| //===----------------------------------------------------------------------===// |
| // |
| // 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, c++20 |
| |
| // zip_view() = default; |
| |
| #include <ranges> |
| |
| #include <cassert> |
| #include <type_traits> |
| #include <utility> |
| |
| 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 NoDefaultCtrView : std::ranges::view_base { |
| NoDefaultCtrView() = delete; |
| int* begin() const; |
| int* end() const; |
| }; |
| |
| // The default constructor requires all underlying views to be default constructible. |
| // It is implicitly required by the tuple's constructor. If any of the iterators are |
| // not default constructible, zip iterator's =default would be implicitly deleted. |
| static_assert(std::is_default_constructible_v<std::ranges::zip_view<DefaultConstructibleView>>); |
| static_assert( |
| std::is_default_constructible_v<std::ranges::zip_view<DefaultConstructibleView, DefaultConstructibleView>>); |
| static_assert(!std::is_default_constructible_v<std::ranges::zip_view<DefaultConstructibleView, NoDefaultCtrView>>); |
| static_assert(!std::is_default_constructible_v<std::ranges::zip_view<NoDefaultCtrView, NoDefaultCtrView>>); |
| static_assert(!std::is_default_constructible_v<std::ranges::zip_view<NoDefaultCtrView>>); |
| |
| constexpr bool test() { |
| { |
| using View = std::ranges::zip_view<DefaultConstructibleView, DefaultConstructibleView>; |
| View v = View(); // the default constructor is not explicit |
| assert(v.size() == 3); |
| auto it = v.begin(); |
| #ifdef _LIBCPP_VERSION // libc++ doesn't implement P2165R4 yet |
| using Value = std::pair<const int&, const int&>; |
| #else |
| using Value = std::tuple<const int&, const int&>; |
| #endif |
| assert(*it++ == Value(buff[0], buff[0])); |
| assert(*it++ == Value(buff[1], buff[1])); |
| assert(*it == Value(buff[2], buff[2])); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |