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 div_sat(T x, T y) noexcept; // freestanding
15
16#include <concepts>
17#include <numeric>
18#include <type_traits>
19
20#include "test_macros.h"
21
22// Constraints
23
24template <typename T, typename U>
25concept CanDo = requires(T x, U y) {
26 { std::div_sat(x, y) } -> std::same_as<T>;
27};
28
29template <typename T, typename U>
30constexpr void test_constraint_success() {
31 static_assert(CanDo<T, T>);
32 static_assert(!CanDo<U, T>);
33 static_assert(!CanDo<T, U>);
34}
35
36template <typename T>
37constexpr void test_constraint_fail() {
38 using I = int;
39 static_assert(!CanDo<T, T>);
40 static_assert(!CanDo<I, T>);
41 static_assert(!CanDo<T, I>);
42}
43
44constexpr void test() {
45 // Contraint success - Signed
46 using SI = long long int;
47 test_constraint_success<signed char, SI>();
48 test_constraint_success<short int, SI>();
49 test_constraint_success<signed char, SI>();
50 test_constraint_success<short int, SI>();
51 test_constraint_success<int, SI>();
52 test_constraint_success<long int, SI>();
53 test_constraint_success<long long int, int>();
54#ifndef TEST_HAS_NO_INT128
55 test_constraint_success<__int128_t, SI>();
56#endif
57 // Contraint success - Unsigned
58 using UI = unsigned long long int;
59 test_constraint_success<unsigned char, UI>();
60 test_constraint_success<unsigned short int, UI>();
61 test_constraint_success<unsigned int, UI>();
62 test_constraint_success<unsigned long int, UI>();
63 test_constraint_success<unsigned long long int, unsigned int>();
64#ifndef TEST_HAS_NO_INT128
65 test_constraint_success<__uint128_t, UI>();
66#endif
67
68 // Contraint failure
69 test_constraint_fail<bool>();
70 test_constraint_fail<char>();
71#ifndef TEST_HAS_NO_INT128
72 test_constraint_fail<wchar_t>();
73#endif
74 test_constraint_fail<char8_t>();
75 test_constraint_fail<char16_t>();
76 test_constraint_fail<char32_t>();
77 test_constraint_fail<float>();
78 test_constraint_fail<double>();
79 test_constraint_fail<long double>();
80}
81
82// A function call expression that violates the precondition in the Preconditions: element is not a core constant expression (7.7 [expr.const]).
83
84template <auto N>
85using QuotT = std::integral_constant<decltype(N), std::div_sat(N, N)>;
86
87template <auto N>
88QuotT<N> div_by_zero();
89
90template <auto N>
91concept CanDivByZero = requires { div_by_zero<N>(); };
92
93static_assert(!CanDivByZero<static_cast<signed char>(0)>);
94static_assert(!CanDivByZero<static_cast<short int>(0)>);
95static_assert(!CanDivByZero<0>);
96static_assert(!CanDivByZero<0L>);
97static_assert(!CanDivByZero<0LL>);
98#ifndef TEST_HAS_NO_INT128
99static_assert(!CanDivByZero<static_cast<__int128_t>(0)>);
100#endif
101static_assert(!CanDivByZero<static_cast<unsigned char>(0)>);
102static_assert(!CanDivByZero<static_cast<unsigned short int>(0)>);
103static_assert(!CanDivByZero<0U>);
104static_assert(!CanDivByZero<0UL>);
105static_assert(!CanDivByZero<0ULL>);
106#ifndef TEST_HAS_NO_INT128
107static_assert(!CanDivByZero<static_cast<__uint128_t>(0)>);
108#endif
109

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