core/num/
nonzero.rs

1//! Definitions of integer that is known not to equal zero.
2
3use super::{IntErrorKind, ParseIntError};
4use crate::clone::UseCloned;
5use crate::cmp::Ordering;
6use crate::hash::{Hash, Hasher};
7use crate::marker::{Freeze, StructuralPartialEq};
8use crate::ops::{BitOr, BitOrAssign, Div, DivAssign, Neg, Rem, RemAssign};
9use crate::panic::{RefUnwindSafe, UnwindSafe};
10use crate::str::FromStr;
11use crate::{fmt, intrinsics, ptr, ub_checks};
12
13/// A marker trait for primitive types which can be zero.
14///
15/// This is an implementation detail for <code>[NonZero]\<T></code> which may disappear or be replaced at any time.
16///
17/// # Safety
18///
19/// Types implementing this trait must be primitives that are valid when zeroed.
20///
21/// The associated `Self::NonZeroInner` type must have the same size+align as `Self`,
22/// but with a niche and bit validity making it so the following `transmutes` are sound:
23///
24/// - `Self::NonZeroInner` to `Option<Self::NonZeroInner>`
25/// - `Option<Self::NonZeroInner>` to `Self`
26///
27/// (And, consequently, `Self::NonZeroInner` to `Self`.)
28#[unstable(
29    feature = "nonzero_internals",
30    reason = "implementation detail which may disappear or be replaced at any time",
31    issue = "none"
32)]
33pub unsafe trait ZeroablePrimitive: Sized + Copy + private::Sealed {
34    #[doc(hidden)]
35    type NonZeroInner: Sized + Copy;
36}
37
38macro_rules! impl_zeroable_primitive {
39    ($($NonZeroInner:ident ( $primitive:ty )),+ $(,)?) => {
40        mod private {
41            #[unstable(
42                feature = "nonzero_internals",
43                reason = "implementation detail which may disappear or be replaced at any time",
44                issue = "none"
45            )]
46            pub trait Sealed {}
47        }
48
49        $(
50            #[unstable(
51                feature = "nonzero_internals",
52                reason = "implementation detail which may disappear or be replaced at any time",
53                issue = "none"
54            )]
55            impl private::Sealed for $primitive {}
56
57            #[unstable(
58                feature = "nonzero_internals",
59                reason = "implementation detail which may disappear or be replaced at any time",
60                issue = "none"
61            )]
62            unsafe impl ZeroablePrimitive for $primitive {
63                type NonZeroInner = super::niche_types::$NonZeroInner;
64            }
65        )+
66    };
67}
68
69impl_zeroable_primitive!(
70    NonZeroU8Inner(u8),
71    NonZeroU16Inner(u16),
72    NonZeroU32Inner(u32),
73    NonZeroU64Inner(u64),
74    NonZeroU128Inner(u128),
75    NonZeroUsizeInner(usize),
76    NonZeroI8Inner(i8),
77    NonZeroI16Inner(i16),
78    NonZeroI32Inner(i32),
79    NonZeroI64Inner(i64),
80    NonZeroI128Inner(i128),
81    NonZeroIsizeInner(isize),
82    NonZeroCharInner(char),
83);
84
85/// A value that is known not to equal zero.
86///
87/// This enables some memory layout optimization.
88/// For example, `Option<NonZero<u32>>` is the same size as `u32`:
89///
90/// ```
91/// use core::{num::NonZero};
92///
93/// assert_eq!(size_of::<Option<NonZero<u32>>>(), size_of::<u32>());
94/// ```
95///
96/// # Layout
97///
98/// `NonZero<T>` is guaranteed to have the same layout and bit validity as `T`
99/// with the exception that the all-zero bit pattern is invalid.
100/// `Option<NonZero<T>>` is guaranteed to be compatible with `T`, including in
101/// FFI.
102///
103/// Thanks to the [null pointer optimization], `NonZero<T>` and
104/// `Option<NonZero<T>>` are guaranteed to have the same size and alignment:
105///
106/// ```
107/// use std::num::NonZero;
108///
109/// assert_eq!(size_of::<NonZero<u32>>(), size_of::<Option<NonZero<u32>>>());
110/// assert_eq!(align_of::<NonZero<u32>>(), align_of::<Option<NonZero<u32>>>());
111/// ```
112///
113/// [null pointer optimization]: crate::option#representation
114///
115/// # Note on generic usage
116///
117/// `NonZero<T>` can only be used with some standard library primitive types
118/// (such as `u8`, `i32`, and etc.). The type parameter `T` must implement the
119/// internal trait [`ZeroablePrimitive`], which is currently permanently unstable
120/// and cannot be implemented by users. Therefore, you cannot use `NonZero<T>`
121/// with your own types, nor can you implement traits for all `NonZero<T>`,
122/// only for concrete types.
123#[stable(feature = "generic_nonzero", since = "1.79.0")]
124#[repr(transparent)]
125#[rustc_nonnull_optimization_guaranteed]
126#[rustc_diagnostic_item = "NonZero"]
127pub struct NonZero<T: ZeroablePrimitive>(T::NonZeroInner);
128
129macro_rules! impl_nonzero_fmt {
130    ($(#[$Attribute:meta] $Trait:ident)*) => {
131        $(
132            #[$Attribute]
133            impl<T> fmt::$Trait for NonZero<T>
134            where
135                T: ZeroablePrimitive + fmt::$Trait,
136            {
137                #[inline]
138                fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
139                    self.get().fmt(f)
140                }
141            }
142        )*
143    };
144}
145
146impl_nonzero_fmt! {
147    #[stable(feature = "nonzero", since = "1.28.0")]
148    Debug
149    #[stable(feature = "nonzero", since = "1.28.0")]
150    Display
151    #[stable(feature = "nonzero", since = "1.28.0")]
152    Binary
153    #[stable(feature = "nonzero", since = "1.28.0")]
154    Octal
155    #[stable(feature = "nonzero", since = "1.28.0")]
156    LowerHex
157    #[stable(feature = "nonzero", since = "1.28.0")]
158    UpperHex
159    #[stable(feature = "nonzero_fmt_exp", since = "1.84.0")]
160    LowerExp
161    #[stable(feature = "nonzero_fmt_exp", since = "1.84.0")]
162    UpperExp
163}
164
165macro_rules! impl_nonzero_auto_trait {
166    (unsafe $Trait:ident) => {
167        #[stable(feature = "nonzero", since = "1.28.0")]
168        unsafe impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
169    };
170    ($Trait:ident) => {
171        #[stable(feature = "nonzero", since = "1.28.0")]
172        impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
173    };
174}
175
176// Implement auto-traits manually based on `T` to avoid docs exposing
177// the `ZeroablePrimitive::NonZeroInner` implementation detail.
178impl_nonzero_auto_trait!(unsafe Freeze);
179impl_nonzero_auto_trait!(RefUnwindSafe);
180impl_nonzero_auto_trait!(unsafe Send);
181impl_nonzero_auto_trait!(unsafe Sync);
182impl_nonzero_auto_trait!(Unpin);
183impl_nonzero_auto_trait!(UnwindSafe);
184
185#[stable(feature = "nonzero", since = "1.28.0")]
186impl<T> Clone for NonZero<T>
187where
188    T: ZeroablePrimitive,
189{
190    #[inline]
191    fn clone(&self) -> Self {
192        *self
193    }
194}
195
196#[unstable(feature = "ergonomic_clones", issue = "132290")]
197impl<T> UseCloned for NonZero<T> where T: ZeroablePrimitive {}
198
199#[stable(feature = "nonzero", since = "1.28.0")]
200impl<T> Copy for NonZero<T> where T: ZeroablePrimitive {}
201
202#[stable(feature = "nonzero", since = "1.28.0")]
203impl<T> PartialEq for NonZero<T>
204where
205    T: ZeroablePrimitive + PartialEq,
206{
207    #[inline]
208    fn eq(&self, other: &Self) -> bool {
209        self.get() == other.get()
210    }
211
212    #[inline]
213    fn ne(&self, other: &Self) -> bool {
214        self.get() != other.get()
215    }
216}
217
218#[unstable(feature = "structural_match", issue = "31434")]
219impl<T> StructuralPartialEq for NonZero<T> where T: ZeroablePrimitive + StructuralPartialEq {}
220
221#[stable(feature = "nonzero", since = "1.28.0")]
222impl<T> Eq for NonZero<T> where T: ZeroablePrimitive + Eq {}
223
224#[stable(feature = "nonzero", since = "1.28.0")]
225impl<T> PartialOrd for NonZero<T>
226where
227    T: ZeroablePrimitive + PartialOrd,
228{
229    #[inline]
230    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
231        self.get().partial_cmp(&other.get())
232    }
233
234    #[inline]
235    fn lt(&self, other: &Self) -> bool {
236        self.get() < other.get()
237    }
238
239    #[inline]
240    fn le(&self, other: &Self) -> bool {
241        self.get() <= other.get()
242    }
243
244    #[inline]
245    fn gt(&self, other: &Self) -> bool {
246        self.get() > other.get()
247    }
248
249    #[inline]
250    fn ge(&self, other: &Self) -> bool {
251        self.get() >= other.get()
252    }
253}
254
255#[stable(feature = "nonzero", since = "1.28.0")]
256impl<T> Ord for NonZero<T>
257where
258    T: ZeroablePrimitive + Ord,
259{
260    #[inline]
261    fn cmp(&self, other: &Self) -> Ordering {
262        self.get().cmp(&other.get())
263    }
264
265    #[inline]
266    fn max(self, other: Self) -> Self {
267        // SAFETY: The maximum of two non-zero values is still non-zero.
268        unsafe { Self::new_unchecked(self.get().max(other.get())) }
269    }
270
271    #[inline]
272    fn min(self, other: Self) -> Self {
273        // SAFETY: The minimum of two non-zero values is still non-zero.
274        unsafe { Self::new_unchecked(self.get().min(other.get())) }
275    }
276
277    #[inline]
278    fn clamp(self, min: Self, max: Self) -> Self {
279        // SAFETY: A non-zero value clamped between two non-zero values is still non-zero.
280        unsafe { Self::new_unchecked(self.get().clamp(min.get(), max.get())) }
281    }
282}
283
284#[stable(feature = "nonzero", since = "1.28.0")]
285impl<T> Hash for NonZero<T>
286where
287    T: ZeroablePrimitive + Hash,
288{
289    #[inline]
290    fn hash<H>(&self, state: &mut H)
291    where
292        H: Hasher,
293    {
294        self.get().hash(state)
295    }
296}
297
298#[stable(feature = "from_nonzero", since = "1.31.0")]
299impl<T> From<NonZero<T>> for T
300where
301    T: ZeroablePrimitive,
302{
303    #[inline]
304    fn from(nonzero: NonZero<T>) -> Self {
305        // Call `get` method to keep range information.
