| 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 | // transform_view() requires std::default_initializable<V> && |
| 12 | // std::default_initializable<F> = default; |
| 13 | |
| 14 | #include <ranges> |
| 15 | |
| 16 | #include <cassert> |
| 17 | #include <type_traits> |
| 18 | |
| 19 | constexpr int buff[] = {1, 2, 3}; |
| 20 | |
| 21 | struct DefaultConstructibleView : std::ranges::view_base { |
| 22 | constexpr DefaultConstructibleView() : begin_(buff), end_(buff + 3) { } |
| 23 | constexpr int const* begin() const { return begin_; } |
| 24 | constexpr int const* end() const { return end_; } |
| 25 | private: |
| 26 | int const* begin_; |
| 27 | int const* end_; |
| 28 | }; |
| 29 | |
| 30 | struct DefaultConstructibleFunction { |
| 31 | int state_; |
| 32 | constexpr DefaultConstructibleFunction() : state_(100) { } |
| 33 | constexpr int operator()(int i) const { return i + state_; } |
| 34 | }; |
| 35 | |
| 36 | struct NoDefaultCtrView : std::ranges::view_base { |
| 37 | NoDefaultCtrView() = delete; |
| 38 | int* begin() const; |
| 39 | int* end() const; |
| 40 | }; |
| 41 | |
| 42 | struct NoDefaultFunction { |
| 43 | NoDefaultFunction() = delete; |
| 44 | constexpr int operator()(int i) const; |
| 45 | }; |
| 46 | |
| 47 | constexpr bool test() { |
| 48 | { |
| 49 | std::ranges::transform_view<DefaultConstructibleView, DefaultConstructibleFunction> view; |
| 50 | assert(view.size() == 3); |
| 51 | assert(view[0] == 101); |
| 52 | assert(view[1] == 102); |
| 53 | assert(view[2] == 103); |
| 54 | } |
| 55 | |
| 56 | { |
| 57 | std::ranges::transform_view<DefaultConstructibleView, DefaultConstructibleFunction> view = {}; |
| 58 | assert(view.size() == 3); |
| 59 | assert(view[0] == 101); |
| 60 | assert(view[1] == 102); |
| 61 | assert(view[2] == 103); |
| 62 | } |
| 63 | |
| 64 | static_assert(!std::is_default_constructible_v<std::ranges::transform_view<NoDefaultCtrView, DefaultConstructibleFunction>>); |
| 65 | static_assert(!std::is_default_constructible_v<std::ranges::transform_view<DefaultConstructibleView, NoDefaultFunction>>); |
| 66 | static_assert(!std::is_default_constructible_v<std::ranges::transform_view<NoDefaultCtrView, NoDefaultFunction>>); |
| 67 | |
| 68 | return true; |
| 69 | } |
| 70 | |
| 71 | int main(int, char**) { |
| 72 | test(); |
| 73 | static_assert(test()); |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |