xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.take/base.pass.cpp (revision b8cb1dc9ea87faa8e8e9ab7a31710a8c0bb8b084)
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 V base() const& requires copy_constructible<V>;
12 // constexpr V base() &&;
13 
14 #include <ranges>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 #include "test_iterators.h"
19 #include "types.h"
20 
hasLValueQualifiedBase(auto && view)21 constexpr bool hasLValueQualifiedBase(auto&& view) {
22     return requires { view.base(); };
23 }
24 
test()25 constexpr bool test() {
26   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
27 
28   {
29     std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 0);
30     assert(tv.base().ptr_ == buffer);
31     assert(std::move(tv).base().ptr_ == buffer);
32 
33     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
34     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
35     static_assert(hasLValueQualifiedBase(tv));
36   }
37 
38   {
39     std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 1);
40     assert(std::move(tv).base().ptr_ == buffer);
41 
42     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), MoveOnlyView);
43     static_assert(!hasLValueQualifiedBase(tv));
44   }
45 
46   {
47     const std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 2);
48     assert(tv.base().ptr_ == buffer);
49     assert(std::move(tv).base().ptr_ == buffer);
50 
51     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
52     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
53     static_assert(hasLValueQualifiedBase(tv));
54   }
55 
56   return true;
57 }
58 
main(int,char **)59 int main(int, char**) {
60   test();
61   static_assert(test());
62 
63   return 0;
64 }
65