104 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// constexpr split_view(View base, Pattern pattern); // explicit since C++2312 13#include <algorithm>14#include <cassert>15#include <ranges>16#include <string_view>17#include <utility>18 19#include "test_convertible.h"20#include "test_macros.h"21 22struct ViewWithCounting : std::ranges::view_base {23 int* times_copied = nullptr;24 int* times_moved = nullptr;25 26 constexpr ViewWithCounting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}27 28 constexpr ViewWithCounting(const ViewWithCounting& rhs)29 : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {30 ++(*times_copied);31 }32 constexpr ViewWithCounting(ViewWithCounting&& rhs) : times_copied(rhs.times_copied), times_moved(rhs.times_moved) {33 ++(*times_moved);34 }35 36 constexpr const char* begin() const { return nullptr; }37 constexpr const char* end() const { return nullptr; }38 39 constexpr ViewWithCounting& operator=(const ViewWithCounting&) = default;40 constexpr ViewWithCounting& operator=(ViewWithCounting&&) = default;41 constexpr bool operator==(const ViewWithCounting&) const { return true; }42};43 44using View = ViewWithCounting;45using Pattern = ViewWithCounting;46 47// SFINAE tests.48 49#if TEST_STD_VER >= 2350 51static_assert(!test_convertible<std::ranges::split_view<View, Pattern>, View, Pattern>(),52 "This constructor must be explicit");53 54#else55 56static_assert( test_convertible<std::ranges::split_view<View, Pattern>, View, Pattern>(),57 "This constructor must not be explicit");58 59#endif // TEST_STD_VER >= 2360 61constexpr bool test() {62 {63 std::string_view input = "abc def";64 std::ranges::split_view<std::string_view, std::string_view> v(input, " ");65 assert(v.base() == input);66 assert(std::ranges::equal(*v.begin(), std::string_view{"abc"}));67 }68 69 // Make sure the arguments are moved, not copied.70 {71 // Arguments are lvalues.72 {73 int view_copied = 0, view_moved = 0, pattern_copied = 0, pattern_moved = 0;74 View view(view_copied, view_moved);75 Pattern pattern(pattern_copied, pattern_moved);76 77 std::ranges::split_view<View, Pattern> v(view, pattern);78 assert(view_copied == 1); // The local variable is copied into the argument.79 assert(view_moved == 1);80 assert(pattern_copied == 1);81 assert(pattern_moved == 1);82 }83 84 // Arguments are rvalues.85 {86 int view_copied = 0, view_moved = 0, pattern_copied = 0, pattern_moved = 0;87 std::ranges::split_view<View, Pattern> v(View(view_copied, view_moved), Pattern(pattern_copied, pattern_moved));88 assert(view_copied == 0);89 assert(view_moved == 1);90 assert(pattern_copied == 0);91 assert(pattern_moved == 1);92 }93 }94 95 return true;96}97 98int main(int, char**) {99 test();100 static_assert(test());101 102 return 0;103}104