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// <functional>
12
13// ranges::less
14
15#include <cassert>
16#include <functional>
17#include <type_traits>
18#include <utility>
19
20#include "test_macros.h"
21#include "compare_types.h"
22#include "MoveOnly.h"
23#include "pointer_comparison_test_helper.h"
24
25struct NotTotallyOrdered {
26 friend bool operator<(const NotTotallyOrdered&, const NotTotallyOrdered&);
27};
28
29static_assert(!std::is_invocable_v<std::ranges::less, NotTotallyOrdered, NotTotallyOrdered>);
30static_assert(!std::is_invocable_v<std::ranges::less, int, MoveOnly>);
31static_assert(std::is_invocable_v<std::ranges::less, explicit_operators, explicit_operators>);
32
33static_assert(requires { typename std::ranges::less::is_transparent; });
34
35constexpr bool test() {
36 auto fn = std::ranges::less();
37
38 assert(fn(MoveOnly(41), MoveOnly(42)));
39
40 ForwardingTestObject a;
41 ForwardingTestObject b;
42 assert(!fn(a, b));
43 assert(fn(std::move(a), std::move(b)));
44
45 assert(fn(1, 2));
46 assert(!fn(2, 2));
47 assert(!fn(2, 1));
48
49 assert(!fn(2, 1L));
50
51 return true;
52}
53
54int main(int, char**) {
55
56 test();
57 static_assert(test());
58
59 // test total ordering of int* for less<int*> and less<void>.
60 do_pointer_comparison_test(std::ranges::less());
61
62 return 0;
63}
64

source code of libcxx/test/std/utilities/function.objects/range.cmp/less.pass.cpp