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// <cast.h> -*- C++ -*- |
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// Copyright (C) 2008-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** @file ext/cast.h |
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* This is an internal header file, included by other library headers. |
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* Do not attempt to use it directly. @headername{ext/pointer.h} |
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*/ |
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#ifndef _GLIBCXX_CAST_H |
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#define _GLIBCXX_CAST_H 1 |
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|
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namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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|
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/** |
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* These functions are here to allow containers to support non standard |
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* pointer types. For normal pointers, these resolve to the use of the |
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* standard cast operation. For other types the functions will perform |
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* the appropriate cast to/from the custom pointer class so long as that |
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* class meets the following conditions: |
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* 1) has a typedef element_type which names tehe type it points to. |
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* 2) has a get() const method which returns element_type*. |
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* 3) has a constructor which can take one element_type* argument. |
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*/ |
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|
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/** |
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* This type supports the semantics of the pointer cast operators (below.) |
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*/ |
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template<typename _ToType> |
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struct _Caster |
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{ typedef typename _ToType::element_type* type; }; |
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|
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template<typename _ToType> |
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struct _Caster<_ToType*> |
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{ typedef _ToType* type; }; |
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|
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/** |
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* Casting operations for cases where _FromType is not a standard pointer. |
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* _ToType can be a standard or non-standard pointer. Given that _FromType |
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* is not a pointer, it must have a get() method that returns the standard |
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* pointer equivalent of the address it points to, and must have an |
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* element_type typedef which names the type it points to. |
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*/ |
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__static_pointer_cast(const _FromType& __arg) |
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{ return _ToType(static_cast<typename _Caster<_ToType>:: |
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type>(__arg.get())); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__dynamic_pointer_cast(const _FromType& __arg) |
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{ return _ToType(dynamic_cast<typename _Caster<_ToType>:: |
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type>(__arg.get())); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__const_pointer_cast(const _FromType& __arg) |
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{ return _ToType(const_cast<typename _Caster<_ToType>:: |
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type>(__arg.get())); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__reinterpret_pointer_cast(const _FromType& __arg) |
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{ return _ToType(reinterpret_cast<typename _Caster<_ToType>:: |
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type>(__arg.get())); } |
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|
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/** |
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* Casting operations for cases where _FromType is a standard pointer. |
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* _ToType can be a standard or non-standard pointer. |
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*/ |
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__static_pointer_cast(_FromType* __arg) |
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{ return _ToType(static_cast<typename _Caster<_ToType>:: |
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type>(__arg)); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__dynamic_pointer_cast(_FromType* __arg) |
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{ return _ToType(dynamic_cast<typename _Caster<_ToType>:: |
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type>(__arg)); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__const_pointer_cast(_FromType* __arg) |
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{ return _ToType(const_cast<typename _Caster<_ToType>:: |
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type>(__arg)); } |
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|
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template<typename _ToType, typename _FromType> |
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inline _ToType |
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__reinterpret_pointer_cast(_FromType* __arg) |
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{ return _ToType(reinterpret_cast<typename _Caster<_ToType>:: |
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type>(__arg)); } |
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|
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_GLIBCXX_END_NAMESPACE_VERSION |
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} // namespace |
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|
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#endif // _GLIBCXX_CAST_H |
