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// ranges::next
12// Make sure we're SFINAE-friendly when the template argument constraints are not met.
13
14#include <iterator>
15
16#include <cstddef>
17#include <memory>
18#include <utility>
19#include "test_iterators.h"
20
21template <class ...Args>
22concept has_ranges_next = requires (Args&& ...args) {
23 { std::ranges::next(std::forward<Args>(args)...) };
24};
25
26using It = std::unique_ptr<int>;
27static_assert(!has_ranges_next<It>);
28static_assert(!has_ranges_next<It, std::ptrdiff_t>);
29static_assert(!has_ranges_next<It, It>);
30static_assert(!has_ranges_next<It, std::ptrdiff_t, It>);
31
32// Test the test
33using It2 = forward_iterator<int*>;
34static_assert(has_ranges_next<It2>);
35static_assert(has_ranges_next<It2, std::ptrdiff_t>);
36static_assert(has_ranges_next<It2, std::ptrdiff_t, It2>);
37

source code of libcxx/test/std/iterators/iterator.primitives/range.iter.ops/range.iter.ops.next/constraints.compile.pass.cpp