bjoernager/rust
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rust/library/core/src/num/int_macros.rs
Josh Triplett 3ece63b64e Temporarily rename int_roundings functions to avoid conflicts 
These functions are unstable, but because they're inherent they still
introduce conflicts with stable trait functions in crates. Temporarily
rename them to fix these conflicts, until we can resolve those conflicts
in a better way.
2021-09-22 13:56:01 -07:00

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macro_rules! int_impl {
($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr,
$rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
$reversed:expr, $le_bytes:expr, $be_bytes:expr,
$to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr) => {
/// The smallest value that can be represented by this integer type,
#[doc = concat!("-2<sup>", $BITS_MINUS_ONE, "</sup>.")]
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")]
/// ```
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
/// The largest value that can be represented by this integer type,
#[doc = concat!("2<sup>", $BITS_MINUS_ONE, "</sup> - 1.")]
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")]
/// ```
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MAX: Self = !Self::MIN;
/// The size of this integer type in bits.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")]
/// ```
#[stable(feature = "int_bits_const", since = "1.53.0")]
pub const BITS: u32 = $BITS;
/// Converts a string slice in a given base to an integer.
///
/// The string is expected to be an optional `+` or `-` sign followed by digits.
/// Leading and trailing whitespace represent an error. Digits are a subset of these characters,
/// depending on `radix`:
///
/// * `0-9`
/// * `a-z`
/// * `A-Z`
///
/// # Panics
///
/// This function panics if `radix` is not in the range from 2 to 36.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::from_str_radix(\"A\", 16), Ok(10));")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError> {
from_str_radix(src, radix)
}
/// Returns the number of ones in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 0b100_0000", stringify!($SelfT), ";")]
///
/// assert_eq!(n.count_ones(), 1);
/// ```
///
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[doc(alias = "popcount")]
#[doc(alias = "popcnt")]
#[inline(always)]
pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() }
/// Returns the number of zeros in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn count_zeros(self) -> u32 {
(!self).count_ones()
}
/// Returns the number of leading zeros in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = -1", stringify!($SelfT), ";")]
///
/// assert_eq!(n.leading_zeros(), 0);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn leading_zeros(self) -> u32 {
(self as $UnsignedT).leading_zeros()
}
/// Returns the number of trailing zeros in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = -4", stringify!($SelfT), ";")]
///
/// assert_eq!(n.trailing_zeros(), 2);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn trailing_zeros(self) -> u32 {
(self as $UnsignedT).trailing_zeros()
}
/// Returns the number of leading ones in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = -1", stringify!($SelfT), ";")]
///
#[doc = concat!("assert_eq!(n.leading_ones(), ", stringify!($BITS), ");")]
/// ```
#[stable(feature = "leading_trailing_ones", since = "1.46.0")]
#[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
#[inline(always)]
pub const fn leading_ones(self) -> u32 {
(self as $UnsignedT).leading_ones()
}
/// Returns the number of trailing ones in the binary representation of `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 3", stringify!($SelfT), ";")]
///
/// assert_eq!(n.trailing_ones(), 2);
/// ```
#[stable(feature = "leading_trailing_ones", since = "1.46.0")]
#[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")]
#[inline(always)]
pub const fn trailing_ones(self) -> u32 {
(self as $UnsignedT).trailing_ones()
}
/// Shifts the bits to the left by a specified amount, `n`,
/// wrapping the truncated bits to the end of the resulting integer.
///
/// Please note this isn't the same operation as the `<<` shifting operator!
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
#[doc = concat!("let m = ", $rot_result, ";")]
///
#[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn rotate_left(self, n: u32) -> Self {
(self as $UnsignedT).rotate_left(n) as Self
}
/// Shifts the bits to the right by a specified amount, `n`,
/// wrapping the truncated bits to the beginning of the resulting
/// integer.
///
/// Please note this isn't the same operation as the `>>` shifting operator!
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
#[doc = concat!("let m = ", $rot_op, ";")]
///
#[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn rotate_right(self, n: u32) -> Self {
(self as $UnsignedT).rotate_right(n) as Self
}
/// Reverses the byte order of the integer.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
///
/// let m = n.swap_bytes();
///
#[doc = concat!("assert_eq!(m, ", $swapped, ");")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn swap_bytes(self) -> Self {
(self as $UnsignedT).swap_bytes() as Self
}
/// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit,
/// second least-significant bit becomes second most-significant bit, etc.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")]
/// let m = n.reverse_bits();
///
#[doc = concat!("assert_eq!(m, ", $reversed, ");")]
#[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")]
/// ```
#[stable(feature = "reverse_bits", since = "1.37.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.37.0")]
#[inline(always)]
#[must_use]
pub const fn reverse_bits(self) -> Self {
(self as $UnsignedT).reverse_bits() as Self
}
/// Converts an integer from big endian to the target's endianness.
///
/// On big endian this is a no-op. On little endian the bytes are swapped.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "big") {
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")]
/// } else {
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")]
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[inline]
pub const fn from_be(x: Self) -> Self {
#[cfg(target_endian = "big")]
{
x
}
#[cfg(not(target_endian = "big"))]
{
x.swap_bytes()
}
}
/// Converts an integer from little endian to the target's endianness.
///
/// On little endian this is a no-op. On big endian the bytes are swapped.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "little") {
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")]
/// } else {
#[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")]
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[inline]
pub const fn from_le(x: Self) -> Self {
#[cfg(target_endian = "little")]
{
x
}
#[cfg(not(target_endian = "little"))]
{
x.swap_bytes()
}
}
/// Converts `self` to big endian from the target's endianness.
///
/// On big endian this is a no-op. On little endian the bytes are swapped.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "big") {
/// assert_eq!(n.to_be(), n)
/// } else {
/// assert_eq!(n.to_be(), n.swap_bytes())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[inline]
pub const fn to_be(self) -> Self { // or not to be?
#[cfg(target_endian = "big")]
{
self
}
#[cfg(not(target_endian = "big"))]
{
self.swap_bytes()
}
}
/// Converts `self` to little endian from the target's endianness.
///
/// On little endian this is a no-op. On big endian the bytes are swapped.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "little") {
/// assert_eq!(n.to_le(), n)
/// } else {
/// assert_eq!(n.to_le(), n.swap_bytes())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[inline]
pub const fn to_le(self) -> Self {
#[cfg(target_endian = "little")]
{
self
}
#[cfg(not(target_endian = "little"))]
{
self.swap_bytes()
}
}
/// Checked integer addition. Computes `self + rhs`, returning `None`
/// if overflow occurred.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_add(self, rhs: Self) -> Option<Self> {
let (a, b) = self.overflowing_add(rhs);
if unlikely!(b) {None} else {Some(a)}
}
/// Unchecked integer addition. Computes `self + rhs`, assuming overflow
/// cannot occur.
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_add`] would return `None`.
///
#[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
#[unstable(
feature = "unchecked_math",
reason = "niche optimization path",
issue = "85122",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
#[inline(always)]
pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
// SAFETY: the caller must uphold the safety contract for
// `unchecked_add`.
unsafe { intrinsics::unchecked_add(self, rhs) }
}
/// Checked integer subtraction. Computes `self - rhs`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
let (a, b) = self.overflowing_sub(rhs);
if unlikely!(b) {None} else {Some(a)}
}
/// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
/// cannot occur.
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_sub`] would return `None`.
///
#[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
#[unstable(
feature = "unchecked_math",
reason = "niche optimization path",
issue = "85122",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
#[inline(always)]
pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
// SAFETY: the caller must uphold the safety contract for
// `unchecked_sub`.
unsafe { intrinsics::unchecked_sub(self, rhs) }
}
/// Checked integer multiplication. Computes `self * rhs`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_mul(self, rhs: Self) -> Option<Self> {
let (a, b) = self.overflowing_mul(rhs);
if unlikely!(b) {None} else {Some(a)}
}
/// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
/// cannot occur.
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_mul`] would return `None`.
///
#[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
#[unstable(
feature = "unchecked_math",
reason = "niche optimization path",
issue = "85122",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
#[inline(always)]
pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
// SAFETY: the caller must uphold the safety contract for
// `unchecked_mul`.
unsafe { intrinsics::unchecked_mul(self, rhs) }
}
/// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
/// or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")]
#[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_div(self, rhs: Self) -> Option<Self> {
if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
None
} else {
// SAFETY: div by zero and by INT_MIN have been checked above
Some(unsafe { intrinsics::unchecked_div(self, rhs) })
}
}
/// Checked Euclidean division. Computes `self.div_euclid(rhs)`,
/// returning `None` if `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")]
#[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")]
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
None
} else {
Some(self.div_euclid(rhs))
}
}
/// Checked integer remainder. Computes `self % rhs`, returning `None` if
/// `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
None
} else {
// SAFETY: div by zero and by INT_MIN have been checked above
Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
}
}
/// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None`
/// if `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")]
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
if unlikely!(rhs == 0 || (self == Self::MIN && rhs == -1)) {
None
} else {
Some(self.rem_euclid(rhs))
}
}
/// Checked negation. Computes `-self`, returning `None` if `self == MIN`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[inline]
pub const fn checked_neg(self) -> Option<Self> {
let (a, b) = self.overflowing_neg();
if unlikely!(b) {None} else {Some(a)}
}
/// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger
/// than or equal to the number of bits in `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
let (a, b) = self.overflowing_shl(rhs);
if unlikely!(b) {None} else {Some(a)}
}
/// Unchecked shift left. Computes `self << rhs`, assuming that
/// `rhs` is less than the number of bits in `self`.
///
/// # Safety
///
/// This results in undefined behavior if `rhs` is larger than
/// or equal to the number of bits in `self`,
/// i.e. when [`checked_shl`] would return `None`.
///
#[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
#[unstable(
feature = "unchecked_math",
reason = "niche optimization path",
issue = "85122",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
#[inline(always)]
pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self {
// SAFETY: the caller must uphold the safety contract for
// `unchecked_shl`.
unsafe { intrinsics::unchecked_shl(self, rhs) }
}
/// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is
/// larger than or equal to the number of bits in `self`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")]
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_shr(self, rhs: u32) -> Option<Self> {
let (a, b) = self.overflowing_shr(rhs);
if unlikely!(b) {None} else {Some(a)}
}
/// Unchecked shift right. Computes `self >> rhs`, assuming that
/// `rhs` is less than the number of bits in `self`.
///
/// # Safety
///
/// This results in undefined behavior if `rhs` is larger than
/// or equal to the number of bits in `self`,
/// i.e. when [`checked_shr`] would return `None`.
///
#[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")]
#[unstable(
feature = "unchecked_math",
reason = "niche optimization path",
issue = "85122",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
#[inline(always)]
pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self {
// SAFETY: the caller must uphold the safety contract for
// `unchecked_shr`.
unsafe { intrinsics::unchecked_shr(self, rhs) }
}
/// Checked absolute value. Computes `self.abs()`, returning `None` if
/// `self == MIN`.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")]
/// ```
#[stable(feature = "no_panic_abs", since = "1.13.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[inline]
pub const fn checked_abs(self) -> Option<Self> {
if self.is_negative() {
self.checked_neg()
} else {
Some(self)
}
}
/// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")]
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
if exp == 0 {
return Some(1);
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
Some(try_opt!(acc.checked_mul(base)))
}
/// Saturating integer addition. Computes `self + rhs`, saturating at the numeric
/// bounds instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn saturating_add(self, rhs: Self) -> Self {
intrinsics::saturating_add(self, rhs)
}
/// Saturating integer subtraction. Computes `self - rhs`, saturating at the
/// numeric bounds instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn saturating_sub(self, rhs: Self) -> Self {
intrinsics::saturating_sub(self, rhs)
}
/// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN`
/// instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")]
/// ```
#[stable(feature = "saturating_neg", since = "1.45.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[inline(always)]
pub const fn saturating_neg(self) -> Self {
intrinsics::saturating_sub(0, self)
}
/// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self ==
/// MIN` instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "saturating_neg", since = "1.45.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[inline]
pub const fn saturating_abs(self) -> Self {
if self.is_negative() {
self.saturating_neg()
} else {
self
}
}
/// Saturating integer multiplication. Computes `self * rhs`, saturating at the
/// numeric bounds instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_mul(self, rhs: Self) -> Self {
match self.checked_mul(rhs) {
Some(x) => x,
None => if (self < 0) == (rhs < 0) {
Self::MAX
} else {
Self::MIN
}
}
}
/// Saturating integer division. Computes `self / rhs`, saturating at the
/// numeric bounds instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(saturating_div)]
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")]
///
/// ```
///
/// ```should_panic
/// #![feature(saturating_div)]
///
#[doc = concat!("let _ = 1", stringify!($SelfT), ".saturating_div(0);")]
///
/// ```
#[unstable(feature = "saturating_div", issue = "87920")]
#[rustc_const_unstable(feature = "saturating_div", issue = "87920")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_div(self, rhs: Self) -> Self {
match self.overflowing_div(rhs) {
(result, false) => result,
(_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow
}
}
/// Saturating integer exponentiation. Computes `self.pow(exp)`,
/// saturating at the numeric bounds instead of overflowing.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_pow(self, exp: u32) -> Self {
match self.checked_pow(exp) {
Some(x) => x,
None if self < 0 && exp % 2 == 1 => Self::MIN,
None => Self::MAX,
}
}
/// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the
/// boundary of the type.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_add(self, rhs: Self) -> Self {
intrinsics::wrapping_add(self, rhs)
}
/// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the
/// boundary of the type.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")]
#[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_sub(self, rhs: Self) -> Self {
intrinsics::wrapping_sub(self, rhs)
}
/// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at
/// the boundary of the type.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")]
/// assert_eq!(11i8.wrapping_mul(12), -124);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_mul(self, rhs: Self) -> Self {
intrinsics::wrapping_mul(self, rhs)
}
/// Wrapping (modular) division. Computes `self / rhs`, wrapping around at the
/// boundary of the type.
///
/// The only case where such wrapping can occur is when one divides `MIN / -1` on a signed type (where
/// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value
/// that is too large to represent in the type. In such a case, this function returns `MIN` itself.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
/// assert_eq!((-128i8).wrapping_div(-1), -128);
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_div(self, rhs: Self) -> Self {
self.overflowing_div(rhs).0
}
/// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`,
/// wrapping around at the boundary of the type.
///
/// Wrapping will only occur in `MIN / -1` on a signed type (where `MIN` is the negative minimal value
/// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the
/// type. In this case, this method returns `MIN` itself.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")]
/// assert_eq!((-128i8).wrapping_div_euclid(-1), -128);
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_div_euclid(self, rhs: Self) -> Self {
self.overflowing_div_euclid(rhs).0
}
/// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the
/// boundary of the type.
///
/// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y`
/// invalid for `MIN / -1` on a signed type (where `MIN` is the negative minimal value). In such a case,
/// this function returns `0`.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
/// assert_eq!((-128i8).wrapping_rem(-1), 0);
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_rem(self, rhs: Self) -> Self {
self.overflowing_rem(rhs).0
}
/// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around
/// at the boundary of the type.
///
/// Wrapping will only occur in `MIN % -1` on a signed type (where `MIN` is the negative minimal value
/// for the type). In this case, this method returns 0.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")]
/// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0);
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self {
self.overflowing_rem_euclid(rhs).0
}
/// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
/// of the type.
///
/// The only case where such wrapping can occur is when one negates `MIN` on a signed type (where `MIN`
/// is the negative minimal value for the type); this is a positive value that is too large to represent
/// in the type. In such a case, this function returns `MIN` itself.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn wrapping_neg(self) -> Self {
(0 as $SelfT).wrapping_sub(self)
}
/// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes
/// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
///
/// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to
/// the range of the type, rather than the bits shifted out of the LHS being returned to the other end.
/// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function,
/// which may be what you want instead.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(7), -128);")]
#[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(128), -1);")]
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_shl(self, rhs: u32) -> Self {
// SAFETY: the masking by the bitsize of the type ensures that we do not shift
// out of bounds
unsafe {
intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT)
}
}
/// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask`
/// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
///
/// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted
/// to the range of the type, rather than the bits shifted out of the LHS being returned to the other
/// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function,
/// which may be what you want instead.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!((-128", stringify!($SelfT), ").wrapping_shr(7), -1);")]
/// assert_eq!((-128i16).wrapping_shr(64), -128);
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_shr(self, rhs: u32) -> Self {
// SAFETY: the masking by the bitsize of the type ensures that we do not shift
// out of bounds
unsafe {
intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT)
}
}
/// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at
/// the boundary of the type.
///
/// The only case where such wrapping can occur is when one takes the absolute value of the negative
/// minimal value for the type; this is a positive value that is too large to represent in the type. In
/// such a case, this function returns `MIN` itself.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")]
/// assert_eq!((-128i8).wrapping_abs() as u8, 128);
/// ```
#[stable(feature = "no_panic_abs", since = "1.13.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[allow(unused_attributes)]
#[inline]
pub const fn wrapping_abs(self) -> Self {
if self.is_negative() {
self.wrapping_neg()
} else {
self
}
}
/// Computes the absolute value of `self` without any wrapping
/// or panicking.
///
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")]
/// assert_eq!((-128i8).unsigned_abs(), 128u8);
/// ```
#[stable(feature = "unsigned_abs", since = "1.51.0")]
#[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")]
#[inline]
pub const fn unsigned_abs(self) -> $UnsignedT {
self.wrapping_abs() as $UnsignedT
}
/// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
/// wrapping around at the boundary of the type.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")]
/// assert_eq!(3i8.wrapping_pow(5), -13);
/// assert_eq!(3i8.wrapping_pow(6), -39);
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_pow(self, mut exp: u32) -> Self {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc.wrapping_mul(base);
}
exp /= 2;
base = base.wrapping_mul(base);
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.wrapping_mul(base)
}
/// Calculates `self` + `rhs`
///
/// Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would
/// occur. If an overflow would have occurred then the wrapped value is returned.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) {
let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT);
(a as Self, b)
}
/// Calculates `self + rhs + carry` without the ability to overflow.
///
/// Performs "ternary addition" which takes in an extra bit to add, and may return an
/// additional bit of overflow. This allows for chaining together multiple additions
/// to create "big integers" which represent larger values.
///
/// # Examples
///
/// Basic usage
///
/// ```
/// #![feature(bigint_helper_methods)]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, false), (7, false));")]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, true), (8, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), (", stringify!($SelfT), "::MIN, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, true), (", stringify!($SelfT), "::MIN + 1, false));")]
/// ```
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
#[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
let (sum, carry) = (self as $UnsignedT).carrying_add(rhs as $UnsignedT, carry);
(sum as $SelfT, carry)
}
/// Calculates `self` - `rhs`
///
/// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
/// would occur. If an overflow would have occurred then the wrapped value is returned.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) {
let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT);
(a as Self, b)
}
/// Calculates `self - rhs - borrow` without the ability to overflow.
///
/// Performs "ternary subtraction" which takes in an extra bit to subtract, and may return
/// an additional bit of overflow. This allows for chaining together multiple subtractions
/// to create "big integers" which represent larger values.
///
/// # Examples
///
/// Basic usage
///
/// ```
/// #![feature(bigint_helper_methods)]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, false), (3, false));")]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, true), (2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, false), (", stringify!($SelfT), "::MAX, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, true), (", stringify!($SelfT), "::MAX - 1, false));")]
/// ```
#[unstable(feature = "bigint_helper_methods", issue = "85532")]
#[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
let (sum, borrow) = (self as $UnsignedT).borrowing_sub(rhs as $UnsignedT, borrow);
(sum as $SelfT, borrow)
}
/// Calculates the multiplication of `self` and `rhs`.
///
/// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow
/// would occur. If an overflow would have occurred then the wrapped value is returned.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")]
/// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true));
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) {
let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT);
(a as Self, b)
}
/// Calculates the divisor when `self` is divided by `rhs`.
///
/// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
/// occur. If an overflow would occur then self is returned.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[inline]
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
if unlikely!(self == Self::MIN && rhs == -1) {
(self, true)
} else {
(self / rhs, false)
}
}
/// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
///
/// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
/// occur. If an overflow would occur then `self` is returned.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[inline]
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) {
if unlikely!(self == Self::MIN && rhs == -1) {
(self, true)
} else {
(self.div_euclid(rhs), false)
}
}
/// Calculates the remainder when `self` is divided by `rhs`.
///
/// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
/// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
///
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")]
/// ```
#[inline]
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) {
if unlikely!(self == Self::MIN && rhs == -1) {
(0, true)
} else {
(self % rhs, false)
}
}
/// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`.
///
/// Returns a tuple of the remainder after dividing along with a boolean indicating whether an
/// arithmetic overflow would occur. If an overflow would occur then 0 is returned.
///
/// # Panics
///
/// This function will panic if `rhs` is 0.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")]
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
if unlikely!(self == Self::MIN && rhs == -1) {
(0, true)
} else {
(self.rem_euclid(rhs), false)
}
}
/// Negates self, overflowing if this is equal to the minimum value.
///
/// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow
/// happened. If `self` is the minimum value (e.g., `i32::MIN` for values of type `i32`), then the
/// minimum value will be returned again and `true` will be returned for an overflow happening.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[inline]
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[allow(unused_attributes)]
pub const fn overflowing_neg(self) -> (Self, bool) {
if unlikely!(self == Self::MIN) {
(Self::MIN, true)
} else {
(-self, false)
}
}
/// Shifts self left by `rhs` bits.
///
/// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
/// value was larger than or equal to the number of bits. If the shift value is too large, then value is
/// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")]
/// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) {
(self.wrapping_shl(rhs), (rhs > ($BITS - 1)))
}
/// Shifts self right by `rhs` bits.
///
/// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
/// value was larger than or equal to the number of bits. If the shift value is too large, then value is
/// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
/// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
(self.wrapping_shr(rhs), (rhs > ($BITS - 1)))
}
/// Computes the absolute value of `self`.
///
/// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow
/// happened. If self is the minimum value
#[doc = concat!("(e.g., ", stringify!($SelfT), "::MIN for values of type ", stringify!($SelfT), "),")]
/// then the minimum value will be returned again and true will be returned
/// for an overflow happening.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")]
#[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[stable(feature = "no_panic_abs", since = "1.13.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline]
pub const fn overflowing_abs(self) -> (Self, bool) {
(self.wrapping_abs(), self == Self::MIN)
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
///
/// Returns a tuple of the exponentiation along with a bool indicating
/// whether an overflow happened.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")]
/// assert_eq!(3i8.overflowing_pow(5), (-13, true));
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
if exp == 0 {
return (1,false);
}
let mut base = self;
let mut acc: Self = 1;
let mut overflown = false;
// Scratch space for storing results of overflowing_mul.
let mut r;
while exp > 1 {
if (exp & 1) == 1 {
r = acc.overflowing_mul(base);
acc = r.0;
overflown |= r.1;
}
exp /= 2;
r = base.overflowing_mul(base);
base = r.0;
overflown |= r.1;
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
r = acc.overflowing_mul(base);
r.1 |= overflown;
r
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")]
///
/// assert_eq!(x.pow(5), 32);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn pow(self, mut exp: u32) -> Self {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc * base;
}
exp /= 2;
base = base * base;
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc * base
}
/// Calculates the quotient of Euclidean division of `self` by `rhs`.
///
/// This computes the integer `q` such that `self = q * rhs + r`, with
/// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`.
///
/// In other words, the result is `self / rhs` rounded to the integer `q`
/// such that `self >= q * rhs`.
/// If `self > 0`, this is equal to round towards zero (the default in Rust);
/// if `self < 0`, this is equal to round towards +/- infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is 0 or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
/// let b = 4;
///
/// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
/// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
/// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
/// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn div_euclid(self, rhs: Self) -> Self {
let q = self / rhs;
if self % rhs < 0 {
return if rhs > 0 { q - 1 } else { q + 1 }
}
q
}
/// Calculates the least nonnegative remainder of `self (mod rhs)`.
///
/// This is done as if by the Euclidean division algorithm -- given
/// `r = self.rem_euclid(rhs)`, `self = rhs * self.div_euclid(rhs) + r`, and
/// `0 <= r < abs(rhs)`.
///
/// # Panics
///
/// This function will panic if `rhs` is 0 or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
/// let b = 4;
///
/// assert_eq!(a.rem_euclid(b), 3);
/// assert_eq!((-a).rem_euclid(b), 1);
/// assert_eq!(a.rem_euclid(-b), 3);
/// assert_eq!((-a).rem_euclid(-b), 1);
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn rem_euclid(self, rhs: Self) -> Self {
let r = self % rhs;
if r < 0 {
if rhs < 0 {
r - rhs
} else {
r + rhs
}
} else {
r
}
}
/// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is 0 or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
/// let b = 3;
///
/// assert_eq!(a.unstable_div_floor(b), 2);
/// assert_eq!(a.unstable_div_floor(-b), -3);
/// assert_eq!((-a).unstable_div_floor(b), -3);
/// assert_eq!((-a).unstable_div_floor(-b), 2);
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn unstable_div_floor(self, rhs: Self) -> Self {
let d = self / rhs;
let r = self % rhs;
if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
d - 1
} else {
d
}
}
/// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is 0 or the division results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
/// let b = 3;
///
/// assert_eq!(a.unstable_div_ceil(b), 3);
/// assert_eq!(a.unstable_div_ceil(-b), -2);
/// assert_eq!((-a).unstable_div_ceil(b), -2);
/// assert_eq!((-a).unstable_div_ceil(-b), 3);
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn unstable_div_ceil(self, rhs: Self) -> Self {
let d = self / rhs;
let r = self % rhs;
if (r > 0 && rhs > 0) || (r < 0 && rhs < 0) {
d + 1
} else {
d
}
}
/// If `rhs` is positive, calculates the smallest value greater than or
/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
/// calculates the largest value less than or equal to `self` that is a
/// multiple of `rhs`.
///
/// # Panics
///
/// This function will panic if `rhs` is 0 or the operation results in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".unstable_next_multiple_of(8), 16);")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".unstable_next_multiple_of(8), 24);")]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".unstable_next_multiple_of(-8), 16);")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".unstable_next_multiple_of(-8), 16);")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").unstable_next_multiple_of(8), -16);")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").unstable_next_multiple_of(8), -16);")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").unstable_next_multiple_of(-8), -16);")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").unstable_next_multiple_of(-8), -24);")]
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn unstable_next_multiple_of(self, rhs: Self) -> Self {
// This would otherwise fail when calculating `r` when self == T::MIN.
if rhs == -1 {
return self;
}
let r = self % rhs;
let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
r + rhs
} else {
r
};
if m == 0 {
self
} else {
self + (rhs - m)
}
}
/// If `rhs` is positive, calculates the smallest value greater than or
/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
/// calculates the largest value less than or equal to `self` that is a
/// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
/// would result in overflow.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")]
#[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
// This would otherwise fail when calculating `r` when self == T::MIN.
if rhs == -1 {
return Some(self);
}
let r = try_opt!(self.checked_rem(rhs));
let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
try_opt!(r.checked_add(rhs))
} else {
r
};
if m == 0 {
Some(self)
} else {
self.checked_add(try_opt!(rhs.checked_sub(m)))
}
}
/// Returns the logarithm of the number with respect to an arbitrary base.
///
/// This method might not be optimized owing to implementation details;
/// `log2` can produce results more efficiently for base 2, and `log10`
/// can produce results more efficiently for base 10.
///
/// # Panics
///
/// When the number is zero, or if the base is not at least 2; it
/// panics in debug mode and the return value is wrapped to 0 in release
/// mode (the only situation in which the method can return 0).
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
#[rustc_inherit_overflow_checks]
#[allow(arithmetic_overflow)]
pub const fn log(self, base: Self) -> u32 {
match self.checked_log(base) {
Some(n) => n,
None => {
// In debug builds, trigger a panic on None.
// This should optimize completely out in release builds.
let _ = Self::MAX + 1;
0
},
}
}
/// Returns the base 2 logarithm of the number.
///
/// # Panics
///
/// When the number is zero it panics in debug mode and the return value
/// is wrapped to 0 in release mode (the only situation in which the
/// method can return 0).
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
#[rustc_inherit_overflow_checks]
#[allow(arithmetic_overflow)]
pub const fn log2(self) -> u32 {
match self.checked_log2() {
Some(n) => n,
None => {
// In debug builds, trigger a panic on None.
// This should optimize completely out in release builds.
let _ = Self::MAX + 1;
0
},
}
}
/// Returns the base 10 logarithm of the number.
///
/// # Panics
///
/// When the number is zero it panics in debug mode and the return value
/// is wrapped to 0 in release mode (the only situation in which the
/// method can return 0).
///
/// # Example
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
#[rustc_inherit_overflow_checks]
#[allow(arithmetic_overflow)]
pub const fn log10(self) -> u32 {
match self.checked_log10() {
Some(n) => n,
None => {
// In debug builds, trigger a panic on None.
// This should optimize completely out in release builds.
let _ = Self::MAX + 1;
0
},
}
}
/// Returns the logarithm of the number with respect to an arbitrary base.
///
/// Returns `None` if the number is negative or zero, or if the base is not at least 2.
///
/// This method might not be optimized owing to implementation details;
/// `checked_log2` can produce results more efficiently for base 2, and
/// `checked_log10` can produce results more efficiently for base 10.
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_log(self, base: Self) -> Option<u32> {
if self <= 0 || base <= 1 {
None
} else {
let mut n = 0;
let mut r = self;
// Optimization for 128 bit wide integers.
if Self::BITS == 128 {
let b = Self::log2(self) / (Self::log2(base) + 1);
n += b;
r /= base.pow(b as u32);
}
while r >= base {
r /= base;
n += 1;
}
Some(n)
}
}
/// Returns the base 2 logarithm of the number.
///
/// Returns `None` if the number is negative or zero.
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_log2(self) -> Option<u32> {
if self <= 0 {
None
} else {
// SAFETY: We just checked that this number is positive
let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 };
Some(log)
}
}
/// Returns the base 10 logarithm of the number.
///
/// Returns `None` if the number is negative or zero.
///
/// # Example
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_log10(self) -> Option<u32> {
int_log10::$ActualT(self as $ActualT)
}
/// Computes the absolute value of `self`.
