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rust/rust/a123594de1feec1732ed9251135bc42ccaaef8f3/./library/core/src/num/int_macros.rs
blob: 1f87f126f9278837c7752a799027eec28541b595 [file]
macro_rules! int_impl {
(
Self = $SelfT:ty,
ActualT = $ActualT:ident,
UnsignedT = $UnsignedT:ty,
// These are all for use *only* in doc comments.
// As such, they're all passed as literals -- passing them as a string
// literal is fine if they need to be multiple code tokens.
// In non-comments, use the associated constants rather than these.
BITS = $BITS:literal,
BITS_MINUS_ONE = $BITS_MINUS_ONE:literal,
Min = $Min:literal,
Max = $Max:literal,
rot = $rot:literal,
rot_op = $rot_op:literal,
rot_result = $rot_result:literal,
swap_op = $swap_op:literal,
swapped = $swapped:literal,
reversed = $reversed:literal,
le_bytes = $le_bytes:literal,
be_bytes = $be_bytes:literal,
to_xe_bytes_doc = $to_xe_bytes_doc:expr,
from_xe_bytes_doc = $from_xe_bytes_doc:expr,
bound_condition = $bound_condition:literal,
) => {
/// The smallest value that can be represented by this integer type
#[doc = concat!("(&minus;2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ").")]
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")]
/// ```
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN: Self = !Self::MAX;
/// The largest value that can be represented by this integer type
#[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> &minus; 1", $bound_condition, ").")]
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")]
/// ```
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MAX: Self = (<$UnsignedT>::MAX >> 1) as Self;
/// 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 = <$UnsignedT>::BITS;
/// Returns the number of ones in the binary representation of `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = 0b100_0000", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() }
/// Returns the number of zeros in the binary representation of `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn count_zeros(self) -> u32 {
(!self).count_ones()
}
/// Returns the number of leading zeros in the binary representation of `self`.
///
/// Depending on what you're doing with the value, you might also be interested in the
/// [`ilog2`] function which returns a consistent number, even if the type widens.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = -1", stringify!($SelfT), ";")]
///
/// assert_eq!(n.leading_zeros(), 0);
/// ```
#[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")]
#[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 leading_zeros(self) -> u32 {
(self as $UnsignedT).leading_zeros()
}
/// Returns the number of trailing zeros in the binary representation of `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = -4", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn trailing_zeros(self) -> u32 {
(self as $UnsignedT).trailing_zeros()
}
/// Returns the number of leading ones in the binary representation of `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = -1", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn leading_ones(self) -> u32 {
(self as $UnsignedT).leading_ones()
}
/// Returns the number of trailing ones in the binary representation of `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = 3", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn trailing_ones(self) -> u32 {
(self as $UnsignedT).trailing_ones()
}
/// Returns `self` with only the most significant bit set, or `0` if
/// the input is `0`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
///
/// assert_eq!(n.isolate_highest_one(), 0b_01000000);
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_highest_one(), 0);")]
/// ```
#[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
#[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn isolate_highest_one(self) -> Self {
self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros()))
}
/// Returns `self` with only the least significant bit set, or `0` if
/// the input is `0`.
///
/// # Examples
///
/// ```
#[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")]
///
/// assert_eq!(n.isolate_lowest_one(), 0b_00000100);
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_lowest_one(), 0);")]
/// ```
#[stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
#[rustc_const_stable(feature = "isolate_most_least_significant_one", since = "1.97.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn isolate_lowest_one(self) -> Self {
self & self.wrapping_neg()
}
/// Returns the index of the highest bit set to one in `self`, or `None`
/// if `self` is `0`.
///
/// Note that for non-negative numbers, this is equivalent to
/// [`checked_ilog2`](Self::checked_ilog2).
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".highest_one(), None);")]
#[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".highest_one(), Some(0));")]
#[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".highest_one(), Some(4));")]
#[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".highest_one(), Some(4));")]
/// ```
#[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
#[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn highest_one(self) -> Option<u32> {
(self as $UnsignedT).highest_one()
}
/// Returns the index of the lowest bit set to one in `self`, or `None`
/// if `self` is `0`.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0b0_", stringify!($SelfT), ".lowest_one(), None);")]
#[doc = concat!("assert_eq!(0b1_", stringify!($SelfT), ".lowest_one(), Some(0));")]
#[doc = concat!("assert_eq!(0b1_0000_", stringify!($SelfT), ".lowest_one(), Some(4));")]
#[doc = concat!("assert_eq!(0b1_1111_", stringify!($SelfT), ".lowest_one(), Some(0));")]
/// ```
#[stable(feature = "int_lowest_highest_one", since = "1.97.0")]
#[rustc_const_stable(feature = "int_lowest_highest_one", since = "1.97.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn lowest_one(self) -> Option<u32> {
(self as $UnsignedT).lowest_one()
}
/// Returns the bit pattern of `self` reinterpreted as an unsigned integer of the same size.
///
/// This produces the same result as an `as` cast, but ensures that the bit-width remains
/// the same.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = -1", stringify!($SelfT), ";")]
///
#[doc = concat!("assert_eq!(n.cast_unsigned(), ", stringify!($UnsignedT), "::MAX);")]
/// ```
#[stable(feature = "integer_sign_cast", since = "1.87.0")]
#[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn cast_unsigned(self) -> $UnsignedT {
self as $UnsignedT
}
/// Saturating conversion of `self` to an unsigned integer of the same size.
///
/// Negative values are clamped to `0`.
///
/// For other kinds of unsigned integer casts, see
/// [`cast_unsigned`](Self::cast_unsigned),
/// [`checked_cast_unsigned`](Self::checked_cast_unsigned),
/// or [`strict_cast_unsigned`](Self::strict_cast_unsigned).
///
/// # Examples
///
/// ```
/// #![feature(integer_cast_extras)]
#[doc = concat!("let n = ", stringify!($SelfT), "::MIN;")]
///
#[doc = concat!("assert_eq!(n.saturating_cast_unsigned(), 0", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!(64", stringify!($SelfT), ".saturating_cast_unsigned(), 64", stringify!($UnsignedT), ");")]
/// ```
#[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
#[unstable(feature = "integer_cast_extras", issue = "154650")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn saturating_cast_unsigned(self) -> $UnsignedT {
if self >= 0 {
self.cast_unsigned()
} else {
0
}
}
/// Checked conversion of `self` to an unsigned integer of the same size,
/// returning `None` if `self` is negative.
///
/// For other kinds of unsigned integer casts, see
/// [`cast_unsigned`](Self::cast_unsigned),
/// [`saturating_cast_unsigned`](Self::saturating_cast_unsigned),
/// or [`strict_cast_unsigned`](Self::strict_cast_unsigned).
///
/// # Examples
///
/// ```
/// #![feature(integer_cast_extras)]
#[doc = concat!("let n = ", stringify!($SelfT), "::MIN;")]
///
#[doc = concat!("assert_eq!(n.checked_cast_unsigned(), None);")]
#[doc = concat!("assert_eq!(64", stringify!($SelfT), ".checked_cast_unsigned(), Some(64", stringify!($UnsignedT), "));")]
/// ```
#[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
#[unstable(feature = "integer_cast_extras", issue = "154650")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn checked_cast_unsigned(self) -> Option<$UnsignedT> {
if self >= 0 {
Some(self.cast_unsigned())
} else {
None
}
}
/// Strict conversion of `self` to an unsigned integer of the same size,
/// which panics if `self` is negative.
///
/// For other kinds of unsigned integer casts, see
/// [`cast_unsigned`](Self::cast_unsigned),
/// [`checked_cast_unsigned`](Self::checked_cast_unsigned),
/// or [`saturating_cast_unsigned`](Self::saturating_cast_unsigned).
///
/// # Examples
///
/// ```should_panic
/// #![feature(integer_cast_extras)]
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_cast_unsigned();")]
/// ```
#[rustc_const_unstable(feature = "integer_cast_extras", issue = "154650")]
#[unstable(feature = "integer_cast_extras", issue = "154650")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_cast_unsigned(self) -> $UnsignedT {
match self.checked_cast_unsigned() {
Some(n) => n,
None => imp::overflow_panic::cast_integer(),
}
}
/// Shifts the bits to the left by a specified amount, `n`,
/// wrapping the truncated bits to the end of the resulting integer.
///
/// `rotate_left(n)` is equivalent to applying `rotate_left(1)` a total of `n` times. In
/// particular, a rotation by the number of bits in `self` returns the input value
/// unchanged.
///
/// Please note this isn't the same operation as the `<<` shifting operator!
///
/// # Examples
///
/// ```
#[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")]
#[doc = concat!("let m = ", $rot_result, ";")]
///
#[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")]
#[doc = concat!("assert_eq!(n.rotate_left(1024), n);")]
/// ```
#[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.
///
/// `rotate_right(n)` is equivalent to applying `rotate_right(1)` a total of `n` times. In
/// particular, a rotation by the number of bits in `self` returns the input value
/// unchanged.
///
/// Please note this isn't the same operation as the `>>` shifting operator!
///
/// # Examples
///
/// ```
#[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")]
#[doc = concat!("let m = ", $rot_op, ";")]
///
#[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")]
#[doc = concat!("assert_eq!(n.rotate_right(1024), n);")]
/// ```
#[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
///
/// ```
#[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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[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
///
/// ```
#[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 = "reverse_bits", since = "1.37.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn reverse_bits(self) -> Self {
(self as $UnsignedT).reverse_bits() as Self
}
/// Converts an integer from big endian to the target's endianness.
///
/// On big endian this is a no-op. On little endian the bytes are swapped.
///
/// See also [from_be_bytes()](Self::from_be_bytes).
///
/// # Examples
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($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")]
#[must_use]
#[inline]
pub const fn from_be(x: Self) -> Self {
cfg_select! {
target_endian = "big" => x,
_ => 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.
///
/// See also [from_le_bytes()](Self::from_le_bytes).
///
/// # Examples
///
/// ```
#[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!($SelfT), "::from_le(n), n.swap_bytes())")]
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[must_use]
#[inline]
pub const fn from_le(x: Self) -> Self {
cfg_select! {
target_endian = "little" => x,
_ => x.swap_bytes(),
}
}
/// Swaps bytes of `self` on little endian targets.
///
/// On big endian this is a no-op.
///
/// The returned value has the same type as `self`, and will be interpreted
/// as (a potentially different) value of a native-endian
#[doc = concat!("`", stringify!($SelfT), "`.")]
///
/// See [`to_be_bytes()`](Self::to_be_bytes) for a type-safe alternative.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "big") {
/// assert_eq!(n.to_be(), n)
/// } else {
/// assert_eq!(n.to_be(), n.swap_bytes())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn to_be(self) -> Self { // or not to be?
cfg_select! {
target_endian = "big" => self,
_ => self.swap_bytes(),
}
}
/// Swaps bytes of `self` on big endian targets.
///
/// On little endian this is a no-op.
///
/// The returned value has the same type as `self`, and will be interpreted
/// as (a potentially different) value of a native-endian
#[doc = concat!("`", stringify!($SelfT), "`.")]
///
/// See [`to_le_bytes()`](Self::to_le_bytes) for a type-safe alternative.
///
/// # Examples
///
/// ```
#[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")]
///
/// if cfg!(target_endian = "little") {
/// assert_eq!(n.to_le(), n)
/// } else {
/// assert_eq!(n.to_le(), n.swap_bytes())
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn to_le(self) -> Self {
cfg_select! {
target_endian = "little" => self,
_ => self.swap_bytes(),
}
}
/// Checked integer addition. Computes `self + rhs`, returning `None`
/// if overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($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 intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Strict integer addition. Computes `self + rhs`, panicking
/// if overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_add(self, rhs: Self) -> Self {
let (a, b) = self.overflowing_add(rhs);
if b { imp::overflow_panic::add() } else { a }
}
/// Unchecked integer addition. Computes `self + rhs`, assuming overflow
/// cannot occur.
///
/// Calling `x.unchecked_add(y)` is semantically equivalent to calling
/// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`.
///
/// If you're just trying to avoid the panic in debug mode, then **do not**
/// use this. Instead, you're looking for [`wrapping_add`].
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_add`] would return `None`.
///
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
#[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")]
#[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")]
#[stable(feature = "unchecked_math", since = "1.79.0")]
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_add cannot overflow"),
(
lhs: $SelfT = self,
rhs: $SelfT = rhs,
) => !lhs.overflowing_add(rhs).1,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_add(self, rhs)
}
}
/// Checked addition with an unsigned integer. Computes `self + rhs`,
/// returning `None` if overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
let (a, b) = self.overflowing_add_unsigned(rhs);
if intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Strict addition with an unsigned integer. Computes `self + rhs`,
/// panicking if overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_unsigned(2), 3);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_unsigned(3);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_add_unsigned(self, rhs: $UnsignedT) -> Self {
let (a, b) = self.overflowing_add_unsigned(rhs);
if b { imp::overflow_panic::add() } else { a }
}
/// Checked integer subtraction. Computes `self - rhs`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($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 intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Strict integer subtraction. Computes `self - rhs`, panicking if
/// overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).strict_sub(1), ", stringify!($SelfT), "::MIN + 1);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub(3);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_sub(self, rhs: Self) -> Self {
let (a, b) = self.overflowing_sub(rhs);
if b { imp::overflow_panic::sub() } else { a }
}
/// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow
/// cannot occur.
///
/// Calling `x.unchecked_sub(y)` is semantically equivalent to calling
/// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`.
///
/// If you're just trying to avoid the panic in debug mode, then **do not**
/// use this. Instead, you're looking for [`wrapping_sub`].
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_sub`] would return `None`.
///
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
#[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")]
#[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")]
#[stable(feature = "unchecked_math", since = "1.79.0")]
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"),
(
lhs: $SelfT = self,
rhs: $SelfT = rhs,
) => !lhs.overflowing_sub(rhs).1,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_sub(self, rhs)
}
}
/// Checked subtraction with an unsigned integer. Computes `self - rhs`,
/// returning `None` if overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option<Self> {
let (a, b) = self.overflowing_sub_unsigned(rhs);
if intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Strict subtraction with an unsigned integer. Computes `self - rhs`,
/// panicking if overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub_unsigned(2), -1);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = (", stringify!($SelfT), "::MIN + 2).strict_sub_unsigned(3);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_sub_unsigned(self, rhs: $UnsignedT) -> Self {
let (a, b) = self.overflowing_sub_unsigned(rhs);
if b { imp::overflow_panic::sub() } else { a }
}
/// Checked integer multiplication. Computes `self * rhs`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($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 intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Strict integer multiplication. Computes `self * rhs`, panicking if
/// overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.strict_mul(1), ", stringify!($SelfT), "::MAX);")]
/// ```
///
/// The following panics because of overflow:
///
/// ``` should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_mul(self, rhs: Self) -> Self {
let (a, b) = self.overflowing_mul(rhs);
if b { imp::overflow_panic::mul() } else { a }
}
/// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow
/// cannot occur.
///
/// Calling `x.unchecked_mul(y)` is semantically equivalent to calling
/// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`.
///
/// If you're just trying to avoid the panic in debug mode, then **do not**
/// use this. Instead, you're looking for [`wrapping_mul`].
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_mul`] would return `None`.
///
/// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked
#[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")]
#[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")]
#[stable(feature = "unchecked_math", since = "1.79.0")]
#[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"),
(
lhs: $SelfT = self,
rhs: $SelfT = rhs,
) => !lhs.overflowing_mul(rhs).1,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_mul(self, rhs)
}
}
/// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0`
/// or the division results in overflow.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($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!($SelfT), ").checked_div(0), None);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_div(self, rhs: Self) -> Option<Self> {
if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
None
} else {
// SAFETY: div by zero and by INT_MIN have been checked above
Some(unsafe { intrinsics::unchecked_div(self, rhs) })
}
}
/// Strict integer division. Computes `self / rhs`, panicking
/// if overflow occurred.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
/// [`MIN`](Self::MIN) is the negative minimal value for the type); the result of this is `-MIN`, a positive value
/// that is too large to represent in the type.
///
/// Note that this is equivalent to normal division: `MIN / -1` will also panic both in
/// debug and release builds.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div(-1), ", stringify!($Max), ");")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div(-1);")]
/// ```
///
/// The following panics because of division by zero:
///
/// ```should_panic
#[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_div(self, rhs: Self) -> Self {
// Normal division already checks for "div-by-minus-1".
self / rhs
}
/// Checked Euclidean division. Computes `self.div_euclid(rhs)`,
/// returning `None` if `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($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!($SelfT), ").checked_div_euclid(0), None);")]
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> {
// Using `&` helps LLVM see that it is the same check made in division.
if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
None
} else {
Some(self.div_euclid(rhs))
}
}
/// Strict Euclidean division. Computes `self.div_euclid(rhs)`, panicking
/// if overflow occurred.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// The only case where such an overflow can occur is when one divides `MIN / -1` on a signed type (where
/// [`MIN`](Self::MIN) is the negative minimal value for the type); the result of this is `-MIN`, a positive value
/// that is too large to represent in the type.
///
/// Note that this is equivalent to `div_euclid`: `MIN.div_euclid(-1)` will also panic both
/// in debug and release builds.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).strict_div_euclid(-1), ", stringify!($Max), ");")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_div_euclid(-1);")]
/// ```
///
/// The following panics because of division by zero:
///
/// ```should_panic
#[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_div_euclid(self, rhs: Self) -> Self {
// Normal `div_euclid` already checks for "div-by-minus-1".
self.div_euclid(rhs)
}
/// Checked integer division without remainder. Computes `self / rhs`,
/// returning `None` if `rhs == 0`, the division results in overflow,
/// or `self % rhs != 0`.
///
/// # Examples
///
/// ```
/// #![feature(exact_div)]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_exact(-1), Some(", stringify!($Max), "));")]
#[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_div_exact(2), None);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_exact(-1), None);")]
#[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_exact(0), None);")]
/// ```
#[unstable(
feature = "exact_div",
issue = "139911",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_div_exact(self, rhs: Self) -> Option<Self> {
if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
None
} else {
// SAFETY: division by zero and overflow are checked above
unsafe {
if intrinsics::unlikely(intrinsics::unchecked_rem(self, rhs) != 0) {
None
} else {
Some(intrinsics::exact_div(self, rhs))
}
}
}
}
/// Integer division without remainder. Computes `self / rhs`, returning `None` if `self % rhs != 0`.
///
/// # Panics
///
/// This function will panic if `rhs == 0`.
///
/// ## Overflow behavior
///
/// On overflow, this function will panic if overflow checks are enabled (default in debug
/// mode) and wrap if overflow checks are disabled (default in release mode).
