core/num/
nonzero.rs

1//! Definitions of integer that is known not to equal zero.
2
3use super::{IntErrorKind, ParseIntError};
4use crate::cmp::Ordering;
5use crate::hash::{Hash, Hasher};
6use crate::marker::{Freeze, StructuralPartialEq};
7use crate::ops::{BitOr, BitOrAssign, Div, DivAssign, Neg, Rem, RemAssign};
8use crate::panic::{RefUnwindSafe, UnwindSafe};
9use crate::str::FromStr;
10use crate::{fmt, intrinsics, ptr, ub_checks};
11
12/// A marker trait for primitive types which can be zero.
13///
14/// This is an implementation detail for <code>[NonZero]\<T></code> which may disappear or be replaced at any time.
15///
16/// # Safety
17///
18/// Types implementing this trait must be primitives that are valid when zeroed.
19///
20/// The associated `Self::NonZeroInner` type must have the same size+align as `Self`,
21/// but with a niche and bit validity making it so the following `transmutes` are sound:
22///
23/// - `Self::NonZeroInner` to `Option<Self::NonZeroInner>`
24/// - `Option<Self::NonZeroInner>` to `Self`
25///
26/// (And, consequently, `Self::NonZeroInner` to `Self`.)
27#[unstable(
28    feature = "nonzero_internals",
29    reason = "implementation detail which may disappear or be replaced at any time",
30    issue = "none"
31)]
32pub unsafe trait ZeroablePrimitive: Sized + Copy + private::Sealed {
33    #[doc(hidden)]
34    type NonZeroInner: Sized + Copy;
35}
36
37macro_rules! impl_zeroable_primitive {
38    ($($NonZeroInner:ident ( $primitive:ty )),+ $(,)?) => {
39        mod private {
40            #[unstable(
41                feature = "nonzero_internals",
42                reason = "implementation detail which may disappear or be replaced at any time",
43                issue = "none"
44            )]
45            pub trait Sealed {}
46        }
47
48        $(
49            #[unstable(
50                feature = "nonzero_internals",
51                reason = "implementation detail which may disappear or be replaced at any time",
52                issue = "none"
53            )]
54            impl private::Sealed for $primitive {}
55
56            #[unstable(
57                feature = "nonzero_internals",
58                reason = "implementation detail which may disappear or be replaced at any time",
59                issue = "none"
60            )]
61            unsafe impl ZeroablePrimitive for $primitive {
62                type NonZeroInner = super::niche_types::$NonZeroInner;
63            }
64        )+
65    };
66}
67
68impl_zeroable_primitive!(
69    NonZeroU8Inner(u8),
70    NonZeroU16Inner(u16),
71    NonZeroU32Inner(u32),
72    NonZeroU64Inner(u64),
73    NonZeroU128Inner(u128),
74    NonZeroUsizeInner(usize),
75    NonZeroI8Inner(i8),
76    NonZeroI16Inner(i16),
77    NonZeroI32Inner(i32),
78    NonZeroI64Inner(i64),
79    NonZeroI128Inner(i128),
80    NonZeroIsizeInner(isize),
81);
82
83/// A value that is known not to equal zero.
84///
85/// This enables some memory layout optimization.
86/// For example, `Option<NonZero<u32>>` is the same size as `u32`:
87///
88/// ```
89/// use core::{mem::size_of, num::NonZero};
90///
91/// assert_eq!(size_of::<Option<NonZero<u32>>>(), size_of::<u32>());
92/// ```
93///
94/// # Layout
95///
96/// `NonZero<T>` is guaranteed to have the same layout and bit validity as `T`
97/// with the exception that the all-zero bit pattern is invalid.
98/// `Option<NonZero<T>>` is guaranteed to be compatible with `T`, including in
99/// FFI.
100///
101/// Thanks to the [null pointer optimization], `NonZero<T>` and
102/// `Option<NonZero<T>>` are guaranteed to have the same size and alignment:
103///
104/// ```
105/// # use std::mem::{size_of, align_of};
106/// use std::num::NonZero;
107///
108/// assert_eq!(size_of::<NonZero<u32>>(), size_of::<Option<NonZero<u32>>>());
109/// assert_eq!(align_of::<NonZero<u32>>(), align_of::<Option<NonZero<u32>>>());
110/// ```
111///
112/// [null pointer optimization]: crate::option#representation
113#[stable(feature = "generic_nonzero", since = "1.79.0")]
114#[repr(transparent)]
115#[rustc_nonnull_optimization_guaranteed]
116#[rustc_diagnostic_item = "NonZero"]
117pub struct NonZero<T: ZeroablePrimitive>(T::NonZeroInner);
118
119macro_rules! impl_nonzero_fmt {
120    ($(#[$Attribute:meta] $Trait:ident)*) => {
121        $(
122            #[$Attribute]
123            impl<T> fmt::$Trait for NonZero<T>
124            where
125                T: ZeroablePrimitive + fmt::$Trait,
126            {
127                #[inline]
128                fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
129                    self.get().fmt(f)
130                }
131            }
132        )*
133    };
134}
135
136impl_nonzero_fmt! {
137    #[stable(feature = "nonzero", since = "1.28.0")]
138    Debug
139    #[stable(feature = "nonzero", since = "1.28.0")]
140    Display
141    #[stable(feature = "nonzero", since = "1.28.0")]
142    Binary
143    #[stable(feature = "nonzero", since = "1.28.0")]
144    Octal
145    #[stable(feature = "nonzero", since = "1.28.0")]
146    LowerHex
147    #[stable(feature = "nonzero", since = "1.28.0")]
148    UpperHex
149    #[stable(feature = "nonzero_fmt_exp", since = "1.84.0")]
150    LowerExp
151    #[stable(feature = "nonzero_fmt_exp", since = "1.84.0")]
152    UpperExp
153}
154
155macro_rules! impl_nonzero_auto_trait {
156    (unsafe $Trait:ident) => {
157        #[stable(feature = "nonzero", since = "1.28.0")]
158        unsafe impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
159    };
160    ($Trait:ident) => {
161        #[stable(feature = "nonzero", since = "1.28.0")]
162        impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
163    };
164}
165
166// Implement auto-traits manually based on `T` to avoid docs exposing
167// the `ZeroablePrimitive::NonZeroInner` implementation detail.
168impl_nonzero_auto_trait!(unsafe Freeze);
169impl_nonzero_auto_trait!(RefUnwindSafe);
170impl_nonzero_auto_trait!(unsafe Send);
171impl_nonzero_auto_trait!(unsafe Sync);
172impl_nonzero_auto_trait!(Unpin);
173impl_nonzero_auto_trait!(UnwindSafe);
174
175#[stable(feature = "nonzero", since = "1.28.0")]
176impl<T> Clone for NonZero<T>
177where
178    T: ZeroablePrimitive,
179{
180    #[inline]
181    fn clone(&self) -> Self {
182        *self
183    }
184}
185
186#[stable(feature = "nonzero", since = "1.28.0")]
187impl<T> Copy for NonZero<T> where T: ZeroablePrimitive {}
188
189#[stable(feature = "nonzero", since = "1.28.0")]
190impl<T> PartialEq for NonZero<T>
191where
192    T: ZeroablePrimitive + PartialEq,
193{
194    #[inline]
195    fn eq(&self, other: &Self) -> bool {
196        self.get() == other.get()
197    }
198
199    #[inline]
200    fn ne(&self, other: &Self) -> bool {
201        self.get() != other.get()
202    }
203}
204
205#[unstable(feature = "structural_match", issue = "31434")]
206impl<T> StructuralPartialEq for NonZero<T> where T: ZeroablePrimitive + StructuralPartialEq {}
207
208#[stable(feature = "nonzero", since = "1.28.0")]
209impl<T> Eq for NonZero<T> where T: ZeroablePrimitive + Eq {}
210
211#[stable(feature = "nonzero", since = "1.28.0")]
212impl<T> PartialOrd for NonZero<T>
213where
214    T: ZeroablePrimitive + PartialOrd,
215{
216    #[inline]
217    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
218        self.get().partial_cmp(&other.get())
219    }
220
221    #[inline]
222    fn lt(&self, other: &Self) -> bool {
223        self.get() < other.get()
224    }
225
226    #[inline]
227    fn le(&self, other: &Self) -> bool {
228        self.get() <= other.get()
229    }
230
231    #[inline]
232    fn gt(&self, other: &Self) -> bool {
233        self.get() > other.get()
234    }
235
236    #[inline]
237    fn ge(&self, other: &Self) -> bool {
238        self.get() >= other.get()
239    }
240}
241
242#[stable(feature = "nonzero", since = "1.28.0")]
243impl<T> Ord for NonZero<T>
244where
245    T: ZeroablePrimitive + Ord,
246{
247    #[inline]
248    fn cmp(&self, other: &Self) -> Ordering {
249        self.get().cmp(&other.get())
250    }
251
252    #[inline]
253    fn max(self, other: Self) -> Self {
254        // SAFETY: The maximum of two non-zero values is still non-zero.
255        unsafe { Self::new_unchecked(self.get().max(other.get())) }
256    }
257
258    #[inline]
259    fn min(self, other: Self) -> Self {
260        // SAFETY: The minimum of two non-zero values is still non-zero.
261        unsafe { Self::new_unchecked(self.get().min(other.get())) }
262    }
263
264    #[inline]
265    fn clamp(self, min: Self, max: Self) -> Self {
266        // SAFETY: A non-zero value clamped between two non-zero values is still non-zero.
267        unsafe { Self::new_unchecked(self.get().clamp(min.get(), max.get())) }
268    }
269}
270
271#[stable(feature = "nonzero", since = "1.28.0")]
272impl<T> Hash for NonZero<T>
273where
274    T: ZeroablePrimitive + Hash,
275{
276    #[inline]
277    fn hash<H>(&self, state: &mut H)
278    where
279        H: Hasher,
280    {
281        self.get().hash(state)
282    }
283}
284
285#[stable(feature = "from_nonzero", since = "1.31.0")]
286impl<T> From<NonZero<T>> for T
287where
288    T: ZeroablePrimitive,
289{
290    #[inline]
291    fn from(nonzero: NonZero<T>) -> Self {
292        // Call `get` method to keep range information.
