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 const iterator_t<Base>& base() const & noexcept;
12// constexpr iterator_t<Base> base() &&;
13
14#include <cassert>
15#include <ranges>
16#include <tuple>
17#include <type_traits>
18#include <utility>
19
20#include "MoveOnly.h"
21#include "../types.h"
22
23// Test Noexcept
24template <class T>
25concept IsBaseNoexcept =
26 requires {
27 { std::declval<T>().base() } noexcept;
28 };
29
30using BaseView = std::ranges::subrange<std::tuple<int>*>;
31using ElementsIter = std::ranges::iterator_t<std::ranges::elements_view<BaseView, 0>>;
32
33static_assert(IsBaseNoexcept<const ElementsIter&>);
34static_assert(IsBaseNoexcept<ElementsIter&>);
35static_assert(IsBaseNoexcept<const ElementsIter&&>);
36LIBCPP_STATIC_ASSERT(!IsBaseNoexcept<ElementsIter&&>);
37
38constexpr bool test() {
39 std::tuple<int> t{5};
40
41 // const &
42 {
43 const ElementsIter it{&t};
44 decltype(auto) base = it.base();
45 static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
46 assert(base == &t);
47 }
48
49 // &
50 {
51 ElementsIter it{&t};
52 decltype(auto) base = it.base();
53 static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
54 assert(base == &t);
55 }
56
57 // &&
58 {
59 ElementsIter it{&t};
60 decltype(auto) base = std::move(it).base();
61 static_assert(std::is_same_v<decltype(base), std::tuple<int>*>);
62 assert(base == &t);
63 }
64
65 // const &&
66 {
67 const ElementsIter it{&t};
68 decltype(auto) base = std::move(it).base();
69 static_assert(std::is_same_v<decltype(base), std::tuple<int>* const&>);
70 assert(base == &t);
71 }
72
73 // move only
74 {
75 struct MoveOnlyIter : IterBase<MoveOnlyIter> {
76 MoveOnly mo;
77 };
78 struct Sent {
79 constexpr bool operator==(const MoveOnlyIter&) const { return true; }
80 };
81
82 using MoveOnlyElemIter =
83 std::ranges::iterator_t<std::ranges::elements_view<std::ranges::subrange<MoveOnlyIter, Sent>, 0>>;
84
85 MoveOnlyElemIter it{MoveOnlyIter{{}, MoveOnly{5}}};
86 decltype(auto) base = std::move(it).base();
87 static_assert(std::is_same_v<decltype(base), MoveOnlyIter>);
88 assert(base.mo.get() == 5);
89 }
90
91 return true;
92}
93
94int main(int, char**) {
95 test();
96 static_assert(test());
97 return 0;
98}
99

source code of libcxx/test/std/ranges/range.adaptors/range.elements/iterator/base.pass.cpp