malachite_base/num/arithmetic/
checked_square.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::CheckedSquare;
10
11macro_rules! impl_checked_square {
12    ($t:ident) => {
13        impl CheckedSquare for $t {
14            type Output = $t;
15
16            /// Squares a number, returning `None` if the result cannot be represented.
17            ///
18            /// $$
19            /// f(x) = \\begin{cases}
20            ///     \operatorname{Some}(x^2) & \text{if} \\quad x^2 < 2^W, \\\\
21            ///     \operatorname{None} & \text{if} \\quad x^2 \geq 2^W,
22            /// \\end{cases}
23            /// $$
24            /// where $W$ is `Self::WIDTH`.
25            ///
26            /// # Worst-case complexity
27            /// Constant time and additional memory.
28            ///
29            /// # Examples
30            /// See [here](super::checked_square#checked_square).
31            #[inline]
32            fn checked_square(self) -> Option<$t> {
33                self.checked_mul(self)
34            }
35        }
36    };
37}
38apply_to_primitive_ints!(impl_checked_square);