| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // transform_view() requires std::default_initializable<V> && |
| // std::default_initializable<F> = default; |
| |
| #include <ranges> |
| |
| #include <cassert> |
| #include <type_traits> |
| |
| constexpr int buff[] = {1, 2, 3}; |
| |
| struct DefaultConstructibleView : std::ranges::view_base { |
| constexpr DefaultConstructibleView() : begin_(buff), end_(buff + 3) { } |
| constexpr int const* begin() const { return begin_; } |
| constexpr int const* end() const { return end_; } |
| private: |
| int const* begin_; |
| int const* end_; |
| }; |
| |
| struct DefaultConstructibleFunction { |
| int state_; |
| constexpr DefaultConstructibleFunction() : state_(100) { } |
| constexpr int operator()(int i) const { return i + state_; } |
| }; |
| |
| struct NoDefaultCtrView : std::ranges::view_base { |
| NoDefaultCtrView() = delete; |
| int* begin() const; |
| int* end() const; |
| }; |
| |
| struct NoDefaultFunction { |
| NoDefaultFunction() = delete; |
| constexpr int operator()(int i) const; |
| }; |
| |
| constexpr bool test() { |
| { |
| std::ranges::transform_view<DefaultConstructibleView, DefaultConstructibleFunction> view; |
| assert(view.size() == 3); |
| assert(view[0] == 101); |
| assert(view[1] == 102); |
| assert(view[2] == 103); |
| } |
| |
| { |
| std::ranges::transform_view<DefaultConstructibleView, DefaultConstructibleFunction> view = {}; |
| assert(view.size() == 3); |
| assert(view[0] == 101); |
| assert(view[1] == 102); |
| assert(view[2] == 103); |
| } |
| |
| static_assert(!std::is_default_constructible_v<std::ranges::transform_view<NoDefaultCtrView, DefaultConstructibleFunction>>); |
| static_assert(!std::is_default_constructible_v<std::ranges::transform_view<DefaultConstructibleView, NoDefaultFunction>>); |
| static_assert(!std::is_default_constructible_v<std::ranges::transform_view<NoDefaultCtrView, NoDefaultFunction>>); |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |