118 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 lazy_split_view(View base, Pattern pattern); // explicit since C++2312 13#include <cassert>14#include <ranges>15#include <string_view>16#include <utility>17 18#include "test_convertible.h"19#include "types.h"20 21struct ViewWithCounting : std::ranges::view_base {22 int* times_copied = nullptr;23 int* times_moved = nullptr;24 25 constexpr ViewWithCounting(int& copies_ctr, int& moves_ctr) : times_copied(&copies_ctr), times_moved(&moves_ctr) {}26 27 constexpr ViewWithCounting(const ViewWithCounting& rhs)28 : times_copied(rhs.times_copied)29 , times_moved(rhs.times_moved) {30 ++(*times_copied);31 }32 constexpr ViewWithCounting(ViewWithCounting&& rhs)33 : times_copied(rhs.times_copied)34 , times_moved(rhs.times_moved) {35 ++(*times_moved);36 }37 38 constexpr const char* begin() const { return nullptr; }39 constexpr const char* end() const { return nullptr; }40 41 constexpr ViewWithCounting& operator=(const ViewWithCounting&) = default;42 constexpr ViewWithCounting& operator=(ViewWithCounting&&) = default;43 constexpr bool operator==(const ViewWithCounting&) const { return true; }44};45 46static_assert(std::ranges::forward_range<ViewWithCounting>);47static_assert(std::ranges::view<ViewWithCounting>);48 49using View = ViewWithCounting;50using Pattern = ViewWithCounting;51 52// SFINAE tests.53 54#if TEST_STD_VER >= 2355 56static_assert(!test_convertible<std::ranges::lazy_split_view<View, Pattern>, View, Pattern>(),57 "This constructor must be explicit");58 59#else60 61static_assert( test_convertible<std::ranges::lazy_split_view<View, Pattern>, View, Pattern>(),62 "This constructor must not be explicit");63 64#endif // TEST_STD_VER >= 2365 66constexpr bool test() {67 // Calling the constructor with `(ForwardView, ForwardView)`.68 {69 CopyableView input = "abc def";70 std::ranges::lazy_split_view<CopyableView, CopyableView> v(input, " ");71 assert(v.base() == input);72 }73 74 // Calling the constructor with `(InputView, TinyView)`.75 {76 InputView input = "abc def";77 std::ranges::lazy_split_view<InputView, ForwardTinyView> v(input, ' ');78 // Note: `InputView` isn't equality comparable.79 (void)v;80 }81 82 // Make sure the arguments are moved, not copied.83 {84 // Arguments are lvalues.85 {86 int view_copied = 0, view_moved = 0, pattern_copied = 0, pattern_moved = 0;87 View view(view_copied, view_moved);88 Pattern pattern(pattern_copied, pattern_moved);89 90 std::ranges::lazy_split_view<View, Pattern> v(view, pattern);91 assert(view_copied == 1); // The local variable is copied into the argument.92 assert(view_moved == 1);93 assert(pattern_copied == 1);94 assert(pattern_moved == 1);95 }96 97 // Arguments are rvalues.98 {99 int view_copied = 0, view_moved = 0, pattern_copied = 0, pattern_moved = 0;100 std::ranges::lazy_split_view<View, Pattern> v(101 View(view_copied, view_moved), Pattern(pattern_copied, pattern_moved));102 assert(view_copied == 0);103 assert(view_moved == 1);104 assert(pattern_copied == 0);105 assert(pattern_moved == 1);106 }107 }108 109 return true;110}111 112int main(int, char**) {113 test();114 static_assert(test());115 116 return 0;117}118