306        nonzero.get()
307    }
308}
309
310#[stable(feature = "nonzero_bitor", since = "1.45.0")]
311impl<T> BitOr for NonZero<T>
312where
313    T: ZeroablePrimitive + BitOr<Output = T>,
314{
315    type Output = Self;
316
317    #[inline]
318    fn bitor(self, rhs: Self) -> Self::Output {
319        // SAFETY: Bitwise OR of two non-zero values is still non-zero.
320        unsafe { Self::new_unchecked(self.get() | rhs.get()) }
321    }
322}
323
324#[stable(feature = "nonzero_bitor", since = "1.45.0")]
325impl<T> BitOr<T> for NonZero<T>
326where
327    T: ZeroablePrimitive + BitOr<Output = T>,
328{
329    type Output = Self;
330
331    #[inline]
332    fn bitor(self, rhs: T) -> Self::Output {
333        // SAFETY: Bitwise OR of a non-zero value with anything is still non-zero.
334        unsafe { Self::new_unchecked(self.get() | rhs) }
335    }
336}
337
338#[stable(feature = "nonzero_bitor", since = "1.45.0")]
339impl<T> BitOr<NonZero<T>> for T
340where
341    T: ZeroablePrimitive + BitOr<Output = T>,
342{
343    type Output = NonZero<T>;
344
345    #[inline]
346    fn bitor(self, rhs: NonZero<T>) -> Self::Output {
347        // SAFETY: Bitwise OR of anything with a non-zero value is still non-zero.
348        unsafe { NonZero::new_unchecked(self | rhs.get()) }
349    }
350}
351
352#[stable(feature = "nonzero_bitor", since = "1.45.0")]
353impl<T> BitOrAssign for NonZero<T>
354where
355    T: ZeroablePrimitive,
356    Self: BitOr<Output = Self>,
357{
358    #[inline]
359    fn bitor_assign(&mut self, rhs: Self) {
360        *self = *self | rhs;
361    }
362}
363
364#[stable(feature = "nonzero_bitor", since = "1.45.0")]
365impl<T> BitOrAssign<T> for NonZero<T>
366where
367    T: ZeroablePrimitive,
368    Self: BitOr<T, Output = Self>,
369{
370    #[inline]
371    fn bitor_assign(&mut self, rhs: T) {
372        *self = *self | rhs;
373    }
374}
375
376impl<T> NonZero<T>
377where
378    T: ZeroablePrimitive,
379{
380    /// Creates a non-zero if the given value is not zero.
381    #[stable(feature = "nonzero", since = "1.28.0")]
382    #[rustc_const_stable(feature = "const_nonzero_int_methods", since = "1.47.0")]
383    #[must_use]
384    #[inline]
385    pub const fn new(n: T) -> Option<Self> {
386        // SAFETY: Memory layout optimization guarantees that `Option<NonZero<T>>` has
387        //         the same layout and size as `T`, with `0` representing `None`.
388        unsafe { intrinsics::transmute_unchecked(n) }
389    }
390
391    /// Creates a non-zero without checking whether the value is non-zero.
392    /// This results in undefined behavior if the value is zero.
393    ///
394    /// # Safety
395    ///
396    /// The value must not be zero.
397    #[stable(feature = "nonzero", since = "1.28.0")]
398    #[rustc_const_stable(feature = "nonzero", since = "1.28.0")]
399    #[must_use]
400    #[inline]
401    #[track_caller]
402    pub const unsafe fn new_unchecked(n: T) -> Self {
403        match Self::new(n) {
404            Some(n) => n,
405            None => {
406                // SAFETY: The caller guarantees that `n` is non-zero, so this is unreachable.
407                unsafe {
408                    ub_checks::assert_unsafe_precondition!(
409                        check_language_ub,
410                        "NonZero::new_unchecked requires the argument to be non-zero",
411                        () => false,
412                    );
413                    intrinsics::unreachable()
414                }
415            }
416        }
417    }
418
419    /// Converts a reference to a non-zero mutable reference
420    /// if the referenced value is not zero.
421    #[unstable(feature = "nonzero_from_mut", issue = "106290")]
422    #[must_use]
423    #[inline]
424    pub fn from_mut(n: &mut T) -> Option<&mut Self> {
425        // SAFETY: Memory layout optimization guarantees that `Option<NonZero<T>>` has
426        //         the same layout and size as `T`, with `0` representing `None`.
427        let opt_n = unsafe { &mut *(ptr::from_mut(n).cast::<Option<Self>>()) };
428
429        opt_n.as_mut()
430    }
431
432    /// Converts a mutable reference to a non-zero mutable reference
433    /// without checking whether the referenced value is non-zero.
434    /// This results in undefined behavior if the referenced value is zero.
435    ///
436    /// # Safety
437    ///
438    /// The referenced value must not be zero.
439    #[unstable(feature = "nonzero_from_mut", issue = "106290")]
440    #[must_use]
441    #[inline]
442    #[track_caller]
443    pub unsafe fn from_mut_unchecked(n: &mut T) -> &mut Self {
444        match Self::from_mut(n) {
445            Some(n) => n,
446            None => {
447                // SAFETY: The caller guarantees that `n` references a value that is non-zero, so this is unreachable.
448                unsafe {
449                    ub_checks::assert_unsafe_precondition!(
450                        check_library_ub,
451                        "NonZero::from_mut_unchecked requires the argument to dereference as non-zero",
452                        () => false,
453                    );
454                    intrinsics::unreachable()
455                }
456            }
457        }
458    }
459
460    /// Returns the contained value as a primitive type.
461    #[stable(feature = "nonzero", since = "1.28.0")]
462    #[rustc_const_stable(feature = "const_nonzero_get", since = "1.34.0")]
463    #[inline]
464    pub const fn get(self) -> T {
465        // Rustc can set range metadata only if it loads `self` from
466        // memory somewhere. If the value of `self` was from by-value argument
467        // of some not-inlined function, LLVM don't have range metadata
468        // to understand that the value cannot be zero.
469        //
470        // Using the transmute `assume`s the range at runtime.
471        //
472        // Even once LLVM supports `!range` metadata for function arguments
473        // (see <https://github.com/llvm/llvm-project/issues/76628>), this can't
474        // be `.0` because MCP#807 bans field-projecting into `scalar_valid_range`
475        // types, and it arguably wouldn't want to be anyway because if this is
476        // MIR-inlined, there's no opportunity to put that argument metadata anywhere.
477        //
478        // The good answer here will eventually be pattern types, which will hopefully
479        // allow it to go back to `.0`, maybe with a cast of some sort.
480        //
481        // SAFETY: `ZeroablePrimitive` guarantees that the size and bit validity
482        // of `.0` is such that this transmute is sound.
483        unsafe { intrinsics::transmute_unchecked(self) }
484    }
485}
486
487macro_rules! nonzero_integer {
488    (
489        #[$stability:meta]
490        Self = $Ty:ident,
491        Primitive = $signedness:ident $Int:ident,
492        SignedPrimitive = $Sint:ty,
493        UnsignedPrimitive = $Uint:ty,
494
495        // Used in doc comments.
496        rot = $rot:literal,
497        rot_op = $rot_op:literal,
498        rot_result = $rot_result:literal,
499        swap_op = $swap_op:literal,
500        swapped = $swapped:literal,
501        reversed = $reversed:literal,
502        leading_zeros_test = $leading_zeros_test:expr,
503    ) => {
504        #[doc = sign_dependent_expr!{
505            $signedness ?
506            if signed {
507                concat!("An [`", stringify!($Int), "`] that is known not to equal zero.")
508            }
509            if unsigned {
510                concat!("A [`", stringify!($Int), "`] that is known not to equal zero.")
511            }
512        }]
513        ///
514        /// This enables some memory layout optimization.
515        #[doc = concat!("For example, `Option<", stringify!($Ty), ">` is the same size as `", stringify!($Int), "`:")]
516        ///
517        /// ```rust
518        #[doc = concat!("assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", stringify!($Int), ">());")]
519        /// ```
520        ///
521        /// # Layout
522        ///
523        #[doc = concat!("`", stringify!($Ty), "` is guaranteed to have the same layout and bit validity as `", stringify!($Int), "`")]
524        /// with the exception that `0` is not a valid instance.
525        #[doc = concat!("`Option<", stringify!($Ty), ">` is guaranteed to be compatible with `", stringify!($Int), "`,")]
526        /// including in FFI.
527        ///
528        /// Thanks to the [null pointer optimization],
529        #[doc = concat!("`", stringify!($Ty), "` and `Option<", stringify!($Ty), ">`")]
530        /// are guaranteed to have the same size and alignment:
531        ///
532        /// ```
533        #[doc = concat!("use std::num::", stringify!($Ty), ";")]
534        ///
535        #[doc = concat!("assert_eq!(size_of::<", stringify!($Ty), ">(), size_of::<Option<", stringify!($Ty), ">>());")]
536        #[doc = concat!("assert_eq!(align_of::<", stringify!($Ty), ">(), align_of::<Option<", stringify!($Ty), ">>());")]
537        /// ```
538        ///
539        /// [null pointer optimization]: crate::option#representation
540        #[$stability]
541        pub type $Ty = NonZero<$Int>;
542
543        impl NonZero<$Int> {
544            /// The size of this non-zero integer type in bits.
545            ///
546            #[doc = concat!("This value is equal to [`", stringify!($Int), "::BITS`].")]
547            ///
548            /// # Examples
549            ///
550            /// ```
551            /// # use std::num::NonZero;
552            /// #
553            #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::BITS, ", stringify!($Int), "::BITS);")]
554            /// ```
555            #[stable(feature = "nonzero_bits", since = "1.67.0")]
556            pub const BITS: u32 = <$Int>::BITS;
557
558            /// Returns the number of leading zeros in the binary representation of `self`.
559            ///
560            /// On many architectures, this function can perform better than `leading_zeros()` on the underlying integer type, as special handling of zero can be avoided.
561            ///
562            /// # Examples
563            ///
564            /// ```
565            /// # use std::num::NonZero;
566            /// #
567            /// # fn main() { test().unwrap(); }
568            /// # fn test() -> Option<()> {
569            #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::new(", $leading_zeros_test, ")?;")]
570            ///
571            /// assert_eq!(n.leading_zeros(), 0);
572            /// # Some(())
573            /// # }
574            /// ```
575            #[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
576            #[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
577            #[must_use = "this returns the result of the operation, \
578                          without modifying the original"]
579            #[inline]
580            pub const fn leading_zeros(self) -> u32 {
581                // SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`.
582                unsafe {
583                    intrinsics::ctlz_nonzero(self.get() as $Uint)
584                }
585            }
586
587            /// Returns the number of trailing zeros in the binary representation
588            /// of `self`.
589            ///
590            /// On many architectures, this function can perform better than `trailing_zeros()` on the underlying integer type, as special handling of zero can be avoided.
591            ///
592            /// # Examples
593            ///
594            /// ```
595            /// # use std::num::NonZero;
596            /// #
597            /// # fn main() { test().unwrap(); }
598            /// # fn test() -> Option<()> {
599            #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::new(0b0101000)?;")]
600            ///
601            /// assert_eq!(n.trailing_zeros(), 3);
602            /// # Some(())
603            /// # }
604            /// ```
605            #[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
606            #[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
607            #[must_use = "this returns the result of the operation, \
608                          without modifying the original"]
609            #[inline]
610            pub const fn trailing_zeros(self) -> u32 {
611                // SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`.
612                unsafe {
613                    intrinsics::cttz_nonzero(self.get() as $Uint)
614                }
615            }
616
617            /// Returns `self` with only the most significant bit set.
618            ///
619            /// # Example
620            ///
621            /// ```
622            /// #![feature(isolate_most_least_significant_one)]
623            ///
624            /// # use core::num::NonZero;
625            /// # fn main() { test().unwrap(); }
626            /// # fn test() -> Option<()> {
627            #[doc = concat!("let a = NonZero::<", stringify!($Int), ">::new(0b_01100100)?;")]
628            #[doc = concat!("let b = NonZero::<", stringify!($Int), ">::new(0b_01000000)?;")]
629            ///
630            /// assert_eq!(a.isolate_most_significant_one(), b);
631            /// # Some(())
632            /// # }
633            /// ```
634            #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
635            #[must_use = "this returns the result of the operation, \
636                        without modifying the original"]
637            #[inline(always)]
638            pub const fn isolate_most_significant_one(self) -> Self {
639                let n = self.get() & (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()));
640
641                // SAFETY:
642                // `self` is non-zero, so masking to preserve only the most
643                // significant set bit will result in a non-zero `n`.
644                unsafe { NonZero::new_unchecked(n) }
645            }
646
647            /// Returns `self` with only the least significant bit set.
648            ///
649            /// # Example
650            ///
651            /// ```
652            /// #![feature(isolate_most_least_significant_one)]
653            ///
654            /// # use core::num::NonZero;
655            /// # fn main() { test().unwrap(); }
656            /// # fn test() -> Option<()> {
657            #[doc = concat!("let a = NonZero::<", stringify!($Int), ">::new(0b_01100100)?;")]
658            #[doc = concat!("let b = NonZero::<", stringify!($Int), ">::new(0b_00000100)?;")]
659            ///
660            /// assert_eq!(a.isolate_least_significant_one(), b);
661            /// # Some(())
662            /// # }
663            /// ```
664            #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")]
665            #[must_use = "this returns the result of the operation, \
666                        without modifying the original"]
667            #[inline(always)]
668            pub const fn isolate_least_significant_one(self) -> Self {
669                let n = self.get();
670                let n = n & n.wrapping_neg();
671
672                // SAFETY: `self` is non-zero, so `self` with only its least
673                // significant set bit will remain non-zero.
674                unsafe { NonZero::new_unchecked(n) }
675            }
676
677            /// Returns the number of ones in the binary representation of `self`.
678            ///
679            /// # Examples
680            ///
681            /// ```
682            /// # use std::num::NonZero;
683            /// #
684            /// # fn main() { test().unwrap(); }
685            /// # fn test() -> Option<()> {
686            #[doc = concat!("let a = NonZero::<", stringify!($Int), ">::new(0b100_0000)?;")]
687            #[doc = concat!("let b = NonZero::<", stringify!($Int), ">::new(0b100_0011)?;")]
688            ///
689            /// assert_eq!(a.count_ones(), NonZero::new(1)?);
690            /// assert_eq!(b.count_ones(), NonZero::new(3)?);
691            /// # Some(())
692            /// # }
693            /// ```
694            ///
695            #[stable(feature = "non_zero_count_ones", since = "1.86.0")]
696            #[rustc_const_stable(feature = "non_zero_count_ones", since = "1.86.0")]
697            #[doc(alias = "popcount")]
698            #[doc(alias = "popcnt")]
699            #[must_use = "this returns the result of the operation, \
700                        without modifying the original"]
701            #[inline(always)]
702            pub const fn count_ones(self) -> NonZero<u32> {
703                // SAFETY:
704                // `self` is non-zero, which means it has at least one bit set, which means
705                // that the result of `count_ones` is non-zero.
706                unsafe { NonZero::new_unchecked(self.get().count_ones()) }
707            }
708
709            /// Shifts the bits to the left by a specified amount, `n`,
710            /// wrapping the truncated bits to the end of the resulting integer.
711            ///
712            /// Please note this isn't the same operation as the `<<` shifting operator!
713            ///
714            /// # Examples
715            ///
716            /// ```
717            /// #![feature(nonzero_bitwise)]
718            /// # use std::num::NonZero;
719            /// #
720            /// # fn main() { test().unwrap(); }
721            /// # fn test() -> Option<()> {
722            #[doc = concat!("let n = NonZero::new(", $rot_op, stringify!($Int), ")?;")]
723            #[doc = concat!("let m = NonZero::new(", $rot_result, ")?;")]
724            ///
725            #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
726            /// # Some(())
727            /// # }
728            /// ```
729            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
730            #[must_use = "this returns the result of the operation, \
731                        without modifying the original"]
732            #[inline(always)]
733            pub const fn rotate_left(self, n: u32) -> Self {
734                let result = self.get().rotate_left(n);
735                // SAFETY: Rotating bits preserves the property int > 0.
736                unsafe { Self::new_unchecked(result) }
737            }
738
739            /// Shifts the bits to the right by a specified amount, `n`,
740            /// wrapping the truncated bits to the beginning of the resulting
741            /// integer.
742            ///
743            /// Please note this isn't the same operation as the `>>` shifting operator!
744            ///
745            /// # Examples
746            ///
747            /// ```
748            /// #![feature(nonzero_bitwise)]
749            /// # use std::num::NonZero;
750            /// #
751            /// # fn main() { test().unwrap(); }
752            /// # fn test() -> Option<()> {
753            #[doc = concat!("let n = NonZero::new(", $rot_result, stringify!($Int), ")?;")]
754            #[doc = concat!("let m = NonZero::new(", $rot_op, ")?;")]
755            ///
756            #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
757            /// # Some(())
758            /// # }
759            /// ```
760            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
761            #[must_use = "this returns the result of the operation, \
762                        without modifying the original"]
763            #[inline(always)]
764            pub const fn rotate_right(self, n: u32) -> Self {
765                let result = self.get().rotate_right(n);
766                // SAFETY: Rotating bits preserves the property int > 0.
767                unsafe { Self::new_unchecked(result) }
768            }
769
770            /// Reverses the byte order of the integer.
771            ///
772            /// # Examples
773            ///
774            /// ```
775            /// #![feature(nonzero_bitwise)]
776            /// # use std::num::NonZero;
777            /// #
778            /// # fn main() { test().unwrap(); }
779            /// # fn test() -> Option<()> {
780            #[doc = concat!("let n = NonZero::new(", $swap_op, stringify!($Int), ")?;")]
781            /// let m = n.swap_bytes();
782            ///
783            #[doc = concat!("assert_eq!(m, NonZero::new(", $swapped, ")?);")]
784            /// # Some(())
785            /// # }
786            /// ```
787            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
788            #[must_use = "this returns the result of the operation, \
789                        without modifying the original"]
790            #[inline(always)]
791            pub const fn swap_bytes(self) -> Self {
792                let result = self.get().swap_bytes();
793                // SAFETY: Shuffling bytes preserves the property int > 0.
794                unsafe { Self::new_unchecked(result) }
795            }
796
797            /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
798            /// second least-significant bit becomes second most-significant bit, etc.
799            ///
800            /// # Examples
801            ///
802            /// ```
803            /// #![feature(nonzero_bitwise)]
804            /// # use std::num::NonZero;
805            /// #
806            /// # fn main() { test().unwrap(); }
807            /// # fn test() -> Option<()> {
808            #[doc = concat!("let n = NonZero::new(", $swap_op, stringify!($Int), ")?;")]
809            /// let m = n.reverse_bits();
810            ///
811            #[doc = concat!("assert_eq!(m, NonZero::new(", $reversed, ")?);")]
812            /// # Some(())
813            /// # }
814            /// ```
815            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
816            #[must_use = "this returns the result of the operation, \
817                        without modifying the original"]
818            #[inline(always)]
819            pub const fn reverse_bits(self) -> Self {
820                let result = self.get().reverse_bits();
821                // SAFETY: Reversing bits preserves the property int > 0.
822                unsafe { Self::new_unchecked(result) }
823            }
824
825            /// Converts an integer from big endian to the target's endianness.
826            ///
827            /// On big endian this is a no-op. On little endian the bytes are
828            /// swapped.
829            ///
830            /// # Examples
831            ///
832            /// ```
833            /// #![feature(nonzero_bitwise)]
834            /// # use std::num::NonZero;
835            #[doc = concat!("use std::num::", stringify!($Ty), ";")]
836            /// #
837            /// # fn main() { test().unwrap(); }
838            /// # fn test() -> Option<()> {
839            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
840            ///
841            /// if cfg!(target_endian = "big") {
842            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_be(n), n)")]
843            /// } else {
844            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_be(n), n.swap_bytes())")]
845            /// }
846            /// # Some(())
847            /// # }
848            /// ```
849            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
850            #[must_use]
851            #[inline(always)]
852            pub const fn from_be(x: Self) -> Self {
853                let result = $Int::from_be(x.get());
854                // SAFETY: Shuffling bytes preserves the property int > 0.
855                unsafe { Self::new_unchecked(result) }
856            }
857
858            /// Converts an integer from little endian to the target's endianness.
859            ///
860            /// On little endian this is a no-op. On big endian the bytes are
861            /// swapped.
862            ///
863            /// # Examples
864            ///
865            /// ```
866            /// #![feature(nonzero_bitwise)]
867            /// # use std::num::NonZero;
868            #[doc = concat!("use std::num::", stringify!($Ty), ";")]
869            /// #
870            /// # fn main() { test().unwrap(); }
871            /// # fn test() -> Option<()> {
872            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
873            ///
874            /// if cfg!(target_endian = "little") {
875            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_le(n), n)")]
876            /// } else {
877            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_le(n), n.swap_bytes())")]
878            /// }
879            /// # Some(())
880            /// # }
881            /// ```
882            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
883            #[must_use]
884            #[inline(always)]
885            pub const fn from_le(x: Self) -> Self {
886                let result = $Int::from_le(x.get());
887                // SAFETY: Shuffling bytes preserves the property int > 0.
888                unsafe { Self::new_unchecked(result) }
889            }
890
891            /// Converts `self` to big endian from the target's endianness.
892            ///
893            /// On big endian this is a no-op. On little endian the bytes are
894            /// swapped.
895            ///
896            /// # Examples
897            ///
898            /// ```
899            /// #![feature(nonzero_bitwise)]
900            /// # use std::num::NonZero;
901            /// #
902            /// # fn main() { test().unwrap(); }
903            /// # fn test() -> Option<()> {
904            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
905            ///
906            /// if cfg!(target_endian = "big") {
907            ///     assert_eq!(n.to_be(), n)
908            /// } else {
909            ///     assert_eq!(n.to_be(), n.swap_bytes())
910            /// }
911            /// # Some(())
912            /// # }
913            /// ```
914            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
915            #[must_use = "this returns the result of the operation, \
916                        without modifying the original"]
917            #[inline(always)]
918            pub const fn to_be(self) -> Self {
919                let result = self.get().to_be();
920                // SAFETY: Shuffling bytes preserves the property int > 0.
921                unsafe { Self::new_unchecked(result) }
922            }
923
924            /// Converts `self` to little endian from the target's endianness.
925            ///
926            /// On little endian this is a no-op. On big endian the bytes are
927            /// swapped.
928            ///
929            /// # Examples
930            ///
931            /// ```
932            /// #![feature(nonzero_bitwise)]
933            /// # use std::num::NonZero;
934            /// #
935            /// # fn main() { test().unwrap(); }
936            /// # fn test() -> Option<()> {
937            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
938            ///
939            /// if cfg!(target_endian = "little") {
940            ///     assert_eq!(n.to_le(), n)
941            /// } else {
942            ///     assert_eq!(n.to_le(), n.swap_bytes())
943            /// }
944            /// # Some(())
945            /// # }
946            /// ```
947            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
948            #[must_use = "this returns the result of the operation, \
949                        without modifying the original"]
950            #[inline(always)]
951            pub const fn to_le(self) -> Self {
952                let result = self.get().to_le();
953                // SAFETY: Shuffling bytes preserves the property int > 0.
954                unsafe { Self::new_unchecked(result) }
955            }
956
957            nonzero_integer_signedness_dependent_methods! {
958                Primitive = $signedness $Int,
959                SignedPrimitive = $Sint,
960                UnsignedPrimitive = $Uint,
961            }
962
963            /// Multiplies two non-zero integers together.
964            /// Checks for overflow and returns [`None`] on overflow.
965            /// As a consequence, the result cannot wrap to zero.
966            ///
967            /// # Examples
968            ///
969            /// ```
970            /// # use std::num::NonZero;
971            /// #
972            /// # fn main() { test().unwrap(); }
973            /// # fn test() -> Option<()> {
974            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
975            #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
976            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
977            ///
978            /// assert_eq!(Some(four), two.checked_mul(two));
979            /// assert_eq!(None, max.checked_mul(two));
980            /// # Some(())
981            /// # }
982            /// ```
983            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
984            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
985            #[must_use = "this returns the result of the operation, \
986                          without modifying the original"]
987            #[inline]
988            pub const fn checked_mul(self, other: Self) -> Option<Self> {
989                if let Some(result) = self.get().checked_mul(other.get()) {
990                    // SAFETY:
991                    // - `checked_mul` returns `None` on overflow
992                    // - `self` and `other` are non-zero
993                    // - the only way to get zero from a multiplication without overflow is for one
994                    //   of the sides to be zero
995                    //
996                    // So the result cannot be zero.
997                    Some(unsafe { Self::new_unchecked(result) })
998                } else {
999                    None
1000                }
1001            }
1002
1003            /// Multiplies two non-zero integers together.
1004            #[doc = concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")]
1005            ///
1006            /// # Examples
1007            ///
1008            /// ```
1009            /// # use std::num::NonZero;
1010            /// #
1011            /// # fn main() { test().unwrap(); }
1012            /// # fn test() -> Option<()> {
1013            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1014            #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1015            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1016            ///
1017            /// assert_eq!(four, two.saturating_mul(two));
1018            /// assert_eq!(max, four.saturating_mul(max));
1019            /// # Some(())
1020            /// # }
1021            /// ```
1022            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1023            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1024            #[must_use = "this returns the result of the operation, \
1025                          without modifying the original"]
1026            #[inline]
1027            pub const fn saturating_mul(self, other: Self) -> Self {
1028                // SAFETY:
1029                // - `saturating_mul` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
1030                //   all of which are non-zero
1031                // - `self` and `other` are non-zero
1032                // - the only way to get zero from a multiplication without overflow is for one
1033                //   of the sides to be zero
1034                //
1035                // So the result cannot be zero.
1036                unsafe { Self::new_unchecked(self.get().saturating_mul(other.get())) }
1037            }
1038
1039            /// Multiplies two non-zero integers together,
1040            /// assuming overflow cannot occur.
1041            /// Overflow is unchecked, and it is undefined behavior to overflow
1042            /// *even if the result would wrap to a non-zero value*.
1043            /// The behavior is undefined as soon as
1044            #[doc = sign_dependent_expr!{
1045                $signedness ?
1046                if signed {
1047                    concat!("`self * rhs > ", stringify!($Int), "::MAX`, ",
1048                            "or `self * rhs < ", stringify!($Int), "::MIN`.")
1049                }
1050                if unsigned {
1051                    concat!("`self * rhs > ", stringify!($Int), "::MAX`.")
1052                }
1053            }]
1054            ///
1055            /// # Examples
1056            ///
1057            /// ```
1058            /// #![feature(nonzero_ops)]
1059            ///
1060            /// # use std::num::NonZero;
1061            /// #
1062            /// # fn main() { test().unwrap(); }
1063            /// # fn test() -> Option<()> {
1064            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1065            #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1066            ///
1067            /// assert_eq!(four, unsafe { two.unchecked_mul(two) });
1068            /// # Some(())
1069            /// # }
1070            /// ```
1071            #[unstable(feature = "nonzero_ops", issue = "84186")]
1072            #[must_use = "this returns the result of the operation, \
1073                          without modifying the original"]
1074            #[inline]
1075            pub const unsafe fn unchecked_mul(self, other: Self) -> Self {
1076                // SAFETY: The caller ensures there is no overflow.
1077                unsafe { Self::new_unchecked(self.get().unchecked_mul(other.get())) }
1078            }
1079
1080            /// Raises non-zero value to an integer power.
1081            /// Checks for overflow and returns [`None`] on overflow.
1082            /// As a consequence, the result cannot wrap to zero.
1083            ///
1084            /// # Examples
1085            ///
1086            /// ```
1087            /// # use std::num::NonZero;
1088            /// #
1089            /// # fn main() { test().unwrap(); }
1090            /// # fn test() -> Option<()> {
1091            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1092            #[doc = concat!("let twenty_seven = NonZero::new(27", stringify!($Int), ")?;")]
1093            #[doc = concat!("let half_max = NonZero::new(", stringify!($Int), "::MAX / 2)?;")]
1094            ///
1095            /// assert_eq!(Some(twenty_seven), three.checked_pow(3));
1096            /// assert_eq!(None, half_max.checked_pow(3));
1097            /// # Some(())
1098            /// # }
1099            /// ```
1100            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1101            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1102            #[must_use = "this returns the result of the operation, \
1103                          without modifying the original"]
1104            #[inline]
1105            pub const fn checked_pow(self, other: u32) -> Option<Self> {
1106                if let Some(result) = self.get().checked_pow(other) {
1107                    // SAFETY:
1108                    // - `checked_pow` returns `None` on overflow/underflow
1109                    // - `self` is non-zero
1110                    // - the only way to get zero from an exponentiation without overflow is
1111                    //   for base to be zero
1112                    //
1113                    // So the result cannot be zero.
1114                    Some(unsafe { Self::new_unchecked(result) })
1115                } else {
1116                    None
1117                }
1118            }
1119
1120            /// Raise non-zero value to an integer power.
1121            #[doc = sign_dependent_expr!{
1122                $signedness ?
1123                if signed {
1124                    concat!("Return [`NonZero::<", stringify!($Int), ">::MIN`] ",
1125                                "or [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")
1126                }
1127                if unsigned {
1128                    concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")
1129                }
1130            }]
1131            ///
1132            /// # Examples
1133            ///
1134            /// ```
1135            /// # use std::num::NonZero;
1136            /// #
1137            /// # fn main() { test().unwrap(); }
1138            /// # fn test() -> Option<()> {
1139            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1140            #[doc = concat!("let twenty_seven = NonZero::new(27", stringify!($Int), ")?;")]
1141            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1142            ///
1143            /// assert_eq!(twenty_seven, three.saturating_pow(3));
1144            /// assert_eq!(max, max.saturating_pow(3));
1145            /// # Some(())
1146            /// # }
1147            /// ```
1148            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1149            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1150            #[must_use = "this returns the result of the operation, \
1151                          without modifying the original"]
1152            #[inline]
1153            pub const fn saturating_pow(self, other: u32) -> Self {
1154                // SAFETY:
1155                // - `saturating_pow` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
1156                //   all of which are non-zero
1157                // - `self` is non-zero
1158                // - the only way to get zero from an exponentiation without overflow is
1159                //   for base to be zero
1160                //
1161                // So the result cannot be zero.
