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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
use crate::num::arithmetic::traits::{CheckedPow, Parity};
macro_rules! impl_checked_pow_unsigned {
($t:ident) => {
impl CheckedPow<u64> for $t {
type Output = $t;
/// This is a wrapper over the `checked_pow` functions in the standard library, for
/// example [this one](u32::checked_pow).
#[inline]
fn checked_pow(self, exp: u64) -> Option<$t> {
if exp == 0 {
Some(1)
} else if self < 2 {
Some(self)
} else {
self.checked_pow(u32::try_from(exp).ok()?)
}
}
}
};
}
apply_to_unsigneds!(impl_checked_pow_unsigned);
macro_rules! impl_checked_pow_signed {
($t:ident) => {
impl CheckedPow<u64> for $t {
type Output = $t;
/// This is a wrapper over the `checked_pow` functions in the standard library, for
/// example [this one](i32::checked_pow).
#[inline]
fn checked_pow(self, exp: u64) -> Option<$t> {
if exp == 0 {
Some(1)
} else if self == 0 || self == 1 {
Some(self)
} else if self == -1 {
Some(if exp.even() { 1 } else { -1 })
} else {
self.checked_pow(u32::try_from(exp).ok()?)
}
}
}
};
}
apply_to_signeds!(impl_checked_pow_signed);