Files
rust/library/core/src/num/nonzero.rs

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

1459 lines
63 KiB
Rust
Raw Normal View History

2020-09-04 13:07:03 +00:00
//! Definitions of integer that is known not to equal zero.
use crate::fmt;
use crate::ops::{BitOr, BitOrAssign, Div, Neg, Rem};
2020-09-04 13:07:03 +00:00
use crate::str::FromStr;
use super::from_str_radix;
use super::{IntErrorKind, ParseIntError};
use crate::intrinsics;
2020-09-04 13:07:03 +00:00
macro_rules! impl_nonzero_fmt {
( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
$(
#[$stability]
impl fmt::$Trait for $Ty {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.get().fmt(f)
}
}
)+
}
}
macro_rules! nonzero_integer {
(
Self = $Ty:ident,
Primitive = $signedness:ident $Int:ident,
feature = $feature:literal,
original_stabilization = $since:literal,
) => {
2023-12-05 18:44:02 -08:00
/// An integer that is known not to equal zero.
///
/// This enables some memory layout optimization.
#[doc = concat!("For example, `Option<", stringify!($Ty), ">` is the same size as `", stringify!($Int), "`:")]
///
/// ```rust
/// use std::mem::size_of;
#[doc = concat!("assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", stringify!($Int), ">());")]
/// ```
///
/// # Layout
///
#[doc = concat!("`", stringify!($Ty), "` is guaranteed to have the same layout and bit validity as `", stringify!($Int), "`")]
/// with the exception that `0` is not a valid instance.
#[doc = concat!("`Option<", stringify!($Ty), ">` is guaranteed to be compatible with `", stringify!($Int), "`,")]
/// including in FFI.
///
/// Thanks to the [null pointer optimization],
#[doc = concat!("`", stringify!($Ty), "` and `Option<", stringify!($Ty), ">`")]
/// are guaranteed to have the same size and alignment:
///
/// ```
/// # use std::mem::{size_of, align_of};
#[doc = concat!("use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(size_of::<", stringify!($Ty), ">(), size_of::<Option<", stringify!($Ty), ">>());")]
#[doc = concat!("assert_eq!(align_of::<", stringify!($Ty), ">(), align_of::<Option<", stringify!($Ty), ">>());")]
/// ```
///
/// [null pointer optimization]: crate::option#representation
#[stable(feature = $feature, since = $since)]
2023-12-05 18:44:02 -08:00
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[repr(transparent)]
#[rustc_layout_scalar_valid_range_start(1)]
#[rustc_nonnull_optimization_guaranteed]
#[rustc_diagnostic_item = stringify!($Ty)]
pub struct $Ty($Int);
impl $Ty {
/// Creates a non-zero without checking whether the value is non-zero.
/// This results in undefined behaviour if the value is zero.
///
2023-12-05 18:44:02 -08:00
/// # Safety
///
2023-12-05 18:44:02 -08:00
/// The value must not be zero.
#[stable(feature = $feature, since = $since)]
#[rustc_const_stable(feature = $feature, since = $since)]
2023-12-05 18:44:02 -08:00
#[must_use]
#[inline]
pub const unsafe fn new_unchecked(n: $Int) -> Self {
crate::panic::debug_assert_nounwind!(
n != 0,
concat!(stringify!($Ty), "::new_unchecked requires a non-zero argument")
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
Self(n)
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
/// Creates a non-zero if the given value is not zero.
#[stable(feature = $feature, since = $since)]
2023-12-05 18:44:02 -08:00
#[rustc_const_stable(feature = "const_nonzero_int_methods", since = "1.47.0")]
#[must_use]
#[inline]
pub const fn new(n: $Int) -> Option<Self> {
if n != 0 {
// SAFETY: we just checked that there's no `0`
Some(unsafe { Self(n) })
} else {
None
2020-09-04 13:07:03 +00:00
}
}
2023-12-05 18:44:02 -08:00
/// Returns the value as a primitive type.
#[stable(feature = $feature, since = $since)]
2023-12-05 18:44:02 -08:00
#[inline]
#[rustc_const_stable(feature = "const_nonzero_get", since = "1.34.0")]
pub const fn get(self) -> $Int {
// FIXME: Remove this after LLVM supports `!range` metadata for function
// arguments https://github.com/llvm/llvm-project/issues/76628
//
// Rustc can set range metadata only if it loads `self` from
// memory somewhere. If the value of `self` was from by-value argument
// of some not-inlined function, LLVM don't have range metadata
// to understand that the value cannot be zero.
// SAFETY: It is an invariant of this type.
unsafe {
intrinsics::assume(self.0 != 0);
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
self.0
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
#[stable(feature = "from_nonzero", since = "1.31.0")]
impl From<$Ty> for $Int {
#[doc = concat!("Converts a `", stringify!($Ty), "` into an `", stringify!($Int), "`")]
#[inline]
fn from(nonzero: $Ty) -> Self {
// Call nonzero to keep information range information
// from get method.
nonzero.get()
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
impl BitOr for $Ty {
type Output = Self;
#[inline]
fn bitor(self, rhs: Self) -> Self::Output {
// SAFETY: since `self` and `rhs` are both nonzero, the
// result of the bitwise-or will be nonzero.
unsafe { $Ty::new_unchecked(self.get() | rhs.get()) }
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
impl BitOr<$Int> for $Ty {
type Output = Self;
#[inline]
fn bitor(self, rhs: $Int) -> Self::Output {
// SAFETY: since `self` is nonzero, the result of the
// bitwise-or will be nonzero regardless of the value of
// `rhs`.
unsafe { $Ty::new_unchecked(self.get() | rhs) }
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
impl BitOr<$Ty> for $Int {
type Output = $Ty;
#[inline]
fn bitor(self, rhs: $Ty) -> Self::Output {
// SAFETY: since `rhs` is nonzero, the result of the
// bitwise-or will be nonzero regardless of the value of
// `self`.
unsafe { $Ty::new_unchecked(self | rhs.get()) }
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
impl BitOrAssign for $Ty {
#[inline]
fn bitor_assign(&mut self, rhs: Self) {
*self = *self | rhs;
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
2023-12-05 18:44:02 -08:00
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
impl BitOrAssign<$Int> for $Ty {
#[inline]
fn bitor_assign(&mut self, rhs: $Int) {
*self = *self | rhs;
2020-09-04 13:07:03 +00:00
}
2023-12-05 18:44:02 -08:00
}
impl_nonzero_fmt! {
#[stable(feature = $feature, since = $since)]
(Debug, Display, Binary, Octal, LowerHex, UpperHex) for $Ty
2023-12-05 18:44:02 -08:00
}
2020-09-04 13:07:03 +00:00
#[stable(feature = "nonzero_parse", since = "1.35.0")]
impl FromStr for $Ty {
2020-09-04 13:07:03 +00:00
type Err = ParseIntError;
fn from_str(src: &str) -> Result<Self, Self::Err> {
Self::new(from_str_radix(src, 10)?)
.ok_or(ParseIntError {
kind: IntErrorKind::Zero
})
}
}
nonzero_integer_impl_div_rem!($Ty $signedness $Int);
};
2020-09-04 13:07:03 +00:00
}
macro_rules! nonzero_leading_trailing_zeros {
( $( $Ty: ident($Uint: ty) , $LeadingTestExpr:expr ;)+ ) => {
$(
impl $Ty {
/// Returns the number of leading zeros in the binary representation of `self`.
///
/// On many architectures, this function can perform better than `leading_zeros()` on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = std::num::", stringify!($Ty), "::new(", stringify!($LeadingTestExpr), ").unwrap();")]
///
/// assert_eq!(n.leading_zeros(), 0);
/// ```
#[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn leading_zeros(self) -> u32 {
// SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`.
unsafe { intrinsics::ctlz_nonzero(self.get() as $Uint) as u32 }
}
/// Returns the number of trailing zeros in the binary representation
/// of `self`.
///
/// On many architectures, this function can perform better than `trailing_zeros()` on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = std::num::", stringify!($Ty), "::new(0b0101000).unwrap();")]
///
/// assert_eq!(n.trailing_zeros(), 3);
/// ```
#[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn trailing_zeros(self) -> u32 {
// SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`.
unsafe { intrinsics::cttz_nonzero(self.get() as $Uint) as u32 }
}
}
)+
}
}
nonzero_leading_trailing_zeros! {
NonZeroU8(u8), u8::MAX;
NonZeroU16(u16), u16::MAX;
NonZeroU32(u32), u32::MAX;
NonZeroU64(u64), u64::MAX;
NonZeroU128(u128), u128::MAX;
NonZeroUsize(usize), usize::MAX;
NonZeroI8(u8), -1i8;
NonZeroI16(u16), -1i16;
NonZeroI32(u32), -1i32;
NonZeroI64(u64), -1i64;
NonZeroI128(u128), -1i128;
NonZeroIsize(usize), -1isize;
}
macro_rules! nonzero_integer_impl_div_rem {
($Ty:ident signed $Int:ty) => {
// nothing for signed ints
};
($Ty:ident unsigned $Int:ty) => {
2020-12-27 03:17:30 -08:00
#[stable(feature = "nonzero_div", since = "1.51.0")]
2023-04-16 06:49:27 +00:00
impl Div<$Ty> for $Int {
type Output = $Int;
/// This operation rounds towards zero,
/// truncating any fractional part of the exact result, and cannot panic.
#[inline]
fn div(self, other: $Ty) -> $Int {
// SAFETY: div by zero is checked because `other` is a nonzero,
// and MIN/-1 is checked because `self` is an unsigned int.
unsafe { crate::intrinsics::unchecked_div(self, other.get()) }
}
}
2020-12-27 03:17:30 -08:00
#[stable(feature = "nonzero_div", since = "1.51.0")]
2023-04-16 06:49:27 +00:00
impl Rem<$Ty> for $Int {
type Output = $Int;
/// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
#[inline]
fn rem(self, other: $Ty) -> $Int {
// SAFETY: rem by zero is checked because `other` is a nonzero,
// and MIN/-1 is checked because `self` is an unsigned int.
unsafe { crate::intrinsics::unchecked_rem(self, other.get()) }
}
}
};
}
2021-04-15 12:10:05 +02:00
// A bunch of methods for unsigned nonzero types only.
macro_rules! nonzero_unsigned_operations {
( $( $Ty: ident($Int: ident); )+ ) => {
2021-04-15 12:10:05 +02:00
$(
impl $Ty {
/// Adds an unsigned integer to a non-zero value.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
///
2021-04-15 12:10:05 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:10:05 +02:00
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(two), one.checked_add(1));
/// assert_eq!(None, max.checked_add(1));
/// # Some(())
2021-04-15 12:10:05 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:10:05 +02:00
#[inline]
pub const fn checked_add(self, other: $Int) -> Option<$Ty> {
if let Some(result) = self.get().checked_add(other) {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `checked_add` returns `None` on overflow
// - `self` is non-zero
2023-11-26 11:47:08 +00:00
// - the only way to get zero from an addition without overflow is for both
// sides to be zero
//
// So the result cannot be zero.
2021-04-15 12:10:05 +02:00
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
2021-04-15 12:12:46 +02:00
/// Adds an unsigned integer to a non-zero value.
#[doc = concat!("Return [`", stringify!($Ty), "::MAX`] on overflow.")]
2021-04-15 12:12:46 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:12:46 +02:00
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(two, one.saturating_add(1));
/// assert_eq!(max, max.saturating_add(1));
/// # Some(())
2021-04-15 12:12:46 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:12:46 +02:00
#[inline]
pub const fn saturating_add(self, other: $Int) -> $Ty {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `saturating_add` returns `u*::MAX` on overflow, which is non-zero
// - `self` is non-zero
2023-11-26 11:47:08 +00:00
// - the only way to get zero from an addition without overflow is for both
// sides to be zero
//
// So the result cannot be zero.
2021-04-15 12:12:46 +02:00
unsafe { $Ty::new_unchecked(self.get().saturating_add(other)) }
}
2021-04-15 12:14:25 +02:00
/// Adds an unsigned integer to a non-zero value,
2021-04-15 12:14:25 +02:00
/// assuming overflow cannot occur.
/// Overflow is unchecked, and it is undefined behaviour to overflow
/// *even if the result would wrap to a non-zero value*.
/// The behaviour is undefined as soon as
#[doc = concat!("`self + rhs > ", stringify!($Int), "::MAX`.")]
2021-04-15 12:14:25 +02:00
///
/// # Examples
///
/// ```
/// #![feature(nonzero_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:14:25 +02:00
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
///
/// assert_eq!(two, unsafe { one.unchecked_add(1) });
/// # Some(())
2021-04-15 12:14:25 +02:00
/// # }
/// ```
#[unstable(feature = "nonzero_ops", issue = "84186")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:14:25 +02:00
#[inline]
pub const unsafe fn unchecked_add(self, other: $Int) -> $Ty {
2021-04-15 12:14:25 +02:00
// SAFETY: The caller ensures there is no overflow.
unsafe { $Ty::new_unchecked(self.get().unchecked_add(other)) }
}
2021-04-15 12:15:51 +02:00
/// Returns the smallest power of two greater than or equal to n.
/// Checks for overflow and returns [`None`]
/// if the next power of two is greater than the types maximum value.
/// As a consequence, the result cannot wrap to zero.
