8643bdd016
This patch makes global tag variables like std::allocator_arg conform to C++17 by defining them as inline constexpr variables. This is possible without creating an ODR violation now that we don't define strong definitions of those variables in the shared library anymore. Differential Revision: https://reviews.llvm.org/D145589
81 lines
2.7 KiB
C++
81 lines
2.7 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___FUNCTIONAL_ALLOCATOR_ARG_T_H
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#define _LIBCPP___FUNCTIONAL_ALLOCATOR_ARG_T_H
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#include <__config>
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#include <__memory/uses_allocator.h>
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#include <__type_traits/integral_constant.h>
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#include <__type_traits/is_constructible.h>
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#include <__type_traits/remove_cvref.h>
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#include <__utility/forward.h>
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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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struct _LIBCPP_TEMPLATE_VIS allocator_arg_t { explicit allocator_arg_t() = default; };
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#if _LIBCPP_STD_VER >= 17
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inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
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#elif !defined(_LIBCPP_CXX03_LANG)
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constexpr allocator_arg_t allocator_arg = allocator_arg_t();
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#endif
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#ifndef _LIBCPP_CXX03_LANG
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// allocator construction
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template <class _Tp, class _Alloc, class ..._Args>
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struct __uses_alloc_ctor_imp
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{
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typedef _LIBCPP_NODEBUG __remove_cvref_t<_Alloc> _RawAlloc;
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static const bool __ua = uses_allocator<_Tp, _RawAlloc>::value;
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static const bool __ic =
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is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
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static const int value = __ua ? 2 - __ic : 0;
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};
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template <class _Tp, class _Alloc, class ..._Args>
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struct __uses_alloc_ctor
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: integral_constant<int, __uses_alloc_ctor_imp<_Tp, _Alloc, _Args...>::value>
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{};
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template <class _Tp, class _Allocator, class... _Args>
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inline _LIBCPP_INLINE_VISIBILITY
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void __user_alloc_construct_impl (integral_constant<int, 0>, _Tp *__storage, const _Allocator &, _Args &&... __args )
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{
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new (__storage) _Tp (_VSTD::forward<_Args>(__args)...);
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}
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// FIXME: This should have a version which takes a non-const alloc.
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template <class _Tp, class _Allocator, class... _Args>
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inline _LIBCPP_INLINE_VISIBILITY
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void __user_alloc_construct_impl (integral_constant<int, 1>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
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{
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new (__storage) _Tp (allocator_arg, __a, _VSTD::forward<_Args>(__args)...);
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}
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// FIXME: This should have a version which takes a non-const alloc.
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template <class _Tp, class _Allocator, class... _Args>
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inline _LIBCPP_INLINE_VISIBILITY
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void __user_alloc_construct_impl (integral_constant<int, 2>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
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{
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new (__storage) _Tp (_VSTD::forward<_Args>(__args)..., __a);
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}
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#endif // _LIBCPP_CXX03_LANG
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___FUNCTIONAL_ALLOCATOR_ARG_T_H
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