293        nonzero.get()
294    }
295}
296
297#[stable(feature = "nonzero_bitor", since = "1.45.0")]
298impl<T> BitOr for NonZero<T>
299where
300    T: ZeroablePrimitive + BitOr<Output = T>,
301{
302    type Output = Self;
303
304    #[inline]
305    fn bitor(self, rhs: Self) -> Self::Output {
306        // SAFETY: Bitwise OR of two non-zero values is still non-zero.
307        unsafe { Self::new_unchecked(self.get() | rhs.get()) }
308    }
309}
310
311#[stable(feature = "nonzero_bitor", since = "1.45.0")]
312impl<T> BitOr<T> for NonZero<T>
313where
314    T: ZeroablePrimitive + BitOr<Output = T>,
315{
316    type Output = Self;
317
318    #[inline]
319    fn bitor(self, rhs: T) -> Self::Output {
320        // SAFETY: Bitwise OR of a non-zero value with anything is still non-zero.
321        unsafe { Self::new_unchecked(self.get() | rhs) }
322    }
323}
324
325#[stable(feature = "nonzero_bitor", since = "1.45.0")]
326impl<T> BitOr<NonZero<T>> for T
327where
328    T: ZeroablePrimitive + BitOr<Output = T>,
329{
330    type Output = NonZero<T>;
331
332    #[inline]
333    fn bitor(self, rhs: NonZero<T>) -> Self::Output {
334        // SAFETY: Bitwise OR of anything with a non-zero value is still non-zero.
335        unsafe { NonZero::new_unchecked(self | rhs.get()) }
336    }
337}
338
339#[stable(feature = "nonzero_bitor", since = "1.45.0")]
340impl<T> BitOrAssign for NonZero<T>
341where
342    T: ZeroablePrimitive,
343    Self: BitOr<Output = Self>,
344{
345    #[inline]
346    fn bitor_assign(&mut self, rhs: Self) {
347        *self = *self | rhs;
348    }
349}
350
351#[stable(feature = "nonzero_bitor", since = "1.45.0")]
352impl<T> BitOrAssign<T> for NonZero<T>
353where
354    T: ZeroablePrimitive,
355    Self: BitOr<T, Output = Self>,
356{
357    #[inline]
358    fn bitor_assign(&mut self, rhs: T) {
359        *self = *self | rhs;
360    }
361}
362
363impl<T> NonZero<T>
364where
365    T: ZeroablePrimitive,
366{
367    /// Creates a non-zero if the given value is not zero.
368    #[stable(feature = "nonzero", since = "1.28.0")]
369    #[rustc_const_stable(feature = "const_nonzero_int_methods", since = "1.47.0")]
370    #[must_use]
371    #[inline]
372    pub const fn new(n: T) -> Option<Self> {
373        // SAFETY: Memory layout optimization guarantees that `Option<NonZero<T>>` has
374        //         the same layout and size as `T`, with `0` representing `None`.
375        unsafe { intrinsics::transmute_unchecked(n) }
376    }
377
378    /// Creates a non-zero without checking whether the value is non-zero.
379    /// This results in undefined behavior if the value is zero.
380    ///
381    /// # Safety
382    ///
383    /// The value must not be zero.
384    #[stable(feature = "nonzero", since = "1.28.0")]
385    #[rustc_const_stable(feature = "nonzero", since = "1.28.0")]
386    #[must_use]
387    #[inline]
388    pub const unsafe fn new_unchecked(n: T) -> Self {
389        match Self::new(n) {
390            Some(n) => n,
391            None => {
392                // SAFETY: The caller guarantees that `n` is non-zero, so this is unreachable.
393                unsafe {
394                    ub_checks::assert_unsafe_precondition!(
395                        check_language_ub,
396                        "NonZero::new_unchecked requires the argument to be non-zero",
397                        () => false,
398                    );
399                    intrinsics::unreachable()
400                }
401            }
402        }
403    }
404
405    /// Converts a reference to a non-zero mutable reference
406    /// if the referenced value is not zero.
407    #[unstable(feature = "nonzero_from_mut", issue = "106290")]
408    #[must_use]
409    #[inline]
410    pub fn from_mut(n: &mut T) -> Option<&mut Self> {
411        // SAFETY: Memory layout optimization guarantees that `Option<NonZero<T>>` has
412        //         the same layout and size as `T`, with `0` representing `None`.
413        let opt_n = unsafe { &mut *(ptr::from_mut(n).cast::<Option<Self>>()) };
414
415        opt_n.as_mut()
416    }
417
418    /// Converts a mutable reference to a non-zero mutable reference
419    /// without checking whether the referenced value is non-zero.
420    /// This results in undefined behavior if the referenced value is zero.
421    ///
422    /// # Safety
423    ///
424    /// The referenced value must not be zero.
425    #[unstable(feature = "nonzero_from_mut", issue = "106290")]
426    #[must_use]
427    #[inline]
428    pub unsafe fn from_mut_unchecked(n: &mut T) -> &mut Self {
429        match Self::from_mut(n) {
430            Some(n) => n,
431            None => {
432                // SAFETY: The caller guarantees that `n` references a value that is non-zero, so this is unreachable.
433                unsafe {
434                    ub_checks::assert_unsafe_precondition!(
435                        check_library_ub,
436                        "NonZero::from_mut_unchecked requires the argument to dereference as non-zero",
437                        () => false,
438                    );
439                    intrinsics::unreachable()
440                }
441            }
442        }
443    }
444
445    /// Returns the contained value as a primitive type.
446    #[stable(feature = "nonzero", since = "1.28.0")]
447    #[rustc_const_stable(feature = "const_nonzero_get", since = "1.34.0")]
448    #[inline]
449    pub const fn get(self) -> T {
450        // Rustc can set range metadata only if it loads `self` from
451        // memory somewhere. If the value of `self` was from by-value argument
452        // of some not-inlined function, LLVM don't have range metadata
453        // to understand that the value cannot be zero.
454        //
455        // Using the transmute `assume`s the range at runtime.
456        //
457        // Even once LLVM supports `!range` metadata for function arguments
458        // (see <https://github.com/llvm/llvm-project/issues/76628>), this can't
459        // be `.0` because MCP#807 bans field-projecting into `scalar_valid_range`
460        // types, and it arguably wouldn't want to be anyway because if this is
461        // MIR-inlined, there's no opportunity to put that argument metadata anywhere.
462        //
463        // The good answer here will eventually be pattern types, which will hopefully
464        // allow it to go back to `.0`, maybe with a cast of some sort.
465        //
466        // SAFETY: `ZeroablePrimitive` guarantees that the size and bit validity
467        // of `.0` is such that this transmute is sound.
468        unsafe { intrinsics::transmute_unchecked(self) }
469    }
470}
471
472macro_rules! nonzero_integer {
473    (
474        #[$stability:meta]
475        Self = $Ty:ident,
476        Primitive = $signedness:ident $Int:ident,
477        SignedPrimitive = $Sint:ty,
478        UnsignedPrimitive = $Uint:ty,
479
480        // Used in doc comments.
481        rot = $rot:literal,
482        rot_op = $rot_op:literal,
483        rot_result = $rot_result:literal,
484        swap_op = $swap_op:literal,
485        swapped = $swapped:literal,
486        reversed = $reversed:literal,
487        leading_zeros_test = $leading_zeros_test:expr,
488    ) => {
489        #[doc = sign_dependent_expr!{
490            $signedness ?
491            if signed {
492                concat!("An [`", stringify!($Int), "`] that is known not to equal zero.")
493            }
494            if unsigned {
495                concat!("A [`", stringify!($Int), "`] that is known not to equal zero.")
496            }
497        }]
498        ///
499        /// This enables some memory layout optimization.
500        #[doc = concat!("For example, `Option<", stringify!($Ty), ">` is the same size as `", stringify!($Int), "`:")]
501        ///
502        /// ```rust
503        /// use std::mem::size_of;
504        #[doc = concat!("assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", stringify!($Int), ">());")]
505        /// ```
506        ///
507        /// # Layout
508        ///
509        #[doc = concat!("`", stringify!($Ty), "` is guaranteed to have the same layout and bit validity as `", stringify!($Int), "`")]
510        /// with the exception that `0` is not a valid instance.
511        #[doc = concat!("`Option<", stringify!($Ty), ">` is guaranteed to be compatible with `", stringify!($Int), "`,")]
512        /// including in FFI.
513        ///
514        /// Thanks to the [null pointer optimization],
515        #[doc = concat!("`", stringify!($Ty), "` and `Option<", stringify!($Ty), ">`")]
516        /// are guaranteed to have the same size and alignment:
517        ///
518        /// ```
519        /// # use std::mem::{size_of, align_of};
520        #[doc = concat!("use std::num::", stringify!($Ty), ";")]
521        ///
522        #[doc = concat!("assert_eq!(size_of::<", stringify!($Ty), ">(), size_of::<Option<", stringify!($Ty), ">>());")]
523        #[doc = concat!("assert_eq!(align_of::<", stringify!($Ty), ">(), align_of::<Option<", stringify!($Ty), ">>());")]
524        /// ```
525        ///
526        /// [null pointer optimization]: crate::option#representation
527        #[$stability]
528        pub type $Ty = NonZero<$Int>;
529
530        impl NonZero<$Int> {
531            /// The size of this non-zero integer type in bits.
532            ///
533            #[doc = concat!("This value is equal to [`", stringify!($Int), "::BITS`].")]
534            ///
535            /// # Examples
536            ///
537            /// ```
538            /// # use std::num::NonZero;
539            /// #
540            #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::BITS, ", stringify!($Int), "::BITS);")]
541            /// ```
542            #[stable(feature = "nonzero_bits", since = "1.67.0")]
543            pub const BITS: u32 = <$Int>::BITS;
544
545            /// Returns the number of leading zeros in the binary representation of `self`.
546            ///
547            /// On many architectures, this function can perform better than `leading_zeros()` on the underlying integer type, as special handling of zero can be avoided.
548            ///
549            /// # Examples
550            ///
551            /// Basic usage:
552            ///
553            /// ```
554            /// # use std::num::NonZero;
555            /// #
556            /// # fn main() { test().unwrap(); }
557            /// # fn test() -> Option<()> {
558            #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::new(", $leading_zeros_test, ")?;")]
559            ///
560            /// assert_eq!(n.leading_zeros(), 0);
561            /// # Some(())
562            /// # }
563            /// ```
564            #[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
565            #[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
566            #[must_use = "this returns the result of the operation, \
567                          without modifying the original"]
568            #[inline]
569            pub const fn leading_zeros(self) -> u32 {
570                // SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`.
571                unsafe {
572                    intrinsics::ctlz_nonzero(self.get() as $Uint)
573                }
574            }
575
576            /// Returns the number of trailing zeros in the binary representation
577            /// of `self`.
578            ///
579            /// On many architectures, this function can perform better than `trailing_zeros()` on the underlying integer type, as special handling of zero can be avoided.
580            ///
581            /// # Examples
582            ///
583            /// Basic usage:
584            ///
585            /// ```
586            /// # use std::num::NonZero;
587            /// #
588            /// # fn main() { test().unwrap(); }
589            /// # fn test() -> Option<()> {
590            #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::new(0b0101000)?;")]
591            ///
592            /// assert_eq!(n.trailing_zeros(), 3);
593            /// # Some(())
594            /// # }
595            /// ```
596            #[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
597            #[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
598            #[must_use = "this returns the result of the operation, \
599                          without modifying the original"]
600            #[inline]
601            pub const fn trailing_zeros(self) -> u32 {
602                // SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`.
603                unsafe {
604                    intrinsics::cttz_nonzero(self.get() as $Uint)
605                }
606            }
607
608            /// Returns the number of ones in the binary representation of `self`.
609            ///
610            /// # Examples
611            ///
612            /// Basic usage:
613            ///
614            /// ```
615            /// # use std::num::NonZero;
616            /// #
617            /// # fn main() { test().unwrap(); }
618            /// # fn test() -> Option<()> {
619            #[doc = concat!("let a = NonZero::<", stringify!($Int), ">::new(0b100_0000)?;")]
620            #[doc = concat!("let b = NonZero::<", stringify!($Int), ">::new(0b100_0011)?;")]
621            ///
622            /// assert_eq!(a.count_ones(), NonZero::new(1)?);
623            /// assert_eq!(b.count_ones(), NonZero::new(3)?);
624            /// # Some(())
625            /// # }
626            /// ```
627            ///
628            #[stable(feature = "non_zero_count_ones", since = "1.86.0")]
629            #[rustc_const_stable(feature = "non_zero_count_ones", since = "1.86.0")]
630            #[doc(alias = "popcount")]
631            #[doc(alias = "popcnt")]
632            #[must_use = "this returns the result of the operation, \
633                        without modifying the original"]
634            #[inline(always)]
635            pub const fn count_ones(self) -> NonZero<u32> {
636                // SAFETY:
637                // `self` is non-zero, which means it has at least one bit set, which means
638                // that the result of `count_ones` is non-zero.
639                unsafe { NonZero::new_unchecked(self.get().count_ones()) }
640            }
641
642            /// Shifts the bits to the left by a specified amount, `n`,
643            /// wrapping the truncated bits to the end of the resulting integer.
644            ///
645            /// Please note this isn't the same operation as the `<<` shifting operator!
646            ///
647            /// # Examples
648            ///
649            /// Basic usage:
650            ///
651            /// ```
652            /// #![feature(nonzero_bitwise)]
653            /// # use std::num::NonZero;
654            /// #
655            /// # fn main() { test().unwrap(); }
656            /// # fn test() -> Option<()> {
657            #[doc = concat!("let n = NonZero::new(", $rot_op, stringify!($Int), ")?;")]
658            #[doc = concat!("let m = NonZero::new(", $rot_result, ")?;")]
659            ///
660            #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
661            /// # Some(())
662            /// # }
663            /// ```
664            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
665            #[must_use = "this returns the result of the operation, \
666                        without modifying the original"]
667            #[inline(always)]
668            pub const fn rotate_left(self, n: u32) -> Self {
669                let result = self.get().rotate_left(n);
670                // SAFETY: Rotating bits preserves the property int > 0.
671                unsafe { Self::new_unchecked(result) }
672            }
673
674            /// Shifts the bits to the right by a specified amount, `n`,
675            /// wrapping the truncated bits to the beginning of the resulting
676            /// integer.
677            ///
678            /// Please note this isn't the same operation as the `>>` shifting operator!
679            ///
680            /// # Examples
681            ///
682            /// Basic usage:
683            ///
684            /// ```
685            /// #![feature(nonzero_bitwise)]
686            /// # use std::num::NonZero;
687            /// #
688            /// # fn main() { test().unwrap(); }
689            /// # fn test() -> Option<()> {
690            #[doc = concat!("let n = NonZero::new(", $rot_result, stringify!($Int), ")?;")]
691            #[doc = concat!("let m = NonZero::new(", $rot_op, ")?;")]
692            ///
693            #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
694            /// # Some(())
695            /// # }
696            /// ```
697            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
698            #[must_use = "this returns the result of the operation, \
699                        without modifying the original"]
700            #[inline(always)]
701            pub const fn rotate_right(self, n: u32) -> Self {
702                let result = self.get().rotate_right(n);
703                // SAFETY: Rotating bits preserves the property int > 0.
704                unsafe { Self::new_unchecked(result) }
705            }
706
707            /// Reverses the byte order of the integer.
708            ///
709            /// # Examples
710            ///
711            /// Basic usage:
712            ///
713            /// ```
714            /// #![feature(nonzero_bitwise)]
715            /// # use std::num::NonZero;
716            /// #
717            /// # fn main() { test().unwrap(); }
718            /// # fn test() -> Option<()> {
719            #[doc = concat!("let n = NonZero::new(", $swap_op, stringify!($Int), ")?;")]
720            /// let m = n.swap_bytes();
721            ///
722            #[doc = concat!("assert_eq!(m, NonZero::new(", $swapped, ")?);")]
723            /// # Some(())
724            /// # }
725            /// ```
726            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
727            #[must_use = "this returns the result of the operation, \
728                        without modifying the original"]
729            #[inline(always)]
730            pub const fn swap_bytes(self) -> Self {
731                let result = self.get().swap_bytes();
732                // SAFETY: Shuffling bytes preserves the property int > 0.
733                unsafe { Self::new_unchecked(result) }
734            }
735
736            /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
737            /// second least-significant bit becomes second most-significant bit, etc.
738            ///
739            /// # Examples
740            ///
741            /// Basic usage:
742            ///
743            /// ```
744            /// #![feature(nonzero_bitwise)]
745            /// # use std::num::NonZero;
746            /// #
747            /// # fn main() { test().unwrap(); }
748            /// # fn test() -> Option<()> {
749            #[doc = concat!("let n = NonZero::new(", $swap_op, stringify!($Int), ")?;")]
750            /// let m = n.reverse_bits();
751            ///
752            #[doc = concat!("assert_eq!(m, NonZero::new(", $reversed, ")?);")]
753            /// # Some(())
754            /// # }
755            /// ```
756            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
757            #[must_use = "this returns the result of the operation, \
758                        without modifying the original"]
759            #[inline(always)]
760            pub const fn reverse_bits(self) -> Self {
761                let result = self.get().reverse_bits();
762                // SAFETY: Reversing bits preserves the property int > 0.
763                unsafe { Self::new_unchecked(result) }
764            }
765
766            /// Converts an integer from big endian to the target's endianness.
767            ///
768            /// On big endian this is a no-op. On little endian the bytes are
769            /// swapped.
770            ///
771            /// # Examples
772            ///
773            /// Basic usage:
774            ///
775            /// ```
776            /// #![feature(nonzero_bitwise)]
777            /// # use std::num::NonZero;
778            #[doc = concat!("use std::num::", stringify!($Ty), ";")]
779            /// #
780            /// # fn main() { test().unwrap(); }
781            /// # fn test() -> Option<()> {
782            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
783            ///
784            /// if cfg!(target_endian = "big") {
785            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_be(n), n)")]
786            /// } else {
787            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_be(n), n.swap_bytes())")]
788            /// }
789            /// # Some(())
790            /// # }
791            /// ```
792            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
793            #[must_use]
794            #[inline(always)]
795            pub const fn from_be(x: Self) -> Self {
796                let result = $Int::from_be(x.get());
797                // SAFETY: Shuffling bytes preserves the property int > 0.
798                unsafe { Self::new_unchecked(result) }
799            }
800
801            /// Converts an integer from little endian to the target's endianness.
802            ///
803            /// On little endian this is a no-op. On big endian the bytes are
804            /// swapped.
805            ///
806            /// # Examples
807            ///
808            /// Basic usage:
809            ///
810            /// ```
811            /// #![feature(nonzero_bitwise)]
812            /// # use std::num::NonZero;
813            #[doc = concat!("use std::num::", stringify!($Ty), ";")]
814            /// #
815            /// # fn main() { test().unwrap(); }
816            /// # fn test() -> Option<()> {
817            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
818            ///
819            /// if cfg!(target_endian = "little") {
820            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_le(n), n)")]
821            /// } else {
822            #[doc = concat!("    assert_eq!(", stringify!($Ty), "::from_le(n), n.swap_bytes())")]
823            /// }
824            /// # Some(())
825            /// # }
826            /// ```
827            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
828            #[must_use]
829            #[inline(always)]
830            pub const fn from_le(x: Self) -> Self {
831                let result = $Int::from_le(x.get());
832                // SAFETY: Shuffling bytes preserves the property int > 0.
833                unsafe { Self::new_unchecked(result) }
834            }
835
836            /// Converts `self` to big endian from the target's endianness.
837            ///
838            /// On big endian this is a no-op. On little endian the bytes are
839            /// swapped.
840            ///
841            /// # Examples
842            ///
843            /// Basic usage:
844            ///
845            /// ```
846            /// #![feature(nonzero_bitwise)]
847            /// # use std::num::NonZero;
848            /// #
849            /// # fn main() { test().unwrap(); }
850            /// # fn test() -> Option<()> {
851            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
852            ///
853            /// if cfg!(target_endian = "big") {
854            ///     assert_eq!(n.to_be(), n)
855            /// } else {
856            ///     assert_eq!(n.to_be(), n.swap_bytes())
857            /// }
858            /// # Some(())
859            /// # }
860            /// ```
861            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
862            #[must_use = "this returns the result of the operation, \
863                        without modifying the original"]
864            #[inline(always)]
865            pub const fn to_be(self) -> Self {
866                let result = self.get().to_be();
867                // SAFETY: Shuffling bytes preserves the property int > 0.
868                unsafe { Self::new_unchecked(result) }
869            }
870
871            /// Converts `self` to little endian from the target's endianness.
872            ///
873            /// On little endian this is a no-op. On big endian the bytes are
874            /// swapped.
875            ///
876            /// # Examples
877            ///
878            /// Basic usage:
879            ///
880            /// ```
881            /// #![feature(nonzero_bitwise)]
882            /// # use std::num::NonZero;
883            /// #
884            /// # fn main() { test().unwrap(); }
885            /// # fn test() -> Option<()> {
886            #[doc = concat!("let n = NonZero::new(0x1A", stringify!($Int), ")?;")]
887            ///
888            /// if cfg!(target_endian = "little") {
889            ///     assert_eq!(n.to_le(), n)
890            /// } else {
891            ///     assert_eq!(n.to_le(), n.swap_bytes())
892            /// }
893            /// # Some(())
894            /// # }
895            /// ```
896            #[unstable(feature = "nonzero_bitwise", issue = "128281")]
897            #[must_use = "this returns the result of the operation, \
898                        without modifying the original"]
899            #[inline(always)]
900            pub const fn to_le(self) -> Self {
901                let result = self.get().to_le();
902                // SAFETY: Shuffling bytes preserves the property int > 0.
903                unsafe { Self::new_unchecked(result) }
904            }
905
906            nonzero_integer_signedness_dependent_methods! {
907                Primitive = $signedness $Int,
908                SignedPrimitive = $Sint,
909                UnsignedPrimitive = $Uint,
910            }
911
912            /// Multiplies two non-zero integers together.
913            /// Checks for overflow and returns [`None`] on overflow.
914            /// As a consequence, the result cannot wrap to zero.
915            ///
916            /// # Examples
917            ///
918            /// ```
919            /// # use std::num::NonZero;
920            /// #
921            /// # fn main() { test().unwrap(); }
922            /// # fn test() -> Option<()> {
923            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
924            #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
925            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
926            ///
927            /// assert_eq!(Some(four), two.checked_mul(two));
928            /// assert_eq!(None, max.checked_mul(two));
929            /// # Some(())
930            /// # }
931            /// ```
932            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
933            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
934            #[must_use = "this returns the result of the operation, \
935                          without modifying the original"]
936            #[inline]
937            pub const fn checked_mul(self, other: Self) -> Option<Self> {
938                if let Some(result) = self.get().checked_mul(other.get()) {
939                    // SAFETY:
940                    // - `checked_mul` returns `None` on overflow
941                    // - `self` and `other` are non-zero
942                    // - the only way to get zero from a multiplication without overflow is for one
943                    //   of the sides to be zero
944                    //
945                    // So the result cannot be zero.
946                    Some(unsafe { Self::new_unchecked(result) })
947                } else {
948                    None
949                }
950            }
951
952            /// Multiplies two non-zero integers together.
953            #[doc = concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")]
954            ///
955            /// # Examples
956            ///
957            /// ```
958            /// # use std::num::NonZero;
959            /// #
960            /// # fn main() { test().unwrap(); }
961            /// # fn test() -> Option<()> {
962            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
963            #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
964            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
965            ///
966            /// assert_eq!(four, two.saturating_mul(two));
967            /// assert_eq!(max, four.saturating_mul(max));
968            /// # Some(())
969            /// # }
970            /// ```
971            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
972            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
973            #[must_use = "this returns the result of the operation, \
974                          without modifying the original"]
975            #[inline]
976            pub const fn saturating_mul(self, other: Self) -> Self {
977                // SAFETY:
978                // - `saturating_mul` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
979                //   all of which are non-zero
980                // - `self` and `other` are non-zero
981                // - the only way to get zero from a multiplication without overflow is for one
982                //   of the sides to be zero
983                //
984                // So the result cannot be zero.
985                unsafe { Self::new_unchecked(self.get().saturating_mul(other.get())) }
986            }
987
988            /// Multiplies two non-zero integers together,
989            /// assuming overflow cannot occur.
990            /// Overflow is unchecked, and it is undefined behavior to overflow
991            /// *even if the result would wrap to a non-zero value*.
992            /// The behavior is undefined as soon as
993            #[doc = sign_dependent_expr!{
994                $signedness ?
995                if signed {
996                    concat!("`self * rhs > ", stringify!($Int), "::MAX`, ",
997                            "or `self * rhs < ", stringify!($Int), "::MIN`.")
998                }
999                if unsigned {
1000                    concat!("`self * rhs > ", stringify!($Int), "::MAX`.")
1001                }
1002            }]
1003            ///
1004            /// # Examples
1005            ///
1006            /// ```
1007            /// #![feature(nonzero_ops)]
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            ///
1016            /// assert_eq!(four, unsafe { two.unchecked_mul(two) });
1017            /// # Some(())
1018            /// # }
1019            /// ```
1020            #[unstable(feature = "nonzero_ops", issue = "84186")]
1021            #[must_use = "this returns the result of the operation, \
1022                          without modifying the original"]
1023            #[inline]
1024            pub const unsafe fn unchecked_mul(self, other: Self) -> Self {
1025                // SAFETY: The caller ensures there is no overflow.
1026                unsafe { Self::new_unchecked(self.get().unchecked_mul(other.get())) }
1027            }
1028
1029            /// Raises non-zero value to an integer power.
1030            /// Checks for overflow and returns [`None`] on overflow.
1031            /// As a consequence, the result cannot wrap to zero.
1032            ///
1033            /// # Examples
1034            ///
1035            /// ```
1036            /// # use std::num::NonZero;
1037            /// #
1038            /// # fn main() { test().unwrap(); }
1039            /// # fn test() -> Option<()> {
1040            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1041            #[doc = concat!("let twenty_seven = NonZero::new(27", stringify!($Int), ")?;")]
1042            #[doc = concat!("let half_max = NonZero::new(", stringify!($Int), "::MAX / 2)?;")]
1043            ///
1044            /// assert_eq!(Some(twenty_seven), three.checked_pow(3));
1045            /// assert_eq!(None, half_max.checked_pow(3));
1046            /// # Some(())
1047            /// # }
1048            /// ```
1049            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1050            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1051            #[must_use = "this returns the result of the operation, \
1052                          without modifying the original"]
1053            #[inline]
1054            pub const fn checked_pow(self, other: u32) -> Option<Self> {
1055                if let Some(result) = self.get().checked_pow(other) {
1056                    // SAFETY:
1057                    // - `checked_pow` returns `None` on overflow/underflow
1058                    // - `self` is non-zero
1059                    // - the only way to get zero from an exponentiation without overflow is
1060                    //   for base to be zero
1061                    //
1062                    // So the result cannot be zero.
1063                    Some(unsafe { Self::new_unchecked(result) })
1064                } else {
1065                    None
1066                }
1067            }
1068
1069            /// Raise non-zero value to an integer power.
1070            #[doc = sign_dependent_expr!{
1071                $signedness ?
1072                if signed {
1073                    concat!("Return [`NonZero::<", stringify!($Int), ">::MIN`] ",
1074                                "or [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")
1075                }
1076                if unsigned {
1077                    concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")
1078                }
1079            }]
1080            ///
1081            /// # Examples
1082            ///
1083            /// ```
1084            /// # use std::num::NonZero;
1085            /// #
1086            /// # fn main() { test().unwrap(); }
1087            /// # fn test() -> Option<()> {
1088            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1089            #[doc = concat!("let twenty_seven = NonZero::new(27", stringify!($Int), ")?;")]
1090            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1091            ///
1092            /// assert_eq!(twenty_seven, three.saturating_pow(3));
1093            /// assert_eq!(max, max.saturating_pow(3));
1094            /// # Some(())
1095            /// # }
1096            /// ```
1097            #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1098            #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1099            #[must_use = "this returns the result of the operation, \
1100                          without modifying the original"]
1101            #[inline]
1102            pub const fn saturating_pow(self, other: u32) -> Self {
1103                // SAFETY:
1104                // - `saturating_pow` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
1105                //   all of which are non-zero
1106                // - `self` is non-zero
1107                // - the only way to get zero from an exponentiation without overflow is
1108                //   for base to be zero
1109                //
1110                // So the result cannot be zero.
1111                unsafe { Self::new_unchecked(self.get().saturating_pow(other)) }
1112            }
1113        }
1114
1115        #[stable(feature = "nonzero_parse", since = "1.35.0")]
1116        impl FromStr for NonZero<$Int> {
1117            type Err = ParseIntError;
1118            fn from_str(src: &str) -> Result<Self, Self::Err> {
1119                Self::new(<$Int>::from_str_radix(src, 10)?)
1120                    .ok_or(ParseIntError {
1121                        kind: IntErrorKind::Zero
1122                    })
1123            }
1124        }
1125
1126        nonzero_integer_signedness_dependent_impls!($signedness $Int);
1127    };
1128
1129    (
1130        Self = $Ty:ident,
1131        Primitive = unsigned $Int:ident,
1132        SignedPrimitive = $Sint:ident,
1133        rot = $rot:literal,
1134        rot_op = $rot_op:literal,
1135        rot_result = $rot_result:literal,
1136        swap_op = $swap_op:literal,
1137        swapped = $swapped:literal,
1138        reversed = $reversed:literal,
1139        $(,)?
1140    ) => {
1141        nonzero_integer! {
1142            #[stable(feature = "nonzero", since = "1.28.0")]
1143            Self = $Ty,
1144            Primitive = unsigned $Int,
1145            SignedPrimitive = $Sint,
1146            UnsignedPrimitive = $Int,
1147            rot = $rot,
1148            rot_op = $rot_op,
1149            rot_result = $rot_result,
1150            swap_op = $swap_op,
1151            swapped = $swapped,
1152            reversed = $reversed,
1153            leading_zeros_test = concat!(stringify!($Int), "::MAX"),
1154        }
1155    };
1156
1157    (
1158        Self = $Ty:ident,
1159        Primitive = signed $Int:ident,
1160        UnsignedPrimitive = $Uint:ident,
1161        rot = $rot:literal,
1162        rot_op = $rot_op:literal,
1163        rot_result = $rot_result:literal,
1164        swap_op = $swap_op:literal,
1165        swapped = $swapped:literal,
1166        reversed = $reversed:literal,
1167    ) => {
1168        nonzero_integer! {
1169            #[stable(feature = "signed_nonzero", since = "1.34.0")]
1170            Self = $Ty,
1171            Primitive = signed $Int,
1172            SignedPrimitive = $Int,
1173            UnsignedPrimitive = $Uint,
1174            rot = $rot,
1175            rot_op = $rot_op,
1176            rot_result = $rot_result,
1177            swap_op = $swap_op,
1178            swapped = $swapped,
1179            reversed = $reversed,
1180            leading_zeros_test = concat!("-1", stringify!($Int)),
1181        }
1182    };
1183}
1184
1185macro_rules! nonzero_integer_signedness_dependent_impls {
1186    // Impls for unsigned nonzero types only.