2021-04-15 12:15:51 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:15:51 +02:00
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(two), two.checked_next_power_of_two() );
/// assert_eq!(Some(four), three.checked_next_power_of_two() );
/// assert_eq!(None, max.checked_next_power_of_two() );
/// # Some(())
2021-04-15 12:15:51 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:15:51 +02:00
#[inline]
pub const fn checked_next_power_of_two(self) -> Option<$Ty> {
if let Some(nz) = self.get().checked_next_power_of_two() {
// SAFETY: The next power of two is positive
// and overflow is checked.
Some(unsafe { $Ty::new_unchecked(nz) })
} else {
None
}
}
/// Returns the base 2 logarithm of the number, rounded down.
///
/// This is the same operation as
#[doc = concat!("[`", stringify!($Int), "::ilog2`],")]
/// except that it has no failure cases to worry about
/// since this value can never be zero.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(7).unwrap().ilog2(), 2);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(8).unwrap().ilog2(), 3);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(9).unwrap().ilog2(), 3);")]
/// ```
2022-12-12 13:50:00 +01:00
#[stable(feature = "int_log", since = "1.67.0")]
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn ilog2(self) -> u32 {
Self::BITS - 1 - self.leading_zeros()
}
/// Returns the base 10 logarithm of the number, rounded down.
///
/// This is the same operation as
#[doc = concat!("[`", stringify!($Int), "::ilog10`],")]
/// except that it has no failure cases to worry about
/// since this value can never be zero.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(99).unwrap().ilog10(), 1);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(100).unwrap().ilog10(), 2);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(101).unwrap().ilog10(), 2);")]
/// ```
2022-12-12 13:50:00 +01:00
#[stable(feature = "int_log", since = "1.67.0")]
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn ilog10(self) -> u32 {
super::int_log10::$Int(self.get())
}
/// Calculates the middle point of `self` and `rhs`.
///
/// `midpoint(a, b)` is `(a + b) >> 1` as if it were performed in a
/// sufficiently-large signed integral type. This implies that the result is
/// always rounded towards negative infinity and that no overflow will ever occur.
///
/// # Examples
///
/// ```
/// #![feature(num_midpoint)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
///
/// assert_eq!(one.midpoint(four), two);
/// assert_eq!(four.midpoint(one), two);
/// # Some(())
/// # }
/// ```
#[unstable(feature = "num_midpoint", issue = "110840")]
#[rustc_const_unstable(feature = "const_num_midpoint", issue = "110840")]
#[rustc_allow_const_fn_unstable(const_num_midpoint)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn midpoint(self, rhs: Self) -> Self {
// SAFETY: The only way to get `0` with midpoint is to have two opposite or
// near opposite numbers: (-5, 5), (0, 1), (0, 0) which is impossible because
// of the unsignedness of this number and also because $Ty is guaranteed to
// never being 0.
unsafe { $Ty::new_unchecked(self.get().midpoint(rhs.get())) }
}
2021-04-15 12:10:05 +02:00
}
)+
}
}
nonzero_unsigned_operations! {
NonZeroU8(u8);
NonZeroU16(u16);
NonZeroU32(u32);
NonZeroU64(u64);
NonZeroU128(u128);
NonZeroUsize(usize);
}
2021-04-15 12:18:04 +02:00
// A bunch of methods for signed nonzero types only.
macro_rules! nonzero_signed_operations {
( $( $Ty: ident($Int: ty) -> $Uty: ident($Uint: ty); )+ ) => {
$(
impl $Ty {
/// Computes the absolute value of self.
#[doc = concat!("See [`", stringify!($Int), "::abs`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:18:04 +02:00
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
///
/// assert_eq!(pos, pos.abs());
/// assert_eq!(pos, neg.abs());
/// # Some(())
2021-04-15 12:18:04 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:18:04 +02:00
#[inline]
pub const fn abs(self) -> $Ty {
// SAFETY: This cannot overflow to zero.
unsafe { $Ty::new_unchecked(self.get().abs()) }
}
2021-04-15 12:19:24 +02:00
/// Checked absolute value.
/// Checks for overflow and returns [`None`] if
#[doc = concat!("`self == ", stringify!($Ty), "::MIN`.")]
/// The result cannot be zero.
2021-04-15 12:19:24 +02:00
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:19:24 +02:00
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(Some(pos), neg.checked_abs());
/// assert_eq!(None, min.checked_abs());
/// # Some(())
2021-04-15 12:19:24 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:19:24 +02:00
#[inline]
pub const fn checked_abs(self) -> Option<$Ty> {
if let Some(nz) = self.get().checked_abs() {
// SAFETY: absolute value of nonzero cannot yield zero values.
Some(unsafe { $Ty::new_unchecked(nz) })
} else {
None
}
}
2021-04-15 12:21:25 +02:00
/// Computes the absolute value of self,
/// with overflow information, see
#[doc = concat!("[`", stringify!($Int), "::overflowing_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:21:25 +02:00
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!((pos, false), pos.overflowing_abs());
/// assert_eq!((pos, false), neg.overflowing_abs());
/// assert_eq!((min, true), min.overflowing_abs());
/// # Some(())
2021-04-15 12:21:25 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:21:25 +02:00
#[inline]
pub const fn overflowing_abs(self) -> ($Ty, bool) {
let (nz, flag) = self.get().overflowing_abs();
(
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(nz) },
flag,
)
}
2021-04-15 12:23:02 +02:00
/// Saturating absolute value, see
#[doc = concat!("[`", stringify!($Int), "::saturating_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:23:02 +02:00
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let min_plus = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN + 1)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos, pos.saturating_abs());
/// assert_eq!(pos, neg.saturating_abs());
/// assert_eq!(max, min.saturating_abs());
/// assert_eq!(max, min_plus.saturating_abs());
/// # Some(())
2021-04-15 12:23:02 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:23:02 +02:00
#[inline]
pub const fn saturating_abs(self) -> $Ty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(self.get().saturating_abs()) }
}
2021-04-15 12:25:13 +02:00
/// Wrapping absolute value, see
#[doc = concat!("[`", stringify!($Int), "::wrapping_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:25:13 +02:00
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
2022-11-20 12:30:14 +01:00
#[doc = concat!("# let max = ", stringify!($Ty), "::new(",
2021-04-15 12:25:13 +02:00
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos, pos.wrapping_abs());
/// assert_eq!(pos, neg.wrapping_abs());
/// assert_eq!(min, min.wrapping_abs());
/// assert_eq!(max, (-max).wrapping_abs());
/// # Some(())
2021-04-15 12:25:13 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:25:13 +02:00
#[inline]
pub const fn wrapping_abs(self) -> $Ty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(self.get().wrapping_abs()) }
}
2021-04-15 12:26:39 +02:00
/// Computes the absolute value of self
/// without any wrapping or panicking.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("# use std::num::", stringify!($Uty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:26:39 +02:00
#[doc = concat!("let u_pos = ", stringify!($Uty), "::new(1)?;")]
#[doc = concat!("let i_pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let i_neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let i_min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let u_max = ", stringify!($Uty), "::new(",
stringify!($Uint), "::MAX / 2 + 1)?;")]
///
/// assert_eq!(u_pos, i_pos.unsigned_abs());
/// assert_eq!(u_pos, i_neg.unsigned_abs());
/// assert_eq!(u_max, i_min.unsigned_abs());
/// # Some(())
2021-04-15 12:26:39 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:26:39 +02:00
#[inline]
pub const fn unsigned_abs(self) -> $Uty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Uty::new_unchecked(self.get().unsigned_abs()) }
}
/// Returns `true` if `self` is positive and `false` if the
/// number is negative.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
///
/// assert!(pos_five.is_positive());
/// assert!(!neg_five.is_positive());
/// # Some(())
/// # }
/// ```
#[must_use]
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn is_positive(self) -> bool {
self.get().is_positive()
}
/// Returns `true` if `self` is negative and `false` if the
/// number is positive.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
///
/// assert!(neg_five.is_negative());
/// assert!(!pos_five.is_negative());
/// # Some(())
/// # }
/// ```
#[must_use]
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn is_negative(self) -> bool {
self.get().is_negative()
}
/// Checked negation. Computes `-self`,
#[doc = concat!("returning `None` if `self == ", stringify!($Ty), "::MIN`.")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.checked_neg(), Some(neg_five));
/// assert_eq!(min.checked_neg(), None);
/// # Some(())
/// # }
/// ```
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn checked_neg(self) -> Option<$Ty> {
if let Some(result) = self.get().checked_neg() {
// SAFETY: negation of nonzero cannot yield zero values.
return Some(unsafe { $Ty::new_unchecked(result) });
}
None
}
/// Negates self, overflowing if this is equal to the minimum value.
///
#[doc = concat!("See [`", stringify!($Int), "::overflowing_neg`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.overflowing_neg(), (neg_five, false));
/// assert_eq!(min.overflowing_neg(), (min, true));
/// # Some(())
/// # }
/// ```
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn overflowing_neg(self) -> ($Ty, bool) {
let (result, overflow) = self.get().overflowing_neg();
// SAFETY: negation of nonzero cannot yield zero values.
((unsafe { $Ty::new_unchecked(result) }), overflow)
}
/// Saturating negation. Computes `-self`,
#[doc = concat!("returning [`", stringify!($Ty), "::MAX`]")]
#[doc = concat!("if `self == ", stringify!($Ty), "::MIN`")]
/// instead of overflowing.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let min_plus_one = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN + 1)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos_five.saturating_neg(), neg_five);
/// assert_eq!(min.saturating_neg(), max);
/// assert_eq!(max.saturating_neg(), min_plus_one);
/// # Some(())
/// # }
/// ```
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn saturating_neg(self) -> $Ty {
if let Some(result) = self.checked_neg() {
return result;
}
$Ty::MAX
}
/// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
/// of the type.
///
#[doc = concat!("See [`", stringify!($Int), "::wrapping_neg`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.wrapping_neg(), neg_five);
/// assert_eq!(min.wrapping_neg(), min);
/// # Some(())
/// # }
/// ```
#[inline]
#[stable(feature = "nonzero_negation_ops", since = "1.71.0")]
#[rustc_const_stable(feature = "nonzero_negation_ops", since = "1.71.0")]
pub const fn wrapping_neg(self) -> $Ty {
let result = self.get().wrapping_neg();
// SAFETY: negation of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(result) }
}
2021-04-15 12:18:04 +02:00
}
#[stable(feature = "signed_nonzero_neg", since = "1.71.0")]
impl Neg for $Ty {
type Output = $Ty;
#[inline]
fn neg(self) -> $Ty {
// SAFETY: negation of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(self.get().neg()) }
}
}
forward_ref_unop! { impl Neg, neg for $Ty,
#[stable(feature = "signed_nonzero_neg", since = "1.71.0")] }
2021-04-15 12:18:04 +02:00
)+
}
}
nonzero_signed_operations! {
NonZeroI8(i8) -> NonZeroU8(u8);
NonZeroI16(i16) -> NonZeroU16(u16);
NonZeroI32(i32) -> NonZeroU32(u32);
NonZeroI64(i64) -> NonZeroU64(u64);
NonZeroI128(i128) -> NonZeroU128(u128);
NonZeroIsize(isize) -> NonZeroUsize(usize);
}
2021-04-15 12:28:45 +02:00
// A bunch of methods for both signed and unsigned nonzero types.
macro_rules! nonzero_unsigned_signed_operations {
( $( $signedness:ident $Ty: ident($Int: ty); )+ ) => {
2021-04-15 12:28:45 +02:00
$(
impl $Ty {
/// Multiplies two non-zero integers together.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
2021-04-15 12:28:45 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:28:45 +02:00
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(four), two.checked_mul(two));
/// assert_eq!(None, max.checked_mul(two));
/// # Some(())
2021-04-15 12:28:45 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:28:45 +02:00
#[inline]
pub const fn checked_mul(self, other: $Ty) -> Option<$Ty> {
if let Some(result) = self.get().checked_mul(other.get()) {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `checked_mul` returns `None` on overflow
// - `self` and `other` are non-zero
// - the only way to get zero from a multiplication without overflow is for one
// of the sides to be zero
//
// So the result cannot be zero.
2021-04-15 12:28:45 +02:00
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
2021-04-15 12:30:13 +02:00
/// Multiplies two non-zero integers together.
#[doc = concat!("Return [`", stringify!($Ty), "::MAX`] on overflow.")]
2021-04-15 12:30:13 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:30:13 +02:00
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(four, two.saturating_mul(two));
/// assert_eq!(max, four.saturating_mul(max));
/// # Some(())
2021-04-15 12:30:13 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:30:13 +02:00
#[inline]
pub const fn saturating_mul(self, other: $Ty) -> $Ty {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `saturating_mul` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
// all of which are non-zero
// - `self` and `other` are non-zero
// - the only way to get zero from a multiplication without overflow is for one
// of the sides to be zero
//
// So the result cannot be zero.
2021-04-15 12:30:13 +02:00
unsafe { $Ty::new_unchecked(self.get().saturating_mul(other.get())) }
}
2021-04-15 12:31:32 +02:00
/// Multiplies two non-zero integers together,
2021-04-15 12:31:32 +02:00
/// assuming overflow cannot occur.
/// Overflow is unchecked, and it is undefined behaviour to overflow
/// *even if the result would wrap to a non-zero value*.
/// The behaviour is undefined as soon as
#[doc = sign_dependent_expr!{
$signedness ?
if signed {
concat!("`self * rhs > ", stringify!($Int), "::MAX`, ",
"or `self * rhs < ", stringify!($Int), "::MIN`.")
}
if unsigned {
concat!("`self * rhs > ", stringify!($Int), "::MAX`.")
