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Diffstat (limited to 'contrib/llvm-project/libcxx/include/__ranges/common_view.h')
-rw-r--r-- | contrib/llvm-project/libcxx/include/__ranges/common_view.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__ranges/common_view.h b/contrib/llvm-project/libcxx/include/__ranges/common_view.h new file mode 100644 index 000000000000..4b5b04c9894b --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__ranges/common_view.h @@ -0,0 +1,144 @@ +// -*- C++ -*- +//===----------------------------------------------------------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#ifndef _LIBCPP___RANGES_COMMON_VIEW_H +#define _LIBCPP___RANGES_COMMON_VIEW_H + +#include <__concepts/constructible.h> +#include <__concepts/copyable.h> +#include <__config> +#include <__iterator/common_iterator.h> +#include <__iterator/iterator_traits.h> +#include <__ranges/access.h> +#include <__ranges/all.h> +#include <__ranges/concepts.h> +#include <__ranges/enable_borrowed_range.h> +#include <__ranges/range_adaptor.h> +#include <__ranges/size.h> +#include <__ranges/view_interface.h> +#include <__utility/forward.h> +#include <__utility/move.h> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +# pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +#if _LIBCPP_STD_VER >= 20 + +namespace ranges { + +template <view _View> + requires(!common_range<_View> && copyable<iterator_t<_View>>) +class common_view : public view_interface<common_view<_View>> { + _View __base_ = _View(); + +public: + _LIBCPP_HIDE_FROM_ABI common_view() + requires default_initializable<_View> + = default; + + _LIBCPP_HIDE_FROM_ABI constexpr explicit common_view(_View __v) : __base_(std::move(__v)) {} + + _LIBCPP_HIDE_FROM_ABI constexpr _View base() const& + requires copy_constructible<_View> + { + return __base_; + } + + _LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); } + + _LIBCPP_HIDE_FROM_ABI constexpr auto begin() { + if constexpr (random_access_range<_View> && sized_range<_View>) + return ranges::begin(__base_); + else + return common_iterator<iterator_t<_View>, sentinel_t<_View>>(ranges::begin(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI constexpr auto begin() const + requires range<const _View> + { + if constexpr (random_access_range<const _View> && sized_range<const _View>) + return ranges::begin(__base_); + else + return common_iterator<iterator_t<const _View>, sentinel_t<const _View>>(ranges::begin(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI constexpr auto end() { + if constexpr (random_access_range<_View> && sized_range<_View>) + return ranges::begin(__base_) + ranges::size(__base_); + else + return common_iterator<iterator_t<_View>, sentinel_t<_View>>(ranges::end(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI constexpr auto end() const + requires range<const _View> + { + if constexpr (random_access_range<const _View> && sized_range<const _View>) + return ranges::begin(__base_) + ranges::size(__base_); + else + return common_iterator<iterator_t<const _View>, sentinel_t<const _View>>(ranges::end(__base_)); + } + + _LIBCPP_HIDE_FROM_ABI constexpr auto size() + requires sized_range<_View> + { + return ranges::size(__base_); + } + + _LIBCPP_HIDE_FROM_ABI constexpr auto size() const + requires sized_range<const _View> + { + return ranges::size(__base_); + } +}; + +template <class _Range> +common_view(_Range&&) -> common_view<views::all_t<_Range>>; + +template <class _View> +inline constexpr bool enable_borrowed_range<common_view<_View>> = enable_borrowed_range<_View>; + +namespace views { +namespace __common { +struct __fn : __range_adaptor_closure<__fn> { + template <class _Range> + requires common_range<_Range> + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range) const + noexcept(noexcept(views::all(std::forward<_Range>(__range)))) + -> decltype(views::all(std::forward<_Range>(__range))) { + return views::all(std::forward<_Range>(__range)); + } + + template <class _Range> + [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range) const + noexcept(noexcept(common_view{std::forward<_Range>(__range)})) + -> decltype(common_view{std::forward<_Range>(__range)}) { + return common_view{std::forward<_Range>(__range)}; + } +}; +} // namespace __common + +inline namespace __cpo { +inline constexpr auto common = __common::__fn{}; +} // namespace __cpo +} // namespace views +} // namespace ranges + +#endif // _LIBCPP_STD_VER >= 20 + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___RANGES_COMMON_VIEW_H |