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// constexpr subrange() requires default_initializable<I>;
12
13#include <ranges>
14
15#include <cassert>
16#include <cstddef>
17
18#include "test_iterators.h"
19
20// An input_or_output_iterator that is not default constructible so we can test
21// the `requires` on subrange's default constructor.
22struct NoDefaultIterator {
23 using difference_type = std::ptrdiff_t;
24 NoDefaultIterator() = delete;
25 NoDefaultIterator& operator++();
26 void operator++(int);
27 int& operator*() const;
28 friend bool operator==(NoDefaultIterator const&, NoDefaultIterator const&);
29};
30static_assert(std::input_or_output_iterator<NoDefaultIterator>);
31
32// A sentinel type for the above iterator
33struct Sentinel {
34 friend bool operator==(NoDefaultIterator const&, Sentinel const&);
35 friend bool operator==(Sentinel const&, NoDefaultIterator const&);
36 friend bool operator!=(NoDefaultIterator const&, Sentinel const&);
37 friend bool operator!=(Sentinel const&, NoDefaultIterator const&);
38};
39
40constexpr bool test() {
41 {
42 static_assert(!std::is_default_constructible_v<std::ranges::subrange<NoDefaultIterator, Sentinel, std::ranges::subrange_kind::sized>>);
43 static_assert(!std::is_default_constructible_v<std::ranges::subrange<NoDefaultIterator, Sentinel, std::ranges::subrange_kind::unsized>>);
44 }
45
46 {
47 using Iter = forward_iterator<int*>;
48 std::ranges::subrange<Iter, Iter, std::ranges::subrange_kind::sized> subrange;
49 assert(subrange.begin() == Iter());
50 assert(subrange.end() == Iter());
51 }
52 {
53 using Iter = forward_iterator<int*>;
54 std::ranges::subrange<Iter, Iter, std::ranges::subrange_kind::unsized> subrange;
55 assert(subrange.begin() == Iter());
56 assert(subrange.end() == Iter());
57 }
58
59 return true;
60}
61
62int main(int, char**) {
63 test();
64 static_assert(test());
65
66 return 0;
67}
68

source code of libcxx/test/std/ranges/range.utility/range.subrange/ctor.default.pass.cpp