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: no-localization
10 // UNSUPPORTED: c++03, c++11, c++14, c++17
11
12 // constexpr explicit iterator(basic_istream_view& parent) noexcept;
13
14 #include <cassert>
15 #include <ranges>
16 #include <sstream>
17 #include <type_traits>
18
19 #include "test_macros.h"
20 #include "../utils.h"
21
22 // test that the constructor is explicit
23 template <class CharT>
24 using IstreamView = std::ranges::basic_istream_view<int, CharT>;
25 template <class CharT>
26 using Iter = std::ranges::iterator_t<IstreamView<CharT>>;
27
28 static_assert(std::constructible_from<Iter<char>, IstreamView<char>&>);
29 static_assert(!std::convertible_to<IstreamView<char>&, Iter<char>>);
30
31 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
32 static_assert(std::constructible_from<Iter<wchar_t>, IstreamView<wchar_t>&>);
33 static_assert(!std::convertible_to<IstreamView<wchar_t>&, Iter<wchar_t>>);
34 #endif
35
36 // test that the constructor is noexcept
37 static_assert(std::is_nothrow_constructible_v<Iter<char>, IstreamView<char>&>);
38 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
39 static_assert(std::is_nothrow_constructible_v<Iter<wchar_t>, IstreamView<wchar_t>&>);
40 #endif
41
42 template <class CharT>
test()43 void test() {
44 auto iss = make_string_stream<CharT>("123");
45 std::ranges::basic_istream_view<int, CharT> isv{iss};
46 Iter<CharT> it{isv};
47 ++it;
48 assert(*it == 123);
49 }
50
main(int,char **)51 int main(int, char**) {
52 test<char>();
53 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
54 test<wchar_t>();
55 #endif
56
57 return 0;
58 }
59