Implement #88581
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@ -1746,6 +1746,173 @@ macro_rules! int_impl {
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}
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}
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/// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity.
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///
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/// # Panics
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///
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/// This function will panic if `rhs` is 0 or the division results in overflow.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(int_roundings)]
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#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
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/// let b = 3;
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///
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/// assert_eq!(a.div_floor(b), 2);
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/// assert_eq!(a.div_floor(-b), -3);
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/// assert_eq!((-a).div_floor(b), -3);
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/// assert_eq!((-a).div_floor(-b), 2);
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/// ```
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#[unstable(feature = "int_roundings", issue = "88581")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline]
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#[rustc_inherit_overflow_checks]
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pub const fn div_floor(self, rhs: Self) -> Self {
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let d = self / rhs;
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let r = self % rhs;
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if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
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d - 1
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} else {
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d
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}
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}
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/// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity.
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///
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/// # Panics
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///
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/// This function will panic if `rhs` is 0 or the division results in overflow.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(int_roundings)]
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#[doc = concat!("let a: ", stringify!($SelfT)," = 8;")]
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/// let b = 3;
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///
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/// assert_eq!(a.div_ceil(b), 3);
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/// assert_eq!(a.div_ceil(-b), -2);
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/// assert_eq!((-a).div_ceil(b), -2);
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/// assert_eq!((-a).div_ceil(-b), 3);
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/// ```
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#[unstable(feature = "int_roundings", issue = "88581")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline]
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#[rustc_inherit_overflow_checks]
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pub const fn div_ceil(self, rhs: Self) -> Self {
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let d = self / rhs;
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let r = self % rhs;
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if (r > 0 && rhs > 0) || (r < 0 && rhs < 0) {
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d + 1
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} else {
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d
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}
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}
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/// If `rhs` is positive, calculates the smallest value greater than or
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/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
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/// calculates the largest value less than or equal to `self` that is a
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/// multiple of `rhs`.
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///
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/// # Panics
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///
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/// This function will panic if `rhs` is 0 or the operation results in overflow.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(int_roundings)]
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#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")]
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#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")]
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#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
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#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")]
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#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
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#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")]
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#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")]
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#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")]
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/// ```
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#[unstable(feature = "int_roundings", issue = "88581")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline]
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#[rustc_inherit_overflow_checks]
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pub const fn next_multiple_of(self, rhs: Self) -> Self {
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// This would otherwise fail when calculating `r` when self == T::MIN.
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if rhs == -1 {
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return self;
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}
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let r = self % rhs;
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let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
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r + rhs
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} else {
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r
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};
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if m == 0 {
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self
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} else {
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self + (rhs - m)
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}
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}
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/// If `rhs` is positive, calculates the smallest value greater than or
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/// equal to `self` that is a multiple of `rhs`. If `rhs` is negative,
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/// calculates the largest value less than or equal to `self` that is a
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/// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation
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/// would result in overflow.
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///
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/// # Examples
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///
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/// Basic usage:
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///
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/// ```
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/// #![feature(int_roundings)]
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#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")]
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#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")]
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#[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
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#[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")]
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#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
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#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")]
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#[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")]
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#[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")]
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#[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")]
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#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")]
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/// ```
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#[unstable(feature = "int_roundings", issue = "88581")]
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#[must_use = "this returns the result of the operation, \
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without modifying the original"]
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#[inline]
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#[rustc_inherit_overflow_checks]
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pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> {
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// This would otherwise fail when calculating `r` when self == T::MIN.
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if rhs == -1 {
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return Some(self);
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}
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let r = try_opt!(self.checked_rem(rhs));
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let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) {
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try_opt!(r.checked_add(rhs))
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} else {
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r
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};
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if m == 0 {
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Some(self)
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} else {
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self.checked_add(try_opt!(rhs.checked_sub(m)))
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}
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}
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/// Returns the logarithm of the number with respect to an arbitrary base.
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///
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/// This method might not be optimized owing to implementation details;
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