368faacac7
This commit reverts5aaefa51(and also partly7f285f48e7andb6d75682f9, which were related to the original commit). As landed,5aaefa51had 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
1.6 KiB
C++
61 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___MEMORY_USES_ALLOCATOR_H
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#define _LIBCPP___MEMORY_USES_ALLOCATOR_H
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#include <__config>
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#include <cstddef>
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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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template <class _Tp>
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struct __has_allocator_type
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{
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private:
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struct __two {char __lx; char __lxx;};
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template <class _Up> static __two __test(...);
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template <class _Up> static char __test(typename _Up::allocator_type* = 0);
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public:
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static const bool value = sizeof(__test<_Tp>(0)) == 1;
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};
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template <class _Tp, class _Alloc, bool = __has_allocator_type<_Tp>::value>
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struct __uses_allocator
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: public integral_constant<bool,
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is_convertible<_Alloc, typename _Tp::allocator_type>::value>
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{
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};
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template <class _Tp, class _Alloc>
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struct __uses_allocator<_Tp, _Alloc, false>
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: public false_type
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{
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};
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template <class _Tp, class _Alloc>
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struct _LIBCPP_TEMPLATE_VIS uses_allocator
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: public __uses_allocator<_Tp, _Alloc>
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{
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};
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#if _LIBCPP_STD_VER > 14
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template <class _Tp, class _Alloc>
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inline constexpr size_t uses_allocator_v = uses_allocator<_Tp, _Alloc>::value;
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#endif
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_LIBCPP_END_NAMESPACE_STD
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#endif // _LIBCPP___MEMORY_USES_ALLOCATOR_H
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