159 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 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++2315 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 27struct Counting {28 int* times_copied = nullptr;29 int* times_moved = nullptr;30 31 constexpr Counting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}32 33 constexpr Counting(const Counting& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {34 ++(*times_copied);35 }36 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 44struct ElementWithCounting : Counting {45 using Counting::Counting;46 47 constexpr bool operator==(const ElementWithCounting&) const { return true; }48};49 50struct RangeWithCounting : Counting {51 using Counting::Counting;52 53 constexpr const ElementWithCounting* begin() const { return nullptr; }54 constexpr const ElementWithCounting* end() const { return nullptr; }55 56 constexpr bool operator==(const RangeWithCounting&) const { return true; }57};58static_assert(std::ranges::forward_range<RangeWithCounting>);59static_assert(!std::ranges::view<RangeWithCounting>);60 61struct StrView : std::ranges::view_base {62 std::string buffer_;63 64 template <std::ranges::range R>65 constexpr StrView(R&& r) : buffer_(std::ranges::begin(r), std::ranges::end(r)) {}66 constexpr const char* begin() const { return buffer_.data(); }67 constexpr const char* end() const { return buffer_.data() + buffer_.size(); }68 constexpr bool operator==(const StrView& rhs) const { return buffer_ == rhs.buffer_; }69};70static_assert(std::ranges::random_access_range<StrView>);71static_assert(std::ranges::view<StrView>);72static_assert(std::is_copy_constructible_v<StrView>);73 74// SFINAE tests.75 76#if TEST_STD_VER >= 2377 78static_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# else83 84static_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 >= 2389 90constexpr 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 153int main(int, char**) {154 test();155 static_assert(test());156 157 return 0;158}159