1187    (unsigned $Int:ty) => {
1188        #[stable(feature = "nonzero_div", since = "1.51.0")]
1189        impl Div<NonZero<$Int>> for $Int {
1190            type Output = $Int;
1191
1192            /// Same as `self / other.get()`, but because `other` is a `NonZero<_>`,
1193            /// there's never a runtime check for division-by-zero.
1194            ///
1195            /// This operation rounds towards zero, truncating any fractional
1196            /// part of the exact result, and cannot panic.
1197            #[doc(alias = "unchecked_div")]
1198            #[inline]
1199            fn div(self, other: NonZero<$Int>) -> $Int {
1200                // SAFETY: Division by zero is checked because `other` is non-zero,
1201                // and MIN/-1 is checked because `self` is an unsigned int.
1202                unsafe { intrinsics::unchecked_div(self, other.get()) }
1203            }
1204        }
1205
1206        #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
1207        impl DivAssign<NonZero<$Int>> for $Int {
1208            /// Same as `self /= other.get()`, but because `other` is a `NonZero<_>`,
1209            /// there's never a runtime check for division-by-zero.
1210            ///
1211            /// This operation rounds towards zero, truncating any fractional
1212            /// part of the exact result, and cannot panic.
1213            #[inline]
1214            fn div_assign(&mut self, other: NonZero<$Int>) {
1215                *self = *self / other;
1216            }
1217        }
1218
1219        #[stable(feature = "nonzero_div", since = "1.51.0")]
1220        impl Rem<NonZero<$Int>> for $Int {
1221            type Output = $Int;
1222
1223            /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
1224            #[inline]
1225            fn rem(self, other: NonZero<$Int>) -> $Int {
1226                // SAFETY: Remainder by zero is checked because `other` is non-zero,
1227                // and MIN/-1 is checked because `self` is an unsigned int.
1228                unsafe { intrinsics::unchecked_rem(self, other.get()) }
1229            }
1230        }
1231
1232        #[stable(feature = "nonzero_div_assign", since = "1.79.0")]
1233        impl RemAssign<NonZero<$Int>> for $Int {
1234            /// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
1235            #[inline]
1236            fn rem_assign(&mut self, other: NonZero<$Int>) {
1237                *self = *self % other;
1238            }
1239        }
1240
1241        impl NonZero<$Int> {
1242            /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
1243            ///
1244            /// The result is guaranteed to be non-zero.
1245            ///
1246            /// # Examples
1247            ///
1248            /// ```
1249            /// # #![feature(unsigned_nonzero_div_ceil)]
1250            /// # use std::num::NonZero;
1251            #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ").unwrap();")]
1252            #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX).unwrap();")]
1253            /// assert_eq!(one.div_ceil(max), one);
1254            ///
1255            #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ").unwrap();")]
1256            #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ").unwrap();")]
1257            /// assert_eq!(three.div_ceil(two), two);
1258            /// ```
1259            #[unstable(feature = "unsigned_nonzero_div_ceil", issue = "132968")]
1260            #[must_use = "this returns the result of the operation, \
1261                          without modifying the original"]
1262            #[inline]
1263            pub const fn div_ceil(self, rhs: Self) -> Self {
1264                let v = self.get().div_ceil(rhs.get());
1265                // SAFETY: ceiled division of two positive integers can never be zero.
1266                unsafe { Self::new_unchecked(v) }
1267            }
1268        }
1269    };
1270    // Impls for signed nonzero types only.
1271    (signed $Int:ty) => {
1272        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")]
1273        impl Neg for NonZero<$Int> {
1274            type Output = Self;
1275
1276            #[inline]
1277            fn neg(self) -> Self {
1278                // SAFETY: negation of nonzero cannot yield zero values.
1279                unsafe { Self::new_unchecked(self.get().neg()) }
1280            }
1281        }
1282
1283        forward_ref_unop! { impl Neg, neg for NonZero<$Int>,
1284        #[stable(feature = "signed_nonzero_neg", since = "1.71.0")] }
1285    };
1286}
1287
1288#[rustfmt::skip] // https://github.com/rust-lang/rustfmt/issues/5974
1289macro_rules! nonzero_integer_signedness_dependent_methods {
1290    // Associated items for unsigned nonzero types only.
1291    (
1292        Primitive = unsigned $Int:ident,
1293        SignedPrimitive = $Sint:ty,
1294        UnsignedPrimitive = $Uint:ty,
1295    ) => {
1296        /// The smallest value that can be represented by this non-zero
1297        /// integer type, 1.
1298        ///
1299        /// # Examples
1300        ///
1301        /// ```
1302        /// # use std::num::NonZero;
1303        /// #
1304        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MIN.get(), 1", stringify!($Int), ");")]
1305        /// ```
1306        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1307        pub const MIN: Self = Self::new(1).unwrap();
1308
1309        /// The largest value that can be represented by this non-zero
1310        /// integer type,
1311        #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
1312        ///
1313        /// # Examples
1314        ///
1315        /// ```
1316        /// # use std::num::NonZero;
1317        /// #
1318        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MAX.get(), ", stringify!($Int), "::MAX);")]
1319        /// ```
1320        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1321        pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
1322
1323        /// Adds an unsigned integer to a non-zero value.
1324        /// Checks for overflow and returns [`None`] on overflow.
1325        /// As a consequence, the result cannot wrap to zero.
1326        ///
1327        ///
1328        /// # Examples
1329        ///
1330        /// ```
1331        /// # use std::num::NonZero;
1332        /// #
1333        /// # fn main() { test().unwrap(); }
1334        /// # fn test() -> Option<()> {
1335        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1336        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1337        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1338        ///
1339        /// assert_eq!(Some(two), one.checked_add(1));
1340        /// assert_eq!(None, max.checked_add(1));
1341        /// # Some(())
1342        /// # }
1343        /// ```
1344        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1345        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1346        #[must_use = "this returns the result of the operation, \
1347                      without modifying the original"]
1348        #[inline]
1349        pub const fn checked_add(self, other: $Int) -> Option<Self> {
1350            if let Some(result) = self.get().checked_add(other) {
1351                // SAFETY:
1352                // - `checked_add` returns `None` on overflow
1353                // - `self` is non-zero
1354                // - the only way to get zero from an addition without overflow is for both
1355                //   sides to be zero
1356                //
1357                // So the result cannot be zero.
1358                Some(unsafe { Self::new_unchecked(result) })
1359            } else {
1360                None
1361            }
1362        }
1363
1364        /// Adds an unsigned integer to a non-zero value.
1365        #[doc = concat!("Return [`NonZero::<", stringify!($Int), ">::MAX`] on overflow.")]
1366        ///
1367        /// # Examples
1368        ///
1369        /// ```
1370        /// # use std::num::NonZero;
1371        /// #
1372        /// # fn main() { test().unwrap(); }
1373        /// # fn test() -> Option<()> {
1374        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1375        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1376        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1377        ///
1378        /// assert_eq!(two, one.saturating_add(1));
1379        /// assert_eq!(max, max.saturating_add(1));
1380        /// # Some(())
1381        /// # }
1382        /// ```
1383        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1384        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1385        #[must_use = "this returns the result of the operation, \
1386                      without modifying the original"]
1387        #[inline]
1388        pub const fn saturating_add(self, other: $Int) -> Self {
1389            // SAFETY:
1390            // - `saturating_add` returns `u*::MAX` on overflow, which is non-zero
1391            // - `self` is non-zero
1392            // - the only way to get zero from an addition without overflow is for both
1393            //   sides to be zero
1394            //
1395            // So the result cannot be zero.
1396            unsafe { Self::new_unchecked(self.get().saturating_add(other)) }
1397        }
1398
1399        /// Adds an unsigned integer to a non-zero value,
1400        /// assuming overflow cannot occur.
1401        /// Overflow is unchecked, and it is undefined behavior to overflow
1402        /// *even if the result would wrap to a non-zero value*.
1403        /// The behavior is undefined as soon as
1404        #[doc = concat!("`self + rhs > ", stringify!($Int), "::MAX`.")]
1405        ///
1406        /// # Examples
1407        ///
1408        /// ```
1409        /// #![feature(nonzero_ops)]
1410        ///
1411        /// # use std::num::NonZero;
1412        /// #
1413        /// # fn main() { test().unwrap(); }
1414        /// # fn test() -> Option<()> {
1415        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1416        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1417        ///
1418        /// assert_eq!(two, unsafe { one.unchecked_add(1) });
1419        /// # Some(())
1420        /// # }
1421        /// ```
1422        #[unstable(feature = "nonzero_ops", issue = "84186")]
1423        #[must_use = "this returns the result of the operation, \
1424                      without modifying the original"]
1425        #[inline]
1426        pub const unsafe fn unchecked_add(self, other: $Int) -> Self {
1427            // SAFETY: The caller ensures there is no overflow.
1428            unsafe { Self::new_unchecked(self.get().unchecked_add(other)) }
1429        }
1430
1431        /// Returns the smallest power of two greater than or equal to `self`.
1432        /// Checks for overflow and returns [`None`]
1433        /// if the next power of two is greater than the type’s maximum value.
1434        /// As a consequence, the result cannot wrap to zero.
1435        ///
1436        /// # Examples
1437        ///
1438        /// ```
1439        /// # use std::num::NonZero;
1440        /// #
1441        /// # fn main() { test().unwrap(); }
1442        /// # fn test() -> Option<()> {
1443        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1444        #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1445        #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1446        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1447        ///
1448        /// assert_eq!(Some(two), two.checked_next_power_of_two() );
1449        /// assert_eq!(Some(four), three.checked_next_power_of_two() );
1450        /// assert_eq!(None, max.checked_next_power_of_two() );
1451        /// # Some(())
1452        /// # }
1453        /// ```
1454        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1455        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1456        #[must_use = "this returns the result of the operation, \
1457                      without modifying the original"]
1458        #[inline]
1459        pub const fn checked_next_power_of_two(self) -> Option<Self> {
1460            if let Some(nz) = self.get().checked_next_power_of_two() {
1461                // SAFETY: The next power of two is positive
1462                // and overflow is checked.
1463                Some(unsafe { Self::new_unchecked(nz) })
1464            } else {
1465                None
1466            }
1467        }
1468
1469        /// Returns the base 2 logarithm of the number, rounded down.
1470        ///
1471        /// This is the same operation as
1472        #[doc = concat!("[`", stringify!($Int), "::ilog2`],")]
1473        /// except that it has no failure cases to worry about
1474        /// since this value can never be zero.
1475        ///
1476        /// # Examples
1477        ///
1478        /// ```
1479        /// # use std::num::NonZero;
1480        /// #
1481        /// # fn main() { test().unwrap(); }
1482        /// # fn test() -> Option<()> {
1483        #[doc = concat!("assert_eq!(NonZero::new(7", stringify!($Int), ")?.ilog2(), 2);")]
1484        #[doc = concat!("assert_eq!(NonZero::new(8", stringify!($Int), ")?.ilog2(), 3);")]
1485        #[doc = concat!("assert_eq!(NonZero::new(9", stringify!($Int), ")?.ilog2(), 3);")]
1486        /// # Some(())
1487        /// # }
1488        /// ```
1489        #[stable(feature = "int_log", since = "1.67.0")]
1490        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1491        #[must_use = "this returns the result of the operation, \
1492                      without modifying the original"]
1493        #[inline]
1494        pub const fn ilog2(self) -> u32 {
1495            Self::BITS - 1 - self.leading_zeros()
1496        }
1497
1498        /// Returns the base 10 logarithm of the number, rounded down.
1499        ///
1500        /// This is the same operation as
1501        #[doc = concat!("[`", stringify!($Int), "::ilog10`],")]
1502        /// except that it has no failure cases to worry about
1503        /// since this value can never be zero.
1504        ///
1505        /// # Examples
1506        ///
1507        /// ```
1508        /// # use std::num::NonZero;
1509        /// #
1510        /// # fn main() { test().unwrap(); }
1511        /// # fn test() -> Option<()> {
1512        #[doc = concat!("assert_eq!(NonZero::new(99", stringify!($Int), ")?.ilog10(), 1);")]
1513        #[doc = concat!("assert_eq!(NonZero::new(100", stringify!($Int), ")?.ilog10(), 2);")]
1514        #[doc = concat!("assert_eq!(NonZero::new(101", stringify!($Int), ")?.ilog10(), 2);")]
1515        /// # Some(())
1516        /// # }
1517        /// ```
1518        #[stable(feature = "int_log", since = "1.67.0")]
1519        #[rustc_const_stable(feature = "int_log", since = "1.67.0")]
1520        #[must_use = "this returns the result of the operation, \
1521                      without modifying the original"]
1522        #[inline]
1523        pub const fn ilog10(self) -> u32 {
1524            super::int_log10::$Int(self.get())
1525        }
1526
1527        /// Calculates the middle point of `self` and `rhs`.
1528        ///
1529        /// `midpoint(a, b)` is `(a + b) >> 1` as if it were performed in a
1530        /// sufficiently-large signed integral type. This implies that the result is
1531        /// always rounded towards negative infinity and that no overflow will ever occur.
1532        ///
1533        /// # Examples
1534        ///
1535        /// ```
1536        /// # use std::num::NonZero;
1537        /// #
1538        /// # fn main() { test().unwrap(); }
1539        /// # fn test() -> Option<()> {
1540        #[doc = concat!("let one = NonZero::new(1", stringify!($Int), ")?;")]
1541        #[doc = concat!("let two = NonZero::new(2", stringify!($Int), ")?;")]
1542        #[doc = concat!("let four = NonZero::new(4", stringify!($Int), ")?;")]
1543        ///
1544        /// assert_eq!(one.midpoint(four), two);
1545        /// assert_eq!(four.midpoint(one), two);
1546        /// # Some(())
1547        /// # }
1548        /// ```
1549        #[stable(feature = "num_midpoint", since = "1.85.0")]
1550        #[rustc_const_stable(feature = "num_midpoint", since = "1.85.0")]
1551        #[must_use = "this returns the result of the operation, \
1552                      without modifying the original"]
1553        #[inline]
1554        pub const fn midpoint(self, rhs: Self) -> Self {
1555            // SAFETY: The only way to get `0` with midpoint is to have two opposite or
1556            // near opposite numbers: (-5, 5), (0, 1), (0, 0) which is impossible because
1557            // of the unsignedness of this number and also because `Self` is guaranteed to
1558            // never being 0.
1559            unsafe { Self::new_unchecked(self.get().midpoint(rhs.get())) }
1560        }
1561
1562        /// Returns `true` if and only if `self == (1 << k)` for some `k`.
1563        ///
1564        /// On many architectures, this function can perform better than `is_power_of_two()`
1565        /// on the underlying integer type, as special handling of zero can be avoided.
1566        ///
1567        /// # Examples
1568        ///
1569        /// Basic usage:
1570        ///
1571        /// ```
1572        /// # use std::num::NonZero;
1573        /// #
1574        /// # fn main() { test().unwrap(); }
1575        /// # fn test() -> Option<()> {
1576        #[doc = concat!("let eight = NonZero::new(8", stringify!($Int), ")?;")]
1577        /// assert!(eight.is_power_of_two());
1578        #[doc = concat!("let ten = NonZero::new(10", stringify!($Int), ")?;")]
1579        /// assert!(!ten.is_power_of_two());
1580        /// # Some(())
1581        /// # }
1582        /// ```
1583        #[must_use]
1584        #[stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
1585        #[rustc_const_stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
1586        #[inline]
1587        pub const fn is_power_of_two(self) -> bool {
1588            // LLVM 11 normalizes `unchecked_sub(x, 1) & x == 0` to the implementation seen here.
1589            // On the basic x86-64 target, this saves 3 instructions for the zero check.
1590            // On x86_64 with BMI1, being nonzero lets it codegen to `BLSR`, which saves an instruction
1591            // compared to the `POPCNT` implementation on the underlying integer type.
1592
1593            intrinsics::ctpop(self.get()) < 2
1594        }
1595
1596        /// Returns the square root of the number, rounded down.
1597        ///
1598        /// # Examples
1599        ///
1600        /// Basic usage:
1601        /// ```
1602        /// # use std::num::NonZero;
1603        /// #
1604        /// # fn main() { test().unwrap(); }
1605        /// # fn test() -> Option<()> {
1606        #[doc = concat!("let ten = NonZero::new(10", stringify!($Int), ")?;")]
1607        #[doc = concat!("let three = NonZero::new(3", stringify!($Int), ")?;")]
1608        ///
1609        /// assert_eq!(ten.isqrt(), three);
1610        /// # Some(())
1611        /// # }
1612        /// ```
1613        #[stable(feature = "isqrt", since = "1.84.0")]
1614        #[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
1615        #[must_use = "this returns the result of the operation, \
1616                      without modifying the original"]
1617        #[inline]
1618        pub const fn isqrt(self) -> Self {
1619            let result = self.get().isqrt();
1620
1621            // SAFETY: Integer square root is a monotonically nondecreasing
1622            // function, which means that increasing the input will never cause
1623            // the output to decrease. Thus, since the input for nonzero
1624            // unsigned integers has a lower bound of 1, the lower bound of the
1625            // results will be sqrt(1), which is 1, so a result can't be zero.
1626            unsafe { Self::new_unchecked(result) }
1627        }
1628
1629        /// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size.
1630        ///
1631        /// # Examples
1632        ///
1633        /// Basic usage:
1634        ///
1635        /// ```
1636        /// #![feature(integer_sign_cast)]
1637        /// # use std::num::NonZero;
1638        ///
1639        #[doc = concat!("let n = NonZero::<", stringify!($Int), ">::MAX;")]
1640        ///
1641        #[doc = concat!("assert_eq!(n.cast_signed(), NonZero::new(-1", stringify!($Sint), ").unwrap());")]
1642        /// ```
1643        #[unstable(feature = "integer_sign_cast", issue = "125882")]
1644        #[must_use = "this returns the result of the operation, \
1645                      without modifying the original"]
1646        #[inline(always)]
1647        pub const fn cast_signed(self) -> NonZero<$Sint> {
1648            // SAFETY: `self.get()` can't be zero
1649            unsafe { NonZero::new_unchecked(self.get().cast_signed()) }
1650        }
1651    };
1652
1653    // Associated items for signed nonzero types only.
1654    (
1655        Primitive = signed $Int:ident,
1656        SignedPrimitive = $Sint:ty,
1657        UnsignedPrimitive = $Uint:ty,
1658    ) => {
1659        /// The smallest value that can be represented by this non-zero
1660        /// integer type,
1661        #[doc = concat!("equal to [`", stringify!($Int), "::MIN`].")]
1662        ///
1663        /// Note: While most integer types are defined for every whole
1664        /// number between `MIN` and `MAX`, signed non-zero integers are
1665        /// a special case. They have a "gap" at 0.
1666        ///
1667        /// # Examples
1668        ///
1669        /// ```
1670        /// # use std::num::NonZero;
1671        /// #
1672        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MIN.get(), ", stringify!($Int), "::MIN);")]
1673        /// ```
1674        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1675        pub const MIN: Self = Self::new(<$Int>::MIN).unwrap();
1676
1677        /// The largest value that can be represented by this non-zero
1678        /// integer type,
1679        #[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
1680        ///
1681        /// Note: While most integer types are defined for every whole
1682        /// number between `MIN` and `MAX`, signed non-zero integers are
1683        /// a special case. They have a "gap" at 0.
1684        ///
1685        /// # Examples
1686        ///
1687        /// ```
1688        /// # use std::num::NonZero;
1689        /// #
1690        #[doc = concat!("assert_eq!(NonZero::<", stringify!($Int), ">::MAX.get(), ", stringify!($Int), "::MAX);")]
1691        /// ```
1692        #[stable(feature = "nonzero_min_max", since = "1.70.0")]
1693        pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
1694
1695        /// Computes the absolute value of self.
1696        #[doc = concat!("See [`", stringify!($Int), "::abs`]")]
1697        /// for documentation on overflow behavior.
1698        ///
1699        /// # Example
1700        ///
1701        /// ```
1702        /// # use std::num::NonZero;
1703        /// #
1704        /// # fn main() { test().unwrap(); }
1705        /// # fn test() -> Option<()> {
1706        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1707        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1708        ///
1709        /// assert_eq!(pos, pos.abs());
1710        /// assert_eq!(pos, neg.abs());
1711        /// # Some(())
1712        /// # }
1713        /// ```
1714        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1715        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1716        #[must_use = "this returns the result of the operation, \
1717                      without modifying the original"]
1718        #[inline]
1719        pub const fn abs(self) -> Self {
1720            // SAFETY: This cannot overflow to zero.
1721            unsafe { Self::new_unchecked(self.get().abs()) }
1722        }
1723
1724        /// Checked absolute value.
1725        /// Checks for overflow and returns [`None`] if
1726        #[doc = concat!("`self == NonZero::<", stringify!($Int), ">::MIN`.")]
1727        /// The result cannot be zero.
1728        ///
1729        /// # Example
1730        ///
1731        /// ```
1732        /// # use std::num::NonZero;
1733        /// #
1734        /// # fn main() { test().unwrap(); }
1735        /// # fn test() -> Option<()> {
1736        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1737        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1738        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1739        ///
1740        /// assert_eq!(Some(pos), neg.checked_abs());
1741        /// assert_eq!(None, min.checked_abs());
1742        /// # Some(())
1743        /// # }
1744        /// ```
1745        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1746        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1747        #[must_use = "this returns the result of the operation, \
1748                      without modifying the original"]
1749        #[inline]
1750        pub const fn checked_abs(self) -> Option<Self> {
1751            if let Some(nz) = self.get().checked_abs() {
1752                // SAFETY: absolute value of nonzero cannot yield zero values.
1753                Some(unsafe { Self::new_unchecked(nz) })
1754            } else {
1755                None
1756            }
1757        }
1758
1759        /// Computes the absolute value of self,
1760        /// with overflow information, see
1761        #[doc = concat!("[`", stringify!($Int), "::overflowing_abs`].")]
1762        ///
1763        /// # Example
1764        ///
1765        /// ```
1766        /// # use std::num::NonZero;
1767        /// #
1768        /// # fn main() { test().unwrap(); }
1769        /// # fn test() -> Option<()> {
1770        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1771        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1772        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1773        ///
1774        /// assert_eq!((pos, false), pos.overflowing_abs());
1775        /// assert_eq!((pos, false), neg.overflowing_abs());
1776        /// assert_eq!((min, true), min.overflowing_abs());
1777        /// # Some(())
1778        /// # }
1779        /// ```
1780        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1781        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1782        #[must_use = "this returns the result of the operation, \
1783                      without modifying the original"]
1784        #[inline]
1785        pub const fn overflowing_abs(self) -> (Self, bool) {
1786            let (nz, flag) = self.get().overflowing_abs();
1787            (
1788                // SAFETY: absolute value of nonzero cannot yield zero values.
1789                unsafe { Self::new_unchecked(nz) },
1790                flag,
1791            )
1792        }
1793
1794        /// Saturating absolute value, see
1795        #[doc = concat!("[`", stringify!($Int), "::saturating_abs`].")]
1796        ///
1797        /// # Example
1798        ///
1799        /// ```
1800        /// # use std::num::NonZero;
1801        /// #
1802        /// # fn main() { test().unwrap(); }
1803        /// # fn test() -> Option<()> {
1804        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1805        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1806        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1807        #[doc = concat!("let min_plus = NonZero::new(", stringify!($Int), "::MIN + 1)?;")]
1808        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1809        ///
1810        /// assert_eq!(pos, pos.saturating_abs());
1811        /// assert_eq!(pos, neg.saturating_abs());
1812        /// assert_eq!(max, min.saturating_abs());
1813        /// assert_eq!(max, min_plus.saturating_abs());
1814        /// # Some(())
1815        /// # }
1816        /// ```
1817        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1818        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1819        #[must_use = "this returns the result of the operation, \
1820                      without modifying the original"]
1821        #[inline]
1822        pub const fn saturating_abs(self) -> Self {
1823            // SAFETY: absolute value of nonzero cannot yield zero values.
1824            unsafe { Self::new_unchecked(self.get().saturating_abs()) }
1825        }
1826
1827        /// Wrapping absolute value, see
1828        #[doc = concat!("[`", stringify!($Int), "::wrapping_abs`].")]
1829        ///
1830        /// # Example
1831        ///
1832        /// ```
1833        /// # use std::num::NonZero;
1834        /// #
1835        /// # fn main() { test().unwrap(); }
1836        /// # fn test() -> Option<()> {
1837        #[doc = concat!("let pos = NonZero::new(1", stringify!($Int), ")?;")]
1838        #[doc = concat!("let neg = NonZero::new(-1", stringify!($Int), ")?;")]
1839        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1840        #[doc = concat!("# let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
1841        ///
1842        /// assert_eq!(pos, pos.wrapping_abs());
1843        /// assert_eq!(pos, neg.wrapping_abs());
1844        /// assert_eq!(min, min.wrapping_abs());
1845        /// assert_eq!(max, (-max).wrapping_abs());
1846        /// # Some(())
1847        /// # }
1848        /// ```
1849        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1850        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1851        #[must_use = "this returns the result of the operation, \
1852                      without modifying the original"]
1853        #[inline]
1854        pub const fn wrapping_abs(self) -> Self {
1855            // SAFETY: absolute value of nonzero cannot yield zero values.
1856            unsafe { Self::new_unchecked(self.get().wrapping_abs()) }
1857        }
1858
1859        /// Computes the absolute value of self
1860        /// without any wrapping or panicking.
1861        ///
1862        /// # Example
1863        ///
1864        /// ```
1865        /// # use std::num::NonZero;
1866        /// #
1867        /// # fn main() { test().unwrap(); }
1868        /// # fn test() -> Option<()> {
1869        #[doc = concat!("let u_pos = NonZero::new(1", stringify!($Uint), ")?;")]
1870        #[doc = concat!("let i_pos = NonZero::new(1", stringify!($Int), ")?;")]
1871        #[doc = concat!("let i_neg = NonZero::new(-1", stringify!($Int), ")?;")]
1872        #[doc = concat!("let i_min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1873        #[doc = concat!("let u_max = NonZero::new(", stringify!($Uint), "::MAX / 2 + 1)?;")]
1874        ///
1875        /// assert_eq!(u_pos, i_pos.unsigned_abs());
1876        /// assert_eq!(u_pos, i_neg.unsigned_abs());
1877        /// assert_eq!(u_max, i_min.unsigned_abs());
1878        /// # Some(())
1879        /// # }
1880        /// ```
1881        #[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
1882        #[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
1883        #[must_use = "this returns the result of the operation, \
1884                      without modifying the original"]
1885        #[inline]
1886        pub const fn unsigned_abs(self) -> NonZero<$Uint> {
1887            // SAFETY: absolute value of nonzero cannot yield zero values.
1888            unsafe { NonZero::new_unchecked(self.get().unsigned_abs()) }
1889        }
1890
1891        /// Returns `true` if `self` is positive and `false` if the
1892        /// number is negative.
1893        ///
1894        /// # Example
1895        ///
1896        /// ```
1897        /// # use std::num::NonZero;
1898        /// #
1899        /// # fn main() { test().unwrap(); }
1900        /// # fn test() -> Option<()> {
1901        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1902        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1903        ///
1904        /// assert!(pos_five.is_positive());
1905        /// assert!(!neg_five.is_positive());
1906        /// # Some(())
1907        /// # }
1908        /// ```
1909        #[must_use]
1910        #[inline]
1911        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1912        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1913        pub const fn is_positive(self) -> bool {
1914            self.get().is_positive()
1915        }
1916
1917        /// Returns `true` if `self` is negative and `false` if the
1918        /// number is positive.
1919        ///
1920        /// # Example
1921        ///
1922        /// ```
1923        /// # use std::num::NonZero;
1924        /// #
1925        /// # fn main() { test().unwrap(); }
1926        /// # fn test() -> Option<()> {
1927        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1928        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1929        ///
1930        /// assert!(neg_five.is_negative());
1931        /// assert!(!pos_five.is_negative());
1932        /// # Some(())
1933        /// # }
1934        /// ```
1935        #[must_use]
1936        #[inline]
1937        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1938        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1939        pub const fn is_negative(self) -> bool {
1940            self.get().is_negative()
1941        }
1942
1943        /// Checked negation. Computes `-self`,
1944        #[doc = concat!("returning `None` if `self == NonZero::<", stringify!($Int), ">::MIN`.")]
1945        ///
1946        /// # Example
1947        ///
1948        /// ```
1949        /// # use std::num::NonZero;
1950        /// #
1951        /// # fn main() { test().unwrap(); }
1952        /// # fn test() -> Option<()> {
1953        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1954        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1955        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1956        ///
1957        /// assert_eq!(pos_five.checked_neg(), Some(neg_five));
1958        /// assert_eq!(min.checked_neg(), None);
1959        /// # Some(())
1960        /// # }
1961        /// ```
1962        #[inline]
1963        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1964        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1965        pub const fn checked_neg(self) -> Option<Self> {
1966            if let Some(result) = self.get().checked_neg() {
1967                // SAFETY: negation of nonzero cannot yield zero values.
1968                return Some(unsafe { Self::new_unchecked(result) });
1969            }
1970            None
1971        }
1972
1973        /// Negates self, overflowing if this is equal to the minimum value.
1974        ///
1975        #[doc = concat!("See [`", stringify!($Int), "::overflowing_neg`]")]
1976        /// for documentation on overflow behavior.
1977        ///
1978        /// # Example
1979        ///
1980        /// ```
1981        /// # use std::num::NonZero;
1982        /// #
1983        /// # fn main() { test().unwrap(); }
1984        /// # fn test() -> Option<()> {
1985        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
1986        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
1987        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
1988        ///
1989        /// assert_eq!(pos_five.overflowing_neg(), (neg_five, false));
1990        /// assert_eq!(min.overflowing_neg(), (min, true));
1991        /// # Some(())
1992        /// # }
1993        /// ```
1994        #[inline]
1995        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1996        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
1997        pub const fn overflowing_neg(self) -> (Self, bool) {
1998            let (result, overflow) = self.get().overflowing_neg();
1999            // SAFETY: negation of nonzero cannot yield zero values.
2000            ((unsafe { Self::new_unchecked(result) }), overflow)
2001        }
2002
2003        /// Saturating negation. Computes `-self`,
2004        #[doc = concat!("returning [`NonZero::<", stringify!($Int), ">::MAX`]")]
2005        #[doc = concat!("if `self == NonZero::<", stringify!($Int), ">::MIN`")]
2006        /// instead of overflowing.
2007        ///
2008        /// # Example
2009        ///
2010        /// ```
2011        /// # use std::num::NonZero;
2012        /// #
2013        /// # fn main() { test().unwrap(); }
2014        /// # fn test() -> Option<()> {
2015        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2016        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2017        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2018        #[doc = concat!("let min_plus_one = NonZero::new(", stringify!($Int), "::MIN + 1)?;")]
2019        #[doc = concat!("let max = NonZero::new(", stringify!($Int), "::MAX)?;")]
2020        ///
2021        /// assert_eq!(pos_five.saturating_neg(), neg_five);
2022        /// assert_eq!(min.saturating_neg(), max);
2023        /// assert_eq!(max.saturating_neg(), min_plus_one);
2024        /// # Some(())
2025        /// # }
2026        /// ```
2027        #[inline]
2028        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2029        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2030        pub const fn saturating_neg(self) -> Self {
2031            if let Some(result) = self.checked_neg() {
2032                return result;
2033            }
2034            Self::MAX
2035        }
2036
2037        /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
2038        /// of the type.
2039        ///
2040        #[doc = concat!("See [`", stringify!($Int), "::wrapping_neg`]")]
2041        /// for documentation on overflow behavior.
2042        ///
2043        /// # Example
2044        ///
2045        /// ```
2046        /// # use std::num::NonZero;
2047        /// #
2048        /// # fn main() { test().unwrap(); }
2049        /// # fn test() -> Option<()> {
2050        #[doc = concat!("let pos_five = NonZero::new(5", stringify!($Int), ")?;")]
2051        #[doc = concat!("let neg_five = NonZero::new(-5", stringify!($Int), ")?;")]
2052        #[doc = concat!("let min = NonZero::new(", stringify!($Int), "::MIN)?;")]
2053        ///
2054        /// assert_eq!(pos_five.wrapping_neg(), neg_five);
2055        /// assert_eq!(min.wrapping_neg(), min);
2056        /// # Some(())
2057        /// # }
2058        /// ```
2059        #[inline]
2060        #[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2061        #[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
2062        pub const fn wrapping_neg(self) -> Self {
2063            let result = self.get().wrapping_neg();
2064            // SAFETY: negation of nonzero cannot yield zero values.
2065            unsafe { Self::new_unchecked(result) }
2066        }
2067
2068        /// Returns the bit pattern of `self` reinterpreted as an unsigned integer of the same size.
2069        ///
2070        /// # Examples
2071        ///
2072        /// Basic usage:
2073        ///
2074        /// ```
2075        /// #![feature(integer_sign_cast)]
2076        /// # use std::num::NonZero;
2077        ///
2078        #[doc = concat!("let n = NonZero::new(-1", stringify!($Int), ").unwrap();")]
2079        ///
2080        #[doc = concat!("assert_eq!(n.cast_unsigned(), NonZero::<", stringify!($Uint), ">::MAX);")]
2081        /// ```
2082        #[unstable(feature = "integer_sign_cast", issue = "125882")]
2083        #[must_use = "this returns the result of the operation, \
2084                      without modifying the original"]
2085        #[inline(always)]
2086        pub const fn cast_unsigned(self) -> NonZero<$Uint> {
2087            // SAFETY: `self.get()` can't be zero
2088            unsafe { NonZero::new_unchecked(self.get().cast_unsigned()) }
2089        }
2090
2091    };
2092}
2093
2094nonzero_integer! {
2095    Self = NonZeroU8,
2096    Primitive = unsigned u8,
2097    SignedPrimitive = i8,
2098    rot = 2,
2099    rot_op = "0x82",
2100    rot_result = "0xa",
2101    swap_op = "0x12",
2102    swapped = "0x12",
2103    reversed = "0x48",
2104}
2105
2106nonzero_integer! {
2107    Self = NonZeroU16,
2108    Primitive = unsigned u16,
2109    SignedPrimitive = i16,
2110    rot = 4,
2111    rot_op = "0xa003",
2112    rot_result = "0x3a",
2113    swap_op = "0x1234",
2114    swapped = "0x3412",
2115    reversed = "0x2c48",
2116}
2117
2118nonzero_integer! {
2119    Self = NonZeroU32,
2120    Primitive = unsigned u32,
2121    SignedPrimitive = i32,
2122    rot = 8,
2123    rot_op = "0x10000b3",
2124    rot_result = "0xb301",
2125    swap_op = "0x12345678",
2126    swapped = "0x78563412",
2127    reversed = "0x1e6a2c48",
2128}
2129
2130nonzero_integer! {
2131    Self = NonZeroU64,
2132    Primitive = unsigned u64,
2133    SignedPrimitive = i64,
2134    rot = 12,
2135    rot_op = "0xaa00000000006e1",
2136    rot_result = "0x6e10aa",
2137    swap_op = "0x1234567890123456",
2138    swapped = "0x5634129078563412",
2139    reversed = "0x6a2c48091e6a2c48",
2140}
2141
2142nonzero_integer! {
2143    Self = NonZeroU128,
2144    Primitive = unsigned u128,
2145    SignedPrimitive = i128,
2146    rot = 16,
2147    rot_op = "0x13f40000000000000000000000004f76",
2148    rot_result = "0x4f7613f4",
2149    swap_op = "0x12345678901234567890123456789012",
2150    swapped = "0x12907856341290785634129078563412",
2151    reversed = "0x48091e6a2c48091e6a2c48091e6a2c48",
2152}
2153
2154#[cfg(target_pointer_width = "16")]
2155nonzero_integer! {
2156    Self = NonZeroUsize,
2157    Primitive = unsigned usize,
2158    SignedPrimitive = isize,
2159    rot = 4,
2160    rot_op = "0xa003",
2161    rot_result = "0x3a",
2162    swap_op = "0x1234",
2163    swapped = "0x3412",
2164    reversed = "0x2c48",
2165}
2166
2167#[cfg(target_pointer_width = "32")]
2168nonzero_integer! {
2169    Self = NonZeroUsize,
2170    Primitive = unsigned usize,
2171    SignedPrimitive = isize,
2172    rot = 8,
2173    rot_op = "0x10000b3",
2174    rot_result = "0xb301",
2175    swap_op = "0x12345678",
2176    swapped = "0x78563412",
2177    reversed = "0x1e6a2c48",
2178}
2179
2180#[cfg(target_pointer_width = "64")]
2181nonzero_integer! {
2182    Self = NonZeroUsize,
2183    Primitive = unsigned usize,
2184    SignedPrimitive = isize,
2185    rot = 12,
2186    rot_op = "0xaa00000000006e1",
2187    rot_result = "0x6e10aa",
2188    swap_op = "0x1234567890123456",
2189    swapped = "0x5634129078563412",
2190    reversed = "0x6a2c48091e6a2c48",
2191}
2192
2193nonzero_integer! {
2194    Self = NonZeroI8,
2195    Primitive = signed i8,
2196    UnsignedPrimitive = u8,
2197    rot = 2,
2198    rot_op = "-0x7e",
2199    rot_result = "0xa",
2200    swap_op = "0x12",
2201    swapped = "0x12",
2202    reversed = "0x48",
2203}
2204
2205nonzero_integer! {
2206    Self = NonZeroI16,
2207    Primitive = signed i16,
2208    UnsignedPrimitive = u16,
2209    rot = 4,
2210    rot_op = "-0x5ffd",
2211    rot_result = "0x3a",
2212    swap_op = "0x1234",
2213    swapped = "0x3412",
2214    reversed = "0x2c48",
2215}
2216
2217nonzero_integer! {
2218    Self = NonZeroI32,
2219    Primitive = signed i32,
2220    UnsignedPrimitive = u32,
2221    rot = 8,
2222    rot_op = "0x10000b3",
2223    rot_result = "0xb301",
2224    swap_op = "0x12345678",
2225    swapped = "0x78563412",
2226    reversed = "0x1e6a2c48",
2227}
2228
2229nonzero_integer! {
2230    Self = NonZeroI64,
2231    Primitive = signed i64,
2232    UnsignedPrimitive = u64,
2233    rot = 12,
2234    rot_op = "0xaa00000000006e1",
2235    rot_result = "0x6e10aa",
2236    swap_op = "0x1234567890123456",
2237    swapped = "0x5634129078563412",
2238    reversed = "0x6a2c48091e6a2c48",
2239}
2240
2241nonzero_integer! {
2242    Self = NonZeroI128,
2243    Primitive = signed i128,
2244    UnsignedPrimitive = u128,
2245    rot = 16,
2246    rot_op = "0x13f40000000000000000000000004f76",
2247    rot_result = "0x4f7613f4",
2248    swap_op = "0x12345678901234567890123456789012",
2249    swapped = "0x12907856341290785634129078563412",
2250    reversed = "0x48091e6a2c48091e6a2c48091e6a2c48",
2251}
2252
2253#[cfg(target_pointer_width = "16")]
2254nonzero_integer! {
2255    Self = NonZeroIsize,
2256    Primitive = signed isize,
2257    UnsignedPrimitive = usize,
2258    rot = 4,
2259    rot_op = "-0x5ffd",
2260    rot_result = "0x3a",
2261    swap_op = "0x1234",
2262    swapped = "0x3412",
2263    reversed = "0x2c48",
2264}
2265
2266#[cfg(target_pointer_width = "32")]
2267nonzero_integer! {
2268    Self = NonZeroIsize,
2269    Primitive = signed isize,
2270    UnsignedPrimitive = usize,
2271    rot = 8,
2272    rot_op = "0x10000b3",
2273    rot_result = "0xb301",
2274    swap_op = "0x12345678",
2275    swapped = "0x78563412",
2276    reversed = "0x1e6a2c48",
2277}
2278
2279#[cfg(target_pointer_width = "64")]
2280nonzero_integer! {
2281    Self = NonZeroIsize,
2282    Primitive = signed isize,
2283    UnsignedPrimitive = usize,
2284    rot = 12,
2285    rot_op = "0xaa00000000006e1",
2286    rot_result = "0x6e10aa",
2287    swap_op = "0x1234567890123456",
2288    swapped = "0x5634129078563412",
2289    reversed = "0x6a2c48091e6a2c48",
2290}