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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /third_party/rust/num-traits/src/pow.rs
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/num-traits/src/pow.rs')
-rw-r--r--third_party/rust/num-traits/src/pow.rs262
1 files changed, 262 insertions, 0 deletions
diff --git a/third_party/rust/num-traits/src/pow.rs b/third_party/rust/num-traits/src/pow.rs
new file mode 100644
index 0000000000..8addc21121
--- /dev/null
+++ b/third_party/rust/num-traits/src/pow.rs
@@ -0,0 +1,262 @@
+use core::num::Wrapping;
+use core::ops::Mul;
+use {CheckedMul, One};
+
+/// Binary operator for raising a value to a power.
+pub trait Pow<RHS> {
+ /// The result after applying the operator.
+ type Output;
+
+ /// Returns `self` to the power `rhs`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use num_traits::Pow;
+ /// assert_eq!(Pow::pow(10u32, 2u32), 100);
+ /// ```
+ fn pow(self, rhs: RHS) -> Self::Output;
+}
+
+macro_rules! pow_impl {
+ ($t:ty) => {
+ pow_impl!($t, u8);
+ pow_impl!($t, usize);
+
+ // FIXME: these should be possible
+ // pow_impl!($t, u16);
+ // pow_impl!($t, u32);
+ // pow_impl!($t, u64);
+ };
+ ($t:ty, $rhs:ty) => {
+ pow_impl!($t, $rhs, usize, pow);
+ };
+ ($t:ty, $rhs:ty, $desired_rhs:ty, $method:expr) => {
+ impl Pow<$rhs> for $t {
+ type Output = $t;
+ #[inline]
+ fn pow(self, rhs: $rhs) -> $t {
+ ($method)(self, <$desired_rhs>::from(rhs))
+ }
+ }
+
+ impl<'a> Pow<&'a $rhs> for $t {
+ type Output = $t;
+ #[inline]
+ fn pow(self, rhs: &'a $rhs) -> $t {
+ ($method)(self, <$desired_rhs>::from(*rhs))
+ }
+ }
+
+ impl<'a> Pow<$rhs> for &'a $t {
+ type Output = $t;
+ #[inline]
+ fn pow(self, rhs: $rhs) -> $t {
+ ($method)(*self, <$desired_rhs>::from(rhs))
+ }
+ }
+
+ impl<'a, 'b> Pow<&'a $rhs> for &'b $t {
+ type Output = $t;
+ #[inline]
+ fn pow(self, rhs: &'a $rhs) -> $t {
+ ($method)(*self, <$desired_rhs>::from(*rhs))
+ }
+ }
+ };
+}
+
+pow_impl!(u8, u8, u32, u8::pow);
+pow_impl!(u8, u16, u32, u8::pow);
+pow_impl!(u8, u32, u32, u8::pow);
+pow_impl!(u8, usize);
+pow_impl!(i8, u8, u32, i8::pow);
+pow_impl!(i8, u16, u32, i8::pow);
+pow_impl!(i8, u32, u32, i8::pow);
+pow_impl!(i8, usize);
+pow_impl!(u16, u8, u32, u16::pow);
+pow_impl!(u16, u16, u32, u16::pow);
+pow_impl!(u16, u32, u32, u16::pow);
+pow_impl!(u16, usize);
+pow_impl!(i16, u8, u32, i16::pow);
+pow_impl!(i16, u16, u32, i16::pow);
+pow_impl!(i16, u32, u32, i16::pow);
+pow_impl!(i16, usize);
+pow_impl!(u32, u8, u32, u32::pow);
+pow_impl!(u32, u16, u32, u32::pow);
+pow_impl!(u32, u32, u32, u32::pow);
+pow_impl!(u32, usize);
+pow_impl!(i32, u8, u32, i32::pow);
+pow_impl!(i32, u16, u32, i32::pow);
+pow_impl!(i32, u32, u32, i32::pow);
+pow_impl!(i32, usize);
+pow_impl!(u64, u8, u32, u64::pow);
+pow_impl!(u64, u16, u32, u64::pow);
+pow_impl!(u64, u32, u32, u64::pow);
+pow_impl!(u64, usize);
+pow_impl!(i64, u8, u32, i64::pow);
+pow_impl!(i64, u16, u32, i64::pow);
+pow_impl!(i64, u32, u32, i64::pow);
+pow_impl!(i64, usize);
+
+#[cfg(has_i128)]
+pow_impl!(u128, u8, u32, u128::pow);
+#[cfg(has_i128)]
+pow_impl!(u128, u16, u32, u128::pow);
+#[cfg(has_i128)]
+pow_impl!(u128, u32, u32, u128::pow);
+#[cfg(has_i128)]
+pow_impl!(u128, usize);
+
+#[cfg(has_i128)]
+pow_impl!(i128, u8, u32, i128::pow);
+#[cfg(has_i128)]
+pow_impl!(i128, u16, u32, i128::pow);
+#[cfg(has_i128)]
+pow_impl!(i128, u32, u32, i128::pow);
+#[cfg(has_i128)]
+pow_impl!(i128, usize);
+
+pow_impl!(usize, u8, u32, usize::pow);
+pow_impl!(usize, u16, u32, usize::pow);
