diff options
Diffstat (limited to 'libcxx/include/__ranges/common_view.h')
-rw-r--r-- | libcxx/include/__ranges/common_view.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/libcxx/include/__ranges/common_view.h b/libcxx/include/__ranges/common_view.h new file mode 100644 index 000000000000..dab82602f671 --- /dev/null +++ b/libcxx/include/__ranges/common_view.h @@ -0,0 +1,113 @@ +// -*- 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 <__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/size.h> +#include <__ranges/view_interface.h> +#include <concepts> +#include <type_traits> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +#if !defined(_LIBCPP_HAS_NO_RANGES) + +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_(_VSTD::move(__v)) { } + + _LIBCPP_HIDE_FROM_ABI + constexpr _View base() const& requires copy_constructible<_View> { return __base_; } + + _LIBCPP_HIDE_FROM_ABI + constexpr _View base() && { return _VSTD::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 ranges + +#endif // !defined(_LIBCPP_HAS_NO_RANGES) + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___RANGES_COMMON_VIEW_H |