368faacac7
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9, which were related to the original commit). As landed, 5aaefa51 had unintended consequences on some downstream bots and didn't have proper coverage upstream due to a few subtle things. Implementing this is something we should do in libc++, however we'll first need to address a few issues listed in https://reviews.llvm.org/D106124#3349710. Differential Revision: https://reviews.llvm.org/D120683
61 lines
1.7 KiB
C++
61 lines
1.7 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___VARIANT_MONOSTATE_H
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#define _LIBCPP___VARIANT_MONOSTATE_H
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#include <__config>
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#include <__functional/hash.h>
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#include <cstddef>
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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 > 14
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struct _LIBCPP_TEMPLATE_VIS monostate {};
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator<(monostate, monostate) noexcept { return false; }
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator>(monostate, monostate) noexcept { return false; }
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator<=(monostate, monostate) noexcept { return true; }
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator>=(monostate, monostate) noexcept { return true; }
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator==(monostate, monostate) noexcept { return true; }
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inline _LIBCPP_INLINE_VISIBILITY
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constexpr bool operator!=(monostate, monostate) noexcept { return false; }
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template <>
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struct _LIBCPP_TEMPLATE_VIS hash<monostate> {
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using argument_type = monostate;
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using result_type = size_t;
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inline _LIBCPP_INLINE_VISIBILITY
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result_type operator()(const argument_type&) const _NOEXCEPT {
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return 66740831; // return a fundamentally attractive random value.
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}
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};
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#endif // _LIBCPP_STD_VER > 14
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___VARIANT_MONOSTATE_H
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