4f15267d3d
This change is almost fully mechanical. The only interesting change is in `generate_feature_test_macro_components.py` to generate `_LIBCPP_STD_VER >=` instead. To avoid churn in the git-blame this commit should be added to the `.git-blame-ignore-revs` once committed. Reviewed By: ldionne, var-const, #libc Spies: jloser, libcxx-commits, arichardson, arphaman, wenlei Differential Revision: https://reviews.llvm.org/D143962
54 lines
1.6 KiB
C++
54 lines
1.6 KiB
C++
// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___RANGES_EMPTY_VIEW_H
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#define _LIBCPP___RANGES_EMPTY_VIEW_H
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#include <__config>
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#include <__ranges/enable_borrowed_range.h>
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#include <__ranges/view_interface.h>
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#include <type_traits>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_BEGIN_NAMESPACE_STD
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#if _LIBCPP_STD_VER >= 20
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namespace ranges {
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template<class _Tp>
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requires is_object_v<_Tp>
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class empty_view : public view_interface<empty_view<_Tp>> {
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public:
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_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* begin() noexcept { return nullptr; }
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_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* end() noexcept { return nullptr; }
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_LIBCPP_HIDE_FROM_ABI static constexpr _Tp* data() noexcept { return nullptr; }
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_LIBCPP_HIDE_FROM_ABI static constexpr size_t size() noexcept { return 0; }
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_LIBCPP_HIDE_FROM_ABI static constexpr bool empty() noexcept { return true; }
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};
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template<class _Tp>
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inline constexpr bool enable_borrowed_range<empty_view<_Tp>> = true;
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namespace views {
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template <class _Tp>
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inline constexpr empty_view<_Tp> empty{};
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} // namespace views
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} // namespace ranges
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#endif // _LIBCPP_STD_VER >= 20
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___RANGES_EMPTY_VIEW_H
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