malachite_base/num/arithmetic/parity.rs
1// Copyright © 2025 Mikhail Hogrefe
2//
3// This file is part of Malachite.
4//
5// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
6// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
7// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
8
9use crate::num::arithmetic::traits::Parity;
10
11macro_rules! impl_parity {
12 ($t:ident) => {
13 impl Parity for $t {
14 /// Tests whether a number is even.
15 ///
16 /// $f(x) = (2|x)$.
17 ///
18 /// $f(x) = (\exists k \in \N \ x = 2k)$.
19 ///
20 /// # Worst-case complexity
21 /// Constant time and additional memory.
22 ///
23 /// # Examples
24 /// See [here](super::parity#even).
25 #[inline]
26 fn even(self) -> bool {
27 (self & 1) == 0
28 }
29
30 /// Tests whether a number is odd.
31 ///
32 /// $f(x) = (2\nmid x)$.
33 ///
34 /// $f(x) = (\exists k \in \N \ x = 2k+1)$.
35 ///
36 /// # Worst-case complexity
37 /// Constant time and additional memory.
38 ///
39 /// # Examples
40 /// See [here](super::parity#odd).
41 #[inline]
42 fn odd(self) -> bool {
43 (self & 1) != 0
44 }
45 }
46 };
47}
48apply_to_primitive_ints!(impl_parity);