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 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 
11 // <utility>
12 
13 //   constexpr bool cmp_greater(T t, U u) noexcept;       // C++20
14 
15 #include <utility>
16 #include <limits>
17 #include <numeric>
18 #include <tuple>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
23 template <typename T>
24 struct Tuple {
25   T min;
26   T max;
27   T mid;
28   constexpr Tuple() {
29     min = std::numeric_limits<T>::min();
30     max = std::numeric_limits<T>::max();
31     mid = std::midpoint(min, max);
32   }
33 };
34 
35 template <typename T>
36 constexpr void test_cmp_greater1() {
37   constexpr Tuple<T> tup;
38   assert(!std::cmp_greater(T(0), T(1)));
39   assert(!std::cmp_greater(T(1), T(2)));
40   assert(!std::cmp_greater(tup.min, tup.max));
41   assert(!std::cmp_greater(tup.min, tup.mid));
42   assert(!std::cmp_greater(tup.mid, tup.max));
43   assert(std::cmp_greater(T(1), T(0)));
44   assert(std::cmp_greater(T(10), T(5)));
45   assert(std::cmp_greater(tup.max, tup.min));
46   assert(std::cmp_greater(tup.mid, tup.min));
47   assert(!std::cmp_greater(tup.mid, tup.mid));
48   assert(!std::cmp_greater(tup.min, tup.min));
49   assert(!std::cmp_greater(tup.max, tup.max));
50   assert(std::cmp_greater(tup.max, 1));
51   assert(std::cmp_greater(1, tup.min));
52   assert(!std::cmp_greater(T(-1), T(-1)));
53   assert(std::cmp_greater(-2, tup.min) == std::is_signed_v<T>);
54   assert(!std::cmp_greater(tup.min, -2) == std::is_signed_v<T>);
55   assert(!std::cmp_greater(-2, tup.max));
56   assert(std::cmp_greater(tup.max, -2));
57 }
58 
59 template <typename T, typename U>
60 constexpr void test_cmp_greater2() {
61   assert(!std::cmp_greater(T(0), U(1)));
62   assert(std::cmp_greater(T(1), U(0)));
63 }
64 
65 template <class... Ts>
66 constexpr void test1(const std::tuple<Ts...>&) {
67   (test_cmp_greater1<Ts>() , ...);
68 }
69 
70 template <class T, class... Us>
71 constexpr void test2_impl(const std::tuple<Us...>&) {
72   (test_cmp_greater2<T, Us>() , ...);
73 }
74 
75 template <class... Ts, class UTuple>
76 constexpr void test2(const std::tuple<Ts...>&, const UTuple& utuple) {
77   (test2_impl<Ts>(utuple) , ...);
78 }
79 
80 constexpr bool test() {
81   std::tuple<
82 #ifndef TEST_HAS_NO_INT128
83       __int128_t, __uint128_t,
84 #endif
85       unsigned long long, long long, unsigned long, long, unsigned int, int,
86       unsigned short, short, unsigned char, signed char> types;
87   test1(types);
88   test2(types, types);
89   return true;
90 }
91 
92 int main(int, char**) {
93   ASSERT_NOEXCEPT(std::cmp_greater(1, 0));
94   test();
95   static_assert(test());
96   return 0;
97 }
98