///
/// # Examples
///
/// ```
/// #![feature(exact_div)]
#[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(2), Some(32));")]
#[doc = concat!("assert_eq!(64", stringify!($SelfT), ".div_exact(32), Some(2));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).div_exact(-1), Some(", stringify!($Max), "));")]
#[doc = concat!("assert_eq!(65", stringify!($SelfT), ".div_exact(2), None);")]
/// ```
/// ```should_panic
/// #![feature(exact_div)]
#[doc = concat!("let _ = 64", stringify!($SelfT),".div_exact(0);")]
/// ```
/// ```should_panic
/// #![feature(exact_div)]
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.div_exact(-1);")]
/// ```
#[unstable(
feature = "exact_div",
issue = "139911",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn div_exact(self, rhs: Self) -> Option<Self> {
if self % rhs != 0 {
None
} else {
Some(self / rhs)
}
}
/// Unchecked integer division without remainder. Computes `self / rhs`.
///
/// # Safety
///
/// This results in undefined behavior when `rhs == 0`, `self % rhs != 0`, or
#[doc = concat!("`self == ", stringify!($SelfT), "::MIN && rhs == -1`,")]
/// i.e. when [`checked_div_exact`](Self::checked_div_exact) would return `None`.
#[unstable(
feature = "exact_div",
issue = "139911",
)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const unsafe fn unchecked_div_exact(self, rhs: Self) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_div_exact cannot overflow, divide by zero, or leave a remainder"),
(
lhs: $SelfT = self,
rhs: $SelfT = rhs,
) => rhs != 0 && lhs % rhs == 0 && (lhs != <$SelfT>::MIN || rhs != -1),
);
// SAFETY: Same precondition
unsafe { intrinsics::exact_div(self, rhs) }
}
/// Checked integer remainder. Computes `self % rhs`, returning `None` if
/// `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// ```
#[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!($SelfT), "::MIN.checked_rem(-1), None);")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_rem(self, rhs: Self) -> Option<Self> {
if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) {
None
} else {
// SAFETY: div by zero and by INT_MIN have been checked above
Some(unsafe { intrinsics::unchecked_rem(self, rhs) })
}
}
/// Strict integer remainder. Computes `self % rhs`, panicking if
/// the division results in overflow.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
/// signed type (where [`MIN`](Self::MIN) is the negative minimal value), which is invalid due to implementation artifacts.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem(2), 1);")]
/// ```
///
/// The following panics because of division by zero:
///
/// ```should_panic
#[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem(-1);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_rem(self, rhs: Self) -> Self {
let (a, b) = self.overflowing_rem(rhs);
if b { imp::overflow_panic::rem() } else { a }
}
/// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None`
/// if `rhs == 0` or the division results in overflow.
///
/// # Examples
///
/// ```
#[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!($SelfT), "::MIN.checked_rem_euclid(-1), None);")]
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> {
// Using `&` helps LLVM see that it is the same check made in division.
if intrinsics::unlikely(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) {
None
} else {
Some(self.rem_euclid(rhs))
}
}
/// Strict Euclidean remainder. Computes `self.rem_euclid(rhs)`, panicking if
/// the division results in overflow.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// The only case where such an overflow can occur is `x % y` for `MIN / -1` on a
/// signed type (where [`MIN`](Self::MIN) is the negative minimal value), which is invalid due to implementation artifacts.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_rem_euclid(2), 1);")]
/// ```
///
/// The following panics because of division by zero:
///
/// ```should_panic
#[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_rem_euclid(-1);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_rem_euclid(self, rhs: Self) -> Self {
let (a, b) = self.overflowing_rem_euclid(rhs);
if b { imp::overflow_panic::rem() } else { a }
}
/// Checked negation. Computes `-self`, returning `None` if `self == MIN`.
///
/// # Examples
///
/// ```
#[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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_neg(self) -> Option<Self> {
let (a, b) = self.overflowing_neg();
if intrinsics::unlikely(b) { None } else { Some(a) }
}
/// Unchecked negation. Computes `-self`, assuming overflow cannot occur.
///
/// # Safety
///
/// This results in undefined behavior when
#[doc = concat!("`self == ", stringify!($SelfT), "::MIN`,")]
/// i.e. when [`checked_neg`] would return `None`.
///
#[doc = concat!("[`checked_neg`]: ", stringify!($SelfT), "::checked_neg")]
#[stable(feature = "unchecked_neg", since = "1.93.0")]
#[rustc_const_stable(feature = "unchecked_neg", since = "1.93.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_neg(self) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_neg cannot overflow"),
(
lhs: $SelfT = self,
) => !lhs.overflowing_neg().1,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_sub(0, self)
}
}
/// Strict negation. Computes `-self`, panicking if `self == MIN`.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_neg(), -5);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_neg();")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_neg(self) -> Self {
let (a, b) = self.overflowing_neg();
if b { imp::overflow_panic::neg() } else { a }
}
/// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger
/// than or equal to the number of bits in `self`.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")]
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")]
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")]
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_shl(self, rhs: u32) -> Option<Self> {
// Not using overflowing_shl as that's a wrapping shift
if rhs < Self::BITS {
// SAFETY: just checked the RHS is in-range
Some(unsafe { self.unchecked_shl(rhs) })
} else {
None
}
}
/// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger
/// than or equal to the number of bits in `self`.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = 0x1", stringify!($SelfT), ".strict_shl(129);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_shl(self, rhs: u32) -> Self {
let (a, b) = self.overflowing_shl(rhs);
if b { imp::overflow_panic::shl() } else { a }
}
/// Unchecked shift left. Computes `self << rhs`, assuming that
/// `rhs` is less than the number of bits in `self`.
///
/// # Safety
///
/// This results in undefined behavior if `rhs` is larger than
/// or equal to the number of bits in `self`,
/// i.e. when [`checked_shl`] would return `None`.
///
#[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")]
#[stable(feature = "unchecked_shifts", since = "1.93.0")]
#[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"),
(
rhs: u32 = rhs,
) => rhs < <$ActualT>::BITS,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_shl(self, rhs)
}
}
/// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`.
///
/// If `rhs` is larger or equal to the number of bits in `self`,
/// the entire value is shifted out, and `0` is returned.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(4), 0x10);")]
#[doc = concat!("assert_eq!(0x1_", stringify!($SelfT), ".unbounded_shl(129), 0);")]
#[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(0), 0b101);")]
#[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(1), 0b1010);")]
#[doc = concat!("assert_eq!(0b101_", stringify!($SelfT), ".unbounded_shl(2), 0b10100);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(", stringify!($BITS), "), 0);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
#[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(", stringify!($BITS), "), 0);")]
#[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shl(1).unbounded_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
/// ```
#[stable(feature = "unbounded_shifts", since = "1.87.0")]
#[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{
if rhs < Self::BITS {
// SAFETY:
// rhs is just checked to be in-range above
unsafe { self.unchecked_shl(rhs) }
} else {
0
}
}
/// Exact shift left. Computes `self << rhs` as long as it can be reversed losslessly.
///
/// Returns `None` if any bits that would be shifted out differ from the resulting sign bit
/// or if `rhs` >=
#[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
/// Otherwise, returns `Some(self << rhs)`.
///
/// # Examples
///
/// ```
/// #![feature(exact_bitshifts)]
///
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(4), Some(0x10));")]
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 2), Some(1 << ", stringify!($SelfT), "::BITS - 2));")]
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
#[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 2), Some(-0x2 << ", stringify!($SelfT), "::BITS - 2));")]
#[doc = concat!("assert_eq!((-0x2", stringify!($SelfT), ").shl_exact(", stringify!($SelfT), "::BITS - 1), None);")]
/// ```
#[unstable(feature = "exact_bitshifts", issue = "144336")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn shl_exact(self, rhs: u32) -> Option<$SelfT> {
if rhs < self.leading_zeros() || rhs < self.leading_ones() {
// SAFETY: rhs is checked above
Some(unsafe { self.unchecked_shl(rhs) })
} else {
None
}
}
/// Unchecked exact shift left. Computes `self << rhs`, assuming the operation can be
/// losslessly reversed and `rhs` cannot be larger than
#[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
///
/// # Safety
///
/// This results in undefined behavior when `rhs >= self.leading_zeros() && rhs >=
/// self.leading_ones()` i.e. when
#[doc = concat!("[`", stringify!($SelfT), "::shl_exact`]")]
/// would return `None`.
#[unstable(feature = "exact_bitshifts", issue = "144336")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const unsafe fn unchecked_shl_exact(self, rhs: u32) -> $SelfT {
assert_unsafe_precondition!(
check_library_ub,
concat!(stringify!($SelfT), "::unchecked_shl_exact cannot shift out bits that would change the value of the first bit"),
(
zeros: u32 = self.leading_zeros(),
ones: u32 = self.leading_ones(),
rhs: u32 = rhs,
) => rhs < zeros || rhs < ones,
);
// SAFETY: this is guaranteed to be safe by the caller
unsafe { self.unchecked_shl(rhs) }
}
/// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is
/// larger than or equal to the number of bits in `self`.
///
/// # Examples
///
/// ```
#[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> {
// Not using overflowing_shr as that's a wrapping shift
if rhs < Self::BITS {
// SAFETY: just checked the RHS is in-range
Some(unsafe { self.unchecked_shr(rhs) })
} else {
None
}
}
/// Strict shift right. Computes `self >> rhs`, panicking if `rhs` is
/// larger than or equal to the number of bits in `self`.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(128);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_shr(self, rhs: u32) -> Self {
let (a, b) = self.overflowing_shr(rhs);
if b { imp::overflow_panic::shr() } else { 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!($SelfT), "::checked_shr")]
#[stable(feature = "unchecked_shifts", since = "1.93.0")]
#[rustc_const_stable(feature = "unchecked_shifts", since = "1.93.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
#[track_caller]
pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"),
(
rhs: u32 = rhs,
) => rhs < <$ActualT>::BITS,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
intrinsics::unchecked_shr(self, rhs)
}
}
/// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`.
///
/// If `rhs` is larger or equal to the number of bits in `self`,
/// the entire value is shifted out, which yields `0` for a positive number,
/// and `-1` for a negative number.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(4), 0x1);")]
#[doc = concat!("assert_eq!(0x10_", stringify!($SelfT), ".unbounded_shr(129), 0);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.unbounded_shr(129), -1);")]
#[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(0), 0b1010);")]
#[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(1), 0b101);")]
#[doc = concat!("assert_eq!(0b1010_", stringify!($SelfT), ".unbounded_shr(2), 0b10);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(", stringify!($BITS), "), 0);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
#[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(", stringify!($BITS), "), -1);")]
#[doc = concat!("assert_eq!((-13_", stringify!($SelfT), ").unbounded_shr(1).unbounded_shr(", stringify!($BITS_MINUS_ONE), "), -1);")]
/// ```
#[stable(feature = "unbounded_shifts", since = "1.87.0")]
#[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{
if rhs < Self::BITS {
// SAFETY:
// rhs is just checked to be in-range above
unsafe { self.unchecked_shr(rhs) }
} else {
// A shift by `Self::BITS-1` suffices for signed integers, because the sign bit is copied for each of the shifted bits.
// SAFETY:
// `Self::BITS-1` is guaranteed to be less than `Self::BITS`
unsafe { self.unchecked_shr(Self::BITS - 1) }
}
}
/// Exact shift right. Computes `self >> rhs` as long as it can be reversed losslessly.
///
/// Returns `None` if any non-zero bits would be shifted out or if `rhs` >=
#[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
/// Otherwise, returns `Some(self >> rhs)`.
///
/// # Examples
///
/// ```
/// #![feature(exact_bitshifts)]
///
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(4), Some(0x1));")]
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".shr_exact(5), None);")]
/// ```
#[unstable(feature = "exact_bitshifts", issue = "144336")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn shr_exact(self, rhs: u32) -> Option<$SelfT> {
if rhs <= self.trailing_zeros() && rhs < <$SelfT>::BITS {
// SAFETY: rhs is checked above
Some(unsafe { self.unchecked_shr(rhs) })
} else {
None
}
}
/// Unchecked exact shift right. Computes `self >> rhs`, assuming the operation can be
/// losslessly reversed and `rhs` cannot be larger than
#[doc = concat!("`", stringify!($SelfT), "::BITS`.")]
///
/// # Safety
///
/// This results in undefined behavior when `rhs > self.trailing_zeros() || rhs >=
#[doc = concat!(stringify!($SelfT), "::BITS`")]
/// i.e. when
#[doc = concat!("[`", stringify!($SelfT), "::shr_exact`]")]
/// would return `None`.
#[unstable(feature = "exact_bitshifts", issue = "144336")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const unsafe fn unchecked_shr_exact(self, rhs: u32) -> $SelfT {
assert_unsafe_precondition!(
check_library_ub,
concat!(stringify!($SelfT), "::unchecked_shr_exact cannot shift out non-zero bits"),
(
zeros: u32 = self.trailing_zeros(),
bits: u32 = <$SelfT>::BITS,
rhs: u32 = rhs,
) => rhs <= zeros && rhs < bits,
);
// SAFETY: this is guaranteed to be safe by the caller
unsafe { self.unchecked_shr(rhs) }
}
/// Checked absolute value. Computes `self.abs()`, returning `None` if
/// `self == MIN`.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")]
/// ```
#[stable(feature = "no_panic_abs", since = "1.13.0")]
#[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_abs(self) -> Option<Self> {
if self.is_negative() {
self.checked_neg()
} else {
Some(self)
}
}
/// Strict absolute value. Computes `self.abs()`, panicking if
/// `self == MIN`.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").strict_abs(), 5);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.strict_abs();")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_abs(self) -> Self {
if self.is_negative() {
self.strict_neg()
} else {
self
}
}
/// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if
/// overflow occurred.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")]
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".checked_pow(0), Some(1));")]
#[doc = concat!("assert_eq!(", stringify!($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> {
let mut base = self;
let mut acc: Self = 1;
if intrinsics::is_val_statically_known(base) && base.unsigned_abs().is_power_of_two() {
let k = base.unsigned_abs().ilog2();
let shift = try_opt!(k.checked_mul(exp));
return if base < 0 && (exp % 2) == 1 {
(-1 as Self).shl_exact(shift)
} else {
(1 as Self).shl_exact(shift)
}
}
if exp == 0 {
return Some(1);
}
if intrinsics::is_val_statically_known(exp) {
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.
return acc.checked_mul(base);
}
loop {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
// since exp!=0, finally the exp must be 1.
if exp == 1 {
return Some(acc);
}
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
}
}
/// Strict exponentiation. Computes `self.pow(exp)`, panicking if
/// overflow occurred.
///
/// # Panics
///
/// ## Overflow behavior
///
/// This function will always panic on overflow, regardless of whether overflow checks are enabled.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(8", stringify!($SelfT), ".strict_pow(2), 64);")]
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".strict_pow(0), 1);")]
/// ```
///
/// The following panics because of overflow:
///
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")]
/// ```
#[stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[rustc_const_stable(feature = "strict_overflow_ops", since = "1.91.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn strict_pow(self, exp: u32) -> Self {
match self.checked_pow(exp) {
Some(x) => x,
None => imp::overflow_panic::pow(),
}
}
/// Returns the integer square root of the number, rounded down.
///
/// This function returns the **principal (non-negative) square root**.
/// For a given number `n`, although both `x` and `-x` satisfy x<sup>2</sup> = n,
/// this function always returns the non-negative value.
///
/// Returns `None` if `self` is negative.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_isqrt(), Some(3));")]
/// ```
#[stable(feature = "isqrt", since = "1.84.0")]
#[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_isqrt(self) -> Option<Self> {
if self < 0 {
None
} else {
// The upper bound of `$UnsignedT::MAX.isqrt()` told to the compiler
// in the unsigned function also tells it that `result >= 0`
let result = self.cast_unsigned().isqrt().cast_signed();
// Inform the optimizer what the range of outputs is. If
// testing `core` crashes with no panic message and a
// `num::int_sqrt::i*` test failed, it's because your edits
// caused these assertions to become false.
//
// SAFETY: Integer square root is a monotonically nondecreasing
// function, which means that increasing the input will never
// cause the output to decrease. Thus, since the input for
// nonnegative signed integers is bounded by
// `[0, <$ActualT>::MAX]`, sqrt(n) will be bounded by
// `[sqrt(0), sqrt(<$ActualT>::MAX)]`.
unsafe {
const MAX_RESULT: $SelfT = <$SelfT>::MAX.cast_unsigned().isqrt().cast_signed();
crate::hint::assert_unchecked(result <= MAX_RESULT);
}
Some(result)
}
}
/// Saturating integer addition. Computes `self + rhs`, saturating at the numeric
/// bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[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!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn saturating_add(self, rhs: Self) -> Self {
intrinsics::saturating_add(self, rhs)
}
/// Saturating addition with an unsigned integer. Computes `self + rhs`,
/// saturating at the numeric bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self {
// Overflow can only happen at the upper bound
// We cannot use `unwrap_or` here because it is not `const`
match self.checked_add_unsigned(rhs) {
Some(x) => x,
None => Self::MAX,
}
}
/// Saturating integer subtraction. Computes `self - rhs`, saturating at the
/// numeric bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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 subtraction with an unsigned integer. Computes `self - rhs`,
/// saturating at the numeric bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self {
// Overflow can only happen at the lower bound
// We cannot use `unwrap_or` here because it is not `const`
match self.checked_sub_unsigned(rhs) {
Some(x) => x,
None => Self::MIN,
}
}
/// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN`
/// instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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!($SelfT), "::MIN + 1);")]
/// ```
#[stable(feature = "saturating_neg", since = "1.45.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn saturating_neg(self) -> Self {
intrinsics::saturating_sub(0, self)
}
/// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self ==
/// MIN` instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "saturating_neg", since = "1.45.0")]
#[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_abs(self) -> Self {
if self.is_negative() {
self.saturating_neg()
} else {
self
}
}
/// Saturating integer multiplication. Computes `self * rhs`, saturating at the
/// numeric bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($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.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[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!($SelfT), "::MAX);")]
///
/// ```
#[stable(feature = "saturating_div", since = "1.58.0")]
#[rustc_const_stable(feature = "saturating_div", since = "1.58.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_div(self, rhs: Self) -> Self {
match self.overflowing_div(rhs) {
(result, false) => result,
(_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow
}
}
/// Saturating integer exponentiation. Computes `self.pow(exp)`,
/// saturating at the numeric bounds instead of overflowing.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")]
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".saturating_pow(0), 1);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")]
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_pow(self, exp: u32) -> Self {
match self.checked_pow(exp) {
Some(x) => x,
None if self < 0 && exp % 2 == 1 => Self::MIN,
None => Self::MAX,
}
}
/// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the
/// boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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) addition with an unsigned integer. Computes
/// `self + rhs`, wrapping around at the boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self {
self.wrapping_add(rhs as Self)
}
/// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the
/// boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")]
#[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_sub(self, rhs: Self) -> Self {
intrinsics::wrapping_sub(self, rhs)
}
/// Wrapping (modular) subtraction with an unsigned integer. Computes
/// `self - rhs`, wrapping around at the boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")]
#[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self {
self.wrapping_sub(rhs as Self)
}
/// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at
/// the boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($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`](Self::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`](Self::MIN) itself.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")]
/// assert_eq!((-128i8).wrapping_div(-1), -128);
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_div(self, rhs: Self) -> Self {
self.overflowing_div(rhs).0
}
/// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`,
/// wrapping around at the boundary of the type.
///
/// Wrapping will only occur in `MIN / -1` on a signed type (where [`MIN`](Self::MIN) is the negative minimal value
/// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the
/// type. In this case, this method returns [`MIN`](Self::MIN) itself.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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`](Self::MIN) is the negative minimal value). In such a case,
/// this function returns `0`.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")]
/// assert_eq!((-128i8).wrapping_rem(-1), 0);
/// ```
#[stable(feature = "num_wrapping", since = "1.2.0")]
#[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_rem(self, rhs: Self) -> Self {
self.overflowing_rem(rhs).0
}
/// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around
/// at the boundary of the type.
///
/// Wrapping will only occur in `MIN % -1` on a signed type (where [`MIN`](Self::MIN) is
/// the negative minimal value for the type). In this case, this method returns 0.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($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`](Self::MIN) on a signed type (where [`MIN`](Self::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`](Self::MIN) itself.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")]
#[doc = concat!("assert_eq!((-100", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn wrapping_neg(self) -> Self {
(0 as $SelfT).wrapping_sub(self)
}
/// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes
/// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type.
///
/// Beware that, unlike most other `wrapping_*` methods on integers, this
/// does *not* give the same result as doing the shift in infinite precision
/// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
/// do on many processors, and is what the `<<` operator does when overflow
/// checks are disabled, but numerically it's weird. Consider, instead,
/// using [`Self::unbounded_shl`] which has nicer behaviour.
///
/// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to
/// the range of the type, rather than the bits shifted out of the LHS being returned to the other end.
/// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function,
/// which may be what you want instead.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(7), -128);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(", stringify!($BITS), "), 42);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shl(1).wrapping_shl(", stringify!($BITS_MINUS_ONE), "), 0);")]
#[doc = concat!("assert_eq!((-1_", stringify!($SelfT), ").wrapping_shl(128), -1);")]
#[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".wrapping_shl(1025), 10);")]
/// ```
#[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 {
self.unchecked_shl(rhs & (Self::BITS - 1))
}
}
/// 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.
///
/// Beware that, unlike most other `wrapping_*` methods on integers, this
/// does *not* give the same result as doing the shift in infinite precision
/// then truncating as needed. Instead, the behaviour of this method matches what shift instructions
/// do on many processors, and is what the `>>` operator does when overflow
/// checks are disabled, but numerically it's weird. Consider, instead,
/// using [`Self::unbounded_shr`] which has nicer behaviour.
///
/// 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
///
/// ```
#[doc = concat!("assert_eq!((-128_", stringify!($SelfT), ").wrapping_shr(7), -1);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(", stringify!($BITS), "), 42);")]
#[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_shr(1).wrapping_shr(", stringify!($BITS_MINUS_ONE), "), 0);")]
/// assert_eq!((-128_i16).wrapping_shr(64), -128);
#[doc = concat!("assert_eq!(10_", stringify!($SelfT), ".wrapping_shr(1025), 5);")]
/// ```
#[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 {
self.unchecked_shr(rhs & (Self::BITS - 1))
}
}
/// 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`](Self::MIN) itself.
///
/// # Examples
///
/// ```
#[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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[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
///
/// ```
#[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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn unsigned_abs(self) -> $UnsignedT {
self.wrapping_abs() as $UnsignedT
}
/// Wrapping (modular) exponentiation. Computes `self.pow(exp)`,
/// wrapping around at the boundary of the type.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")]
/// assert_eq!(3i8.wrapping_pow(5), -13);
/// assert_eq!(3i8.wrapping_pow(6), -39);
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_pow(0), 1);")]
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_pow(self, exp: u32) -> Self {
let (a, _) = self.overflowing_pow(exp);
a
}
/// Calculates `self` + `rhs`.
///
/// Returns a tuple of the addition along with a boolean indicating
/// whether an arithmetic overflow would occur. If an overflow would have
/// occurred then the wrapped value is returned (negative if overflowed
/// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($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 $ActualT);
(a as Self, b)
}
/// Calculates `self` + `rhs` + `carry` and checks for overflow.
///
/// Performs "ternary addition" of two integer operands and a carry-in
/// bit, and returns a tuple of the sum along with a boolean indicating
/// whether an arithmetic overflow would occur. On overflow, the wrapped
/// value is returned.
///
/// This allows chaining together multiple additions to create a wider
/// addition, and can be useful for bignum addition. This method should
/// only be used for the most significant word; for the less significant
/// words the unsigned method
#[doc = concat!("[`", stringify!($UnsignedT), "::carrying_add`]")]
/// should be used.
///
/// The output boolean returned by this method is *not* a carry flag,
/// and should *not* be added to a more significant word.
///
/// If overflow occurred, the wrapped value is returned (negative if overflowed
/// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
///
/// If the input carry is false, this method is equivalent to
/// [`overflowing_add`](Self::overflowing_add).
///
/// # Examples
///
/// ```
/// #![feature(signed_bigint_helpers)]
/// // Only the most significant word is signed.
/// //
#[doc = concat!("// 10 MAX (a = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
#[doc = concat!("// + -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
/// // ---------
#[doc = concat!("// 6 8 (sum = 6 × 2^", stringify!($BITS), " + 8)")]
///
#[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (10, ", stringify!($UnsignedT), "::MAX);")]
#[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
/// let carry0 = false;
///
#[doc = concat!("// ", stringify!($UnsignedT), "::carrying_add for the less significant words")]
/// let (sum0, carry1) = a0.carrying_add(b0, carry0);
/// assert_eq!(carry1, true);
///
#[doc = concat!("// ", stringify!($SelfT), "::carrying_add for the most significant word")]
/// let (sum1, overflow) = a1.carrying_add(b1, carry1);
/// assert_eq!(overflow, false);
///
/// assert_eq!((sum1, sum0), (6, 8));
/// ```
#[unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[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) {
// note: longer-term this should be done via an intrinsic.
// note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
let (a, b) = self.overflowing_add(rhs);
let (c, d) = a.overflowing_add(carry as $SelfT);
(c, b != d)
}
/// Calculates `self` + `rhs` with an unsigned `rhs`.
///
/// Returns a tuple of the addition along with a boolean indicating
/// whether an arithmetic overflow would occur. If an overflow would
/// have occurred then the wrapped value is returned.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
let rhs = rhs as Self;
let (res, overflowed) = self.overflowing_add(rhs);
(res, overflowed ^ (rhs < 0))
}
/// Calculates `self` - `rhs`.
///
/// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
/// would occur. If an overflow would have occurred then the wrapped value is returned
/// (negative if overflowed above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($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 $ActualT);
(a as Self, b)
}
/// Calculates `self` &minus; `rhs` &minus; `borrow` and checks for
/// overflow.
///
/// Performs "ternary subtraction" by subtracting both an integer
/// operand and a borrow-in bit from `self`, and returns a tuple of the
/// difference along with a boolean indicating whether an arithmetic
/// overflow would occur. On overflow, the wrapped value is returned.
///
/// This allows chaining together multiple subtractions to create a
/// wider subtraction, and can be useful for bignum subtraction. This
/// method should only be used for the most significant word; for the
/// less significant words the unsigned method
#[doc = concat!("[`", stringify!($UnsignedT), "::borrowing_sub`]")]
/// should be used.
///
/// The output boolean returned by this method is *not* a borrow flag,
/// and should *not* be subtracted from a more significant word.
///
/// If overflow occurred, the wrapped value is returned (negative if overflowed
/// above [`MAX`](Self::MAX), non-negative if below [`MIN`](Self::MIN)).
///
/// If the input borrow is false, this method is equivalent to
/// [`overflowing_sub`](Self::overflowing_sub).
///
/// # Examples
///
/// ```
/// #![feature(signed_bigint_helpers)]
/// // Only the most significant word is signed.
/// //
#[doc = concat!("// 6 8 (a = 6 × 2^", stringify!($BITS), " + 8)")]
#[doc = concat!("// - -5 9 (b = -5 × 2^", stringify!($BITS), " + 9)")]
/// // ---------
#[doc = concat!("// 10 MAX (diff = 10 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")]
///
#[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (6, 8);")]
#[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($UnsignedT), ") = (-5, 9);")]
/// let borrow0 = false;
///
#[doc = concat!("// ", stringify!($UnsignedT), "::borrowing_sub for the less significant words")]
/// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
/// assert_eq!(borrow1, true);
///
#[doc = concat!("// ", stringify!($SelfT), "::borrowing_sub for the most significant word")]
/// let (diff1, overflow) = a1.borrowing_sub(b1, borrow1);
/// assert_eq!(overflow, false);
///
#[doc = concat!("assert_eq!((diff1, diff0), (10, ", stringify!($UnsignedT), "::MAX));")]
/// ```
#[unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[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) {
// note: longer-term this should be done via an intrinsic.
// note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946).
let (a, b) = self.overflowing_sub(rhs);
let (c, d) = a.overflowing_sub(borrow as $SelfT);
(c, b != d)
}
/// Calculates `self` - `rhs` with an unsigned `rhs`.
///
/// Returns a tuple of the subtraction along with a boolean indicating
/// whether an arithmetic overflow would occur. If an overflow would
/// have occurred then the wrapped value is returned.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")]
#[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")]
/// ```
#[stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) {
let rhs = rhs as Self;
let (res, overflowed) = self.overflowing_sub(rhs);
(res, overflowed ^ (rhs < 0))
}
/// Calculates the multiplication of `self` and `rhs`.
///
/// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow
/// would occur. If an overflow would have occurred then the wrapped value is returned.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($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 $ActualT);
(a as Self, b)
}
/// Calculates the "full multiplication" `self * rhs + carry`
/// without the possibility to overflow.
///
/// This returns the low-order (wrapping) bits and the high-order (overflow) bits
/// of the result as two separate values, in that order.
///
/// Performs "long multiplication" which takes in an extra amount to add, and may return an
/// additional amount of overflow. This allows for chaining together multiple
/// multiplications to create "big integers" which represent larger values.
///
/// # Examples
///
/// Please note that this example is shared among integer types, which is why [`i32`] is used.
///
/// ```
/// #![feature(signed_bigint_helpers)]
/// assert_eq!(5i32.carrying_mul(-2, 0), (4294967286, -1));
/// assert_eq!(5i32.carrying_mul(-2, 10), (0, 0));
/// assert_eq!(1_000_000_000i32.carrying_mul(-10, 0), (2884901888, -3));
/// assert_eq!(1_000_000_000i32.carrying_mul(-10, 10), (2884901898, -3));
#[doc = concat!("assert_eq!(",
stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
"(", stringify!($SelfT), "::MAX.unsigned_abs() + 1, ", stringify!($SelfT), "::MAX / 2));"
)]
/// ```
#[unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[rustc_const_unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn carrying_mul(self, rhs: Self, carry: Self) -> ($UnsignedT, Self) {
Self::carrying_mul_add(self, rhs, carry, 0)
}
/// Calculates the "full multiplication" `self * rhs + carry + add`
/// without the possibility to overflow.
///
/// This returns the low-order (wrapping) bits and the high-order (overflow) bits
/// of the result as two separate values, in that order.
///
/// Performs "long multiplication" which takes in an extra amount to add, and may return an
/// additional amount of overflow. This allows for chaining together multiple
/// multiplications to create "big integers" which represent larger values.
///
/// If you only need one `carry`, then you can use [`Self::carrying_mul`] instead.
///
/// # Examples
///
/// Please note that this example is shared among integer types, which is why `i32` is used.
///
/// ```
/// #![feature(signed_bigint_helpers)]
/// assert_eq!(5i32.carrying_mul_add(-2, 0, 0), (4294967286, -1));
/// assert_eq!(5i32.carrying_mul_add(-2, 10, 10), (10, 0));
/// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 0, 0), (2884901888, -3));
/// assert_eq!(1_000_000_000i32.carrying_mul_add(-10, 10, 10), (2884901908, -3));
#[doc = concat!("assert_eq!(",
stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
"(", stringify!($UnsignedT), "::MAX, ", stringify!($SelfT), "::MAX / 2));"
)]
/// ```
#[unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[rustc_const_unstable(feature = "signed_bigint_helpers", issue = "151989")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> ($UnsignedT, Self) {
intrinsics::carrying_mul_add(self, rhs, carry, add)
}
/// 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 zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[inline]
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) {
// Using `&` helps LLVM see that it is the same check made in division.
if intrinsics::unlikely((self == Self::MIN) & (rhs == -1)) {
(self, true)
} else {
(self / rhs, false)
}
}
/// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`.
///
/// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would
/// occur. If an overflow would occur then `self` is returned.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($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) {
// Using `&` helps LLVM see that it is the same check made in division.
if intrinsics::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 zero.
///
/// # Examples
///
/// ```
#[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 intrinsics::unlikely(rhs == -1) {
(0, self == Self::MIN)
} 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 zero.
///
/// # Examples
///
/// ```
#[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]
#[track_caller]
pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) {
if intrinsics::unlikely(rhs == -1) {
(0, self == Self::MIN)
} 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
///
/// ```
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")]
/// ```
#[inline]
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[allow(unused_attributes)]
pub const fn overflowing_neg(self) -> (Self, bool) {
if intrinsics::unlikely(self == Self::MIN) {
(Self::MIN, true)
} else {
(-self, false)
}
}
/// Shifts self left by `rhs` bits.
///
/// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift
/// value was larger than or equal to the number of bits. If the shift value is too large, then value is
/// masked (N-1) where N is the number of bits, and this value is then used to perform the shift.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")]
/// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")]
/// ```
#[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 >= Self::BITS)
}
/// 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
///
/// ```
#[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")]
/// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
/// ```
#[stable(feature = "wrapping", since = "1.7.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) {
(self.wrapping_shr(rhs), rhs >= Self::BITS)
}
/// Computes the absolute value of `self`.
///
/// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow
/// happened. If self is the minimum value
#[doc = concat!("(e.g., [`", stringify!($SelfT), "::MIN`] for values of type [`", stringify!($SelfT), "`]),")]
/// then the minimum value will be returned again and true will be returned
/// for an overflow happening.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($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!($SelfT), "::MIN, true));")]
/// ```
#[stable(feature = "no_panic_abs", since = "1.13.0")]
#[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_abs(self) -> (Self, bool) {
(self.wrapping_abs(), self == Self::MIN)
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
///
/// Returns a tuple of the exponentiation along with a bool indicating
/// whether an overflow happened.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")]
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".overflowing_pow(0), (1, false));")]
/// assert_eq!(3i8.overflowing_pow(5), (-13, true));
/// ```
#[stable(feature = "no_panic_pow", since = "1.34.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
let mut base = self;
let mut acc: Self = 1;
let mut overflow = false;
let mut tmp_overflow;
if intrinsics::is_val_statically_known(base) && base.unsigned_abs().is_power_of_two() {
let k = base.unsigned_abs().ilog2();
let Some(shift) = k.checked_mul(exp) else {
return (0, true)
};
let base: Self = if base < 0 && (exp % 2) != 0 { -1 } else { 1 };
return (base.unbounded_shl(shift), base.shl_exact(shift).is_none());
}
if exp == 0 {
return (1, false);
}
if intrinsics::is_val_statically_known(exp) {
while exp > 1 {
if (exp & 1) == 1 {
(acc, tmp_overflow) = acc.overflowing_mul(base);
overflow |= tmp_overflow;
}
exp /= 2;
(base, tmp_overflow) = base.overflowing_mul(base);
overflow |= tmp_overflow;
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
(acc, tmp_overflow) = acc.overflowing_mul(base);
overflow |= tmp_overflow;
return (acc, overflow);
}
loop {
if (exp & 1) == 1 {
(acc, tmp_overflow) = acc.overflowing_mul(base);
overflow |= tmp_overflow;
// since exp!=0, finally the exp must be 1.
if exp == 1 {
return (acc, overflow);
}
}
exp /= 2;
(base, tmp_overflow) = base.overflowing_mul(base);
overflow |= tmp_overflow;
}
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
///
/// # Examples
///
/// ```
#[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")]
///
/// assert_eq!(x.pow(5), 32);
#[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".pow(0), 1);")]
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn pow(self, exp: u32) -> Self {
if intrinsics::overflow_checks() {
self.strict_pow(exp)
} else {
self.wrapping_pow(exp)
}
}
/// Returns the integer square root of the number, rounded down.
///
/// This function returns the **principal (non-negative) square root**.
/// For a given number `n`, although both `x` and `-x` satisfy x<sup>2</sup> = n,
/// this function always returns the non-negative value.
///
/// # Panics
///
/// This function will panic if `self` is negative.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")]
/// ```
#[stable(feature = "isqrt", since = "1.84.0")]
#[rustc_const_stable(feature = "isqrt", since = "1.84.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn isqrt(self) -> Self {
match self.checked_isqrt() {
Some(sqrt) => sqrt,
None => imp::int_sqrt::panic_for_negative_argument(),
}
}
/// 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 rounding towards zero (the default in Rust);
/// if `self < 0`, this is equal to rounding away from zero (towards +/- infinity).
/// If `rhs > 0`, this is equal to rounding towards -infinity;
/// if `rhs < 0`, this is equal to rounding towards +infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
/// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
///
/// # Examples
///
/// ```
#[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")]
/// let b = 4;
///
/// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
/// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
/// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
/// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
/// ```
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn div_euclid(self, rhs: Self) -> Self {
let q = self / rhs;
if self % rhs < 0 {
return if rhs > 0 { q - 1 } else { q + 1 }
}
q
}
/// Calculates the least nonnegative remainder of `self` when
/// divided by `rhs`.
///
/// This is done as if by the Euclidean division algorithm -- given
/// `r = self.rem_euclid(rhs)`, the result satisfies
/// `self = rhs * self.div_euclid(rhs) + r` and `0 <= r < abs(rhs)`.
///
/// # Panics
///
/// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`] and
/// `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
///
/// # Examples
///
/// ```
#[doc = concat!("let a: ", stringify!($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);
/// ```
///
/// This will panic:
/// ```should_panic
#[doc = concat!("let _ = ", stringify!($SelfT), "::MIN.rem_euclid(-1);")]
/// ```
#[doc(alias = "modulo", alias = "mod")]
#[stable(feature = "euclidean_division", since = "1.38.0")]
#[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn rem_euclid(self, rhs: Self) -> Self {
let r = self % rhs;
if r < 0 {
// Semantically equivalent to `if rhs < 0 { r - rhs } else { r + rhs }`.
// If `rhs` is not `Self::MIN`, then `r + abs(rhs)` will not overflow
// and is clearly equivalent, because `r` is negative.
// Otherwise, `rhs` is `Self::MIN`, then we have
// `r.wrapping_add(Self::MIN.wrapping_abs())`, which evaluates
// to `r.wrapping_add(Self::MIN)`, which is equivalent to
// `r - Self::MIN`, which is what we wanted (and will not overflow
// for negative `r`).
r.wrapping_add(rhs.wrapping_abs())
} else {
r
}
}
/// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
/// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
///
/// # Examples
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
/// let b = 3;
///
/// assert_eq!(a.div_floor(b), 2);
/// assert_eq!(a.div_floor(-b), -3);
/// assert_eq!((-a).div_floor(b), -3);
/// assert_eq!((-a).div_floor(-b), 2);
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn div_floor(self, rhs: Self) -> Self {
let d = self / rhs;
let r = self % rhs;
// If the remainder is non-zero, we need to subtract one if the
// signs of self and rhs differ, as this means we rounded upwards
// instead of downwards. We do this branchlessly by creating a mask
// which is all-ones iff the signs differ, and 0 otherwise. Then by
// adding this mask (which corresponds to the signed value -1), we
// get our correction.
let correction = (self ^ rhs) >> (Self::BITS - 1);
if r != 0 {
d + correction
} else {
d
}
}
/// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
///
/// # Panics
///
/// This function will panic if `rhs` is zero or if `self` is [`Self::MIN`]
/// and `rhs` is -1. This behavior is not affected by the `overflow-checks` flag.
///
/// # Examples
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
/// let b = 3;
///
/// assert_eq!(a.div_ceil(b), 3);
/// assert_eq!(a.div_ceil(-b), -2);
/// assert_eq!((-a).div_ceil(b), -2);
/// assert_eq!((-a).div_ceil(-b), 3);
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn div_ceil(self, rhs: Self) -> Self {
let d = self / rhs;
let r = self % rhs;
// When remainder is non-zero we have a.div_ceil(b) == 1 + a.div_floor(b),
// so we can re-use the algorithm from div_floor, just adding 1.
let correction = 1 + ((self ^ rhs) >> (Self::BITS - 1));
if r != 0 {
d + correction
} else {
d
}
}
/// If `rhs` is positive, calculates the smallest value greater than or
/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
/// calculates the largest value less than or equal to `self` that is a
/// multiple of `rhs`.
///
/// # Panics
///
/// This function will panic if `rhs` is zero.
///
/// ## Overflow behavior
///
/// On overflow, this function will panic if overflow checks are enabled (default in debug
/// mode) and wrap if overflow checks are disabled (default in release mode).
///
/// # Examples
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")]
#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")]
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[rustc_inherit_overflow_checks]
pub const fn next_multiple_of(self, rhs: Self) -> Self {
// This would otherwise fail when calculating `r` when self == T::MIN.
if rhs == -1 {
return self;
}
let r = self % rhs;
let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
r + rhs
} else {
r
};
if m == 0 {
self
} else {
self + (rhs - m)
}
}
/// If `rhs` is positive, calculates the smallest value greater than or
/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
/// calculates the largest value less than or equal to `self` that is a
/// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
/// would result in overflow.
///
/// # Examples
///
/// ```
/// #![feature(int_roundings)]
#[doc = concat!("assert_eq!(16_", stringify!($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!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
/// ```
#[unstable(feature = "int_roundings", issue = "88581")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
// This would otherwise fail when calculating `r` when self == T::MIN.
if rhs == -1 {
return Some(self);
}
let r = try_opt!(self.checked_rem(rhs));
let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
// r + rhs cannot overflow because they have opposite signs
r + rhs
} else {
r
};
if m == 0 {
Some(self)
} else {
// rhs - m cannot overflow because m has the same sign as rhs
self.checked_add(rhs - m)
}
}
/// Returns the logarithm of the number with respect to an arbitrary base,
/// rounded down.
///
/// This method might not be optimized owing to implementation details;
/// [`ilog2`][Self::ilog2] can produce results more efficiently for base 2,
/// and [`ilog10`](Self::ilog10) can produce results more efficiently for base 10.
///
/// # Panics
///
/// This function will panic if `self` is less than or equal to zero,
/// or if `base` is less than 2.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")]
/// ```
#[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]
#[track_caller]
pub const fn ilog(self, base: Self) -> u32 {
assert!(base >= 2, "base of integer logarithm must be at least 2");
if let Some(log) = self.checked_ilog(base) {
log
} else {
imp::int_log10::panic_for_nonpositive_argument()
}
}
/// Returns the base 2 logarithm of the number, rounded down.
///
/// # Panics
///
/// This function will panic if `self` is less than or equal to zero.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")]
/// ```
#[stable(feature = "int_log", since = "1.67.0")]
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
#[track_caller]
pub const fn ilog2(self) -> u32 {
if let Some(log) = self.checked_ilog2() {
log
} else {
imp::int_log10::panic_for_nonpositive_argument()
}
}
/// Returns the base 10 logarithm of the number, rounded down.
///
/// # Panics
///
/// This function will panic if `self` is less than or equal to zero.
///
/// # Example
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")]
/// ```
#[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]
#[track_caller]
pub const fn ilog10(self) -> u32 {
if let Some(log) = self.checked_ilog10() {
log
} else {
imp::int_log10::panic_for_nonpositive_argument()
}
}
/// Returns the logarithm of the number with respect to an arbitrary base,
/// rounded down.
///
/// 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_ilog2` can produce results more efficiently for base 2, and
/// `checked_ilog10` can produce results more efficiently for base 10.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")]
/// ```
#[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 checked_ilog(self, base: Self) -> Option<u32> {
if self <= 0 || base <= 1 {
None
} else {
// Delegate to the unsigned implementation.
// The condition makes sure that both casts are exact.
(self as $UnsignedT).checked_ilog(base as $UnsignedT)
}
}
/// Returns the base 2 logarithm of the number, rounded down.
///
/// Returns `None` if the number is negative or zero.
///
/// Note that for non-negative numbers, this is equivalent to
/// [`highest_one`](Self::highest_one).
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")]
/// ```
#[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 checked_ilog2(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, rounded down.
///
/// Returns `None` if the number is negative or zero.
///
/// # Example
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")]
/// ```
#[stable(feature = "int_log", since = "1.67.0")]
#[rustc_const_stable(feature = "int_log", since = "1.67.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_ilog10(self) -> Option<u32> {
imp::int_log10::$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. If you do not want this behavior, consider
/// using [`unsigned_abs`](Self::unsigned_abs) instead.
///
/// # Examples
///
/// ```
#[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)]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[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
}
}
/// Computes the absolute difference between `self` and `other`.
///
/// This function always returns the correct answer without overflow or
/// panics by returning an unsigned integer.
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")]
/// ```
#[stable(feature = "int_abs_diff", since = "1.60.0")]
#[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn abs_diff(self, other: Self) -> $UnsignedT {
if self < other {
// Converting a non-negative x from signed to unsigned by using
// `x as U` is left unchanged, but a negative x is converted
// to value x + 2^N. Thus if `s` and `o` are binary variables
// respectively indicating whether `self` and `other` are
// negative, we are computing the mathematical value:
//
// (other + o*2^N) - (self + s*2^N) mod 2^N
// other - self + (o-s)*2^N mod 2^N
// other - self mod 2^N
//
// Finally, taking the mod 2^N of the mathematical value of
// `other - self` does not change it as it already is
// in the range [0, 2^N).
(other as $UnsignedT).wrapping_sub(self as $UnsignedT)
} else {
(self as $UnsignedT).wrapping_sub(other as $UnsignedT)
}
}
/// Returns a number representing sign of `self`.
///
/// - `0` if the number is zero
/// - `1` if the number is positive
/// - `-1` if the number is negative
///
/// # Examples
///
/// ```
#[doc = concat!("assert_eq!(10", stringify!($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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline(always)]
pub const fn signum(self) -> Self {
// Picking the right way to phrase this is complicated
// (<https://graphics.stanford.edu/~seander/bithacks.html#CopyIntegerSign>)
// so delegate it to `Ord` which is already producing -1/0/+1
// exactly like we need and can be the place to deal with the complexity.
crate::intrinsics::three_way_compare(self, 0) as Self
}
/// Returns `true` if `self` is positive and `false` if the number is zero or
/// negative.
///
/// # Examples
///
/// ```
#[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")]
#[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")]
/// ```
#[must_use]
#[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
///
/// ```
#[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")]
#[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")]
/// ```
#[must_use]
#[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 }
/// Returns 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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn to_be_bytes(self) -> [u8; size_of::<Self>()] {
self.to_be().to_ne_bytes()
}
/// Returns 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")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
self.to_le().to_ne_bytes()
}
/// Returns 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")]
#[allow(unnecessary_transmutes)]
// SAFETY: const sound because integers are plain old datatypes so we can always
// transmute them to arrays of bytes
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn to_ne_bytes(self) -> [u8; size_of::<Self>()] {
// SAFETY: integers are plain old datatypes so we can always transmute them to
// arrays of bytes
unsafe { mem::transmute(self) }
}
/// Creates an integer value from its representation as a byte array in
/// big endian.
///
#[doc = $from_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")]
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
#[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($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")]
#[must_use]
#[inline]
pub const fn from_be_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
Self::from_be(Self::from_ne_bytes(bytes))
}
/// Creates an integer value from its representation as a byte array in
/// little endian.
///
#[doc = $from_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")]
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
#[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($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")]
#[must_use]
#[inline]
pub const fn from_le_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
Self::from_le(Self::from_ne_bytes(bytes))
}
/// Creates 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 = $from_xe_bytes_doc]
///
/// # Examples
///
/// ```
#[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")]
#[doc = concat!(" ", $be_bytes)]
/// } else {
#[doc = concat!(" ", $le_bytes)]
/// });
#[doc = concat!("assert_eq!(value, ", $swap_op, ");")]
/// ```
///
/// When starting from a slice rather than an array, fallible conversion APIs can be used:
///
/// ```
#[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")]
#[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")]
/// *input = rest;
#[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")]
/// }
/// ```
#[stable(feature = "int_to_from_bytes", since = "1.32.0")]
#[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")]
#[allow(unnecessary_transmutes)]
#[must_use]
// SAFETY: const sound because integers are plain old datatypes so we can always
// transmute to them
#[inline]
pub const fn from_ne_bytes(bytes: [u8; size_of::<Self>()]) -> Self {
// SAFETY: integers are plain old datatypes so we can always transmute to them
unsafe { mem::transmute(bytes) }
}
/// New code should prefer to use
#[doc = concat!("[`", stringify!($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")]
#[deprecated(since = "CURRENT_RUSTC_VERSION", note = "replaced by the `MIN` associated constant on this type")]
#[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")]
pub const fn min_value() -> Self {
Self::MIN
}
/// New code should prefer to use
#[doc = concat!("[`", stringify!($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")]
#[deprecated(since = "CURRENT_RUSTC_VERSION", note = "replaced by the `MAX` associated constant on this type")]
#[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")]
pub const fn max_value() -> Self {
Self::MAX
}
/// Clamps this number to a symmetric range centred around zero.
///
/// The method clamps the number's magnitude (absolute value) to be at most `limit`.
///
/// This is functionally equivalent to `self.clamp(-limit, limit)`, but is more
/// explicit about the intent.
///
/// # Examples
///
/// ```
/// #![feature(clamp_magnitude)]
#[doc = concat!("assert_eq!(120", stringify!($SelfT), ".clamp_magnitude(100), 100);")]
#[doc = concat!("assert_eq!(-120", stringify!($SelfT), ".clamp_magnitude(100), -100);")]
#[doc = concat!("assert_eq!(80", stringify!($SelfT), ".clamp_magnitude(100), 80);")]
#[doc = concat!("assert_eq!(-80", stringify!($SelfT), ".clamp_magnitude(100), -80);")]
/// ```
#[must_use = "this returns the clamped value and does not modify the original"]
#[unstable(feature = "clamp_magnitude", issue = "148519")]
#[inline]
pub fn clamp_magnitude(self, limit: $UnsignedT) -> Self {
if let Ok(limit) = core::convert::TryInto::<$SelfT>::try_into(limit) {
self.clamp(-limit, limit)
} else {
self
}
}
/// Truncate an integer to an integer of the same size or smaller, preserving the least
/// significant bits.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".truncate());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").truncate());")]
/// assert_eq!(120i8, 376i32.truncate());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[inline]
pub const fn truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
{
traits::TruncateTarget::internal_truncate(self)
}
/// Truncate an integer to an integer of the same size or smaller, saturating at numeric bounds
/// instead of truncating.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120i8, 120", stringify!($SelfT), ".saturating_truncate());")]
#[doc = concat!("assert_eq!(-120i8, (-120", stringify!($SelfT), ").saturating_truncate());")]
/// assert_eq!(127i8, 376i32.saturating_truncate());
/// assert_eq!(-128i8, (-1000i32).saturating_truncate());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[inline]
pub const fn saturating_truncate<Target>(self) -> Target
where Self: [const] traits::TruncateTarget<Target>
{
traits::TruncateTarget::internal_saturating_truncate(self)
}
/// Truncate an integer to an integer of the same size or smaller, returning `None` if the value
/// is outside the bounds of the smaller type.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(Some(120i8), 120", stringify!($SelfT), ".checked_truncate());")]
#[doc = concat!("assert_eq!(Some(-120i8), (-120", stringify!($SelfT), ").checked_truncate());")]
/// assert_eq!(None, 376i32.checked_truncate::<i8>());
/// assert_eq!(None, (-1000i32).checked_truncate::<i8>());
/// ```
#[must_use = "this returns the truncated value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[inline]
pub const fn checked_truncate<Target>(self) -> Option<Target>
where Self: [const] traits::TruncateTarget<Target>
{
traits::TruncateTarget::internal_checked_truncate(self)
}
/// Widen to an integer of the same size or larger, preserving its value.
///
/// # Examples
///
/// ```
/// #![feature(integer_widen_truncate)]
#[doc = concat!("assert_eq!(120i128, 120i8.widen());")]
#[doc = concat!("assert_eq!(-120i128, (-120i8).widen());")]
/// ```
#[must_use = "this returns the widened value and does not modify the original"]
#[unstable(feature = "integer_widen_truncate", issue = "154330")]
#[rustc_const_unstable(feature = "integer_widen_truncate", issue = "154330")]
#[inline]
pub const fn widen<Target>(self) -> Target
where Self: [const] traits::WidenTarget<Target>
{
traits::WidenTarget::internal_widen(self)
}
/// Converts `self` to the target integer type, saturating at the numeric
/// bounds instead of overflowing.
///
/// # Examples
///
/// ```
/// #![feature(integer_casts)]
#[doc = concat!("assert_eq!(i8::MAX, ", stringify!($SelfT), "::MAX.saturating_cast());")]
#[doc = concat!("assert_eq!(i8::MIN, ", stringify!($SelfT), "::MIN.saturating_cast());")]
#[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".saturating_cast());")]
#[doc = concat!("assert_eq!(0u8, (-42", stringify!($SelfT), ").saturating_cast());")]
/// ```
#[must_use = "this returns the cast result and does not modify the original"]
#[unstable(feature = "integer_casts", issue = "157388")]
#[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
#[inline(always)]
pub const fn saturating_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
T::saturating_cast_from(self)
}
/// Converts `self` to the target integer type, wrapping around at the
/// boundary of the target type.
///
/// # Examples
///
/// ```
/// #![feature(integer_casts)]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX as i8, ", stringify!($SelfT), "::MAX.wrapping_cast());")]
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN as i8, ", stringify!($SelfT), "::MIN.wrapping_cast());")]
#[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".wrapping_cast());")]
#[doc = concat!("assert_eq!(u8::MAX - 41, (-42", stringify!($SelfT), ").wrapping_cast());")]
/// ```
#[must_use = "this returns the cast result and does not modify the original"]
#[unstable(feature = "integer_casts", issue = "157388")]
#[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
#[inline(always)]
pub const fn wrapping_cast<T: [const] BoundedCastFromInt<Self>>(self) -> T {
T::wrapping_cast_from(self)
}
/// Converts `self` to the target integer type, returning `None` if the value
/// is not representable by the target type.
///
/// # Examples
///
/// ```
/// #![feature(integer_casts)]
#[doc = concat!("assert_eq!(Some(42u8), 42", stringify!($SelfT), ".checked_cast());")]
#[doc = concat!("assert_eq!((-42", stringify!($SelfT), ").checked_cast::<u8>(), None);")]
/// ```
#[must_use = "this returns the cast result and does not modify the original"]
#[unstable(feature = "integer_casts", issue = "157388")]
#[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
#[inline(always)]
pub const fn checked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> Option<T> {
T::checked_cast_from(self)
}
/// Converts `self` to the target integer type, panicking if the value
/// is not representable by the target type.
///
/// # Panics
///
/// This function will panic if the value is not representable by the target type.
///
/// # Examples
///
/// ```
/// #![feature(integer_casts)]
#[doc = concat!("assert_eq!(42u8, 42", stringify!($SelfT), ".strict_cast());")]
/// ```
///
/// The following will panic:
///
/// ```should_panic
/// #![feature(integer_casts)]
#[doc = concat!("let _ = (-42", stringify!($SelfT), ").strict_cast::<u8>();")]
/// ```
#[must_use = "this returns the cast result and does not modify the original"]
#[unstable(feature = "integer_casts", issue = "157388")]
#[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
#[inline(always)]
#[track_caller]
pub const fn strict_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
T::strict_cast_from(self)
}
/// Converts `self` to the target integer type, assuming the value is
/// representable by the target type.
///
/// # Safety
///
/// This results in undefined behavior if the integer value of `self` is bigger than `T::MAX`,
/// or smaller than `T::MIN`, where `T` is the target type.
#[must_use = "this returns the cast result and does not modify the original"]
#[unstable(feature = "integer_casts", issue = "157388")]
#[rustc_const_unstable(feature = "integer_casts", issue = "157388")]
#[inline(always)]
pub const unsafe fn unchecked_cast<T: [const] CheckedCastFromInt<Self>>(self) -> T {
assert_unsafe_precondition!(
check_language_ub,
concat!(stringify!($SelfT), "::unchecked_cast must fit in the target type"),
(
// Check has to be performed up-front because it depends on generic T.
in_bounds: bool = {
let cast_val = self.checked_cast::<T>();
let ret = cast_val.is_some();
core::mem::forget(cast_val); // We don't have const Drop, but we know it's an int.
ret
},
) => in_bounds,
);
// SAFETY: this is guaranteed to be safe by the caller.
unsafe { T::unchecked_cast_from(self) }
}
}
}