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// template <input_range Range>
12// requires constructible_from<View, views::all_t<Range>> &&
13// constructible_from<Pattern, single_view<range_value_t<Range>>>
14// constexpr lazy_split_view(Range&& r, range_value_t<Range> e); // explicit since C++23
15
16#include <ranges>
17
18#include <cassert>
19#include <string>
20#include <string_view>
21#include <type_traits>
22#include <utility>
23
24#include "test_convertible.h"
25#include "test_macros.h"
26#include "types.h"
27
28struct ElementWithCounting {
29 int* times_copied = nullptr;
30 int* times_moved = nullptr;
31
32 constexpr ElementWithCounting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}
33
34 constexpr ElementWithCounting(const ElementWithCounting& rhs)
35 : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
36 ++(*times_copied);
37 }
38 constexpr ElementWithCounting(ElementWithCounting&& rhs)
39 : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
40 ++(*times_moved);
41 }
42
43 constexpr bool operator==(const ElementWithCounting&) const { return true; }
44};
45
46struct RangeWithCounting {
47 using value_type = ElementWithCounting;
48
49 int* times_copied = nullptr;
50 int* times_moved = nullptr;
51
52 constexpr RangeWithCounting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}
53
54 constexpr RangeWithCounting(const RangeWithCounting& rhs)
55 : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
56 ++(*times_copied);
57 }
58 constexpr RangeWithCounting(RangeWithCounting&& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
59 ++(*times_moved);
60 }
61
62 constexpr const ElementWithCounting* begin() const { return nullptr; }
63 constexpr const ElementWithCounting* end() const { return nullptr; }
64
65 constexpr RangeWithCounting& operator=(const RangeWithCounting&) = default;
66 constexpr RangeWithCounting& operator=(RangeWithCounting&&) = default;
67 constexpr bool operator==(const RangeWithCounting&) const { return true; }
68};
69static_assert(std::ranges::forward_range<RangeWithCounting>);
70static_assert(!std::ranges::view<RangeWithCounting>);
71
72struct StrView : std::ranges::view_base {
73 std::string_view buffer_;
74 constexpr explicit StrView() = default;
75 constexpr StrView(const char* ptr) : buffer_(ptr) {}
76 // Intentionally don't forward to range constructor for std::string_view since
77 // this test needs to work on C++20 as well and the range constructor is only for
78 // C++23 and later.
79 template <std::ranges::range R>
80 constexpr StrView(R&& r) : buffer_(r.begin(), r.end()) {}
81 constexpr std::string_view::const_iterator begin() const { return buffer_.begin(); }
82 constexpr std::string_view::const_iterator end() const { return buffer_.end(); }
83 constexpr bool operator==(const StrView& rhs) const { return buffer_ == rhs.buffer_; }
84};
85static_assert(std::ranges::random_access_range<StrView>);
86static_assert(std::ranges::view<StrView>);
87static_assert(std::is_copy_constructible_v<StrView>);
88
89// SFINAE tests.
90
91#if TEST_STD_VER >= 23
92
93static_assert(
94 !test_convertible<std::ranges::lazy_split_view<StrView, StrView>, StrView, std::ranges::range_value_t<StrView>>(),
95 "This constructor must be explicit");
96
97#else
98
99static_assert(
100 test_convertible<std::ranges::lazy_split_view<StrView, StrView>, StrView, std::ranges::range_value_t<StrView>>(),
101 "This constructor must not be explicit");
102
103#endif // TEST_STD_VER >= 23
104
105constexpr bool test() {
106 {
107 using V = std::ranges::lazy_split_view<StrView, StrView>;
108
109 // Calling the constructor with `(std::string, range_value_t)`.
110 {
111 std::string input;
112 V v(input, ' ');
113 assert(v.base() == input);
114 }
115
116 // Calling the constructor with `(StrView, range_value_t)`.
117 {
118 StrView input("abc def");
119 V v(input, ' ');
120 assert(v.base() == input);
121 }
122
123 struct Empty {};
124 static_assert(!std::is_constructible_v<V, Empty, std::string_view>);
125 static_assert(!std::is_constructible_v<V, std::string_view, Empty>);
126 }
127
128 // Make sure the arguments are moved, not copied.
129 {
130 using Range = RangeWithCounting;
131 using Element = ElementWithCounting;
132 using Pattern = std::ranges::single_view<Element>;
133
134 // Arguments are lvalues.
135 {
136 using View = std::ranges::ref_view<Range>;
137
138 int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
139 Range range(range_copied, range_moved);
140 Element element(element_copied, element_moved);
141
142 std::ranges::lazy_split_view<View, Pattern> v(range, element);
143 assert(range_copied == 0); // `ref_view` does neither copy...
144 assert(range_moved == 0); // ...nor move the element.
145 assert(element_copied == 1); // The element is copied into the argument...
146#ifndef TEST_COMPILER_GCC
147 //https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98995
148 assert(element_moved == 1); // ...and moved into the member variable.
149#endif
150 }
151
152 // Arguments are rvalues.
153 {
154 using View = std::ranges::owning_view<Range>;
155
156 int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
157 std::ranges::lazy_split_view<View, Pattern> v(
158 Range(range_copied, range_moved), Element(element_copied, element_moved));
159 assert(range_copied == 0);
160 assert(range_moved == 1); // `owning_view` moves the given argument.
161 assert(element_copied == 0);
162#ifndef TEST_COMPILER_GCC
163 //https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98995
164 assert(element_moved == 1);
165#endif
166 }
167 }
168
169 return true;
170}
171
172int main(int, char**) {
173 test();
174 static_assert(test());
175
176 return 0;
177}
178

source code of libcxx/test/std/ranges/range.adaptors/range.lazy.split/ctor.range.pass.cpp