fixed_bigint/fixeduint/
abs_diff_impl.rs

1// Copyright 2021 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15//! Absolute difference implementation for FixedUInt.
16
17use super::{FixedUInt, MachineWord};
18use crate::const_numtraits::ConstAbsDiff;
19use crate::machineword::ConstMachineWord;
20
21c0nst::c0nst! {
22    impl<T: [c0nst] ConstMachineWord + MachineWord, const N: usize> c0nst ConstAbsDiff for FixedUInt<T, N> {
23        fn abs_diff(self, other: Self) -> Self {
24            if self >= other {
25                self - other
26            } else {
27                other - self
28            }
29        }
30    }
31}
32
33#[cfg(test)]
34mod tests {
35    use super::*;
36
37    #[test]
38    fn test_abs_diff() {
39        type U16 = FixedUInt<u8, 2>;
40
41        assert_eq!(
42            ConstAbsDiff::abs_diff(U16::from(10u8), U16::from(3u8)),
43            U16::from(7u8)
44        );
45        assert_eq!(
46            ConstAbsDiff::abs_diff(U16::from(3u8), U16::from(10u8)),
47            U16::from(7u8)
48        );
49        assert_eq!(
50            ConstAbsDiff::abs_diff(U16::from(5u8), U16::from(5u8)),
51            U16::from(0u8)
52        );
53        assert_eq!(
54            ConstAbsDiff::abs_diff(U16::from(0u8), U16::from(100u8)),
55            U16::from(100u8)
56        );
57        assert_eq!(
58            ConstAbsDiff::abs_diff(U16::from(255u8), U16::from(0u8)),
59            U16::from(255u8)
60        );
61    }
62
63    c0nst::c0nst! {
64        pub c0nst fn const_abs_diff<T: [c0nst] ConstMachineWord + MachineWord, const N: usize>(
65            a: FixedUInt<T, N>,
66            b: FixedUInt<T, N>,
67        ) -> FixedUInt<T, N> {
68            ConstAbsDiff::abs_diff(a, b)
69        }
70    }
71
72    #[test]
73    fn test_const_abs_diff() {
74        type U16 = FixedUInt<u8, 2>;
75
76        assert_eq!(
77            const_abs_diff(U16::from(10u8), U16::from(3u8)),
78            U16::from(7u8)
79        );
80
81        #[cfg(feature = "nightly")]
82        {
83            const A: U16 = FixedUInt { array: [10, 0] };
84            const B: U16 = FixedUInt { array: [3, 0] };
85            const DIFF: U16 = const_abs_diff(A, B);
86            assert_eq!(DIFF, FixedUInt { array: [7, 0] });
87        }
88    }
89}
fixed_bigint/fixeduint/abs_diff_impl.rs

fixed_bigint/fixeduint/
abs_diff_impl.rs
