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// <iterator>
10
11// reverse_iterator
12
13// template <RandomAccessIterator Iter1, RandomAccessIterator Iter2>
14// requires HasGreater<Iter1, Iter2>
15// bool operator<(const reverse_iterator<Iter1>& x, const reverse_iterator<Iter2>& y); // constexpr in C++17
16
17#include <iterator>
18#include <cassert>
19
20#include "test_macros.h"
21#include "test_iterators.h"
22
23template <class It>
24TEST_CONSTEXPR_CXX17 void test(It l, It r, bool x) {
25 const std::reverse_iterator<It> r1(l);
26 const std::reverse_iterator<It> r2(r);
27 assert((r1 < r2) == x);
28}
29
30TEST_CONSTEXPR_CXX17 bool tests() {
31 const char* s = "1234567890";
32 test(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s), false);
33 test(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s+1), false);
34 test(random_access_iterator<const char*>(s+1), random_access_iterator<const char*>(s), true);
35#if TEST_STD_VER >= 20
36 test(cpp20_random_access_iterator<const char*>(s), cpp20_random_access_iterator<const char*>(s), false);
37 test(cpp20_random_access_iterator<const char*>(s), cpp20_random_access_iterator<const char*>(s + 1), false);
38 test(cpp20_random_access_iterator<const char*>(s + 1), cpp20_random_access_iterator<const char*>(s), true);
39#endif
40 test(s, s, false);
41 test(s, s+1, false);
42 test(s+1, s, true);
43 return true;
44}
45
46int main(int, char**) {
47 tests();
48#if TEST_STD_VER > 14
49 static_assert(tests(), "");
50#endif
51 return 0;
52}
53

source code of libcxx/test/std/iterators/predef.iterators/reverse.iterators/reverse.iter.cmp/less.pass.cpp