///
/// # Overflow behavior
///
/// The absolute value of
#[doc = concat!("`", stringify!($SelfT), "::MIN`")]
/// cannot be represented as an
#[doc = concat!("`", stringify!($SelfT), "`,")]
/// and attempting to calculate it will cause an overflow. This means
/// that code in debug mode will trigger a panic on this case and
/// optimized code will return
#[doc = concat!("`", stringify!($SelfT), "::MIN`")]
/// without a panic.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")]
#[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[allow(unused_attributes)]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn abs(self) -> Self {
// Note that the #[rustc_inherit_overflow_checks] and #[inline]
// above mean that the overflow semantics of the subtraction
// depend on the crate we're being called from.
if self.is_negative() {
-self
} else {
self
}
}
/// Returns a number representing sign of `self`.
///
/// - `0` if the number is zero
/// - `1` if the number is positive
/// - `-1` if the number is negative
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")]
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")]
#[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")]
#[inline(always)]
pub const fn signum(self) -> Self {
match self {
n if n > 0 => 1,
0 => 0,
_ => -1,
}
}
/// Returns `true` if `self` is positive and `false` if the number is zero or
/// negative.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")]
#[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn is_positive(self) -> bool { self > 0 }
/// Returns `true` if `self` is negative and `false` if the number is zero or
/// positive.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")]
#[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[inline(always)]
pub const fn is_negative(self) -> bool { self < 0 }
/// Return the memory representation of this integer as a byte array in
/// big-endian (network) byte order.
///
#[doc = $to_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")]
#[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")]
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
#[inline]
pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
self.to_be().to_ne_bytes()
}
/// Return the memory representation of this integer as a byte array in
/// little-endian byte order.
///
#[doc = $to_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")]
#[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")]
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
#[inline]
pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
self.to_le().to_ne_bytes()
}
/// Return the memory representation of this integer as a byte array in
/// native byte order.
///
/// As the target platform's native endianness is used, portable code
/// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate,
/// instead.
///
#[doc = $to_xe_bytes_doc]
///
/// [`to_be_bytes`]: Self::to_be_bytes
/// [`to_le_bytes`]: Self::to_le_bytes
///
/// # Examples
///
/// ```
#[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")]
/// assert_eq!(
/// bytes,
/// if cfg!(target_endian = "big") {
#[doc = concat!(" ", $be_bytes)]
/// } else {
#[doc = concat!(" ", $le_bytes)]
/// }
/// );
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
// SAFETY: const sound because integers are plain old datatypes so we can always
// transmute them to arrays of bytes
#[inline]
pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
// SAFETY: integers are plain old datatypes so we can always transmute them to
// arrays of bytes
unsafe { mem::transmute(self) }
}
/// Create an integer value from its representation as a byte array in
/// big endian.
///
#[doc = $to_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
/// use std::convert::TryInto;
///
#[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
/// *input = rest;
#[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")]
/// }
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
#[inline]
pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
Self::from_be(Self::from_ne_bytes(bytes))
}
/// Create an integer value from its representation as a byte array in
/// little endian.
///
#[doc = $to_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
/// use std::convert::TryInto;
///
#[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
/// *input = rest;
#[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")]
/// }
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
#[inline]
pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
Self::from_le(Self::from_ne_bytes(bytes))
}
/// Create an integer value from its memory representation as a byte
/// array in native endianness.
///
/// As the target platform's native endianness is used, portable code
/// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
/// appropriate instead.
///
/// [`from_be_bytes`]: Self::from_be_bytes
/// [`from_le_bytes`]: Self::from_le_bytes
///
#[doc = $to_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
#[doc = concat!(" ", $be_bytes)]
/// } else {
#[doc = concat!(" ", $le_bytes)]
/// });
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
/// use std::convert::TryInto;
///
#[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")]
/// *input = rest;
#[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
/// }
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
// SAFETY: const sound because integers are plain old datatypes so we can always
// transmute to them
#[inline]
pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
// SAFETY: integers are plain old datatypes so we can always transmute to them
unsafe { mem::transmute(bytes) }
}
/// New code should prefer to use
#[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")]
///
/// Returns the smallest value that can be represented by this integer type.
#[stable(feature = "rust1", since = "1.0.0")]
#[inline(always)]
#[rustc_promotable]
#[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
#[rustc_deprecated(since = "TBD", reason = "replaced by the `MIN` associated constant on this type")]
pub const fn min_value() -> Self {
Self::MIN
}
/// New code should prefer to use
#[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")]
///
/// Returns the largest value that can be represented by this integer type.
#[stable(feature = "rust1", since = "1.0.0")]
#[inline(always)]
#[rustc_promotable]
#[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
#[rustc_deprecated(since = "TBD", reason = "replaced by the `MAX` associated constant on this type")]
pub const fn max_value() -> Self {
Self::MAX
}
}
}
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