| 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 | // REQUIRES: std-at-least-c++23 |
| 10 | |
| 11 | // <ranges> |
| 12 | |
| 13 | // constexpr explicit join_with_view(V base, Pattern pattern); |
| 14 | |
| 15 | #include <ranges> |
| 16 | |
| 17 | #include <algorithm> |
| 18 | #include <array> |
| 19 | #include <cassert> |
| 20 | #include <utility> |
| 21 | |
| 22 | #include "../types.h" |
| 23 | |
| 24 | class View : public std::ranges::view_base { |
| 25 | using OuterRange = std::array<std::array<int, 2>, 3>; |
| 26 | |
| 27 | static constexpr OuterRange default_range = {._M_elems: {{1, 2}, {3, 4}, {5, 6}}}; |
| 28 | static constexpr OuterRange range_on_move = {._M_elems: {{6, 5}, {4, 3}, {2, 1}}}; |
| 29 | |
| 30 | const OuterRange* r_ = &default_range; |
| 31 | |
| 32 | public: |
| 33 | View() = default; |
| 34 | constexpr View(const View&) : r_(&default_range) {} |
| 35 | constexpr View(View&&) : r_(&range_on_move) {} |
| 36 | |
| 37 | constexpr View& operator=(View) { |
| 38 | r_ = &default_range; |
| 39 | return *this; |
| 40 | } |
| 41 | |
| 42 | constexpr auto begin() { return r_->begin(); } |
| 43 | constexpr auto end() { return r_->end(); } |
| 44 | }; |
| 45 | |
| 46 | class Pattern : public std::ranges::view_base { |
| 47 | using PatternRange = std::array<int, 2>; |
| 48 | |
| 49 | static constexpr PatternRange default_range = {0, 0}; |
| 50 | static constexpr PatternRange range_on_move = {7, 7}; |
| 51 | |
| 52 | const PatternRange* val_ = &default_range; |
| 53 | |
| 54 | public: |
| 55 | Pattern() = default; |
| 56 | constexpr Pattern(const Pattern&) : val_(&default_range) {} |
| 57 | constexpr Pattern(Pattern&&) : val_(&range_on_move) {} |
| 58 | |
| 59 | constexpr Pattern& operator=(Pattern) { |
| 60 | val_ = &default_range; |
| 61 | return *this; |
| 62 | } |
| 63 | |
| 64 | constexpr auto begin() { return val_->begin(); } |
| 65 | constexpr auto end() { return val_->end(); } |
| 66 | }; |
| 67 | |
| 68 | constexpr bool test() { |
| 69 | { // Check construction from `view` and `pattern` |
| 70 | { // `view` and `pattern` are glvalues |
| 71 | View v; |
| 72 | Pattern p; |
| 73 | std::ranges::join_with_view<View, Pattern> jwv(v, p); |
| 74 | assert(std::ranges::equal(jwv, std::array{6, 5, 7, 7, 4, 3, 7, 7, 2, 1})); |
| 75 | } |
| 76 | |
| 77 | { // `view` and `pattern` are const glvalues |
| 78 | const View v; |
| 79 | const Pattern p; |
| 80 | std::ranges::join_with_view<View, Pattern> jwv(v, p); |
| 81 | assert(std::ranges::equal(jwv, std::array{6, 5, 7, 7, 4, 3, 7, 7, 2, 1})); |
| 82 | } |
| 83 | |
| 84 | { // `view` and `pattern` are prvalues |
| 85 | std::ranges::join_with_view<View, Pattern> jwv(View{}, Pattern{}); |
| 86 | assert(std::ranges::equal(jwv, std::array{6, 5, 7, 7, 4, 3, 7, 7, 2, 1})); |
| 87 | } |
| 88 | |
| 89 | { // `view` and `pattern` are xvalues |
| 90 | View v; |
| 91 | Pattern p; |
| 92 | std::ranges::join_with_view<View, Pattern> jwv(std::move(v), std::move(p)); |
| 93 | assert(std::ranges::equal(jwv, std::array{6, 5, 7, 7, 4, 3, 7, 7, 2, 1})); |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | // Check explicitness |
| 98 | static_assert(ConstructionIsExplicit<std::ranges::join_with_view<View, Pattern>, View, Pattern>); |
| 99 | static_assert(ConstructionIsExplicit<std::ranges::join_with_view<View, Pattern>, View&, Pattern&>); |
| 100 | static_assert(ConstructionIsExplicit<std::ranges::join_with_view<View, Pattern>, const View, const Pattern>); |
| 101 | static_assert(ConstructionIsExplicit<std::ranges::join_with_view<View, Pattern>, const View&, const Pattern&>); |
| 102 | |
| 103 | return true; |
| 104 | } |
| 105 | |
| 106 | int main(int, char**) { |
| 107 | test(); |
| 108 | static_assert(test()); |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |