[must_use = "this returns the result of the operation, \
2050                      without modifying the original"]
2051        #[inline]
2052        pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
2053            // Not using overflowing_shl as that's a wrapping shift
2054            if rhs < Self::BITS {
2055                // SAFETY: just checked the RHS is in-range
2056                Some(unsafe { self.unchecked_shl(rhs) })
2057            } else {
2058                None
2059            }
2060        }
2061
2062        /// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
2063        /// than or equal to the number of bits in `self`.
2064        ///
2065        /// # Panics
2066        ///
2067        /// ## Overflow behavior
2068        ///
2069        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
2070        ///
2071        /// # Examples
2072        ///
2073        /// ```
2074        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
2075        /// ```
2076        ///
2077        /// The following panics because of overflow:
2078        ///
2079        /// ```should_panic
2080        #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shl(129);")]
2081        /// ```
2082        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
2083        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
2084        #[must_use = "this returns the result of the operation, \
2085                      without modifying the original"]
2086        #[inline]
2087        #[track_caller]
2088        pub const fn strict_shl(self, rhs: u32) -> Self {
2089            let (a, b) = self.overflowing_shl(rhs);
2090            if b { imp::overflow_panic::shl() } else { a }
2091        }
2092
2093        /// Unchecked shift left. Computes `self << rhs`, assuming that
2094        /// `rhs` is less than the number of bits in `self`.
2095        ///
2096        /// # Safety
2097        ///
2098        /// This results in undefined behavior if `rhs` is larger than
2099        /// or equal to the number of bits in `self`,
2100        /// i.e. when [`checked_shl`] would return `None`.
2101        ///
2102        #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
2103        #[stable(feature = "unchecked_shifts", since = "1.93.0")]
2104        #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
2105        #[must_use = "this returns the result of the operation, \
2106                      without modifying the original"]
2107        #[inline(always)]
2108        #[track_caller]
2109        pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
2110            assert_unsafe_precondition!(
2111                check_language_ub,
2112                concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
2113                (
2114                    rhs: u32 = rhs,
2115                ) => rhs < <$ActualT>::BITS,
2116            );
2117
2118            // SAFETY: this is guaranteed to be safe by the caller.
2119            unsafe {
2120                intrinsics::unchecked_shl(self, rhs)
2121            }
2122        }
2123
2124        /// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
2125        ///
2126        /// If `rhs` is larger or equal to the number of bits in `self`,
2127        /// the entire value is shifted out, and `0` is returned.
2128        ///
2129        /// # Examples
2130        ///
2131        /// ```
2132        #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
2133        #[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(129), 0);")]
2134        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(0), 0b101);")]
2135        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(1), 0b1010);")]
2136        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(2), 0b10100);")]
2137        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(", stringify!($BITS), "), 0);")]
2138        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
2139        ///
2140        #[doc = concat!("let start : ", stringify!($SelfT), " = 13;")]
2141        /// let mut running = start;
2142        /// for i in 0..160 {
2143        ///     // The unbounded shift left by i is the same as `<< 1` i times
2144        ///     assert_eq!(running, start.unbounded_shl(i));
2145        ///     // Which is not always the case for a wrapping shift
2146        #[doc = concat!("    assert_eq!(running == start.wrapping_shl(i), i < ", stringify!($BITS), ");")]
2147        ///
2148        ///     running <<= 1;
2149        /// }
2150        /// ```
2151        #[stable(feature = "unbounded_shifts", since = "1.87.0")]
2152        #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
2153        #[must_use = "this returns the result of the operation, \
2154                      without modifying the original"]
2155        #[inline]
2156        pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
2157            if rhs < Self::BITS {
2158                // SAFETY:
2159                // rhs is just checked to be in-range above
2160                unsafe { self.unchecked_shl(rhs) }
2161            } else {
2162                0
2163            }
2164        }
2165
2166        /// Exact shift left. Computes `self << rhs` as long as it can be reversed losslessly.
2167        ///
2168        /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
2169        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2170        /// Otherwise, returns `Some(self << rhs)`.
2171        ///
2172        /// # Examples
2173        ///
2174        /// ```
2175        /// #![feature(exact_bitshifts)]
2176        ///
2177        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(4), Some(0x10));")]
2178        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(129), None);")]
2179        /// ```
2180        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2181        #[must_use = "this returns the result of the operation, \
2182                      without modifying the original"]
2183        #[inline]
2184        pub const fn shl_exact(self, rhs: u32) -> Option<$SelfT> {
2185            if rhs <= self.leading_zeros() && rhs < <$SelfT>::BITS {
2186                // SAFETY: rhs is checked above
2187                Some(unsafe { self.unchecked_shl(rhs) })
2188            } else {
2189                None
2190            }
2191        }
2192
2193        /// Unchecked exact shift left. Computes `self << rhs`, assuming the operation can be
2194        /// losslessly reversed `rhs` cannot be larger than
2195        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2196        ///
2197        /// # Safety
2198        ///
2199        /// This results in undefined behavior when `rhs > self.leading_zeros() || rhs >=
2200        #[doc = concat!(stringify!($SelfT), "::BITS`")]
2201        /// i.e. when
2202        #[doc = concat!("[`", stringify!($SelfT), "::shl_exact`]")]
2203        /// would return `None`.
2204        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2205        #[must_use = "this returns the result of the operation, \
2206                      without modifying the original"]
2207        #[inline]
2208        pub const unsafe fn unchecked_shl_exact(self, rhs: u32) -> $SelfT {
2209            assert_unsafe_precondition!(
2210                check_library_ub,
2211                concat!(stringify!($SelfT), "::unchecked_shl_exact cannot shift out non-zero bits"),
2212                (
2213                    zeros: u32 = self.leading_zeros(),
2214                    bits: u32 =  <$SelfT>::BITS,
2215                    rhs: u32 = rhs,
2216                ) => rhs <= zeros && rhs < bits,
2217            );
2218
2219            // SAFETY: this is guaranteed to be safe by the caller
2220            unsafe { self.unchecked_shl(rhs) }
2221        }
2222
2223        /// Checked shift right. Computes `self >> rhs`, returning `None`
2224        /// if `rhs` is larger than or equal to the number of bits in `self`.
2225        ///
2226        /// # Examples
2227        ///
2228        /// ```
2229        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
2230        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(129), None);")]
2231        /// ```
2232        #[stable(feature = "wrapping", since = "1.7.0")]
2233        #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
2234        #[must_use = "this returns the result of the operation, \
2235                      without modifying the original"]
2236        #[inline]
2237        pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
2238            // Not using overflowing_shr as that's a wrapping shift
2239            if rhs < Self::BITS {
2240                // SAFETY: just checked the RHS is in-range
2241                Some(unsafe { self.unchecked_shr(rhs) })
2242            } else {
2243                None
2244            }
2245        }
2246
2247        /// Strict shift right. Computes `self >> rhs`, panicking if `rhs` is
2248        /// larger than or equal to the number of bits in `self`.
2249        ///
2250        /// # Panics
2251        ///
2252        /// ## Overflow behavior
2253        ///
2254        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
2255        ///
2256        /// # Examples
2257        ///
2258        /// ```
2259        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
2260        /// ```
2261        ///
2262        /// The following panics because of overflow:
2263        ///
2264        /// ```should_panic
2265        #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(129);")]
2266        /// ```
2267        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
2268        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
2269        #[must_use = "this returns the result of the operation, \
2270                      without modifying the original"]
2271        #[inline]
2272        #[track_caller]
2273        pub const fn strict_shr(self, rhs: u32) -> Self {
2274            let (a, b) = self.overflowing_shr(rhs);
2275            if b { imp::overflow_panic::shr() } else { a }
2276        }
2277
2278        /// Unchecked shift right. Computes `self >> rhs`, assuming that
2279        /// `rhs` is less than the number of bits in `self`.
2280        ///
2281        /// # Safety
2282        ///
2283        /// This results in undefined behavior if `rhs` is larger than
2284        /// or equal to the number of bits in `self`,
2285        /// i.e. when [`checked_shr`] would return `None`.
2286        ///
2287        #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
2288        #[stable(feature = "unchecked_shifts", since = "1.93.0")]
2289        #[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
2290        #[must_use = "this returns the result of the operation, \
2291                      without modifying the original"]
2292        #[inline(always)]
2293        #[track_caller]
2294        pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
2295            assert_unsafe_precondition!(
2296                check_language_ub,
2297                concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
2298                (
2299                    rhs: u32 = rhs,
2300                ) => rhs < <$ActualT>::BITS,
2301            );
2302
2303            // SAFETY: this is guaranteed to be safe by the caller.
2304            unsafe {
2305                intrinsics::unchecked_shr(self, rhs)
2306            }
2307        }
2308
2309        /// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
2310        ///
2311        /// If `rhs` is larger or equal to the number of bits in `self`,
2312        /// the entire value is shifted out, and `0` is returned.
2313        ///
2314        /// # Examples
2315        ///
2316        /// ```
2317        #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
2318        #[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(129), 0);")]
2319        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(0), 0b1010);")]
2320        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(1), 0b101);")]
2321        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(2), 0b10);")]
2322        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(", stringify!($BITS), "), 0);")]
2323        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
2324        ///
2325        #[doc = concat!("let start = ", stringify!($SelfT), "::rotate_right(13, 4);")]
2326        /// let mut running = start;
2327        /// for i in 0..160 {
2328        ///     // The unbounded shift right by i is the same as `>> 1` i times
2329        ///     assert_eq!(running, start.unbounded_shr(i));
2330        ///     // Which is not always the case for a wrapping shift
2331        #[doc = concat!("    assert_eq!(running == start.wrapping_shr(i), i < ", stringify!($BITS), ");")]
2332        ///
2333        ///     running >>= 1;
2334        /// }
2335        /// ```
2336        #[stable(feature = "unbounded_shifts", since = "1.87.0")]
2337        #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
2338        #[must_use = "this returns the result of the operation, \
2339                      without modifying the original"]
2340        #[inline]
2341        pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
2342            if rhs < Self::BITS {
2343                // SAFETY:
2344                // rhs is just checked to be in-range above
2345                unsafe { self.unchecked_shr(rhs) }
2346            } else {
2347                0
2348            }
2349        }
2350
2351        /// Exact shift right. Computes `self >> rhs` as long as it can be reversed losslessly.
2352        ///
2353        /// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
2354        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2355        /// Otherwise, returns `Some(self >> rhs)`.
2356        ///
2357        /// # Examples
2358        ///
2359        /// ```
2360        /// #![feature(exact_bitshifts)]
2361        ///
2362        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(4), Some(0x1));")]
2363        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(5), None);")]
2364        /// ```
2365        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2366        #[must_use = "this returns the result of the operation, \
2367                      without modifying the original"]
2368        #[inline]
2369        pub const fn shr_exact(self, rhs: u32) -> Option<$SelfT> {
2370            if rhs <= self.trailing_zeros() && rhs < <$SelfT>::BITS {
2371                // SAFETY: rhs is checked above
2372                Some(unsafe { self.unchecked_shr(rhs) })
2373            } else {
2374                None
2375            }
2376        }
2377
2378        /// Unchecked exact shift right. Computes `self >> rhs`, assuming the operation can be
2379        /// losslessly reversed and `rhs` cannot be larger than
2380        #[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
2381        ///
2382        /// # Safety
2383        ///
2384        /// This results in undefined behavior when `rhs > self.trailing_zeros() || rhs >=
2385        #[doc = concat!(stringify!($SelfT), "::BITS`")]
2386        /// i.e. when
2387        #[doc = concat!("[`", stringify!($SelfT), "::shr_exact`]")]
2388        /// would return `None`.
2389        #[unstable(feature = "exact_bitshifts", issue = "144336")]
2390        #[must_use = "this returns the result of the operation, \
2391                      without modifying the original"]
2392        #[inline]
2393        pub const unsafe fn unchecked_shr_exact(self, rhs: u32) -> $SelfT {
2394            assert_unsafe_precondition!(
2395                check_library_ub,
2396                concat!(stringify!($SelfT), "::unchecked_shr_exact cannot shift out non-zero bits"),
2397                (
2398                    zeros: u32 = self.trailing_zeros(),
2399                    bits: u32 =  <$SelfT>::BITS,
2400                    rhs: u32 = rhs,
2401                ) => rhs <= zeros && rhs < bits,
2402            );
2403
2404            // SAFETY: this is guaranteed to be safe by the caller
2405            unsafe { self.unchecked_shr(rhs) }
2406        }
2407
2408        /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
2409        /// overflow occurred.
2410        ///
2411        /// # Examples
2412        ///
2413        /// ```
2414        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_pow(5), Some(32));")]
2415        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".checked_pow(0), Some(1));")]
2416        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
2417        /// ```
2418        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2419        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2420        #[must_use = "this returns the result of the operation, \
2421                      without modifying the original"]
2422        #[inline]
2423        pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
2424            let mut base = self;
2425            let mut acc: Self = 1;
2426
2427            if intrinsics::is_val_statically_known(base) && base.is_power_of_two() {
2428                // change of base:
2429                // if base == 2 ** k, then
2430                //    (2 ** k) ** n
2431                // == 2 ** (k * n)
2432                // == 1 << (k * n)
2433                let k = base.ilog2();
2434                let shift = try_opt!(k.checked_mul(exp));
2435                return (1 as Self).checked_shl(shift);
2436            }
2437
2438            if exp == 0 {
2439                return Some(1);
2440            }
2441
2442            if intrinsics::is_val_statically_known(exp) {
2443                while exp > 1 {
2444                    if (exp & 1) == 1 {
2445                        acc = try_opt!(acc.checked_mul(base));
2446                    }
2447                    exp /= 2;
2448                    base = try_opt!(base.checked_mul(base));
2449                }
2450
2451                // since exp!=0, finally the exp must be 1.
2452                // Deal with the final bit of the exponent separately, since
2453                // squaring the base afterwards is not necessary and may cause a
2454                // needless overflow.
2455                return acc.checked_mul(base);
2456            }
2457
2458            loop {
2459                if (exp & 1) == 1 {
2460                    acc = try_opt!(acc.checked_mul(base));
2461                    // since exp!=0, finally the exp must be 1.
2462                    if exp == 1 {
2463                        return Some(acc);
2464                    }
2465                }
2466                exp /= 2;
2467                base = try_opt!(base.checked_mul(base));
2468            }
2469        }
2470
2471        /// Strict exponentiation. Computes `self.pow(exp)`, panicking if
2472        /// overflow occurred.
2473        ///
2474        /// # Panics
2475        ///
2476        /// ## Overflow behavior
2477        ///
2478        /// This function will always panic on overflow, regardless of whether overflow checks are enabled.
2479        ///
2480        /// # Examples
2481        ///
2482        /// ```
2483        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".strict_pow(5), 32);")]
2484        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".strict_pow(0), 1);")]
2485        /// ```
2486        ///
2487        /// The following panics because of overflow:
2488        ///
2489        /// ```should_panic
2490        #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
2491        /// ```
2492        #[stable(feature = "strict_overflow_ops", since = "1.91.0")]
2493        #[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
2494        #[must_use = "this returns the result of the operation, \
2495                      without modifying the original"]
2496        #[inline]
2497        #[track_caller]
2498        pub const fn strict_pow(self, exp: u32) -> Self {
2499            match self.checked_pow(exp) {
2500                None => imp::overflow_panic::pow(),
2501                Some(a) => a,
2502            }
2503        }
2504
2505        /// Saturating integer addition. Computes `self + rhs`, saturating at
2506        /// the numeric bounds instead of overflowing.
2507        ///
2508        /// # Examples
2509        ///
2510        /// ```
2511        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
2512        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(127), ", stringify!($SelfT), "::MAX);")]
2513        /// ```
2514        #[stable(feature = "rust1", since = "1.0.0")]
2515        #[must_use = "this returns the result of the operation, \
2516                      without modifying the original"]
2517        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2518        #[inline(always)]
2519        pub const fn saturating_add(self, rhs: Self) -> Self {
2520            intrinsics::saturating_add(self, rhs)
2521        }
2522
2523        /// Saturating addition with a signed integer. Computes `self + rhs`,
2524        /// saturating at the numeric bounds instead of overflowing.
2525        ///
2526        /// # Examples
2527        ///
2528        /// ```
2529        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(2), 3);")]
2530        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(-2), 0);")]
2531        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_add_signed(4), ", stringify!($SelfT), "::MAX);")]
2532        /// ```
2533        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2534        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2535        #[must_use = "this returns the result of the operation, \
2536                      without modifying the original"]
2537        #[inline]
2538        pub const fn saturating_add_signed(self, rhs: $SignedT) -> Self {
2539            let (res, overflow) = self.overflowing_add(rhs as Self);
2540            if overflow == (rhs < 0) {
2541                res
2542            } else if overflow {
2543                Self::MAX
2544            } else {
2545                0
2546            }
2547        }
2548
2549        /// Saturating integer subtraction. Computes `self - rhs`, saturating
2550        /// at the numeric bounds instead of overflowing.
2551        ///
2552        /// # Examples
2553        ///
2554        /// ```
2555        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(27), 73);")]
2556        #[doc = concat!("assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);")]
2557        /// ```
2558        #[stable(feature = "rust1", since = "1.0.0")]
2559        #[must_use = "this returns the result of the operation, \
2560                      without modifying the original"]
2561        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2562        #[inline(always)]
2563        pub const fn saturating_sub(self, rhs: Self) -> Self {
2564            intrinsics::saturating_sub(self, rhs)
2565        }
2566
2567        /// Saturating integer subtraction. Computes `self` - `rhs`, saturating at
2568        /// the numeric bounds instead of overflowing.
2569        ///
2570        /// # Examples
2571        ///
2572        /// ```
2573        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(2), 0);")]
2574        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(-2), 3);")]
2575        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_sub_signed(-4), ", stringify!($SelfT), "::MAX);")]
2576        /// ```
2577        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2578        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2579        #[must_use = "this returns the result of the operation, \
2580                      without modifying the original"]
2581        #[inline]
2582        pub const fn saturating_sub_signed(self, rhs: $SignedT) -> Self {
2583            let (res, overflow) = self.overflowing_sub_signed(rhs);
2584
2585            if !overflow {
2586                res
2587            } else if rhs < 0 {
2588                Self::MAX
2589            } else {
2590                0
2591            }
2592        }
2593
2594        /// Saturating integer multiplication. Computes `self * rhs`,
2595        /// saturating at the numeric bounds instead of overflowing.
2596        ///
2597        /// # Examples
2598        ///
2599        /// ```
2600        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".saturating_mul(10), 20);")]
2601        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).saturating_mul(10), ", stringify!($SelfT),"::MAX);")]
2602        /// ```
2603        #[stable(feature = "wrapping", since = "1.7.0")]
2604        #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
2605        #[must_use = "this returns the result of the operation, \
2606                      without modifying the original"]
2607        #[inline]
2608        pub const fn saturating_mul(self, rhs: Self) -> Self {
2609            match self.checked_mul(rhs) {
2610                Some(x) => x,
2611                None => Self::MAX,
2612            }
2613        }
2614
2615        /// Saturating integer division. Computes `self / rhs`, saturating at the
2616        /// numeric bounds instead of overflowing.
2617        ///
2618        /// # Panics
2619        ///
2620        /// This function will panic if `rhs` is zero.
2621        ///
2622        /// # Examples
2623        ///
2624        /// ```
2625        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
2626        ///
2627        /// ```
2628        #[stable(feature = "saturating_div", since = "1.58.0")]
2629        #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
2630        #[must_use = "this returns the result of the operation, \
2631                      without modifying the original"]
2632        #[inline]
2633        #[track_caller]
2634        pub const fn saturating_div(self, rhs: Self) -> Self {
2635            // on unsigned types, there is no overflow in integer division
2636            self.wrapping_div(rhs)
2637        }
2638
2639        /// Saturating integer exponentiation. Computes `self.pow(exp)`,
2640        /// saturating at the numeric bounds instead of overflowing.
2641        ///
2642        /// # Examples
2643        ///
2644        /// ```
2645        #[doc = concat!("assert_eq!(4", stringify!($SelfT), ".saturating_pow(3), 64);")]
2646        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".saturating_pow(0), 1);")]
2647        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
2648        /// ```
2649        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2650        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2651        #[must_use = "this returns the result of the operation, \
2652                      without modifying the original"]
2653        #[inline]
2654        pub const fn saturating_pow(self, exp: u32) -> Self {
2655            match self.checked_pow(exp) {
2656                Some(x) => x,
2657                None => Self::MAX,
2658            }
2659        }
2660
2661        /// Wrapping (modular) addition. Computes `self + rhs`,
2662        /// wrapping around at the boundary of the type.
2663        ///
2664        /// # Examples
2665        ///
2666        /// ```
2667        #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(55), 255);")]
2668        #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::MAX), 199);")]
2669        /// ```
2670        #[stable(feature = "rust1", since = "1.0.0")]
2671        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2672        #[must_use = "this returns the result of the operation, \
2673                      without modifying the original"]
2674        #[inline(always)]
2675        pub const fn wrapping_add(self, rhs: Self) -> Self {
2676            intrinsics::wrapping_add(self, rhs)
2677        }
2678
2679        /// Wrapping (modular) addition with a signed integer. Computes
2680        /// `self + rhs`, wrapping around at the boundary of the type.
2681        ///
2682        /// # Examples
2683        ///
2684        /// ```
2685        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(2), 3);")]
2686        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(-2), ", stringify!($SelfT), "::MAX);")]
2687        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_add_signed(4), 1);")]
2688        /// ```
2689        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
2690        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
2691        #[must_use = "this returns the result of the operation, \
2692                      without modifying the original"]
2693        #[inline]
2694        pub const fn wrapping_add_signed(self, rhs: $SignedT) -> Self {
2695            self.wrapping_add(rhs as Self)
2696        }
2697
2698        /// Wrapping (modular) subtraction. Computes `self - rhs`,
2699        /// wrapping around at the boundary of the type.
2700        ///
2701        /// # Examples
2702        ///
2703        /// ```
2704        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(100), 0);")]
2705        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::MAX), 101);")]
2706        /// ```
2707        #[stable(feature = "rust1", since = "1.0.0")]
2708        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2709        #[must_use = "this returns the result of the operation, \
2710                      without modifying the original"]
2711        #[inline(always)]
2712        pub const fn wrapping_sub(self, rhs: Self) -> Self {
2713            intrinsics::wrapping_sub(self, rhs)
2714        }
2715
2716        /// Wrapping (modular) subtraction with a signed integer. Computes
2717        /// `self - rhs`, wrapping around at the boundary of the type.
2718        ///
2719        /// # Examples
2720        ///
2721        /// ```
2722        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(2), ", stringify!($SelfT), "::MAX);")]
2723        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(-2), 3);")]
2724        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_sub_signed(-4), 1);")]
2725        /// ```
2726        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2727        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
2728        #[must_use = "this returns the result of the operation, \
2729                      without modifying the original"]
2730        #[inline]
2731        pub const fn wrapping_sub_signed(self, rhs: $SignedT) -> Self {
2732            self.wrapping_sub(rhs as Self)
2733        }
2734
2735        /// Wrapping (modular) multiplication. Computes `self *
2736        /// rhs`, wrapping around at the boundary of the type.
2737        ///
2738        /// # Examples
2739        ///
2740        /// Please note that this example is shared among integer types, which is why `u8` is used.
2741        ///
2742        /// ```
2743        /// assert_eq!(10u8.wrapping_mul(12), 120);
2744        /// assert_eq!(25u8.wrapping_mul(12), 44);
2745        /// ```
2746        #[stable(feature = "rust1", since = "1.0.0")]
2747        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2748        #[must_use = "this returns the result of the operation, \
2749                      without modifying the original"]
2750        #[inline(always)]
2751        pub const fn wrapping_mul(self, rhs: Self) -> Self {
2752            intrinsics::wrapping_mul(self, rhs)
2753        }
2754
2755        /// Wrapping (modular) division. Computes `self / rhs`.
2756        ///
2757        /// Wrapped division on unsigned types is just normal division. There's
2758        /// no way wrapping could ever happen. This function exists so that all
2759        /// operations are accounted for in the wrapping operations.
2760        ///
2761        /// # Panics
2762        ///
2763        /// This function will panic if `rhs` is zero.
2764        ///
2765        /// # Examples
2766        ///
2767        /// ```
2768        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
2769        /// ```
2770        #[stable(feature = "num_wrapping", since = "1.2.0")]
2771        #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2772        #[must_use = "this returns the result of the operation, \
2773                      without modifying the original"]
2774        #[inline(always)]
2775        #[track_caller]
2776        pub const fn wrapping_div(self, rhs: Self) -> Self {
2777            self / rhs
2778        }
2779
2780        /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`.
2781        ///
2782        /// Wrapped division on unsigned types is just normal division. There's
2783        /// no way wrapping could ever happen. This function exists so that all
2784        /// operations are accounted for in the wrapping operations. Since, for
2785        /// the positive integers, all common definitions of division are equal,
2786        /// this is exactly equal to `self.wrapping_div(rhs)`.
2787        ///
2788        /// # Panics
2789        ///
2790        /// This function will panic if `rhs` is zero.
2791        ///
2792        /// # Examples
2793        ///
2794        /// ```
2795        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
2796        /// ```
2797        #[stable(feature = "euclidean_division", since = "1.38.0")]
2798        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2799        #[must_use = "this returns the result of the operation, \
2800                      without modifying the original"]
2801        #[inline(always)]
2802        #[track_caller]
2803        pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
2804            self / rhs
2805        }
2806
2807        /// Wrapping (modular) remainder. Computes `self % rhs`.
2808        ///
2809        /// Wrapped remainder calculation on unsigned types is just the regular
2810        /// remainder calculation. There's no way wrapping could ever happen.
2811        /// This function exists so that all operations are accounted for in the
2812        /// wrapping operations.
2813        ///
2814        /// # Panics
2815        ///
2816        /// This function will panic if `rhs` is zero.
2817        ///
2818        /// # Examples
2819        ///
2820        /// ```
2821        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
2822        /// ```
2823        #[stable(feature = "num_wrapping", since = "1.2.0")]
2824        #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
2825        #[must_use = "this returns the result of the operation, \
2826                      without modifying the original"]
2827        #[inline(always)]
2828        #[track_caller]
2829        pub const fn wrapping_rem(self, rhs: Self) -> Self {
2830            self % rhs
2831        }
2832
2833        /// Wrapping Euclidean modulo. Computes `self.rem_euclid(rhs)`.
2834        ///
2835        /// Wrapped modulo calculation on unsigned types is just the regular
2836        /// remainder calculation. There's no way wrapping could ever happen.
2837        /// This function exists so that all operations are accounted for in the
2838        /// wrapping operations. Since, for the positive integers, all common
2839        /// definitions of division are equal, this is exactly equal to
2840        /// `self.wrapping_rem(rhs)`.
2841        ///
2842        /// # Panics
2843        ///
2844        /// This function will panic if `rhs` is zero.
2845        ///
2846        /// # Examples
2847        ///
2848        /// ```
2849        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
2850        /// ```
2851        #[stable(feature = "euclidean_division", since = "1.38.0")]
2852        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
2853        #[must_use = "this returns the result of the operation, \
2854                      without modifying the original"]
2855        #[inline(always)]
2856        #[track_caller]
2857        pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
2858            self % rhs
2859        }
2860
2861        /// Wrapping (modular) negation. Computes `-self`,
2862        /// wrapping around at the boundary of the type.
2863        ///
2864        /// Since unsigned types do not have negative equivalents
2865        /// all applications of this function will wrap (except for `-0`).
2866        /// For values smaller than the corresponding signed type's maximum
2867        /// the result is the same as casting the corresponding signed value.
2868        /// Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)` where
2869        /// `MAX` is the corresponding signed type's maximum.
2870        ///
2871        /// # Examples
2872        ///
2873        /// ```
2874        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_neg(), 0);")]
2875        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_neg(), 1);")]
2876        #[doc = concat!("assert_eq!(13_", stringify!($SelfT), ".wrapping_neg(), (!13) + 1);")]
2877        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_neg(), !(42 - 1));")]
2878        /// ```
2879        #[stable(feature = "num_wrapping", since = "1.2.0")]
2880        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2881        #[must_use = "this returns the result of the operation, \
2882                      without modifying the original"]
2883        #[inline(always)]
2884        pub const fn wrapping_neg(self) -> Self {
2885            (0 as $SelfT).wrapping_sub(self)
2886        }
2887
2888        /// Panic-free bitwise shift-left; yields `self << mask(rhs)`,
2889        /// where `mask` removes any high-order bits of `rhs` that
2890        /// would cause the shift to exceed the bitwidth of the type.
2891        ///
2892        /// Beware that, unlike most other `wrapping_*` methods on integers, this
2893        /// does *not* give the same result as doing the shift in infinite precision
2894        /// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
2895        /// do on many processors, and is what the `<<` operator does when overflow
2896        /// checks are disabled, but numerically it's weird.  Consider, instead,
2897        /// using [`Self::unbounded_shl`] which has nicer behaviour.
2898        ///
2899        /// Note that this is *not* the same as a rotate-left; the
2900        /// RHS of a wrapping shift-left is restricted to the range
2901        /// of the type, rather than the bits shifted out of the LHS
2902        /// being returned to the other end. The primitive integer
2903        /// types all implement a [`rotate_left`](Self::rotate_left) function,
2904        /// which may be what you want instead.
2905        ///
2906        /// # Examples
2907        ///
2908        /// ```
2909        #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".wrapping_shl(7), 128);")]
2910        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".wrapping_shl(0), 0b101);")]
2911        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".wrapping_shl(1), 0b1010);")]
2912        #[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".wrapping_shl(2), 0b10100);")]
2913        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_shl(2), ", stringify!($SelfT), "::MAX - 3);")]
2914        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(", stringify!($BITS), "), 42);")]
2915        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(1).wrapping_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
2916        #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".wrapping_shl(128), 1);")]
2917        #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".wrapping_shl(1025), 10);")]
2918        /// ```
2919        #[stable(feature = "num_wrapping", since = "1.2.0")]
2920        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2921        #[must_use = "this returns the result of the operation, \
2922                      without modifying the original"]
2923        #[inline(always)]
2924        pub const fn wrapping_shl(self, rhs: u32) -> Self {
2925            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2926            // out of bounds
2927            unsafe {
2928                self.unchecked_shl(rhs & (Self::BITS - 1))
2929            }
2930        }
2931
2932        /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`,
2933        /// where `mask` removes any high-order bits of `rhs` that
2934        /// would cause the shift to exceed the bitwidth of the type.
2935        ///
2936        /// Beware that, unlike most other `wrapping_*` methods on integers, this
2937        /// does *not* give the same result as doing the shift in infinite precision
2938        /// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
2939        /// do on many processors, and is what the `>>` operator does when overflow
2940        /// checks are disabled, but numerically it's weird.  Consider, instead,
2941        /// using [`Self::unbounded_shr`] which has nicer behaviour.
2942        ///
2943        /// Note that this is *not* the same as a rotate-right; the
2944        /// RHS of a wrapping shift-right is restricted to the range
2945        /// of the type, rather than the bits shifted out of the LHS
2946        /// being returned to the other end. The primitive integer
2947        /// types all implement a [`rotate_right`](Self::rotate_right) function,
2948        /// which may be what you want instead.
2949        ///
2950        /// # Examples
2951        ///
2952        /// ```
2953        #[doc = concat!("assert_eq!(128_", stringify!($SelfT), ".wrapping_shr(7), 1);")]
2954        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".wrapping_shr(0), 0b1010);")]
2955        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".wrapping_shr(1), 0b101);")]
2956        #[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".wrapping_shr(2), 0b10);")]
2957        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_shr(1), ", stringify!($SignedT), "::MAX.cast_unsigned());")]
2958        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(", stringify!($BITS), "), 42);")]
2959        #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(1).wrapping_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
2960        #[doc = concat!("assert_eq!(128_", stringify!($SelfT), ".wrapping_shr(128), 128);")]
2961        #[doc = concat!("assert_eq!(10_", stringify!($SelfT), ".wrapping_shr(1025), 5);")]
2962        /// ```
2963        #[stable(feature = "num_wrapping", since = "1.2.0")]
2964        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
2965        #[must_use = "this returns the result of the operation, \
2966                      without modifying the original"]
2967        #[inline(always)]
2968        pub const fn wrapping_shr(self, rhs: u32) -> Self {
2969            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
2970            // out of bounds
2971            unsafe {
2972                self.unchecked_shr(rhs & (Self::BITS - 1))
2973            }
2974        }
2975
2976        /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
2977        /// wrapping around at the boundary of the type.
2978        ///
2979        /// # Examples
2980        ///
2981        /// ```
2982        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(5), 243);")]
2983        /// assert_eq!(3u8.wrapping_pow(6), 217);
2984        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_pow(0), 1);")]
2985        /// ```
2986        #[stable(feature = "no_panic_pow", since = "1.34.0")]
2987        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
2988        #[must_use = "this returns the result of the operation, \
2989                      without modifying the original"]
2990        #[inline]
2991        pub const fn wrapping_pow(self, exp: u32) -> Self {
2992            let (a, _) = self.overflowing_pow(exp);
2993            a
2994        }
2995
2996        /// Calculates `self` + `rhs`.
2997        ///
2998        /// Returns a tuple of the addition along with a boolean indicating
2999        /// whether an arithmetic overflow would occur. If an overflow would
3000        /// have occurred then the wrapped value is returned.
3001        ///
3002        /// # Examples
3003        ///
3004        /// ```
3005        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
3006        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));")]
3007        /// ```
3008        #[stable(feature = "wrapping", since = "1.7.0")]
3009        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3010        #[must_use = "this returns the result of the operation, \
3011                      without modifying the original"]
3012        #[inline(always)]
3013        pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
3014            let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
3015            (a as Self, b)
3016        }
3017
3018        /// Calculates `self` + `rhs` + `carry` and returns a tuple containing
3019        /// the sum and the output carry (in that order).
3020        ///
3021        /// Performs "ternary addition" of two integer operands and a carry-in
3022        /// bit, and returns an output integer and a carry-out bit. This allows
3023        /// chaining together multiple additions to create a wider addition, and
3024        /// can be useful for bignum addition.
3025        ///
3026        #[doc = concat!("This can be thought of as a ", stringify!($BITS), "-bit \"full adder\", in the electronics sense.")]
3027        ///
3028        /// If the input carry is false, this method is equivalent to
3029        /// [`overflowing_add`](Self::overflowing_add), and the output carry is
3030        /// equal to the overflow flag. Note that although carry and overflow
3031        /// flags are similar for unsigned integers, they are different for
3032        /// signed integers.
3033        ///
3034        /// # Examples
3035        ///
3036        /// ```
3037        #[doc = concat!("//    3  MAX    (a = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
3038        #[doc = concat!("// +  5    7    (b = 5 × 2^", stringify!($BITS), " + 7)")]
3039        /// // ---------
3040        #[doc = concat!("//    9    6    (sum = 9 × 2^", stringify!($BITS), " + 6)")]
3041        ///
3042        #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (3, ", stringify!($SelfT), "::MAX);")]
3043        #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
3044        /// let carry0 = false;
3045        ///
3046        /// let (sum0, carry1) = a0.carrying_add(b0, carry0);
3047        /// assert_eq!(carry1, true);
3048        /// let (sum1, carry2) = a1.carrying_add(b1, carry1);
3049        /// assert_eq!(carry2, false);
3050        ///
3051        /// assert_eq!((sum1, sum0), (9, 6));
3052        /// ```
3053        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
3054        #[rustc_const_unstable(feature = "const_unsigned_bigint_helpers", issue = "152015")]
3055        #[must_use = "this returns the result of the operation, \
3056                      without modifying the original"]
3057        #[inline]
3058        pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
3059            // note: longer-term this should be done via an intrinsic, but this has been shown
3060            //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
3061            let (a, c1) = self.overflowing_add(rhs);
3062            let (b, c2) = a.overflowing_add(carry as $SelfT);
3063            // Ideally LLVM would know this is disjoint without us telling them,
3064            // but it doesn't <https://github.com/llvm/llvm-project/issues/118162>
3065            // SAFETY: Only one of `c1` and `c2` can be set.
3066            // For c1 to be set we need to have overflowed, but if we did then
3067            // `a` is at most `MAX-1`, which means that `c2` cannot possibly
3068            // overflow because it's adding at most `1` (since it came from `bool`)
3069            (b, unsafe { intrinsics::disjoint_bitor(c1, c2) })
3070        }
3071
3072        /// Calculates `self` + `rhs` with a signed `rhs`.
3073        ///
3074        /// Returns a tuple of the addition along with a boolean indicating
3075        /// whether an arithmetic overflow would occur. If an overflow would
3076        /// have occurred then the wrapped value is returned.
3077        ///
3078        /// # Examples
3079        ///
3080        /// ```
3081        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(2), (3, false));")]
3082        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(-2), (", stringify!($SelfT), "::MAX, true));")]
3083        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_signed(4), (1, true));")]
3084        /// ```
3085        #[stable(feature = "mixed_integer_ops", since = "1.66.0")]
3086        #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
3087        #[must_use = "this returns the result of the operation, \
3088                      without modifying the original"]
3089        #[inline]
3090        pub const fn overflowing_add_signed(self, rhs: $SignedT) -> (Self, bool) {
3091            let (res, overflowed) = self.overflowing_add(rhs as Self);
3092            (res, overflowed ^ (rhs < 0))
3093        }
3094
3095        /// Calculates `self` - `rhs`.
3096        ///
3097        /// Returns a tuple of the subtraction along with a boolean indicating
3098        /// whether an arithmetic overflow would occur. If an overflow would
3099        /// have occurred then the wrapped value is returned.
3100        ///
3101        /// # Examples
3102        ///
3103        /// ```
3104        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
3105        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
3106        /// ```
3107        #[stable(feature = "wrapping", since = "1.7.0")]
3108        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3109        #[must_use = "this returns the result of the operation, \
3110                      without modifying the original"]
3111        #[inline(always)]
3112        pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
3113            let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
3114            (a as Self, b)
3115        }
3116
3117        /// Calculates `self` &minus; `rhs` &minus; `borrow` and returns a tuple
3118        /// containing the difference and the output borrow.
3119        ///
3120        /// Performs "ternary subtraction" by subtracting both an integer
3121        /// operand and a borrow-in bit from `self`, and returns an output
3122        /// integer and a borrow-out bit. This allows chaining together multiple
3123        /// subtractions to create a wider subtraction, and can be useful for
3124        /// bignum subtraction.
3125        ///
3126        /// # Examples
3127        ///
3128        /// ```
3129        #[doc = concat!("//    9    6    (a = 9 × 2^", stringify!($BITS), " + 6)")]
3130        #[doc = concat!("// -  5    7    (b = 5 × 2^", stringify!($BITS), " + 7)")]
3131        /// // ---------
3132        #[doc = concat!("//    3  MAX    (diff = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
3133        ///
3134        #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (9, 6);")]
3135        #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")]
3136        /// let borrow0 = false;
3137        ///
3138        /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
3139        /// assert_eq!(borrow1, true);
3140        /// let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1);
3141        /// assert_eq!(borrow2, false);
3142        ///
3143        #[doc = concat!("assert_eq!((diff1, diff0), (3, ", stringify!($SelfT), "::MAX));")]
3144        /// ```
3145        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
3146        #[rustc_const_unstable(feature = "const_unsigned_bigint_helpers", issue = "152015")]
3147        #[must_use = "this returns the result of the operation, \
3148                      without modifying the original"]
3149        #[inline]
3150        pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
3151            // note: longer-term this should be done via an intrinsic, but this has been shown
3152            //   to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic
3153            let (a, c1) = self.overflowing_sub(rhs);
3154            let (b, c2) = a.overflowing_sub(borrow as $SelfT);
3155            // SAFETY: Only one of `c1` and `c2` can be set.
3156            // For c1 to be set we need to have underflowed, but if we did then
3157            // `a` is nonzero, which means that `c2` cannot possibly
3158            // underflow because it's subtracting at most `1` (since it came from `bool`)
3159            (b, unsafe { intrinsics::disjoint_bitor(c1, c2) })
3160        }
3161
3162        /// Calculates `self` - `rhs` with a signed `rhs`
3163        ///
3164        /// Returns a tuple of the subtraction along with a boolean indicating
3165        /// whether an arithmetic overflow would occur. If an overflow would
3166        /// have occurred then the wrapped value is returned.
3167        ///
3168        /// # Examples
3169        ///
3170        /// ```
3171        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(2), (", stringify!($SelfT), "::MAX, true));")]
3172        #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(-2), (3, false));")]
3173        #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_sub_signed(-4), (1, true));")]
3174        /// ```
3175        #[stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
3176        #[rustc_const_stable(feature = "mixed_integer_ops_unsigned_sub", since = "1.90.0")]
3177        #[must_use = "this returns the result of the operation, \
3178                      without modifying the original"]
3179        #[inline]
3180        pub const fn overflowing_sub_signed(self, rhs: $SignedT) -> (Self, bool) {
3181            let (res, overflow) = self.overflowing_sub(rhs as Self);
3182
3183            (res, overflow ^ (rhs < 0))
3184        }
3185
3186        /// Computes the absolute difference between `self` and `other`.
3187        ///
3188        /// # Examples
3189        ///
3190        /// ```
3191        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($SelfT), ");")]
3192        #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($SelfT), ");")]
3193        /// ```
3194        #[stable(feature = "int_abs_diff", since = "1.60.0")]
3195        #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
3196        #[must_use = "this returns the result of the operation, \
3197                      without modifying the original"]
3198        #[inline]
3199        pub const fn abs_diff(self, other: Self) -> Self {
3200            if size_of::<Self>() == 1 {
3201                // Trick LLVM into generating the psadbw instruction when SSE2
3202                // is available and this function is autovectorized for u8's.
3203                (self as i32).wrapping_sub(other as i32).unsigned_abs() as Self
3204            } else {
3205                if self < other {
3206                    other - self
3207                } else {
3208                    self - other
3209                }
3210            }
3211        }
3212
3213        /// Calculates the multiplication of `self` and `rhs`.
3214        ///
3215        /// Returns a tuple of the multiplication along with a boolean
3216        /// indicating whether an arithmetic overflow would occur. If an
3217        /// overflow would have occurred then the wrapped value is returned.
3218        ///
3219        /// If you want the *value* of the overflow, rather than just *whether*
3220        /// an overflow occurred, see [`Self::carrying_mul`].
3221        ///
3222        /// # Examples
3223        ///
3224        /// Please note that this example is shared among integer types, which is why `u32` is used.
3225        ///
3226        /// ```
3227        /// assert_eq!(5u32.overflowing_mul(2), (10, false));
3228        /// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
3229        /// ```
3230        #[stable(feature = "wrapping", since = "1.7.0")]
3231        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3232        #[must_use = "this returns the result of the operation, \
3233                          without modifying the original"]
3234        #[inline(always)]
3235        pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
3236            let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
3237            (a as Self, b)
3238        }
3239
3240        /// Calculates the "full multiplication" `self * rhs + carry`
3241        /// without the possibility to overflow.
3242        ///
3243        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
3244        /// of the result as two separate values, in that order.
3245        ///
3246        /// Performs "long multiplication" which takes in an extra amount to add, and may return an
3247        /// additional amount of overflow. This allows for chaining together multiple
3248        /// multiplications to create "big integers" which represent larger values.
3249        ///
3250        /// If you also need to add a value, then use [`Self::carrying_mul_add`].
3251        ///
3252        /// # Examples
3253        ///
3254        /// Please note that this example is shared among integer types, which is why `u32` is used.
3255        ///
3256        /// ```
3257        /// assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
3258        /// assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
3259        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
3260        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
3261        #[doc = concat!("assert_eq!(",
3262            stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
3263            "(0, ", stringify!($SelfT), "::MAX));"
3264        )]
3265        /// ```
3266        ///
3267        /// This is the core operation needed for scalar multiplication when
3268        /// implementing it for wider-than-native types.
3269        ///
3270        /// ```
3271        /// fn scalar_mul_eq(little_endian_digits: &mut Vec<u16>, multiplicand: u16) {
3272        ///     let mut carry = 0;
3273        ///     for d in little_endian_digits.iter_mut() {
3274        ///         (*d, carry) = d.carrying_mul(multiplicand, carry);
3275        ///     }
3276        ///     if carry != 0 {
3277        ///         little_endian_digits.push(carry);
3278        ///     }
3279        /// }
3280        ///
3281        /// let mut v = vec![10, 20];
3282        /// scalar_mul_eq(&mut v, 3);
3283        /// assert_eq!(v, [30, 60]);
3284        ///
3285        /// assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D);
3286        /// let mut v = vec![0x4321, 0x8765];
3287        /// scalar_mul_eq(&mut v, 0xFEED);
3288        /// assert_eq!(v, [0xE38D, 0xD159, 0x86D3]);
3289        /// ```
3290        ///
3291        /// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul),
3292        /// except that it gives the value of the overflow instead of just whether one happened:
3293        ///
3294        /// ```
3295        /// # #![allow(unused_features)]
3296        /// #![feature(const_unsigned_bigint_helpers)]
3297        /// let r = u8::carrying_mul(7, 13, 0);
3298        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
3299        /// let r = u8::carrying_mul(13, 42, 0);
3300        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
3301        /// ```
3302        ///
3303        /// The value of the first field in the returned tuple matches what you'd get
3304        /// by combining the [`wrapping_mul`](Self::wrapping_mul) and
3305        /// [`wrapping_add`](Self::wrapping_add) methods:
3306        ///
3307        /// ```
3308        /// # #![allow(unused_features)]
3309        /// #![feature(const_unsigned_bigint_helpers)]
3310        /// assert_eq!(
3311        ///     789_u16.carrying_mul(456, 123).0,
3312        ///     789_u16.wrapping_mul(456).wrapping_add(123),
3313        /// );
3314        /// ```
3315        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
3316        #[rustc_const_unstable(feature = "const_unsigned_bigint_helpers", issue = "152015")]
3317        #[must_use = "this returns the result of the operation, \
3318                      without modifying the original"]
3319        #[inline]
3320        pub const fn carrying_mul(self, rhs: Self, carry: Self) -> (Self, Self) {
3321            Self::carrying_mul_add(self, rhs, carry, 0)
3322        }
3323
3324        /// Calculates the "full multiplication" `self * rhs + carry + add`.
3325        ///
3326        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
3327        /// of the result as two separate values, in that order.
3328        ///
3329        /// This cannot overflow, as the double-width result has exactly enough
3330        /// space for the largest possible result. This is equivalent to how, in
3331        /// decimal, 9 × 9 + 9 + 9 = 81 + 18 = 99 = 9×10⁰ + 9×10¹ = 10² - 1.
3332        ///
3333        /// Performs "long multiplication" which takes in an extra amount to add, and may return an
3334        /// additional amount of overflow. This allows for chaining together multiple
3335        /// multiplications to create "big integers" which represent larger values.
3336        ///
3337        /// If you don't need the `add` part, then you can use [`Self::carrying_mul`] instead.
3338        ///
3339        /// # Examples
3340        ///
3341        /// Please note that this example is shared between integer types,
3342        /// which explains why `u32` is used here.
3343        ///
3344        /// ```
3345        /// assert_eq!(5u32.carrying_mul_add(2, 0, 0), (10, 0));
3346        /// assert_eq!(5u32.carrying_mul_add(2, 10, 10), (30, 0));
3347        /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 0, 0), (1410065408, 2));
3348        /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 10, 10), (1410065428, 2));
3349        #[doc = concat!("assert_eq!(",
3350            stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
3351            "(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX));"
3352        )]
3353        /// ```
3354        ///
3355        /// This is the core per-digit operation for "grade school" O(n²) multiplication.
3356        ///
3357        /// Please note that this example is shared between integer types,
3358        /// using `u8` for simplicity of the demonstration.
3359        ///
3360        /// ```
3361        /// fn quadratic_mul<const N: usize>(a: [u8; N], b: [u8; N]) -> [u8; N] {
3362        ///     let mut out = [0; N];
3363        ///     for j in 0..N {
3364        ///         let mut carry = 0;
3365        ///         for i in 0..(N - j) {
3366        ///             (out[j + i], carry) = u8::carrying_mul_add(a[i], b[j], out[j + i], carry);
3367        ///         }
3368        ///     }
3369        ///     out
3370        /// }
3371        ///
3372        /// // -1 * -1 == 1
3373        /// assert_eq!(quadratic_mul([0xFF; 3], [0xFF; 3]), [1, 0, 0]);
3374        ///
3375        /// assert_eq!(u32::wrapping_mul(0x9e3779b9, 0x7f4a7c15), 0xcffc982d);
3376        /// assert_eq!(
3377        ///     quadratic_mul(u32::to_le_bytes(0x9e3779b9), u32::to_le_bytes(0x7f4a7c15)),
3378        ///     u32::to_le_bytes(0xcffc982d)
3379        /// );
3380        /// ```
3381        #[stable(feature = "unsigned_bigint_helpers", since = "1.91.0")]
3382        #[rustc_const_unstable(feature = "const_unsigned_bigint_helpers", issue = "152015")]
3383        #[must_use = "this returns the result of the operation, \
3384                      without modifying the original"]
3385        #[inline]
3386        pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> (Self, Self) {
3387            intrinsics::carrying_mul_add(self, rhs, carry, add)
3388        }
3389
3390        /// Calculates the divisor when `self` is divided by `rhs`.
3391        ///
3392        /// Returns a tuple of the divisor along with a boolean indicating
3393        /// whether an arithmetic overflow would occur. Note that for unsigned
3394        /// integers overflow never occurs, so the second value is always
3395        /// `false`.
3396        ///
3397        /// # Panics
3398        ///
3399        /// This function will panic if `rhs` is zero.
3400        ///
3401        /// # Examples
3402        ///
3403        /// ```
3404        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
3405        /// ```
3406        #[inline(always)]
3407        #[stable(feature = "wrapping", since = "1.7.0")]
3408        #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
3409        #[must_use = "this returns the result of the operation, \
3410                      without modifying the original"]
3411        #[track_caller]
3412        pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
3413            (self / rhs, false)
3414        }
3415
3416        /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
3417        ///
3418        /// Returns a tuple of the divisor along with a boolean indicating
3419        /// whether an arithmetic overflow would occur. Note that for unsigned
3420        /// integers overflow never occurs, so the second value is always
3421        /// `false`.
3422        /// Since, for the positive integers, all common
3423        /// definitions of division are equal, this
3424        /// is exactly equal to `self.overflowing_div(rhs)`.
3425        ///
3426        /// # Panics
3427        ///
3428        /// This function will panic if `rhs` is zero.
3429        ///
3430        /// # Examples
3431        ///
3432        /// ```
3433        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
3434        /// ```
3435        #[inline(always)]
3436        #[stable(feature = "euclidean_division", since = "1.38.0")]
3437        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3438        #[must_use = "this returns the result of the operation, \
3439                      without modifying the original"]
3440        #[track_caller]
3441        pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
3442            (self / rhs, false)
3443        }
3444
3445        /// Calculates the remainder when `self` is divided by `rhs`.
3446        ///
3447        /// Returns a tuple of the remainder after dividing along with a boolean
3448        /// indicating whether an arithmetic overflow would occur. Note that for
3449        /// unsigned integers overflow never occurs, so the second value is
3450        /// always `false`.
3451        ///
3452        /// # Panics
3453        ///
3454        /// This function will panic if `rhs` is zero.
3455        ///
3456        /// # Examples
3457        ///
3458        /// ```
3459        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
3460        /// ```
3461        #[inline(always)]
3462        #[stable(feature = "wrapping", since = "1.7.0")]
3463        #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
3464        #[must_use = "this returns the result of the operation, \
3465                      without modifying the original"]
3466        #[track_caller]
3467        pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
3468            (self % rhs, false)
3469        }
3470
3471        /// Calculates the remainder `self.rem_euclid(rhs)` as if by Euclidean division.
3472        ///
3473        /// Returns a tuple of the modulo after dividing along with a boolean
3474        /// indicating whether an arithmetic overflow would occur. Note that for
3475        /// unsigned integers overflow never occurs, so the second value is
3476        /// always `false`.
3477        /// Since, for the positive integers, all common
3478        /// definitions of division are equal, this operation
3479        /// is exactly equal to `self.overflowing_rem(rhs)`.
3480        ///
3481        /// # Panics
3482        ///
3483        /// This function will panic if `rhs` is zero.
3484        ///
3485        /// # Examples
3486        ///
3487        /// ```
3488        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
3489        /// ```
3490        #[inline(always)]
3491        #[stable(feature = "euclidean_division", since = "1.38.0")]
3492        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3493        #[must_use = "this returns the result of the operation, \
3494                      without modifying the original"]
3495        #[track_caller]
3496        pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
3497            (self % rhs, false)
3498        }
3499
3500        /// Negates self in an overflowing fashion.
3501        ///
3502        /// Returns `!self + 1` using wrapping operations to return the value
3503        /// that represents the negation of this unsigned value. Note that for
3504        /// positive unsigned values overflow always occurs, but negating 0 does
3505        /// not overflow.
3506        ///
3507        /// # Examples
3508        ///
3509        /// ```
3510        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_neg(), (0, false));")]
3511        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!($SelfT), ", true));")]
3512        /// ```
3513        #[inline(always)]
3514        #[stable(feature = "wrapping", since = "1.7.0")]
3515        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3516        #[must_use = "this returns the result of the operation, \
3517                      without modifying the original"]
3518        pub const fn overflowing_neg(self) -> (Self, bool) {
3519            ((!self).wrapping_add(1), self != 0)
3520        }
3521
3522        /// Shifts self left by `rhs` bits.
3523        ///
3524        /// Returns a tuple of the shifted version of self along with a boolean
3525        /// indicating whether the shift value was larger than or equal to the
3526        /// number of bits. If the shift value is too large, then value is
3527        /// masked (N-1) where N is the number of bits, and this value is then
3528        /// used to perform the shift.
3529        ///
3530        /// # Examples
3531        ///
3532        /// ```
3533        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(4), (0x10, false));")]
3534        #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));")]
3535        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
3536        /// ```
3537        #[stable(feature = "wrapping", since = "1.7.0")]
3538        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3539        #[must_use = "this returns the result of the operation, \
3540                      without modifying the original"]
3541        #[inline(always)]
3542        pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
3543            (self.wrapping_shl(rhs), rhs >= Self::BITS)
3544        }
3545
3546        /// Shifts self right by `rhs` bits.
3547        ///
3548        /// Returns a tuple of the shifted version of self along with a boolean
3549        /// indicating whether the shift value was larger than or equal to the
3550        /// number of bits. If the shift value is too large, then value is
3551        /// masked (N-1) where N is the number of bits, and this value is then
3552        /// used to perform the shift.
3553        ///
3554        /// # Examples
3555        ///
3556        /// ```
3557        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
3558        #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));")]
3559        /// ```
3560        #[stable(feature = "wrapping", since = "1.7.0")]
3561        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
3562        #[must_use = "this returns the result of the operation, \
3563                      without modifying the original"]
3564        #[inline(always)]
3565        pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
3566            (self.wrapping_shr(rhs), rhs >= Self::BITS)
3567        }
3568
3569        /// Raises self to the power of `exp`, using exponentiation by squaring.
3570        ///
3571        /// Returns a tuple of the exponentiation along with a bool indicating
3572        /// whether an overflow happened.
3573        ///
3574        /// # Examples
3575        ///
3576        /// ```
3577        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(5), (243, false));")]
3578        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".overflowing_pow(0), (1, false));")]
3579        /// assert_eq!(3u8.overflowing_pow(6), (217, true));
3580        /// ```
3581        #[stable(feature = "no_panic_pow", since = "1.34.0")]
3582        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3583        #[must_use = "this returns the result of the operation, \
3584                      without modifying the original"]
3585        #[inline]
3586        pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
3587            let mut base = self;
3588            let mut acc: Self = 1;
3589            let mut overflow = false;
3590            let mut tmp_overflow;
3591
3592            if intrinsics::is_val_statically_known(base) && base.is_power_of_two() {
3593                // change of base:
3594                // if base == 2 ** k, then
3595                //    (2 ** k) ** n
3596                // == 2 ** (k * n)
3597                // == 1 << (k * n)
3598                let k = base.ilog2();
3599                let Some(shift) = k.checked_mul(exp) else {
3600                    return (0, true)
3601                };
3602                return ((1 as Self).unbounded_shl(shift), shift >= Self::BITS)
3603            }
3604
3605            if exp == 0 {
3606                return (1, false);
3607            }
3608
3609            if intrinsics::is_val_statically_known(exp) {
3610                while exp > 1 {
3611                    if (exp & 1) == 1 {
3612                        (acc, tmp_overflow) = acc.overflowing_mul(base);
3613                        overflow |= tmp_overflow;
3614                    }
3615                    exp /= 2;
3616                    (base, tmp_overflow) = base.overflowing_mul(base);
3617                    overflow |= tmp_overflow;
3618                }
3619
3620                // since exp!=0, finally the exp must be 1.
3621                // Deal with the final bit of the exponent separately, since
3622                // squaring the base afterwards is not necessary and may cause a
3623                // needless overflow.
3624                (acc, tmp_overflow) = acc.overflowing_mul(base);
3625                overflow |= tmp_overflow;
3626                return (acc, overflow);
3627            }
3628
3629            loop {
3630                if (exp & 1) == 1 {
3631                    (acc, tmp_overflow) = acc.overflowing_mul(base);
3632                    overflow |= tmp_overflow;
3633                    // since exp!=0, finally the exp must be 1.
3634                    if exp == 1 {
3635                        return (acc, overflow);
3636                    }
3637                }
3638                exp /= 2;
3639                (base, tmp_overflow) = base.overflowing_mul(base);
3640                overflow |= tmp_overflow;
3641            }
3642        }
3643
3644        /// Raises self to the power of `exp`, using exponentiation by squaring.
3645        ///
3646        /// # Examples
3647        ///
3648        /// ```
3649        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".pow(5), 32);")]
3650        #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".pow(0), 1);")]
3651        /// ```
3652        #[stable(feature = "rust1", since = "1.0.0")]
3653        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3654        #[must_use = "this returns the result of the operation, \
3655                      without modifying the original"]
3656        #[inline]
3657        #[rustc_inherit_overflow_checks]
3658        pub const fn pow(self, exp: u32) -> Self {
3659            if intrinsics::overflow_checks() {
3660                self.strict_pow(exp)
3661            } else {
3662                self.wrapping_pow(exp)
3663            }
3664        }
3665
3666        /// Returns the square root of the number, rounded down.
3667        ///
3668        /// # Examples
3669        ///
3670        /// ```
3671        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
3672        /// ```
3673        #[stable(feature = "isqrt", since = "1.84.0")]
3674        #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
3675        #[must_use = "this returns the result of the operation, \
3676                      without modifying the original"]
3677        #[inline]
3678        pub const fn isqrt(self) -> Self {
3679            let result = imp::int_sqrt::$ActualT(self as $ActualT) as Self;
3680
3681            // Inform the optimizer what the range of outputs is. If testing
3682            // `core` crashes with no panic message and a `num::int_sqrt::u*`
3683            // test failed, it's because your edits caused these assertions or
3684            // the assertions in `fn isqrt` of `nonzero.rs` to become false.
3685            //
3686            // SAFETY: Integer square root is a monotonically nondecreasing
3687            // function, which means that increasing the input will never
3688            // cause the output to decrease. Thus, since the input for unsigned
3689            // integers is bounded by `[0, <$ActualT>::MAX]`, sqrt(n) will be
3690            // bounded by `[sqrt(0), sqrt(<$ActualT>::MAX)]` and bounding the
3691            // input by `[1, <$ActualT>::MAX]` bounds sqrt(n) by
3692            // `[sqrt(1), sqrt(<$ActualT>::MAX)]`.
3693            unsafe {
3694                const MAX_RESULT: $SelfT = imp::int_sqrt::$ActualT(<$ActualT>::MAX) as $SelfT;
3695                crate::hint::assert_unchecked(result <= MAX_RESULT)
3696            }
3697
3698            if self >= 1 {
3699                // SAFETY: The above statements about monotonicity also apply here.
3700                // Since the input in this branch is bounded by `[1, <$ActualT>::MAX]`,
3701                // sqrt(n) is bounded by `[sqrt(1), sqrt(<$ActualT>::MAX)]`, and
3702                // `sqrt(1) == 1`.
3703                unsafe { crate::hint::assert_unchecked(result >= 1) }
3704            }
3705
3706            // SAFETY: the isqrt implementation returns the square root and rounds down,
3707            // meaning `result * result <= self`. This implies `result <= self`.
3708            // The compiler needs both to optimize for both.
3709            // `result * result <= self` implies the multiplication will not overflow.
3710            unsafe {
3711                crate::hint::assert_unchecked(result.unchecked_mul(result) <= self);
3712                crate::hint::assert_unchecked(result <= self);
3713            }
3714
3715            result
3716        }
3717
3718        /// Performs Euclidean division.
3719        ///
3720        /// Since, for the positive integers, all common
3721        /// definitions of division are equal, this
3722        /// is exactly equal to `self / rhs`.
3723        ///
3724        /// # Panics
3725        ///
3726        /// This function will panic if `rhs` is zero.
3727        ///
3728        /// # Examples
3729        ///
3730        /// ```
3731        #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".div_euclid(4), 1); // or any other integer type")]
3732        /// ```
3733        #[stable(feature = "euclidean_division", since = "1.38.0")]
3734        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3735        #[must_use = "this returns the result of the operation, \
3736                      without modifying the original"]
3737        #[inline(always)]
3738        #[track_caller]
3739        pub const fn div_euclid(self, rhs: Self) -> Self {
3740            self / rhs
3741        }
3742
3743
3744        /// Calculates the least remainder of `self` when divided by
3745        /// `rhs`.
3746        ///
3747        /// Since, for the positive integers, all common
3748        /// definitions of division are equal, this
3749        /// is exactly equal to `self % rhs`.
3750        ///
3751        /// # Panics
3752        ///
3753        /// This function will panic if `rhs` is zero.
3754        ///
3755        /// # Examples
3756        ///
3757        /// ```
3758        #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".rem_euclid(4), 3); // or any other integer type")]
3759        /// ```
3760        #[doc(alias = "modulo", alias = "mod")]
3761        #[stable(feature = "euclidean_division", since = "1.38.0")]
3762        #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
3763        #[must_use = "this returns the result of the operation, \
3764                      without modifying the original"]
3765        #[inline(always)]
3766        #[track_caller]
3767        pub const fn rem_euclid(self, rhs: Self) -> Self {
3768            self % rhs
3769        }
3770
3771        /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
3772        ///
3773        /// This is the same as performing `self / rhs` for all unsigned integers.
3774        ///
3775        /// # Panics
3776        ///
3777        /// This function will panic if `rhs` is zero.
3778        ///
3779        /// # Examples
3780        ///
3781        /// ```
3782        /// #![feature(int_roundings)]
3783        #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_floor(4), 1);")]
3784        /// ```
3785        #[unstable(feature = "int_roundings", issue = "88581")]
3786        #[must_use = "this returns the result of the operation, \
3787                      without modifying the original"]
3788        #[inline(always)]
3789        #[track_caller]
3790        pub const fn div_floor(self, rhs: Self) -> Self {
3791            self / rhs
3792        }
3793
3794        /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
3795        ///
3796        /// # Panics
3797        ///
3798        /// This function will panic if `rhs` is zero.
3799        ///
3800        /// # Examples
3801        ///
3802        /// ```
3803        #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_ceil(4), 2);")]
3804        /// ```
3805        #[stable(feature = "int_roundings1", since = "1.73.0")]
3806        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3807        #[must_use = "this returns the result of the operation, \
3808                      without modifying the original"]
3809        #[inline]
3810        #[track_caller]
3811        pub const fn div_ceil(self, rhs: Self) -> Self {
3812            let d = self / rhs;
3813            let r = self % rhs;
3814            if r > 0 {
3815                d + 1
3816            } else {
3817                d
3818            }
3819        }
3820
3821        /// Calculates the smallest value greater than or equal to `self` that
3822        /// is a multiple of `rhs`.
3823        ///
3824        /// # Panics
3825        ///
3826        /// This function will panic if `rhs` is zero.
3827        ///
3828        /// ## Overflow behavior
3829        ///
3830        /// On overflow, this function will panic if overflow checks are enabled (default in debug
3831        /// mode) and wrap if overflow checks are disabled (default in release mode).
3832        ///
3833        /// # Examples
3834        ///
3835        /// ```
3836        #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
3837        #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
3838        /// ```
3839        #[stable(feature = "int_roundings1", since = "1.73.0")]
3840        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3841        #[must_use = "this returns the result of the operation, \
3842                      without modifying the original"]
3843        #[inline]
3844        #[rustc_inherit_overflow_checks]
3845        pub const fn next_multiple_of(self, rhs: Self) -> Self {
3846            match self % rhs {
3847                0 => self,
3848                r => self + (rhs - r)
3849            }
3850        }
3851
3852        /// Calculates the smallest value greater than or equal to `self` that
3853        /// is a multiple of `rhs`. Returns `None` if `rhs` is zero or the
3854        /// operation would result in overflow.
3855        ///
3856        /// # Examples
3857        ///
3858        /// ```
3859        #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
3860        #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
3861        #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
3862        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
3863        /// ```
3864        #[stable(feature = "int_roundings1", since = "1.73.0")]
3865        #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")]
3866        #[must_use = "this returns the result of the operation, \
3867                      without modifying the original"]
3868        #[inline]
3869        pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
3870            match try_opt!(self.checked_rem(rhs)) {
3871                0 => Some(self),
3872                // rhs - r cannot overflow because r is smaller than rhs
3873                r => self.checked_add(rhs - r)
3874            }
3875        }
3876
3877        /// Returns `true` if `self` is an integer multiple of `rhs`, and false otherwise.
3878        ///
3879        /// This function is equivalent to `self % rhs == 0`, except that it will not panic
3880        /// for `rhs == 0`. Instead, `0.is_multiple_of(0) == true`, and for any non-zero `n`,
3881        /// `n.is_multiple_of(0) == false`.
3882        ///
3883        /// # Examples
3884        ///
3885        /// ```
3886        #[doc = concat!("assert!(6_", stringify!($SelfT), ".is_multiple_of(2));")]
3887        #[doc = concat!("assert!(!5_", stringify!($SelfT), ".is_multiple_of(2));")]
3888        ///
3889        #[doc = concat!("assert!(0_", stringify!($SelfT), ".is_multiple_of(0));")]
3890        #[doc = concat!("assert!(!6_", stringify!($SelfT), ".is_multiple_of(0));")]
3891        /// ```
3892        #[stable(feature = "unsigned_is_multiple_of", since = "1.87.0")]
3893        #[rustc_const_stable(feature = "unsigned_is_multiple_of", since = "1.87.0")]
3894        #[must_use]
3895        #[inline]
3896        pub const fn is_multiple_of(self, rhs: Self) -> bool {
3897            match rhs {
3898                0 => self == 0,
3899                _ => self % rhs == 0,
3900            }
3901        }
3902
3903        /// Returns `true` if and only if `self == 2^k` for some unsigned integer `k`.
3904        ///
3905        /// # Examples
3906        ///
3907        /// ```
3908        #[doc = concat!("assert!(16", stringify!($SelfT), ".is_power_of_two());")]
3909        #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_power_of_two());")]
3910        /// ```
3911        #[must_use]
3912        #[stable(feature = "rust1", since = "1.0.0")]
3913        #[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")]
3914        #[inline(always)]
3915        pub const fn is_power_of_two(self) -> bool {
3916            self.count_ones() == 1
3917        }
3918
3919        /// Returns the smallest power of two greater than or equal to `self`.
3920        ///
3921        /// When return value overflows (i.e., `self > (1 << (N-1))` for type
3922        /// `uN`), it panics in debug mode and the return value is wrapped to 0 in
3923        /// release mode (the only situation in which this method can return 0).
3924        ///
3925        /// # Examples
3926        ///
3927        /// ```
3928        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".next_power_of_two(), 2);")]
3929        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);")]
3930        #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".next_power_of_two(), 1);")]
3931        /// ```
3932        #[stable(feature = "rust1", since = "1.0.0")]
3933        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3934        #[must_use = "this returns the result of the operation, \
3935                      without modifying the original"]
3936        #[inline]
3937        #[rustc_inherit_overflow_checks]
3938        pub const fn next_power_of_two(self) -> Self {
3939            if let Some(npot) = self.checked_next_power_of_two() {
3940                npot
3941            } else {
3942                #[expect(arithmetic_overflow)]
3943                {
3944                    // Zero but in a way that panics in debug
3945                    Self::MAX + 1
3946                }
3947            }
3948        }
3949
3950        /// Returns the smallest power of two greater than or equal to `self`. If
3951        /// the next power of two is greater than the type's maximum value,
3952        /// `None` is returned, otherwise the power of two is wrapped in `Some`.
3953        ///
3954        /// # Examples
3955        ///
3956        /// ```
3957        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_next_power_of_two(), Some(2));")]
3958        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));")]
3959        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_power_of_two(), None);")]
3960        /// ```
3961        #[inline]
3962        #[stable(feature = "rust1", since = "1.0.0")]
3963        #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
3964        #[must_use = "this returns the result of the operation, \
3965                      without modifying the original"]
3966        pub const fn checked_next_power_of_two(self) -> Option<Self> {
3967            let m1 = self.saturating_sub(1);
3968            if m1.cast_signed() >= 0 {
3969                let exp = m1.bit_width();
3970                Some(1 << exp)
3971            } else {
3972                None
3973            }
3974        }
3975
3976        /// Returns the smallest power of two greater than or equal to `n`. If
3977        /// the next power of two is greater than the type's maximum value,
3978        /// the return value is wrapped to `0`.
3979        ///
3980        /// # Examples
3981        ///
3982        /// ```
3983        /// #![feature(wrapping_next_power_of_two)]
3984        ///
3985        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".wrapping_next_power_of_two(), 2);")]
3986        #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_next_power_of_two(), 4);")]
3987        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_next_power_of_two(), 0);")]
3988        /// ```
3989        #[inline]
3990        #[unstable(feature = "wrapping_next_power_of_two", issue = "32463",
3991                   reason = "needs decision on wrapping behavior")]
3992        #[rustc_const_unstable(feature = "wrapping_next_power_of_two", issue = "32463")]
3993        #[must_use = "this returns the result of the operation, \
3994                      without modifying the original"]
3995        pub const fn wrapping_next_power_of_two(self) -> Self {
3996            self.checked_next_power_of_two().unwrap_or(0)
3997        }
3998
3999        /// Returns the memory representation of this integer as a byte array in
4000        /// big-endian (network) byte order.
4001        ///
4002        #[doc = $to_xe_bytes_doc]
4003        ///
4004        /// # Examples
4005        ///
4006        /// ```
4007        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
4008        #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
4009        /// ```
4010        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4011        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4012        #[must_use = "this returns the result of the operation, \
4013                      without modifying the original"]
4014        #[inline]
4015        pub const fn to_be_bytes(self) -> [u8; size_of::<Self>()] {
4016            self.to_be().to_ne_bytes()
4017        }
4018
4019        /// Returns the memory representation of this integer as a byte array in
4020        /// little-endian byte order.
4021        ///
4022        #[doc = $to_xe_bytes_doc]
4023        ///
4024        /// # Examples
4025        ///
4026        /// ```
4027        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
4028        #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
4029        /// ```
4030        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4031        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4032        #[must_use = "this returns the result of the operation, \
4033                      without modifying the original"]
4034        #[inline]
4035        pub const fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
4036            self.to_le().to_ne_bytes()
4037        }
4038
4039        /// Returns the memory representation of this integer as a byte array in
4040        /// native byte order.
4041        ///
4042        /// As the target platform's native endianness is used, portable code
4043        /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
4044        /// instead.
4045        ///
4046        #[doc = $to_xe_bytes_doc]
4047        ///
4048        /// [`to_be_bytes`]: Self::to_be_bytes
4049        /// [`to_le_bytes`]: Self::to_le_bytes
4050        ///
4051        /// # Examples
4052        ///
4053        /// ```
4054        #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
4055        /// assert_eq!(
4056        ///     bytes,
4057        ///     if cfg!(target_endian = "big") {
4058        #[doc = concat!("        ", $be_bytes)]
4059        ///     } else {
4060        #[doc = concat!("        ", $le_bytes)]
4061        ///     }
4062        /// );
4063        /// ```
4064        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4065        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4066        #[must_use = "this returns the result of the operation, \
4067                      without modifying the original"]
4068        #[allow(unnecessary_transmutes)]
4069        // SAFETY: const sound because integers are plain old datatypes so we can always
4070        // transmute them to arrays of bytes
4071        #[inline]
4072        pub const fn to_ne_bytes(self) -> [u8; size_of::<Self>()] {
4073            // SAFETY: integers are plain old datatypes so we can always transmute them to
4074            // arrays of bytes
4075            unsafe { mem::transmute(self) }
4076        }
4077
4078        /// Creates a native endian integer value from its representation
4079        /// as a byte array in big endian.
4080        ///
4081        #[doc = $from_xe_bytes_doc]
4082        ///
4083        /// # Examples
4084        ///
4085        /// ```
4086        #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
4087        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
4088        /// ```
4089        ///
4090        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
4091        ///
4092        /// ```
4093        #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
4094        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
4095        ///     *input = rest;
4096        #[doc = concat!("    ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
4097        /// }
4098        /// ```
4099        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4100        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4101        #[must_use]
4102        #[inline]
4103        pub const fn from_be_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
4104            Self::from_be(Self::from_ne_bytes(bytes))
4105        }
4106
4107        /// Creates a native endian integer value from its representation
4108        /// as a byte array in little endian.
4109        ///
4110        #[doc = $from_xe_bytes_doc]
4111        ///
4112        /// # Examples
4113        ///
4114        /// ```
4115        #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
4116        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
4117        /// ```
4118        ///
4119        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
4120        ///
4121        /// ```
4122        #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
4123        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
4124        ///     *input = rest;
4125        #[doc = concat!("    ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
4126        /// }
4127        /// ```
4128        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4129        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4130        #[must_use]
4131        #[inline]
4132        pub const fn from_le_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
4133            Self::from_le(Self::from_ne_bytes(bytes))
4134        }
4135
4136        /// Creates a native endian integer value from its memory representation
4137        /// as a byte array in native endianness.
4138        ///
4139        /// As the target platform's native endianness is used, portable code
4140        /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
4141        /// appropriate instead.
4142        ///
4143        /// [`from_be_bytes`]: Self::from_be_bytes
4144        /// [`from_le_bytes`]: Self::from_le_bytes
4145        ///
4146        #[doc = $from_xe_bytes_doc]
4147        ///
4148        /// # Examples
4149        ///
4150        /// ```
4151        #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
4152        #[doc = concat!("    ", $be_bytes, "")]
4153        /// } else {
4154        #[doc = concat!("    ", $le_bytes, "")]
4155        /// });
4156        #[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
4157        /// ```
4158        ///
4159        /// When starting from a slice rather than an array, fallible conversion APIs can be used:
4160        ///
4161        /// ```
4162        #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
4163        #[doc = concat!("    let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
4164        ///     *input = rest;
4165        #[doc = concat!("    ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
4166        /// }
4167        /// ```
4168        #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
4169        #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
4170        #[allow(unnecessary_transmutes)]
4171        #[must_use]
4172        // SAFETY: const sound because integers are plain old datatypes so we can always
4173        // transmute to them
4174        #[inline]
4175        pub const fn from_ne_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
4176            // SAFETY: integers are plain old datatypes so we can always transmute to them
4177            unsafe { mem::transmute(bytes) }
4178        }
4179
4180        /// New code should prefer to use
4181        #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
4182        ///
4183        /// Returns the smallest value that can be represented by this integer type.
4184        #[stable(feature = "rust1", since = "1.0.0")]
4185        #[rustc_promotable]
4186        #[inline(always)]
4187        #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
4188        #[deprecated(since = "1.99.0", note = "replaced by the `MIN` associated constant on this type")]
4189        #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
4190        pub const fn min_value() -> Self { Self::MIN }
4191
4192        /// New code should prefer to use
4193        #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
4194        ///
4195        /// Returns the largest value that can be represented by this integer type.
4196        #[stable(feature = "rust1", since = "1.0.0")]
4197        #[rustc_promotable]
4198        #[inline(always)]
4199        #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
4200        #[deprecated(since = "1.99.0", note = "replaced by the `MAX` associated constant on this type")]
4201        #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
4202        pub const fn max_value() -> Self { Self::MAX }
4203
4204        /// Truncate an integer to an integer of the same size or smaller, preserving the least
4205        /// significant bits.
4206        ///
4207        /// # Examples
4208        ///
4209        /// ```
4210        /// #![feature(integer_widen_truncate)]
4211        #[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".truncate());")]
4212        /// assert_eq!(120u8, 376u32.truncate());
4213        /// ```
4214        #[must_use = "this returns the truncated value and does not modify the original"]
4215        #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4216        #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4217        #[inline]
4218        pub const fn truncate<Target>(self) -> Target
4219            where Self: [const] traits::TruncateTarget<Target>
4220        {
4221            traits::TruncateTarget::internal_truncate(self)
4222        }
4223
4224        /// Truncate an integer to an integer of the same size or smaller, saturating at numeric bounds
4225        /// instead of truncating.
4226        ///
4227        /// # Examples
4228        ///
4229        /// ```
4230        /// #![feature(integer_widen_truncate)]
4231        #[doc = concat!("assert_eq!(120u8, 120", stringify!($SelfT), ".saturating_truncate());")]
4232        /// assert_eq!(255u8, 376u32.saturating_truncate());
4233        /// ```
4234        #[must_use = "this returns the truncated value and does not modify the original"]
4235        #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4236        #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4237        #[inline]
4238        pub const fn saturating_truncate<Target>(self) -> Target
4239            where Self: [const] traits::TruncateTarget<Target>
4240        {
4241            traits::TruncateTarget::internal_saturating_truncate(self)
4242        }
4243
4244        /// Truncate an integer to an integer of the same size or smaller, returning `None` if the value
4245        /// is outside the bounds of the smaller type.
4246        ///
4247        /// # Examples
4248        ///
4249        /// ```
4250        /// #![feature(integer_widen_truncate)]
4251        #[doc = concat!("assert_eq!(Some(120u8), 120", stringify!($SelfT), ".checked_truncate());")]
4252        /// assert_eq!(None, 376u32.checked_truncate::<u8>());
4253        /// ```
4254        #[must_use = "this returns the truncated value and does not modify the original"]
4255        #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4256        #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4257        #[inline]
4258        pub const fn checked_truncate<Target>(self) -> Option<Target>
4259            where Self: [const] traits::TruncateTarget<Target>
4260        {
4261            traits::TruncateTarget::internal_checked_truncate(self)
4262        }
4263
4264        /// Widen to an integer of the same size or larger, preserving its value.
4265        ///
4266        /// # Examples
4267        ///
4268        /// ```
4269        /// #![feature(integer_widen_truncate)]
4270        #[doc = concat!("assert_eq!(120u128, 120u8.widen());")]
4271        /// ```
4272        #[must_use = "this returns the widened value and does not modify the original"]
4273        #[unstable(feature = "integer_widen_truncate", issue = "154330")]
4274        #[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
4275        #[inline]
4276        pub const fn widen<Target>(self) -> Target
4277            where Self: [const] traits::WidenTarget<Target>
4278        {
4279            traits::WidenTarget::internal_widen(self)
4280        }
4281
4282        /// Converts `self` to the target integer type, saturating at the numeric
4283        /// bounds instead of overflowing.
4284        ///
4285        /// # Examples
4286        ///
4287        /// ```
4288        /// #![feature(integer_casts)]
4289        #[doc = concat!("assert_eq!(255u8, ", stringify!($SelfT), "::MAX.saturating_cast());")]
4290        #[doc = concat!("assert_eq!(127i8, ", stringify!($SelfT), "::MAX.saturating_cast());")]
4291        #[doc = concat!("assert_eq!(42i8, 42", stringify!($SelfT), ".saturating_cast());")]
4292        /// ```
4293        #[must_use = "this returns the cast result and does not modify the original"]
4294        #[unstable(feature = "integer_casts", issue = "157388")]
4295        #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4296        #[inline(always)]
4297        pub const fn saturating_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
4298            T::saturating_cast_from(self)
4299        }
4300
4301        /// Converts `self` to the target integer type, wrapping around at the
4302        /// boundary of the target type.
4303        ///
4304        /// # Examples
4305        ///
4306        /// ```
4307        /// #![feature(integer_casts)]
4308        #[doc = concat!("assert_eq!(255u8, ", stringify!($SelfT), "::MAX.wrapping_cast());")]
4309        #[doc = concat!("assert_eq!(42i8, 42", stringify!($SelfT), ".wrapping_cast());")]
4310        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX as i8, ", stringify!($SelfT), "::MAX.wrapping_cast());")]
4311        /// ```
4312        #[must_use = "this returns the cast result and does not modify the original"]
4313        #[unstable(feature = "integer_casts", issue = "157388")]
4314        #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4315        #[inline(always)]
4316        pub const fn wrapping_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
4317            T::wrapping_cast_from(self)
4318        }
4319
4320        /// Converts `self` to the target integer type, returning `None` if the value
4321        /// is not representable by the target type.
4322        ///
4323        /// # Examples
4324        ///
4325        /// ```
4326        /// #![feature(integer_casts)]
4327        #[doc = concat!("assert_eq!(Some(42u8), 42", stringify!($SelfT), ".checked_cast());")]
4328        #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_cast::<i8>(), None);")]
4329        /// ```
4330        #[must_use = "this returns the cast result and does not modify the original"]
4331        #[unstable(feature = "integer_casts", issue = "157388")]
4332        #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4333        #[inline(always)]
4334        pub const fn checked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> Option<T> {
4335            T::checked_cast_from(self)
4336        }
4337
4338        /// Converts `self` to the target integer type, panicking if the value
4339        /// is not representable by the target type.
4340        ///
4341        /// # Panics
4342        ///
4343        /// This function will panic if the value is not representable by the target type.
4344        ///
4345        /// # Examples
4346        ///
4347        /// ```
4348        /// #![feature(integer_casts)]
4349        #[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".strict_cast());")]
4350        /// ```
4351        ///
4352        /// The following will panic:
4353        ///
4354        /// ```should_panic
4355        /// #![feature(integer_casts)]
4356        #[doc = concat!("let _ = 128", stringify!($SelfT), ".strict_cast::<i8>();")]
4357        /// ```
4358        #[must_use = "this returns the cast result and does not modify the original"]
4359        #[unstable(feature = "integer_casts", issue = "157388")]
4360        #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4361        #[inline(always)]
4362        #[track_caller]
4363        pub const fn strict_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
4364            T::strict_cast_from(self)
4365        }
4366
4367        /// Converts `self` to the target integer type, assuming the value is
4368        /// representable by the target type.
4369        ///
4370        /// # Safety
4371        ///
4372        /// This results in undefined behavior if the integer value of `self` is bigger than `T::MAX`,
4373        /// or smaller than `T::MIN`, where `T` is the target type.
4374        #[must_use = "this returns the cast result and does not modify the original"]
4375        #[unstable(feature = "integer_casts", issue = "157388")]
4376        #[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
4377        #[inline(always)]
4378        pub const unsafe fn unchecked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
4379            assert_unsafe_precondition!(
4380                check_language_ub,
4381                concat!(stringify!($SelfT), "::unchecked_cast must fit in the target type"),
4382                (
4383                    // Check has to be performed up-front because it depends on generic T.
4384                    in_bounds: bool = {
4385                        let cast_val = self.checked_cast::<T>();
4386                        let ret = cast_val.is_some();
4387                        core::mem::forget(cast_val); // We don't have const Drop, but we know it's an int.
4388                        ret
4389                    },
4390                ) => in_bounds,
4391            );
4392
4393            // SAFETY: this is guaranteed to be safe by the caller.
4394            unsafe { T::unchecked_cast_from(self) }
4395        }
4396    }
4397}