1162                unsafe { Self::new_unchecked(self.get().saturating_pow(other)) }
1163            }
1164        }
1165
1166        #[stable(feature = "nonzero_parse", since = "1.35.0")]
1167        impl FromStr for NonZero<$Int> {
1168            type Err = ParseIntError;
1169            fn from_str(src: &str) -> Result<Self, Self::Err> {
1170                Self::new(<$Int>::from_str_radix(src, 10)?)
1171                    .ok_or(ParseIntError {
1172                        kind: IntErrorKind::Zero
1173                    })
1174            }
1175        }
1176
1177        nonzero_integer_signedness_dependent_impls!($signedness $Int);
1178    };
1179
1180    (
1181        Self = $Ty:ident,
1182        Primitive = unsigned $Int:ident,
1183        SignedPrimitive = $Sint:ident,
1184        rot = $rot:literal,
1185        rot_op = $rot_op:literal,
1186        rot_result = $rot_result:literal,
1187        swap_op = $swap_op:literal,
1188        swapped = $swapped:literal,
1189        reversed = $reversed:literal,
1190        $(,)?
1191    ) => {
1192        nonzero_integer! {
1193            #[stable(feature = "nonzero", since = "1.28.0")]
1194            Self = $Ty,
1195            Primitive = unsigned $Int,
1196            SignedPrimitive = $Sint,
1197            UnsignedPrimitive = $Int,
1198            rot = $rot,
1199            rot_op = $rot_op,
1200            rot_result = $rot_result,
1201            swap_op = $swap_op,
1202            swapped = $swapped,
1203            reversed = $reversed,
1204            leading_zeros_test = concat!(stringify!($Int), "::MAX"),
1205        }
1206    };
1207
1208    (
1209        Self = $Ty:ident,
1210        Primitive = signed $Int:ident,
1211        UnsignedPrimitive = $Uint:ident,
1212        rot = $rot:literal,
1213        rot_op = $rot_op:literal,
1214        rot_result = $rot_result:literal,
1215        swap_op = $swap_op:literal,
1216        swapped = $swapped:literal,
1217        reversed = $reversed:literal,
1218    ) => {
1219        nonzero_integer! {
1220            #[stable(feature = "signed_nonzero", since = "1.34.0")]
1221            Self = $Ty,
1222            Primitive = signed $Int,
1223            SignedPrimitive = $Int,
1224            UnsignedPrimitive = $Uint,
1225            rot = $rot,
1226            rot_op = $rot_op,
1227            rot_result = $rot_result,
1228            swap_op = $swap_op,
1229            swapped = $swapped,
1230            reversed = $reversed,
1231            leading_zeros_test = concat!("-1", stringify!($Int)),
1232        }
1233    };
1234}
1235
1236macro_rules! nonzero_integer_signedness_dependent_impls {
1237    // Impls for unsigned nonzero types only.
1238    (unsigned $Int:ty) => {
1239        #[stable(feature = "nonzero_div", since = "1.51.0")]
1240        impl Div<NonZero<$Int>> for $Int {
1241            type Output = $Int;
1242
1243            /// Same as `self / other.get()`, but because `other` is a `NonZero<_>`,
1244            /// there's never a runtime check for division-by-zero.
1245            ///
1246            /// This operation rounds towards zero, truncating any fractional
1247            /// part of the exact result, and cannot panic.
1248            #[doc(alias = "unchecked_div")]
1249            #[inline]
1250            fn div(self, other: NonZero<$Int>) -> $Int {
1251                // SAFETY: Division by zero is checked because `other` is non-zero,
1252                // and MIN/-1 is checked because `self` is an unsigned int.
1253                unsafe { intrinsics::unchecked_div(self, other.get()) }
1254            }
1255        }
1256
1257        #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
1258        impl DivAssign<NonZero<$Int>> for $Int {
1259            /// Same as `self /= other.get()`, but because `other` is a `NonZero<_>`,
1260            /// there's never a runtime check for division-by-zero.
1261            ///
1262            /// This operation rounds towards zero, truncating any fractional
1263            /// part of the exact result, and cannot panic.
1264            #[inline]
1265            fn div_assign(&mut self, other: NonZero<$Int>) {
1266                *self = *self / other;
1267            }
1268        }
1269
1270        #[stable(feature = "nonzero_div", since = "1.51.0")]
1271        impl Rem<NonZero<$Int>> for $Int {
1272            type Output = $Int;
1273
1274            /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
1275            #[inline]
1276            fn rem(self, other: NonZero<$Int>) -> $Int {
1277                // SAFETY: Remainder by zero is checked because `other` is non-zero,
1278                // and MIN/-1 is checked because `self` is an unsigned int.
1279                unsafe { intrinsics::unchecked_rem(self, other.get()) }
1280            }
1281        }
1282
1283        #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
1284        impl RemAssign<NonZero<$Int>> for $Int {
1285            /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
1286            #[inline]
1287            fn rem_assign(&mut self, other: NonZero<$Int>) {
1288                *self = *self % other;
1289            }
1290        }
1291
1292        impl NonZero<$Int> {
1293            /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
1294            ///
1295            /// The result is guaranteed to be non-zero.
1296            ///
1297            /// # Examples
1298            ///
1299            /// ```
1300            /// # #![feature(unsigned_nonzero_div_ceil)]
1301            /// # use std::num::NonZero;
1302            #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ").unwrap();")]
1303            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX).unwrap();")]
1304            /// assert_eq!(one.div_ceil(max), one);
1305            ///
1306            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ").unwrap();")]
1307            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ").unwrap();")]
1308            /// assert_eq!(three.div_ceil(two), two);
1309            /// ```
1310            #[unstable(feature = "unsigned_nonzero_div_ceil", issue = "132968")]
1311            #[must_use = "this returns the result of the operation, \
1312                          without modifying the original"]
1313            #[inline]
1314            pub const fn div_ceil(self, rhs: Self) -> Self {
1315                let v = self.get().div_ceil(rhs.get());
1316                // SAFETY: ceiled division of two positive integers can never be zero.
1317                unsafe { Self::new_unchecked(v) }
1318            }
1319        }
1320    };
1321    // Impls for signed nonzero types only.
1322    (signed $Int:ty) => {
1323        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")]
1324        impl Neg for NonZero<$Int> {
1325            type Output = Self;
1326
1327            #[inline]
1328            fn neg(self) -> Self {
1329                // SAFETY: negation of nonzero cannot yield zero values.
1330                unsafe { Self::new_unchecked(self.get().neg()) }
1331            }
1332        }
1333
1334        forward_ref_unop! { impl Neg, neg for NonZero<$Int>,
1335        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")] }
1336    };
1337}
1338
1339#[rustfmt::skip] // https://github.com/rust-lang/rustfmt/issues/5974
1340macro_rules! nonzero_integer_signedness_dependent_methods {
1341    // Associated items for unsigned nonzero types only.
1342    (
1343        Primitive = unsigned $Int:ident,
1344        SignedPrimitive = $Sint:ty,
1345        UnsignedPrimitive = $Uint:ty,
1346    ) => {
1347        /// The smallest value that can be represented by this non-zero
1348        /// integer type, 1.
1349        ///
1350        /// # Examples
1351        ///
1352        /// ```
1353        /// # use std::num::NonZero;
1354        /// #
1355        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MIN.get(), 1", stringify!($Int), ");")]
1356        /// ```
1357        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1358        pub const MIN: Self = Self::new(1).unwrap();
1359
1360        /// The largest value that can be represented by this non-zero
1361        /// integer type,
1362        #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
1363        ///
1364        /// # Examples
1365        ///
1366        /// ```
1367        /// # use std::num::NonZero;
1368        /// #
1369        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MAX.get(), ", stringify!($Int), "::MAX);")]
1370        /// ```
1371        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1372        pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
1373
1374        /// Adds an unsigned integer to a non-zero value.
1375        /// Checks for overflow and returns [`None`] on overflow.
1376        /// As a consequence, the result cannot wrap to zero.
1377        ///
1378        ///
1379        /// # Examples
1380        ///
1381        /// ```
1382        /// # use std::num::NonZero;
1383        /// #
1384        /// # fn main() { test().unwrap(); }
1385        /// # fn test() -> Option<()> {
1386        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1387        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1388        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1389        ///
1390        /// assert_eq!(Some(two), one.checked_add(1));
1391        /// assert_eq!(None, max.checked_add(1));
1392        /// # Some(())
1393        /// # }
1394        /// ```
1395        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1396        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1397        #[must_use = "this returns the result of the operation, \
1398                      without modifying the original"]
1399        #[inline]
1400        pub const fn checked_add(self, other: $Int) -> Option<Self> {
1401            if let Some(result) = self.get().checked_add(other) {
1402                // SAFETY:
1403                // - `checked_add` returns `None` on overflow
1404                // - `self` is non-zero
1405                // - the only way to get zero from an addition without overflow is for both
1406                //   sides to be zero
1407                //
1408                // So the result cannot be zero.
1409                Some(unsafe { Self::new_unchecked(result) })
1410            } else {
1411                None
1412            }
1413        }
1414
1415        /// Adds an unsigned integer to a non-zero value.
1416        #[doc = concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")]
1417        ///
1418        /// # Examples
1419        ///
1420        /// ```
1421        /// # use std::num::NonZero;
1422        /// #
1423        /// # fn main() { test().unwrap(); }
1424        /// # fn test() -> Option<()> {
1425        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1426        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1427        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1428        ///
1429        /// assert_eq!(two, one.saturating_add(1));
1430        /// assert_eq!(max, max.saturating_add(1));
1431        /// # Some(())
1432        /// # }
1433        /// ```
1434        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1435        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1436        #[must_use = "this returns the result of the operation, \
1437                      without modifying the original"]
1438        #[inline]
1439        pub const fn saturating_add(self, other: $Int) -> Self {
1440            // SAFETY:
1441            // - `saturating_add` returns `u*::MAX` on overflow, which is non-zero
1442            // - `self` is non-zero
1443            // - the only way to get zero from an addition without overflow is for both
1444            //   sides to be zero
1445            //
1446            // So the result cannot be zero.
1447            unsafe { Self::new_unchecked(self.get().saturating_add(other)) }
1448        }
1449
1450        /// Adds an unsigned integer to a non-zero value,
1451        /// assuming overflow cannot occur.
1452        /// Overflow is unchecked, and it is undefined behavior to overflow
1453        /// *even if the result would wrap to a non-zero value*.
1454        /// The behavior is undefined as soon as
1455        #[doc = concat!("`self + rhs > ", stringify!($Int), "::MAX`.")]
1456        ///
1457        /// # Examples
1458        ///
1459        /// ```
1460        /// #![feature(nonzero_ops)]
1461        ///
1462        /// # use std::num::NonZero;
1463        /// #
1464        /// # fn main() { test().unwrap(); }
1465        /// # fn test() -> Option<()> {
1466        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1467        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1468        ///
1469        /// assert_eq!(two, unsafe { one.unchecked_add(1) });
1470        /// # Some(())
1471        /// # }
1472        /// ```
1473        #[unstable(feature = "nonzero_ops", issue = "84186")]
1474        #[must_use = "this returns the result of the operation, \
1475                      without modifying the original"]
1476        #[inline]
1477        pub const unsafe fn unchecked_add(self, other: $Int) -> Self {
1478            // SAFETY: The caller ensures there is no overflow.
1479            unsafe { Self::new_unchecked(self.get().unchecked_add(other)) }
1480        }
1481
1482        /// Returns the smallest power of two greater than or equal to `self`.
1483        /// Checks for overflow and returns [`None`]
1484        /// if the next power of two is greater than the type’s maximum value.
1485        /// As a consequence, the result cannot wrap to zero.
1486        ///
1487        /// # Examples
1488        ///
1489        /// ```
1490        /// # use std::num::NonZero;
1491        /// #
1492        /// # fn main() { test().unwrap(); }
1493        /// # fn test() -> Option<()> {
1494        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1495        #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1496        #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1497        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1498        ///
1499        /// assert_eq!(Some(two), two.checked_next_power_of_two() );
1500        /// assert_eq!(Some(four), three.checked_next_power_of_two() );
1501        /// assert_eq!(None, max.checked_next_power_of_two() );
1502        /// # Some(())
1503        /// # }
1504        /// ```
1505        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1506        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1507        #[must_use = "this returns the result of the operation, \
1508                      without modifying the original"]
1509        #[inline]
1510        pub const fn checked_next_power_of_two(self) -> Option<Self> {
1511            if let Some(nz) = self.get().checked_next_power_of_two() {
1512                // SAFETY: The next power of two is positive
1513                // and overflow is checked.
1514                Some(unsafe { Self::new_unchecked(nz) })
1515            } else {
1516                None
1517            }
1518        }
1519
1520        /// Returns the base 2 logarithm of the number, rounded down.
1521        ///
1522        /// This is the same operation as
1523        #[doc = concat!("[`", stringify!($Int), "::ilog2`],")]
1524        /// except that it has no failure cases to worry about
1525        /// since this value can never be zero.
1526        ///
1527        /// # Examples
1528        ///
1529        /// ```
1530        /// # use std::num::NonZero;
1531        /// #
1532        /// # fn main() { test().unwrap(); }
1533        /// # fn test() -> Option<()> {
1534        #[doc = concat!("assert_eq!(NonZero::new(7", stringify!($Int), ")?.ilog2(), 2);")]
1535        #[doc = concat!("assert_eq!(NonZero::new(8", stringify!($Int), ")?.ilog2(), 3);")]
1536        #[doc = concat!("assert_eq!(NonZero::new(9", stringify!($Int), ")?.ilog2(), 3);")]
1537        /// # Some(())
1538        /// # }
1539        /// ```
1540        #[stable(feature = "int_log", since = "1.67.0")]
1541        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1542        #[must_use = "this returns the result of the operation, \
1543                      without modifying the original"]
1544        #[inline]
1545        pub const fn ilog2(self) -> u32 {
1546            Self::BITS - 1 - self.leading_zeros()
1547        }
1548
1549        /// Returns the base 10 logarithm of the number, rounded down.
1550        ///
1551        /// This is the same operation as
1552        #[doc = concat!("[`", stringify!($Int), "::ilog10`],")]
1553        /// except that it has no failure cases to worry about
1554        /// since this value can never be zero.
1555        ///
1556        /// # Examples
1557        ///
1558        /// ```
1559        /// # use std::num::NonZero;
1560        /// #
1561        /// # fn main() { test().unwrap(); }
1562        /// # fn test() -> Option<()> {
1563        #[doc = concat!("assert_eq!(NonZero::new(99", stringify!($Int), ")?.ilog10(), 1);")]
1564        #[doc = concat!("assert_eq!(NonZero::new(100", stringify!($Int), ")?.ilog10(), 2);")]
1565        #[doc = concat!("assert_eq!(NonZero::new(101", stringify!($Int), ")?.ilog10(), 2);")]
1566        /// # Some(())
1567        /// # }
1568        /// ```
1569        #[stable(feature = "int_log", since = "1.67.0")]
1570        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1571        #[must_use = "this returns the result of the operation, \
1572                      without modifying the original"]
1573        #[inline]
1574        pub const fn ilog10(self) -> u32 {
1575            super::int_log10::$Int(self.get())
1576        }
1577
1578        /// Calculates the midpoint (average) between `self` and `rhs`.
1579        ///
1580        /// `midpoint(a, b)` is `(a + b) >> 1` as if it were performed in a
1581        /// sufficiently-large signed integral type. This implies that the result is
1582        /// always rounded towards negative infinity and that no overflow will ever occur.
1583        ///
1584        /// # Examples
1585        ///
1586        /// ```
1587        /// # use std::num::NonZero;
1588        /// #
1589        /// # fn main() { test().unwrap(); }
1590        /// # fn test() -> Option<()> {
1591        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1592        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1593        #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1594        ///
1595        /// assert_eq!(one.midpoint(four), two);
1596        /// assert_eq!(four.midpoint(one), two);
1597        /// # Some(())
1598        /// # }
1599        /// ```
1600        #[stable(feature = "num_midpoint", since = "1.85.0")]
1601        #[rustc_const_stable(feature = "num_midpoint", since = "1.85.0")]
1602        #[must_use = "this returns the result of the operation, \
1603                      without modifying the original"]
1604        #[doc(alias = "average_floor")]
1605        #[doc(alias = "average")]
1606        #[inline]
1607        pub const fn midpoint(self, rhs: Self) -> Self {
1608            // SAFETY: The only way to get `0` with midpoint is to have two opposite or
1609            // near opposite numbers: (-5, 5), (0, 1), (0, 0) which is impossible because
1610            // of the unsignedness of this number and also because `Self` is guaranteed to
1611            // never being 0.
1612            unsafe { Self::new_unchecked(self.get().midpoint(rhs.get())) }
1613        }
1614
1615        /// Returns `true` if and only if `self == (1 << k)` for some `k`.
1616        ///
1617        /// On many architectures, this function can perform better than `is_power_of_two()`
1618        /// on the underlying integer type, as special handling of zero can be avoided.
1619        ///
1620        /// # Examples
1621        ///
1622        /// ```
1623        /// # use std::num::NonZero;
1624        /// #
1625        /// # fn main() { test().unwrap(); }
1626        /// # fn test() -> Option<()> {
1627        #[doc = concat!("let eight = NonZero::new(8", stringify!($Int), ")?;")]
1628        /// assert!(eight.is_power_of_two());
1629        #[doc = concat!("let ten = NonZero::new(10", stringify!($Int), ")?;")]
1630        /// assert!(!ten.is_power_of_two());
1631        /// # Some(())
1632        /// # }
1633        /// ```
1634        #[must_use]
1635        #[stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
1636        #[rustc_const_stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
1637        #[inline]
1638        pub const fn is_power_of_two(self) -> bool {
1639            // LLVM 11 normalizes `unchecked_sub(x, 1) & x == 0` to the implementation seen here.
1640            // On the basic x86-64 target, this saves 3 instructions for the zero check.
1641            // On x86_64 with BMI1, being nonzero lets it codegen to `BLSR`, which saves an instruction
1642            // compared to the `POPCNT` implementation on the underlying integer type.
1643
1644            intrinsics::ctpop(self.get()) < 2
1645        }
1646
1647        /// Returns the square root of the number, rounded down.
1648        ///
1649        /// # Examples
1650        ///
1651        /// ```
1652        /// # use std::num::NonZero;
1653        /// #
1654        /// # fn main() { test().unwrap(); }
1655        /// # fn test() -> Option<()> {
1656        #[doc = concat!("let ten = NonZero::new(10", stringify!($Int), ")?;")]
1657        #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1658        ///
1659        /// assert_eq!(ten.isqrt(), three);
1660        /// # Some(())
1661        /// # }
1662        /// ```
1663        #[stable(feature = "isqrt", since = "1.84.0")]
1664        #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
1665        #[must_use = "this returns the result of the operation, \
1666                      without modifying the original"]
1667        #[inline]
1668        pub const fn isqrt(self) -> Self {
1669            let result = self.get().isqrt();
1670
1671            // SAFETY: Integer square root is a monotonically nondecreasing
1672            // function, which means that increasing the input will never cause
1673            // the output to decrease. Thus, since the input for nonzero
1674            // unsigned integers has a lower bound of 1, the lower bound of the
1675            // results will be sqrt(1), which is 1, so a result can't be zero.
1676            unsafe { Self::new_unchecked(result) }
1677        }
1678
1679        /// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size.
1680        ///
1681        /// # Examples
1682        ///
1683        /// ```
1684        /// # use std::num::NonZero;
1685        ///
1686        #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::MAX;")]
1687        ///
1688        #[doc = concat!("assert_eq!(n.cast_signed(), NonZero::new(-1", stringify!($Sint), ").unwrap());")]
1689        /// ```
1690        #[stable(feature = "integer_sign_cast", since = "1.87.0")]
1691        #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
1692        #[must_use = "this returns the result of the operation, \
1693                      without modifying the original"]
1694        #[inline(always)]
1695        pub const fn cast_signed(self) -> NonZero<$Sint> {
1696            // SAFETY: `self.get()` can't be zero
1697            unsafe { NonZero::new_unchecked(self.get().cast_signed()) }
1698        }
1699    };
1700
1701    // Associated items for signed nonzero types only.
1702    (
1703        Primitive = signed $Int:ident,
1704        SignedPrimitive = $Sint:ty,
1705        UnsignedPrimitive = $Uint:ty,
1706    ) => {
1707        /// The smallest value that can be represented by this non-zero
1708        /// integer type,
1709        #[doc = concat!("equal to [`", stringify!($Int), "::MIN`].")]
1710        ///
1711        /// Note: While most integer types are defined for every whole
1712        /// number between `MIN` and `MAX`, signed non-zero integers are
1713        /// a special case. They have a "gap" at 0.
1714        ///
1715        /// # Examples
1716        ///
1717        /// ```
1718        /// # use std::num::NonZero;
1719        /// #
1720        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MIN.get(), ", stringify!($Int), "::MIN);")]
1721        /// ```
1722        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1723        pub const MIN: Self = Self::new(<$Int>::MIN).unwrap();
1724
1725        /// The largest value that can be represented by this non-zero
1726        /// integer type,
1727        #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
1728        ///
1729        /// Note: While most integer types are defined for every whole
1730        /// number between `MIN` and `MAX`, signed non-zero integers are
1731        /// a special case. They have a "gap" at 0.
