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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
11 
12 // iterator() requires default_initializable<OuterIter> = default;
13 
14 #include <ranges>
15 
16 #include <cassert>
17 #include <type_traits>
18 #include "test_iterators.h"
19 #include "../types.h"
20 
21 template <class It>
22 struct view : std::ranges::view_base {
23   It begin() const;
24   sentinel_wrapper<It> end() const;
25 };
26 
27 template <class It>
test_default_constructible()28 constexpr void test_default_constructible() {
29   using JoinView = std::ranges::join_view<view<It>>;
30   using JoinIterator = std::ranges::iterator_t<JoinView>;
31   static_assert(std::is_default_constructible_v<JoinIterator>);
32   JoinIterator it; (void)it;
33 }
34 
35 template <class It>
test_non_default_constructible()36 constexpr void test_non_default_constructible() {
37   using JoinView = std::ranges::join_view<view<It>>;
38   using JoinIterator = std::ranges::iterator_t<JoinView>;
39   static_assert(!std::is_default_constructible_v<JoinIterator>);
40 }
41 
test()42 constexpr bool test() {
43   test_non_default_constructible<cpp17_input_iterator<ChildView*>>();
44   // NOTE: cpp20_input_iterator can't be used with join_view because it is not copyable.
45   test_default_constructible<forward_iterator<ChildView*>>();
46   test_default_constructible<bidirectional_iterator<ChildView*>>();
47   test_default_constructible<random_access_iterator<ChildView*>>();
48   test_default_constructible<contiguous_iterator<ChildView*>>();
49   return true;
50 }
51 
main(int,char **)52 int main(int, char**) {
53   test();
54   static_assert(test());
55   return 0;
56 }
57