91 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			91 lines
		
	
	
		
			2.7 KiB
		
	
	
	
		
			C++
		
	
	
	
| // -*- C++ -*-
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| //===----------------------------------------------------------------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is dual licensed under the MIT and the University of Illinois Open
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| // Source Licenses. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef _LIBCPP_EXPERIMENTAL___MEMORY
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| #define _LIBCPP_EXPERIMENTAL___MEMORY
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| 
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| #include <experimental/__config>
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| #include <experimental/utility> // for erased_type
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| #include <__functional_base>
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| #include <type_traits>
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| 
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| _LIBCPP_BEGIN_NAMESPACE_LFTS
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| 
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| template <
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|     class _Tp, class _Alloc
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|   , bool = uses_allocator<_Tp, _Alloc>::value
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|   , bool = __has_allocator_type<_Tp>::value
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|   >
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| struct __lfts_uses_allocator : public false_type {};
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| 
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| template <class _Tp, class _Alloc>
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| struct __lfts_uses_allocator<_Tp, _Alloc, false, false> : public false_type {};
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| 
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| template <class _Tp, class _Alloc, bool HasAlloc>
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| struct __lfts_uses_allocator<_Tp, _Alloc, true, HasAlloc> : public true_type {};
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| 
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| template <class _Tp, class _Alloc>
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| struct __lfts_uses_allocator<_Tp, _Alloc, false, true>
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|   : public integral_constant<bool
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|     , is_convertible<_Alloc, typename _Tp::allocator_type>::value
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|       || is_same<erased_type, typename _Tp::allocator_type>::value
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|     >
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| {};
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| 
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| template <bool _UsesAlloc, class _Tp, class _Alloc, class ..._Args>
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| struct __lfts_uses_alloc_ctor_imp
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| {
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|     static const int value = 0;
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| };
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| 
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| template <class _Tp, class _Alloc, class ..._Args>
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| struct __lfts_uses_alloc_ctor_imp<true, _Tp, _Alloc, _Args...>
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| {
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|     static const bool __ic_first
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|         = is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
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| 
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|     static const bool __ic_second =
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|         conditional<
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|             __ic_first,
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|             false_type,
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|             is_constructible<_Tp, _Args..., _Alloc>
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|         >::type::value;
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| 
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|     static_assert(__ic_first || __ic_second,
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|                   "Request for uses allocator construction is ill-formed");
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| 
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|     static const int value = __ic_first ? 1 : 2;
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| };
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| 
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| template <class _Tp, class _Alloc, class ..._Args>
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| struct __lfts_uses_alloc_ctor
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|   : integral_constant<int,
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|         __lfts_uses_alloc_ctor_imp<
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|             __lfts_uses_allocator<_Tp, _Alloc>::value
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|           , _Tp, _Alloc, _Args...
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|         >::value
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|     >
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| {};
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| 
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| template <class _Tp, class _Alloc, class ..._Args>
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| inline _LIBCPP_INLINE_VISIBILITY
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| void __lfts_user_alloc_construct(
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|     _Tp * __store, const _Alloc & __a, _Args &&... __args)
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| {
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|     _VSTD::__user_alloc_construct_impl(
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|         typename __lfts_uses_alloc_ctor<_Tp, _Alloc, _Args...>::type()
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|        , __store, __a, _VSTD::forward<_Args>(__args)...
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|        );
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| }
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| 
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| _LIBCPP_END_NAMESPACE_LFTS
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| 
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| #endif /* _LIBCPP_EXPERIMENTAL___MEMORY */
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