+pow_impl!(usize, u32, u32, usize::pow);
+pow_impl!(usize, usize);
+pow_impl!(isize, u8, u32, isize::pow);
+pow_impl!(isize, u16, u32, isize::pow);
+pow_impl!(isize, u32, u32, isize::pow);
+pow_impl!(isize, usize);
+pow_impl!(Wrapping<u8>);
+pow_impl!(Wrapping<i8>);
+pow_impl!(Wrapping<u16>);
+pow_impl!(Wrapping<i16>);
+pow_impl!(Wrapping<u32>);
+pow_impl!(Wrapping<i32>);
+pow_impl!(Wrapping<u64>);
+pow_impl!(Wrapping<i64>);
+#[cfg(has_i128)]
+pow_impl!(Wrapping<u128>);
+#[cfg(has_i128)]
+pow_impl!(Wrapping<i128>);
+pow_impl!(Wrapping<usize>);
+pow_impl!(Wrapping<isize>);
+
+// FIXME: these should be possible
+// pow_impl!(u8, u64);
+// pow_impl!(i16, u64);
+// pow_impl!(i8, u64);
+// pow_impl!(u16, u64);
+// pow_impl!(u32, u64);
+// pow_impl!(i32, u64);
+// pow_impl!(u64, u64);
+// pow_impl!(i64, u64);
+// pow_impl!(usize, u64);
+// pow_impl!(isize, u64);
+
+#[cfg(any(feature = "std", feature = "libm"))]
+mod float_impls {
+ use super::Pow;
+ use Float;
+
+ pow_impl!(f32, i8, i32, <f32 as Float>::powi);
+ pow_impl!(f32, u8, i32, <f32 as Float>::powi);
+ pow_impl!(f32, i16, i32, <f32 as Float>::powi);
+ pow_impl!(f32, u16, i32, <f32 as Float>::powi);
+ pow_impl!(f32, i32, i32, <f32 as Float>::powi);
+ pow_impl!(f64, i8, i32, <f64 as Float>::powi);
+ pow_impl!(f64, u8, i32, <f64 as Float>::powi);
+ pow_impl!(f64, i16, i32, <f64 as Float>::powi);
+ pow_impl!(f64, u16, i32, <f64 as Float>::powi);
+ pow_impl!(f64, i32, i32, <f64 as Float>::powi);
+ pow_impl!(f32, f32, f32, <f32 as Float>::powf);
+ pow_impl!(f64, f32, f64, <f64 as Float>::powf);
+ pow_impl!(f64, f64, f64, <f64 as Float>::powf);
+}
+
+/// Raises a value to the power of exp, using exponentiation by squaring.
+///
+/// Note that `0⁰` (`pow(0, 0)`) returns `1`. Mathematically this is undefined.
+///
+/// # Example
+///
+/// ```rust
+/// use num_traits::pow;
+///
+/// assert_eq!(pow(2i8, 4), 16);
+/// assert_eq!(pow(6u8, 3), 216);
+/// assert_eq!(pow(0u8, 0), 1); // Be aware if this case affects you
+/// ```
+#[inline]
+pub fn pow<T: Clone + One + Mul<T, Output = T>>(mut base: T, mut exp: usize) -> T {
+ if exp == 0 {
+ return T::one();
+ }
+
+ while exp & 1 == 0 {
+ base = base.clone() * base;
+ exp >>= 1;
+ }
+ if exp == 1 {
+ return base;
+ }
+
+ let mut acc = base.clone();
+ while exp > 1 {
+ exp >>= 1;
+ base = base.clone() * base;
+ if exp & 1 == 1 {
+ acc = acc * base.clone();
+ }
+ }
+ acc
+}
+
+/// Raises a value to the power of exp, returning `None` if an overflow occurred.
+///
+/// Note that `0⁰` (`checked_pow(0, 0)`) returns `Some(1)`. Mathematically this is undefined.
+///
+/// Otherwise same as the `pow` function.
+///
+/// # Example
+///
+/// ```rust
+/// use num_traits::checked_pow;
+///
+/// assert_eq!(checked_pow(2i8, 4), Some(16));
+/// assert_eq!(checked_pow(7i8, 8), None);
+/// assert_eq!(checked_pow(7u32, 8), Some(5_764_801));
+/// assert_eq!(checked_pow(0u32, 0), Some(1)); // Be aware if this case affect you
+/// ```
+#[inline]
+pub fn checked_pow<T: Clone + One + CheckedMul>(mut base: T, mut exp: usize) -> Option<T> {
+ if exp == 0 {
+ return Some(T::one());
+ }
+
+ macro_rules! optry {
+ ($expr:expr) => {
+ if let Some(val) = $expr {
+ val
+ } else {
+ return None;
+ }
+ };
+ }
+
+ while exp & 1 == 0 {
+ base = optry!(base.checked_mul(&base));
+ exp >>= 1;
+ }
+ if exp == 1 {
+ return Some(base);
+ }
+
+ let mut acc = base.clone();
+ while exp > 1 {
+ exp >>= 1;
+ base = optry!(base.checked_mul(&base));
+ if exp & 1 == 1 {
+ acc = optry!(acc.checked_mul(&base));
+ }
+ }
+ Some(acc)
+}