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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___RANGES_REF_VIEW_H11#define _LIBCPP___RANGES_REF_VIEW_H12 13#include <__concepts/convertible_to.h>14#include <__concepts/different_from.h>15#include <__config>16#include <__iterator/concepts.h>17#include <__iterator/incrementable_traits.h>18#include <__iterator/iterator_traits.h>19#include <__memory/addressof.h>20#include <__ranges/access.h>21#include <__ranges/concepts.h>22#include <__ranges/data.h>23#include <__ranges/empty.h>24#include <__ranges/enable_borrowed_range.h>25#include <__ranges/size.h>26#include <__ranges/view_interface.h>27#include <__type_traits/is_object.h>28#include <__utility/declval.h>29#include <__utility/forward.h>30 31#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)32# pragma GCC system_header33#endif34 35_LIBCPP_BEGIN_NAMESPACE_STD36 37#if _LIBCPP_STD_VER >= 2038 39namespace ranges {40template <range _Range>41 requires is_object_v<_Range>42class ref_view : public view_interface<ref_view<_Range>> {43 _Range* __range_;44 45 static void __fun(_Range&);46 static void __fun(_Range&&) = delete; // NOLINT(modernize-use-equals-delete) ; This is llvm.org/PR5427647 48public:49 template <class _Tp>50 requires __different_from<_Tp, ref_view> && convertible_to<_Tp, _Range&> && requires { __fun(std::declval<_Tp>()); }51 _LIBCPP_HIDE_FROM_ABI constexpr ref_view(_Tp&& __t)52 : __range_(std::addressof(static_cast<_Range&>(std::forward<_Tp>(__t)))) {}53 54 _LIBCPP_HIDE_FROM_ABI constexpr _Range& base() const { return *__range_; }55 56 _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Range> begin() const { return ranges::begin(*__range_); }57 _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Range> end() const { return ranges::end(*__range_); }58 59 _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const60 requires requires { ranges::empty(*__range_); }61 {62 return ranges::empty(*__range_);63 }64 65 _LIBCPP_HIDE_FROM_ABI constexpr auto size() const66 requires sized_range<_Range>67 {68 return ranges::size(*__range_);69 }70 71 _LIBCPP_HIDE_FROM_ABI constexpr auto data() const72 requires contiguous_range<_Range>73 {74 return ranges::data(*__range_);75 }76};77 78template <class _Range>79ref_view(_Range&) -> ref_view<_Range>;80 81template <class _Tp>82inline constexpr bool enable_borrowed_range<ref_view<_Tp>> = true;83} // namespace ranges84 85#endif // _LIBCPP_STD_VER >= 2086 87_LIBCPP_END_NAMESPACE_STD88 89#endif // _LIBCPP___RANGES_REF_VIEW_H90