123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121 |
- // <cast.h> -*- C++ -*-
- // Copyright (C) 2008-2015 Free Software Foundation, Inc.
- //
- // This file is part of the GNU ISO C++ Library. This library is free
- // software; you can redistribute it and/or modify it under the
- // terms of the GNU General Public License as published by the
- // Free Software Foundation; either version 3, or (at your option)
- // any later version.
- // This library is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU General Public License for more details.
- // Under Section 7 of GPL version 3, you are granted additional
- // permissions described in the GCC Runtime Library Exception, version
- // 3.1, as published by the Free Software Foundation.
- // You should have received a copy of the GNU General Public License and
- // a copy of the GCC Runtime Library Exception along with this program;
- // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
- // <http://www.gnu.org/licenses/>.
- /** @file ext/cast.h
- * This is an internal header file, included by other library headers.
- * Do not attempt to use it directly. @headername{ext/pointer.h}
- */
- #ifndef _GLIBCXX_CAST_H
- #define _GLIBCXX_CAST_H 1
- namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
- {
- _GLIBCXX_BEGIN_NAMESPACE_VERSION
- /**
- * These functions are here to allow containers to support non standard
- * pointer types. For normal pointers, these resolve to the use of the
- * standard cast operation. For other types the functions will perform
- * the appropriate cast to/from the custom pointer class so long as that
- * class meets the following conditions:
- * 1) has a typedef element_type which names tehe type it points to.
- * 2) has a get() const method which returns element_type*.
- * 3) has a constructor which can take one element_type* argument.
- */
- /**
- * This type supports the semantics of the pointer cast operators (below.)
- */
- template<typename _ToType>
- struct _Caster
- { typedef typename _ToType::element_type* type; };
- template<typename _ToType>
- struct _Caster<_ToType*>
- { typedef _ToType* type; };
- /**
- * Casting operations for cases where _FromType is not a standard pointer.
- * _ToType can be a standard or non-standard pointer. Given that _FromType
- * is not a pointer, it must have a get() method that returns the standard
- * pointer equivalent of the address it points to, and must have an
- * element_type typedef which names the type it points to.
- */
- template<typename _ToType, typename _FromType>
- inline _ToType
- __static_pointer_cast(const _FromType& __arg)
- { return _ToType(static_cast<typename _Caster<_ToType>::
- type>(__arg.get())); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __dynamic_pointer_cast(const _FromType& __arg)
- { return _ToType(dynamic_cast<typename _Caster<_ToType>::
- type>(__arg.get())); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __const_pointer_cast(const _FromType& __arg)
- { return _ToType(const_cast<typename _Caster<_ToType>::
- type>(__arg.get())); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __reinterpret_pointer_cast(const _FromType& __arg)
- { return _ToType(reinterpret_cast<typename _Caster<_ToType>::
- type>(__arg.get())); }
- /**
- * Casting operations for cases where _FromType is a standard pointer.
- * _ToType can be a standard or non-standard pointer.
- */
- template<typename _ToType, typename _FromType>
- inline _ToType
- __static_pointer_cast(_FromType* __arg)
- { return _ToType(static_cast<typename _Caster<_ToType>::
- type>(__arg)); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __dynamic_pointer_cast(_FromType* __arg)
- { return _ToType(dynamic_cast<typename _Caster<_ToType>::
- type>(__arg)); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __const_pointer_cast(_FromType* __arg)
- { return _ToType(const_cast<typename _Caster<_ToType>::
- type>(__arg)); }
- template<typename _ToType, typename _FromType>
- inline _ToType
- __reinterpret_pointer_cast(_FromType* __arg)
- { return _ToType(reinterpret_cast<typename _Caster<_ToType>::
- type>(__arg)); }
- _GLIBCXX_END_NAMESPACE_VERSION
- } // namespace
- #endif // _GLIBCXX_CAST_H
|