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> { return base_; }
12// constexpr V base() && { return std::move(base_); }
13
14#include <cassert>
15#include <ranges>
16#include <type_traits>
17#include <utility>
18
19#include "MoveOnly.h"
20#include "types.h"
21
22struct View : std::ranges::view_interface<View> {
23 int i;
24 int* begin() const;
25 int* end() const;
26};
27
28struct MoveOnlyView : View {
29 MoveOnly mo;
30};
31
32template <class T>
33concept HasBase = requires(T&& t) { std::forward<T>(t).base(); };
34
35struct Pred {
36 constexpr bool operator()(int i) const { return i > 5; }
37};
38
39static_assert(HasBase<std::ranges::take_while_view<View, Pred> const&>);
40static_assert(HasBase<std::ranges::take_while_view<View, Pred>&&>);
41
42static_assert(!HasBase<std::ranges::take_while_view<MoveOnlyView, Pred> const&>);
43static_assert(HasBase<std::ranges::take_while_view<MoveOnlyView, Pred>&&>);
44
45constexpr bool test() {
46 // const &
47 {
48 const std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
49 std::same_as<View> decltype(auto) v = twv.base();
50 assert(v.i == 5);
51 }
52
53 // &
54 {
55 std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
56 std::same_as<View> decltype(auto) v = twv.base();
57 assert(v.i == 5);
58 }
59
60 // &&
61 {
62 std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
63 std::same_as<View> decltype(auto) v = std::move(twv).base();
64 assert(v.i == 5);
65 }
66
67 // const &&
68 {
69 const std::ranges::take_while_view<View, Pred> twv{View{{}, 5}, {}};
70 std::same_as<View> decltype(auto) v = std::move(twv).base();
71 assert(v.i == 5);
72 }
73
74 // move only
75 {
76 std::ranges::take_while_view<MoveOnlyView, Pred> twv{MoveOnlyView{{}, 5}, {}};
77 std::same_as<MoveOnlyView> decltype(auto) v = std::move(twv).base();
78 assert(v.mo.get() == 5);
79 }
80 return true;
81}
82
83int main(int, char**) {
84 test();
85 static_assert(test());
86 return 0;
87}
88

source code of libcxx/test/std/ranges/range.adaptors/range.take.while/base.pass.cpp