}
}]
2021-04-15 12:31:32 +02:00
///
/// # Examples
///
/// ```
/// #![feature(nonzero_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:31:32 +02:00
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
///
/// assert_eq!(four, unsafe { two.unchecked_mul(two) });
/// # Some(())
2021-04-15 12:31:32 +02:00
/// # }
/// ```
#[unstable(feature = "nonzero_ops", issue = "84186")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:31:32 +02:00
#[inline]
pub const unsafe fn unchecked_mul(self, other: $Ty) -> $Ty {
2021-04-15 12:31:32 +02:00
// SAFETY: The caller ensures there is no overflow.
unsafe { $Ty::new_unchecked(self.get().unchecked_mul(other.get())) }
}
2021-04-15 12:32:48 +02:00
/// Raises non-zero value to an integer power.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
2021-04-15 12:32:48 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:32:48 +02:00
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let twenty_seven = ", stringify!($Ty), "::new(27)?;")]
#[doc = concat!("let half_max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX / 2)?;")]
///
/// assert_eq!(Some(twenty_seven), three.checked_pow(3));
/// assert_eq!(None, half_max.checked_pow(3));
/// # Some(())
2021-04-15 12:32:48 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:32:48 +02:00
#[inline]
pub const fn checked_pow(self, other: u32) -> Option<$Ty> {
if let Some(result) = self.get().checked_pow(other) {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `checked_pow` returns `None` on overflow/underflow
// - `self` is non-zero
// - the only way to get zero from an exponentiation without overflow is
// for base to be zero
//
// So the result cannot be zero.
2021-04-15 12:32:48 +02:00
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
2021-04-15 12:34:03 +02:00
/// Raise non-zero value to an integer power.
#[doc = sign_dependent_expr!{
$signedness ?
if signed {
concat!("Return [`", stringify!($Ty), "::MIN`] ",
"or [`", stringify!($Ty), "::MAX`] on overflow.")
}
if unsigned {
concat!("Return [`", stringify!($Ty), "::MAX`] on overflow.")
}
}]
2021-04-15 12:34:03 +02:00
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
2021-04-15 12:34:03 +02:00
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let twenty_seven = ", stringify!($Ty), "::new(27)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(twenty_seven, three.saturating_pow(3));
/// assert_eq!(max, max.saturating_pow(3));
/// # Some(())
2021-04-15 12:34:03 +02:00
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
2021-04-15 12:34:03 +02:00
#[inline]
pub const fn saturating_pow(self, other: u32) -> $Ty {
2023-11-26 11:47:08 +00:00
// SAFETY:
// - `saturating_pow` returns `u*::MAX`/`i*::MAX`/`i*::MIN` on overflow/underflow,
// all of which are non-zero
// - `self` is non-zero
// - the only way to get zero from an exponentiation without overflow is
// for base to be zero
//
// So the result cannot be zero.
2021-04-15 12:34:03 +02:00
unsafe { $Ty::new_unchecked(self.get().saturating_pow(other)) }
}
2021-04-15 12:28:45 +02:00
}
)+
}
}
// Use this when the generated code should differ between signed and unsigned types.
macro_rules! sign_dependent_expr {
(signed ? if signed { $signed_case:expr } if unsigned { $unsigned_case:expr } ) => {
$signed_case
};
(unsigned ? if signed { $signed_case:expr } if unsigned { $unsigned_case:expr } ) => {
$unsigned_case
};
}
2021-04-15 12:28:45 +02:00
nonzero_unsigned_signed_operations! {
unsigned NonZeroU8(u8);
unsigned NonZeroU16(u16);
unsigned NonZeroU32(u32);
unsigned NonZeroU64(u64);
unsigned NonZeroU128(u128);
unsigned NonZeroUsize(usize);
signed NonZeroI8(i8);
signed NonZeroI16(i16);
signed NonZeroI32(i32);
signed NonZeroI64(i64);
signed NonZeroI128(i128);
signed NonZeroIsize(isize);
2021-04-15 12:28:45 +02:00
}
macro_rules! nonzero_unsigned_is_power_of_two {
( $( $Ty: ident )+ ) => {
$(
impl $Ty {
/// Returns `true` if and only if `self == (1 << k)` for some `k`.
///
/// On many architectures, this function can perform better than `is_power_of_two()`
/// on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let eight = std::num::", stringify!($Ty), "::new(8).unwrap();")]
/// assert!(eight.is_power_of_two());
#[doc = concat!("let ten = std::num::", stringify!($Ty), "::new(10).unwrap();")]
/// assert!(!ten.is_power_of_two());
/// ```
#[must_use]
#[stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
2021-11-17 21:08:16 -05:00
#[rustc_const_stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
#[inline]
pub const fn is_power_of_two(self) -> bool {
// LLVM 11 normalizes `unchecked_sub(x, 1) & x == 0` to the implementation seen here.
