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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::integer::Integer;
use malachite_base::num::arithmetic::traits::Parity;
impl Parity for &Integer {
/// Tests whether an [`Integer`] is even.
///
/// $f(x) = (2|x)$.
///
/// $f(x) = (\exists k \in \N : x = 2k)$.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::{Parity, Pow};
/// use malachite_base::num::basic::traits::{One, Zero};
/// use malachite_nz::integer::Integer;
///
/// assert_eq!(Integer::ZERO.even(), true);
/// assert_eq!(Integer::from(123).even(), false);
/// assert_eq!(Integer::from(-0x80).even(), true);
/// assert_eq!(Integer::from(10u32).pow(12).even(), true);
/// assert_eq!((-Integer::from(10u32).pow(12) - Integer::ONE).even(), false);
/// ```
fn even(self) -> bool {
self.abs.even()
}
/// Tests whether an [`Integer`] is odd.
///
/// $f(x) = (2\nmid x)$.
///
/// $f(x) = (\exists k \in \N : x = 2k+1)$.
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::{Parity, Pow};
/// use malachite_base::num::basic::traits::{One, Zero};
/// use malachite_nz::integer::Integer;
///
/// assert_eq!(Integer::ZERO.odd(), false);
/// assert_eq!(Integer::from(123).odd(), true);
/// assert_eq!(Integer::from(-0x80).odd(), false);
/// assert_eq!(Integer::from(10u32).pow(12).odd(), false);
/// assert_eq!((-Integer::from(10u32).pow(12) - Integer::ONE).odd(), true);
/// ```
fn odd(self) -> bool {
self.abs.odd()
}
}