xref: /llvm-project/libcxx/test/std/ranges/range.adaptors/range.take/base.pass.cpp (revision d2baefae6846765eef6a6dd69d4fdf1082ce29ad)
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 // constexpr V base() const& requires copy_constructible<V>;
13 // constexpr V base() &&;
14 
15 #include <ranges>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 #include "test_iterators.h"
20 #include "types.h"
21 
22 constexpr bool hasLValueQualifiedBase(auto&& view) {
23     return requires { view.base(); };
24 }
25 
26 constexpr bool test() {
27   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
28 
29   {
30     std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 0);
31     assert(tv.base().ptr_ == buffer);
32     assert(std::move(tv).base().ptr_ == buffer);
33 
34     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
35     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
36     static_assert(hasLValueQualifiedBase(tv));
37   }
38 
39   {
40     std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 1);
41     assert(std::move(tv).base().ptr_ == buffer);
42 
43     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), MoveOnlyView);
44     static_assert(!hasLValueQualifiedBase(tv));
45   }
46 
47   {
48     const std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 2);
49     assert(tv.base().ptr_ == buffer);
50     assert(std::move(tv).base().ptr_ == buffer);
51 
52     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
53     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
54     static_assert(hasLValueQualifiedBase(tv));
55   }
56 
57   return true;
58 }
59 
60 int main(int, char**) {
61   test();
62   static_assert(test());
63 
64   return 0;
65 }
66