1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// REQUIRES: std-at-least-c++26
10
11// <numeric>
12
13// template<class T>
14// constexpr T sub_sat(T x, T y) noexcept; // freestanding
15
16#include <concepts>
17#include <numeric>
18
19#include "test_macros.h"
20
21template <typename T, typename U>
22concept CanDo = requires(T x, U y) {
23 { std::sub_sat(x, y) } -> std::same_as<T>;
24};
25
26template <typename T, typename U>
27constexpr void test_constraint_success() {
28 static_assert(CanDo<T, T>);
29 static_assert(!CanDo<U, T>);
30 static_assert(!CanDo<T, U>);
31}
32
33template <typename T>
34constexpr void test_constraint_fail() {
35 using I = int;
36 static_assert(!CanDo<T, T>);
37 static_assert(!CanDo<I, T>);
38 static_assert(!CanDo<T, I>);
39}
40
41constexpr void test() {
42 // Contraint success - Signed
43 using SI = long long int;
44 test_constraint_success<signed char, SI>();
45 test_constraint_success<short int, SI>();
46 test_constraint_success<signed char, SI>();
47 test_constraint_success<short int, SI>();
48 test_constraint_success<int, SI>();
49 test_constraint_success<long int, SI>();
50 test_constraint_success<long long int, int>();
51#ifndef TEST_HAS_NO_INT128
52 test_constraint_success<__int128_t, SI>();
53#endif
54 // Contraint success - Unsigned
55 using UI = unsigned long long int;
56 test_constraint_success<unsigned char, UI>();
57 test_constraint_success<unsigned short int, UI>();
58 test_constraint_success<unsigned int, UI>();
59 test_constraint_success<unsigned long int, UI>();
60 test_constraint_success<unsigned long long int, unsigned int>();
61#ifndef TEST_HAS_NO_INT128
62 test_constraint_success<__uint128_t, UI>();
63#endif
64
65 // Contraint failure
66 test_constraint_fail<bool>();
67 test_constraint_fail<char>();
68#ifndef TEST_HAS_NO_INT128
69 test_constraint_fail<wchar_t>();
70#endif
71 test_constraint_fail<char8_t>();
72 test_constraint_fail<char16_t>();
73 test_constraint_fail<char32_t>();
74 test_constraint_fail<float>();
75 test_constraint_fail<double>();
76 test_constraint_fail<long double>();
77}
78

source code of libcxx/test/std/numerics/numeric.ops/numeric.ops.sat/sub_sat.compile.pass.cpp