1732        ///
1733        /// # Examples
1734        ///
1735        /// ```
1736        /// # use std::num::NonZero;
1737        /// #
1738        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MAX.get(), ", stringify!($Int), "::MAX);")]
1739        /// ```
1740        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1741        pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
1742
1743        /// Computes the absolute value of self.
1744        #[doc = concat!("See [`", stringify!($Int), "::abs`]")]
1745        /// for documentation on overflow behavior.
1746        ///
1747        /// # Example
1748        ///
1749        /// ```
1750        /// # use std::num::NonZero;
1751        /// #
1752        /// # fn main() { test().unwrap(); }
1753        /// # fn test() -> Option<()> {
1754        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1755        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1756        ///
1757        /// assert_eq!(pos, pos.abs());
1758        /// assert_eq!(pos, neg.abs());
1759        /// # Some(())
1760        /// # }
1761        /// ```
1762        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1763        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1764        #[must_use = "this returns the result of the operation, \
1765                      without modifying the original"]
1766        #[inline]
1767        pub const fn abs(self) -> Self {
1768            // SAFETY: This cannot overflow to zero.
1769            unsafe { Self::new_unchecked(self.get().abs()) }
1770        }
1771
1772        /// Checked absolute value.
1773        /// Checks for overflow and returns [`None`] if
1774        #[doc = concat!("`self == NonZero::<", stringify!($Int), ">::MIN`.")]
1775        /// The result cannot be zero.
1776        ///
1777        /// # Example
1778        ///
1779        /// ```
1780        /// # use std::num::NonZero;
1781        /// #
1782        /// # fn main() { test().unwrap(); }
1783        /// # fn test() -> Option<()> {
1784        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1785        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1786        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1787        ///
1788        /// assert_eq!(Some(pos), neg.checked_abs());
1789        /// assert_eq!(None, min.checked_abs());
1790        /// # Some(())
1791        /// # }
1792        /// ```
1793        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1794        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1795        #[must_use = "this returns the result of the operation, \
1796                      without modifying the original"]
1797        #[inline]
1798        pub const fn checked_abs(self) -> Option<Self> {
1799            if let Some(nz) = self.get().checked_abs() {
1800                // SAFETY: absolute value of nonzero cannot yield zero values.
1801                Some(unsafe { Self::new_unchecked(nz) })
1802            } else {
1803                None
1804            }
1805        }
1806
1807        /// Computes the absolute value of self,
1808        /// with overflow information, see
1809        #[doc = concat!("[`", stringify!($Int), "::overflowing_abs`].")]
1810        ///
1811        /// # Example
1812        ///
1813        /// ```
1814        /// # use std::num::NonZero;
1815        /// #
1816        /// # fn main() { test().unwrap(); }
1817        /// # fn test() -> Option<()> {
1818        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1819        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1820        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1821        ///
1822        /// assert_eq!((pos, false), pos.overflowing_abs());
1823        /// assert_eq!((pos, false), neg.overflowing_abs());
1824        /// assert_eq!((min, true), min.overflowing_abs());
1825        /// # Some(())
1826        /// # }
1827        /// ```
1828        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1829        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1830        #[must_use = "this returns the result of the operation, \
1831                      without modifying the original"]
1832        #[inline]
1833        pub const fn overflowing_abs(self) -> (Self, bool) {
1834            let (nz, flag) = self.get().overflowing_abs();
1835            (
1836                // SAFETY: absolute value of nonzero cannot yield zero values.
1837                unsafe { Self::new_unchecked(nz) },
1838                flag,
1839            )
1840        }
1841
1842        /// Saturating absolute value, see
1843        #[doc = concat!("[`", stringify!($Int), "::saturating_abs`].")]
1844        ///
1845        /// # Example
1846        ///
1847        /// ```
1848        /// # use std::num::NonZero;
1849        /// #
1850        /// # fn main() { test().unwrap(); }
1851        /// # fn test() -> Option<()> {
1852        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1853        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1854        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1855        #[doc = concat!("let min_plus = NonZero::new(", stringify!($Int), "::MIN + 1)?;")]
1856        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1857        ///
1858        /// assert_eq!(pos, pos.saturating_abs());
1859        /// assert_eq!(pos, neg.saturating_abs());
1860        /// assert_eq!(max, min.saturating_abs());
1861        /// assert_eq!(max, min_plus.saturating_abs());
1862        /// # Some(())
1863        /// # }
1864        /// ```
1865        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1866        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1867        #[must_use = "this returns the result of the operation, \
1868                      without modifying the original"]
1869        #[inline]
1870        pub const fn saturating_abs(self) -> Self {
1871            // SAFETY: absolute value of nonzero cannot yield zero values.
1872            unsafe { Self::new_unchecked(self.get().saturating_abs()) }
1873        }
1874
1875        /// Wrapping absolute value, see
1876        #[doc = concat!("[`", stringify!($Int), "::wrapping_abs`].")]
1877        ///
1878        /// # Example
1879        ///
1880        /// ```
1881        /// # use std::num::NonZero;
1882        /// #
1883        /// # fn main() { test().unwrap(); }
1884        /// # fn test() -> Option<()> {
1885        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1886        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1887        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1888        #[doc = concat!("# let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1889        ///
1890        /// assert_eq!(pos, pos.wrapping_abs());
1891        /// assert_eq!(pos, neg.wrapping_abs());
1892        /// assert_eq!(min, min.wrapping_abs());
1893        /// assert_eq!(max, (-max).wrapping_abs());
1894        /// # Some(())
1895        /// # }
1896        /// ```
1897        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1898        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1899        #[must_use = "this returns the result of the operation, \
1900                      without modifying the original"]
1901        #[inline]
1902        pub const fn wrapping_abs(self) -> Self {
1903            // SAFETY: absolute value of nonzero cannot yield zero values.
1904            unsafe { Self::new_unchecked(self.get().wrapping_abs()) }
1905        }
1906
1907        /// Computes the absolute value of self
1908        /// without any wrapping or panicking.
1909        ///
1910        /// # Example
1911        ///
1912        /// ```
1913        /// # use std::num::NonZero;
1914        /// #
1915        /// # fn main() { test().unwrap(); }
1916        /// # fn test() -> Option<()> {
1917        #[doc = concat!("let u_pos = NonZero::new(1", stringify!($Uint), ")?;")]
1918        #[doc = concat!("let i_pos = NonZero::new(1", stringify!($Int), ")?;")]
1919        #[doc = concat!("let i_neg = NonZero::new(-1", stringify!($Int), ")?;")]
1920        #[doc = concat!("let i_min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1921        #[doc = concat!("let u_max = NonZero::new(", stringify!($Uint), "::MAX / 2 + 1)?;")]
1922        ///
1923        /// assert_eq!(u_pos, i_pos.unsigned_abs());
1924        /// assert_eq!(u_pos, i_neg.unsigned_abs());
1925        /// assert_eq!(u_max, i_min.unsigned_abs());
1926        /// # Some(())
1927        /// # }
1928        /// ```
1929        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1930        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1931        #[must_use = "this returns the result of the operation, \
1932                      without modifying the original"]
1933        #[inline]
1934        pub const fn unsigned_abs(self) -> NonZero<$Uint> {
1935            // SAFETY: absolute value of nonzero cannot yield zero values.
1936            unsafe { NonZero::new_unchecked(self.get().unsigned_abs()) }
1937        }
1938
1939        /// Returns `true` if `self` is positive and `false` if the
1940        /// number is negative.
1941        ///
1942        /// # Example
1943        ///
1944        /// ```
1945        /// # use std::num::NonZero;
1946        /// #
1947        /// # fn main() { test().unwrap(); }
1948        /// # fn test() -> Option<()> {
1949        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1950        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1951        ///
1952        /// assert!(pos_five.is_positive());
1953        /// assert!(!neg_five.is_positive());
1954        /// # Some(())
1955        /// # }
1956        /// ```
1957        #[must_use]
1958        #[inline]
1959        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1960        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1961        pub const fn is_positive(self) -> bool {
1962            self.get().is_positive()
1963        }
1964
1965        /// Returns `true` if `self` is negative and `false` if the
1966        /// number is positive.
1967        ///
1968        /// # Example
1969        ///
1970        /// ```
1971        /// # use std::num::NonZero;
1972        /// #
1973        /// # fn main() { test().unwrap(); }
1974        /// # fn test() -> Option<()> {
1975        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1976        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1977        ///
1978        /// assert!(neg_five.is_negative());
1979        /// assert!(!pos_five.is_negative());
1980        /// # Some(())
1981        /// # }
1982        /// ```
1983        #[must_use]
1984        #[inline]
1985        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1986        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1987        pub const fn is_negative(self) -> bool {
1988            self.get().is_negative()
1989        }
1990
1991        /// Checked negation. Computes `-self`,
1992        #[doc = concat!("returning `None` if `self == NonZero::<", stringify!($Int), ">::MIN`.")]
1993        ///
1994        /// # Example
1995        ///
1996        /// ```
1997        /// # use std::num::NonZero;
1998        /// #
1999        /// # fn main() { test().unwrap(); }
2000        /// # fn test() -> Option<()> {
2001        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2002        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2003        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2004        ///
2005        /// assert_eq!(pos_five.checked_neg(), Some(neg_five));
2006        /// assert_eq!(min.checked_neg(), None);
2007        /// # Some(())
2008        /// # }
2009        /// ```
2010        #[inline]
2011        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2012        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2013        pub const fn checked_neg(self) -> Option<Self> {
2014            if let Some(result) = self.get().checked_neg() {
2015                // SAFETY: negation of nonzero cannot yield zero values.
2016                return Some(unsafe { Self::new_unchecked(result) });
2017            }
2018            None
2019        }
2020
2021        /// Negates self, overflowing if this is equal to the minimum value.
2022        ///
2023        #[doc = concat!("See [`", stringify!($Int), "::overflowing_neg`]")]
2024        /// for documentation on overflow behavior.
2025        ///
2026        /// # Example
2027        ///
2028        /// ```
2029        /// # use std::num::NonZero;
2030        /// #
2031        /// # fn main() { test().unwrap(); }
2032        /// # fn test() -> Option<()> {
2033        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2034        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2035        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2036        ///
2037        /// assert_eq!(pos_five.overflowing_neg(), (neg_five, false));
2038        /// assert_eq!(min.overflowing_neg(), (min, true));
2039        /// # Some(())
2040        /// # }
2041        /// ```
2042        #[inline]
2043        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2044        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2045        pub const fn overflowing_neg(self) -> (Self, bool) {
2046            let (result, overflow) = self.get().overflowing_neg();
2047            // SAFETY: negation of nonzero cannot yield zero values.
2048            ((unsafe { Self::new_unchecked(result) }), overflow)
2049        }
2050
2051        /// Saturating negation. Computes `-self`,
2052        #[doc = concat!("returning [`NonZero::<", stringify!($Int), ">::MAX`]")]
2053        #[doc = concat!("if `self == NonZero::<", stringify!($Int), ">::MIN`")]
2054        /// instead of overflowing.
2055        ///
2056        /// # Example
2057        ///
2058        /// ```
2059        /// # use std::num::NonZero;
2060        /// #
2061        /// # fn main() { test().unwrap(); }
2062        /// # fn test() -> Option<()> {
2063        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2064        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2065        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2066        #[doc = concat!("let min_plus_one = NonZero::new(", stringify!($Int), "::MIN + 1)?;")]
2067        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
2068        ///
2069        /// assert_eq!(pos_five.saturating_neg(), neg_five);
2070        /// assert_eq!(min.saturating_neg(), max);
2071        /// assert_eq!(max.saturating_neg(), min_plus_one);
2072        /// # Some(())
2073        /// # }
2074        /// ```
2075        #[inline]
2076        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2077        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2078        pub const fn saturating_neg(self) -> Self {
2079            if let Some(result) = self.checked_neg() {
2080                return result;
2081            }
2082            Self::MAX
2083        }
2084
2085        /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
2086        /// of the type.
2087        ///
2088        #[doc = concat!("See [`", stringify!($Int), "::wrapping_neg`]")]
2089        /// for documentation on overflow behavior.
2090        ///
2091        /// # Example
2092        ///
2093        /// ```
2094        /// # use std::num::NonZero;
2095        /// #
2096        /// # fn main() { test().unwrap(); }
2097        /// # fn test() -> Option<()> {
2098        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2099        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2100        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2101        ///
2102        /// assert_eq!(pos_five.wrapping_neg(), neg_five);
2103        /// assert_eq!(min.wrapping_neg(), min);
2104        /// # Some(())
2105        /// # }
2106        /// ```
2107        #[inline]
2108        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2109        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2110        pub const fn wrapping_neg(self) -> Self {
2111            let result = self.get().wrapping_neg();
2112            // SAFETY: negation of nonzero cannot yield zero values.
2113            unsafe { Self::new_unchecked(result) }
2114        }
2115
2116        /// Returns the bit pattern of `self` reinterpreted as an unsigned integer of the same size.
2117        ///
2118        /// # Examples
2119        ///
2120        /// ```
2121        /// # use std::num::NonZero;
2122        ///
2123        #[doc = concat!("let n = NonZero::new(-1", stringify!($Int), ").unwrap();")]
2124        ///
2125        #[doc = concat!("assert_eq!(n.cast_unsigned(), NonZero::<", stringify!($Uint), ">::MAX);")]
2126        /// ```
2127        #[stable(feature = "integer_sign_cast", since = "1.87.0")]
2128        #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
2129        #[must_use = "this returns the result of the operation, \
2130                      without modifying the original"]
2131        #[inline(always)]
2132        pub const fn cast_unsigned(self) -> NonZero<$Uint> {
2133            // SAFETY: `self.get()` can't be zero
2134            unsafe { NonZero::new_unchecked(self.get().cast_unsigned()) }
2135        }
2136
2137    };
2138}
2139
2140nonzero_integer! {
2141    Self = NonZeroU8,
2142    Primitive = unsigned u8,
2143    SignedPrimitive = i8,
2144    rot = 2,
2145    rot_op = "0x82",
2146    rot_result = "0xa",
2147    swap_op = "0x12",
2148    swapped = "0x12",
2149    reversed = "0x48",
2150}
2151
2152nonzero_integer! {
2153    Self = NonZeroU16,
2154    Primitive = unsigned u16,
2155    SignedPrimitive = i16,
2156    rot = 4,
2157    rot_op = "0xa003",
2158    rot_result = "0x3a",
2159    swap_op = "0x1234",
2160    swapped = "0x3412",
2161    reversed = "0x2c48",
2162}
2163
2164nonzero_integer! {
2165    Self = NonZeroU32,
2166    Primitive = unsigned u32,
2167    SignedPrimitive = i32,
2168    rot = 8,
2169    rot_op = "0x10000b3",
2170    rot_result = "0xb301",
2171    swap_op = "0x12345678",
2172    swapped = "0x78563412",
2173    reversed = "0x1e6a2c48",
2174}
2175
2176nonzero_integer! {
2177    Self = NonZeroU64,
2178    Primitive = unsigned u64,
2179    SignedPrimitive = i64,
2180    rot = 12,
2181    rot_op = "0xaa00000000006e1",
2182    rot_result = "0x6e10aa",
2183    swap_op = "0x1234567890123456",
2184    swapped = "0x5634129078563412",
2185    reversed = "0x6a2c48091e6a2c48",
2186}
2187
2188nonzero_integer! {
2189    Self = NonZeroU128,
2190    Primitive = unsigned u128,
2191    SignedPrimitive = i128,
2192    rot = 16,
2193    rot_op = "0x13f40000000000000000000000004f76",
2194    rot_result = "0x4f7613f4",
2195    swap_op = "0x12345678901234567890123456789012",
2196    swapped = "0x12907856341290785634129078563412",
2197    reversed = "0x48091e6a2c48091e6a2c48091e6a2c48",
2198}
2199
2200#[cfg(target_pointer_width = "16")]
2201nonzero_integer! {
2202    Self = NonZeroUsize,
2203    Primitive = unsigned usize,
2204    SignedPrimitive = isize,
2205    rot = 4,
2206    rot_op = "0xa003",
2207    rot_result = "0x3a",
2208    swap_op = "0x1234",
2209    swapped = "0x3412",
2210    reversed = "0x2c48",
2211}
2212
2213#[cfg(target_pointer_width = "32")]
2214nonzero_integer! {
2215    Self = NonZeroUsize,
2216    Primitive = unsigned usize,
2217    SignedPrimitive = isize,
2218    rot = 8,
2219    rot_op = "0x10000b3",
2220    rot_result = "0xb301",
2221    swap_op = "0x12345678",
2222    swapped = "0x78563412",
2223    reversed = "0x1e6a2c48",
2224}
2225
2226#[cfg(target_pointer_width = "64")]
2227nonzero_integer! {
2228    Self = NonZeroUsize,
2229    Primitive = unsigned usize,
2230    SignedPrimitive = isize,
2231    rot = 12,
2232    rot_op = "0xaa00000000006e1",
2233    rot_result = "0x6e10aa",
2234    swap_op = "0x1234567890123456",
2235    swapped = "0x5634129078563412",
2236    reversed = "0x6a2c48091e6a2c48",
2237}
2238
2239nonzero_integer! {
2240    Self = NonZeroI8,
2241    Primitive = signed i8,
2242    UnsignedPrimitive = u8,
2243    rot = 2,
2244    rot_op = "-0x7e",
2245    rot_result = "0xa",
2246    swap_op = "0x12",
2247    swapped = "0x12",
2248    reversed = "0x48",
2249}
2250
2251nonzero_integer! {
2252    Self = NonZeroI16,
2253    Primitive = signed i16,
2254    UnsignedPrimitive = u16,
2255    rot = 4,
2256    rot_op = "-0x5ffd",
2257    rot_result = "0x3a",
2258    swap_op = "0x1234",
2259    swapped = "0x3412",
2260    reversed = "0x2c48",
2261}
2262
2263nonzero_integer! {
2264    Self = NonZeroI32,
2265    Primitive = signed i32,
2266    UnsignedPrimitive = u32,
2267    rot = 8,
2268    rot_op = "0x10000b3",
2269    rot_result = "0xb301",
2270    swap_op = "0x12345678",
2271    swapped = "0x78563412",
2272    reversed = "0x1e6a2c48",
2273}
2274
2275nonzero_integer! {
2276    Self = NonZeroI64,
2277    Primitive = signed i64,
2278    UnsignedPrimitive = u64,
2279    rot = 12,
2280    rot_op = "0xaa00000000006e1",
2281    rot_result = "0x6e10aa",
2282    swap_op = "0x1234567890123456",
2283    swapped = "0x5634129078563412",
2284    reversed = "0x6a2c48091e6a2c48",
2285}
2286
2287nonzero_integer! {
2288    Self = NonZeroI128,
2289    Primitive = signed i128,
2290    UnsignedPrimitive = u128,
2291    rot = 16,
2292    rot_op = "0x13f40000000000000000000000004f76",
2293    rot_result = "0x4f7613f4",
2294    swap_op = "0x12345678901234567890123456789012",
2295    swapped = "0x12907856341290785634129078563412",
2296    reversed = "0x48091e6a2c48091e6a2c48091e6a2c48",
2297}
2298
2299#[cfg(target_pointer_width = "16")]
2300nonzero_integer! {
2301    Self = NonZeroIsize,
2302    Primitive = signed isize,
2303    UnsignedPrimitive = usize,
2304    rot = 4,
2305    rot_op = "-0x5ffd",
2306    rot_result = "0x3a",
2307    swap_op = "0x1234",
2308    swapped = "0x3412",
2309    reversed = "0x2c48",
2310}
2311
2312#[cfg(target_pointer_width = "32")]
2313nonzero_integer! {
2314    Self = NonZeroIsize,
2315    Primitive = signed isize,
2316    UnsignedPrimitive = usize,
2317    rot = 8,
2318    rot_op = "0x10000b3",
2319    rot_result = "0xb301",
2320    swap_op = "0x12345678",
2321    swapped = "0x78563412",
2322    reversed = "0x1e6a2c48",
2323}
2324
2325#[cfg(target_pointer_width = "64")]
2326nonzero_integer! {
2327    Self = NonZeroIsize,
2328    Primitive = signed isize,
2329    UnsignedPrimitive = usize,
2330    rot = 12,
2331    rot_op = "0xaa00000000006e1",
2332    rot_result = "0x6e10aa",
2333    swap_op = "0x1234567890123456",
2334    swapped = "0x5634129078563412",
2335    reversed = "0x6a2c48091e6a2c48",
2336}