216 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			216 lines
		
	
	
		
			6.6 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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| 
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| #ifndef _LIBCPP___MEMORY_POINTER_TRAITS_H
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| #define _LIBCPP___MEMORY_POINTER_TRAITS_H
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| 
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| #include <__config>
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| #include <type_traits>
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| 
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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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| 
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| _LIBCPP_PUSH_MACROS
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| #include <__undef_macros>
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| 
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| _LIBCPP_BEGIN_NAMESPACE_STD
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| 
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| template <class _Tp, class = void>
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| struct __has_element_type : false_type {};
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| 
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| template <class _Tp>
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| struct __has_element_type<_Tp,
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|               typename __void_t<typename _Tp::element_type>::type> : true_type {};
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| 
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| template <class _Ptr, bool = __has_element_type<_Ptr>::value>
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| struct __pointer_traits_element_type;
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| 
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| template <class _Ptr>
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| struct __pointer_traits_element_type<_Ptr, true>
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| {
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::element_type type;
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| };
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| 
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| template <template <class, class...> class _Sp, class _Tp, class ..._Args>
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| struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
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| {
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::element_type type;
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| };
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| 
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| template <template <class, class...> class _Sp, class _Tp, class ..._Args>
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| struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
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| {
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|     typedef _LIBCPP_NODEBUG_TYPE _Tp type;
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| };
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| 
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| template <class _Tp, class = void>
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| struct __has_difference_type : false_type {};
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| 
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| template <class _Tp>
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| struct __has_difference_type<_Tp,
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|             typename __void_t<typename _Tp::difference_type>::type> : true_type {};
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| 
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| template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
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| struct __pointer_traits_difference_type
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| {
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|     typedef _LIBCPP_NODEBUG_TYPE ptrdiff_t type;
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| };
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| 
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| template <class _Ptr>
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| struct __pointer_traits_difference_type<_Ptr, true>
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| {
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
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| };
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| 
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| template <class _Tp, class _Up>
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| struct __has_rebind
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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 _Xp> static __two __test(...);
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|     _LIBCPP_SUPPRESS_DEPRECATED_PUSH
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|     template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
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|     _LIBCPP_SUPPRESS_DEPRECATED_POP
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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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| 
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| template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
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| struct __pointer_traits_rebind
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| {
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| #ifndef _LIBCPP_CXX03_LANG
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up> type;
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| #else
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
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| #endif
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| };
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| 
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| template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
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| struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
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| {
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| #ifndef _LIBCPP_CXX03_LANG
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
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| #else
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|     typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
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| #endif
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| };
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| 
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| template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
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| struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
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| {
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|     typedef _Sp<_Up, _Args...> type;
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| };
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| 
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| template <class _Ptr>
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| struct _LIBCPP_TEMPLATE_VIS pointer_traits
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| {
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|     typedef _Ptr                                                     pointer;
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|     typedef typename __pointer_traits_element_type<pointer>::type    element_type;
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|     typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
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| 
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| #ifndef _LIBCPP_CXX03_LANG
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|     template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
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| #else
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|     template <class _Up> struct rebind
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|         {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
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| #endif // _LIBCPP_CXX03_LANG
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| 
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| private:
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|     struct __nat {};
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| public:
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|     _LIBCPP_INLINE_VISIBILITY
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|     static pointer pointer_to(typename conditional<is_void<element_type>::value,
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|                                            __nat, element_type>::type& __r)
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|         {return pointer::pointer_to(__r);}
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| };
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| 
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| template <class _Tp>
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| struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
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| {
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|     typedef _Tp*      pointer;
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|     typedef _Tp       element_type;
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|     typedef ptrdiff_t difference_type;
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| 
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| #ifndef _LIBCPP_CXX03_LANG
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|     template <class _Up> using rebind = _Up*;
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| #else
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|     template <class _Up> struct rebind {typedef _Up* other;};
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| #endif
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| 
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| private:
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|     struct __nat {};
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| public:
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|     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
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|     static pointer pointer_to(typename conditional<is_void<element_type>::value,
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|                                       __nat, element_type>::type& __r) _NOEXCEPT
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|         {return _VSTD::addressof(__r);}
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| };
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| 
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| template <class _From, class _To>
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| struct __rebind_pointer {
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| #ifndef _LIBCPP_CXX03_LANG
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|     typedef typename pointer_traits<_From>::template rebind<_To>        type;
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| #else
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|     typedef typename pointer_traits<_From>::template rebind<_To>::other type;
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| #endif
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| };
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| 
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| // to_address
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| 
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| template <class _Pointer, class = void>
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| struct __to_address_helper;
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| 
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| template <class _Tp>
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| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
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| _Tp* __to_address(_Tp* __p) _NOEXCEPT {
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|     static_assert(!is_function<_Tp>::value, "_Tp is a function type");
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|     return __p;
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| }
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| 
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| // enable_if is needed here to avoid instantiating checks for fancy pointers on raw pointers
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| template <class _Pointer, class = _EnableIf<!is_pointer<_Pointer>::value> >
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| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
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| typename decay<decltype(__to_address_helper<_Pointer>::__call(declval<const _Pointer&>()))>::type
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| __to_address(const _Pointer& __p) _NOEXCEPT {
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|     return __to_address_helper<_Pointer>::__call(__p);
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| }
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| 
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| template <class _Pointer, class>
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| struct __to_address_helper {
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|     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
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|     static decltype(_VSTD::__to_address(declval<const _Pointer&>().operator->()))
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|     __call(const _Pointer&__p) _NOEXCEPT {
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|         return _VSTD::__to_address(__p.operator->());
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|     }
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| };
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| 
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| template <class _Pointer>
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| struct __to_address_helper<_Pointer, decltype((void)pointer_traits<_Pointer>::to_address(declval<const _Pointer&>()))> {
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|     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
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|     static decltype(pointer_traits<_Pointer>::to_address(declval<const _Pointer&>()))
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|     __call(const _Pointer&__p) _NOEXCEPT {
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|         return pointer_traits<_Pointer>::to_address(__p);
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|     }
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| };
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| 
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| #if _LIBCPP_STD_VER > 17
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| template <class _Pointer>
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| inline _LIBCPP_INLINE_VISIBILITY constexpr
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| auto to_address(const _Pointer& __p) noexcept {
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|     return _VSTD::__to_address(__p);
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| }
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| #endif
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| 
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| _LIBCPP_END_NAMESPACE_STD
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| 
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| _LIBCPP_POP_MACROS
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| 
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| #endif // _LIBCPP___MEMORY_POINTER_TRAITS_H
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