// On the basic x86-64 target, this saves 3 instructions for the zero check.
// On x86_64 with BMI1, being nonzero lets it codegen to `BLSR`, which saves an instruction
// compared to the `POPCNT` implementation on the underlying integer type.
intrinsics::ctpop(self.get()) < 2
}
}
)+
}
}
nonzero_unsigned_is_power_of_two! { NonZeroU8 NonZeroU16 NonZeroU32 NonZeroU64 NonZeroU128 NonZeroUsize }
macro_rules! nonzero_min_max_unsigned {
( $( $Ty: ident($Int: ident); )+ ) => {
$(
impl $Ty {
/// The smallest value that can be represented by this non-zero
/// integer type, 1.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), 1", stringify!($Int), ");")]
/// ```
2023-04-16 16:33:38 +02:00
#[stable(feature = "nonzero_min_max", since = "1.70.0")]
pub const MIN: Self = Self::new(1).unwrap();
/// The largest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
/// ```
2023-04-16 16:33:38 +02:00
#[stable(feature = "nonzero_min_max", since = "1.70.0")]
pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
}
)+
}
}
macro_rules! nonzero_min_max_signed {
( $( $Ty: ident($Int: ident); )+ ) => {
$(
impl $Ty {
/// The smallest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MIN`].")]
///
/// Note: While most integer types are defined for every whole
/// number between `MIN` and `MAX`, signed non-zero integers are
/// a special case. They have a "gap" at 0.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), ", stringify!($Int), "::MIN);")]
/// ```
2023-04-16 16:33:38 +02:00
#[stable(feature = "nonzero_min_max", since = "1.70.0")]
pub const MIN: Self = Self::new(<$Int>::MIN).unwrap();
/// The largest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
///
/// Note: While most integer types are defined for every whole
/// number between `MIN` and `MAX`, signed non-zero integers are
/// a special case. They have a "gap" at 0.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
/// ```
2023-04-16 16:33:38 +02:00
#[stable(feature = "nonzero_min_max", since = "1.70.0")]
pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
}
)+
}
}
nonzero_min_max_unsigned! {
NonZeroU8(u8);
NonZeroU16(u16);
NonZeroU32(u32);
NonZeroU64(u64);
NonZeroU128(u128);
NonZeroUsize(usize);
}
nonzero_min_max_signed! {
NonZeroI8(i8);
NonZeroI16(i16);
NonZeroI32(i32);
NonZeroI64(i64);
NonZeroI128(i128);
NonZeroIsize(isize);
}
macro_rules! nonzero_bits {
( $( $Ty: ident($Int: ty); )+ ) => {
$(
impl $Ty {
/// The size of this non-zero integer type in bits.
///
#[doc = concat!("This value is equal to [`", stringify!($Int), "::BITS`].")]
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::BITS, ", stringify!($Int), "::BITS);")]
/// ```
2022-12-12 13:50:00 +01:00
#[stable(feature = "nonzero_bits", since = "1.67.0")]
pub const BITS: u32 = <$Int>::BITS;
}
)+
}
}
nonzero_bits! {
NonZeroU8(u8);
NonZeroI8(i8);
NonZeroU16(u16);
NonZeroI16(i16);
NonZeroU32(u32);
NonZeroI32(i32);
NonZeroU64(u64);
NonZeroI64(i64);
NonZeroU128(u128);
NonZeroI128(i128);
NonZeroUsize(usize);
NonZeroIsize(isize);
}
nonzero_integer! {
Self = NonZeroU8,
Primitive = unsigned u8,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroU16,
Primitive = unsigned u16,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroU32,
Primitive = unsigned u32,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroU64,
Primitive = unsigned u64,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroU128,
Primitive = unsigned u128,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroUsize,
Primitive = unsigned usize,
feature = "nonzero",
original_stabilization = "1.28.0",
}
nonzero_integer! {
Self = NonZeroI8,
Primitive = signed i8,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}
nonzero_integer! {
Self = NonZeroI16,
Primitive = signed i16,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}
nonzero_integer! {
Self = NonZeroI32,
Primitive = signed i32,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}
nonzero_integer! {
Self = NonZeroI64,
Primitive = signed i64,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}
nonzero_integer! {
Self = NonZeroI128,
Primitive = signed i128,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}
nonzero_integer! {
Self = NonZeroIsize,
Primitive = signed isize,
feature = "signed_nonzero",
original_stabilization = "1.34.0",
}