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 split_view(Range&& r, range_value_t<Range> e); // explicit since C++23
15
16 #include <algorithm>
17 #include <cassert>
18 #include <ranges>
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
27 struct Counting {
28 int* times_copied = nullptr;
29 int* times_moved = nullptr;
30
CountingCounting31 constexpr Counting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}
32
CountingCounting33 constexpr Counting(const Counting& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
34 ++(*times_copied);
35 }
CountingCounting36 constexpr Counting(Counting&& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {
37 ++(*times_moved);
38 }
39
40 constexpr Counting& operator=(const Counting&) = default;
41 constexpr Counting& operator=(Counting&&) = default;
42 };
43
44 struct ElementWithCounting : Counting {
45 using Counting::Counting;
46
operator ==ElementWithCounting47 constexpr bool operator==(const ElementWithCounting&) const { return true; }
48 };
49
50 struct RangeWithCounting : Counting {
51 using Counting::Counting;
52
beginRangeWithCounting53 constexpr const ElementWithCounting* begin() const { return nullptr; }
endRangeWithCounting54 constexpr const ElementWithCounting* end() const { return nullptr; }
55
operator ==RangeWithCounting56 constexpr bool operator==(const RangeWithCounting&) const { return true; }
57 };
58 static_assert(std::ranges::forward_range<RangeWithCounting>);
59 static_assert(!std::ranges::view<RangeWithCounting>);
60
61 struct StrView : std::ranges::view_base {
62 std::string buffer_;
63
64 template <std::ranges::range R>
StrViewStrView65 constexpr StrView(R&& r) : buffer_(std::ranges::begin(r), std::ranges::end(r)) {}
beginStrView66 constexpr const char* begin() const { return buffer_.data(); }
endStrView67 constexpr const char* end() const { return buffer_.data() + buffer_.size(); }
operator ==StrView68 constexpr bool operator==(const StrView& rhs) const { return buffer_ == rhs.buffer_; }
69 };
70 static_assert(std::ranges::random_access_range<StrView>);
71 static_assert(std::ranges::view<StrView>);
72 static_assert(std::is_copy_constructible_v<StrView>);
73
74 // SFINAE tests.
75
76 #if TEST_STD_VER >= 23
77
78 static_assert(
79 !test_convertible<std::ranges::split_view<StrView, StrView>, StrView, std::ranges::range_value_t<StrView>>(),
80 "This constructor must be explicit");
81
82 # else
83
84 static_assert(
85 test_convertible<std::ranges::split_view<StrView, StrView>, StrView, std::ranges::range_value_t<StrView>>(),
86 "This constructor must not be explicit");
87
88 #endif // TEST_STD_VER >= 23
89
test()90 constexpr bool test() {
91 {
92 using V = std::ranges::split_view<StrView, StrView>;
93
94 // Calling the constructor with `(std::string, range_value_t)`.
95 {
96 std::string input("abc def");
97 V v(input, ' ');
98 assert(v.base() == input);
99 assert(std::ranges::equal(*v.begin(), std::string_view("abc")));
100 }
101
102 // Calling the constructor with `(StrView, range_value_t)`.
103 {
104 StrView input("abc def");
105 V v(input, ' ');
106 assert(v.base() == input);
107 assert(std::ranges::equal(*v.begin(), std::string_view("abc")));
108 }
109
110 struct Empty {};
111 static_assert(!std::is_constructible_v<V, Empty, std::string_view>);
112 static_assert(!std::is_constructible_v<V, std::string_view, Empty>);
113 }
114
115 // Make sure the arguments are moved, not copied.
116 {
117 using Range = RangeWithCounting;
118 using Element = ElementWithCounting;
119 using Pattern = std::ranges::single_view<Element>;
120
121 // Arguments are lvalues.
122 {
123 using View = std::ranges::ref_view<Range>;
124
125 int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
126 Range range(range_copied, range_moved);
127 Element element(element_copied, element_moved);
128
129 std::ranges::split_view<View, Pattern> v(range, element);
130 assert(range_copied == 0); // `ref_view` does neither copy...
131 assert(range_moved == 0); // ...nor move the element.
132 assert(element_copied == 1); // The element is copied into the argument...
133 assert(element_moved == 1); // ...and moved into the member variable.
134 }
135
136 // Arguments are rvalues.
137 {
138 using View = std::ranges::owning_view<Range>;
139
140 int range_copied = 0, range_moved = 0, element_copied = 0, element_moved = 0;
141 std::ranges::split_view<View, Pattern> v(
142 Range(range_copied, range_moved), Element(element_copied, element_moved));
143 assert(range_copied == 0);
144 assert(range_moved == 1); // `owning_view` moves the given argument.
145 assert(element_copied == 0);
146 assert(element_moved == 1);
147 }
148 }
149
150 return true;
151 }
152
main(int,char **)153 int main(int, char**) {
154 test();
155 static_assert(test());
156
157 return 0;
158 }
159