forked from OSchip/llvm-project
46 lines
1.6 KiB
C++
46 lines
1.6 KiB
C++
// -*- 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_EMPTY_VIEW_H
|
|
#define _LIBCPP___RANGES_EMPTY_VIEW_H
|
|
|
|
#include <__config>
|
|
#include <__ranges/enable_borrowed_range.h>
|
|
#include <__ranges/view_interface.h>
|
|
#include <type_traits>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
|
|
|
|
namespace ranges {
|
|
template<class _Tp>
|
|
requires is_object_v<_Tp>
|
|
class empty_view : public view_interface<empty_view<_Tp>> {
|
|
public:
|
|
_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* begin() noexcept { return nullptr; }
|
|
_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* end() noexcept { return nullptr; }
|
|
_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* data() noexcept { return nullptr; }
|
|
_LIBCPP_HIDE_FROM_ABI static constexpr size_t size() noexcept { return 0; }
|
|
_LIBCPP_HIDE_FROM_ABI static constexpr bool empty() noexcept { return true; }
|
|
};
|
|
|
|
template<class _Tp>
|
|
inline constexpr bool enable_borrowed_range<empty_view<_Tp>> = true;
|
|
} // namespace ranges
|
|
|
|
#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
#endif // _LIBCPP___RANGES_EMPTY_VIEW_H
|