From 9f4a4394397cba5d9431410a94325b35f8432ef2 Mon Sep 17 00:00:00 2001 From: Paolo Carlini Date: Fri, 7 Nov 2008 15:43:57 +0000 Subject: [PATCH] 2008-11-07 Paolo Carlini * Complete last commit. From-SVN: r141675 --- libstdc++-v3/include/ext/cast.h | 121 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 libstdc++-v3/include/ext/cast.h diff --git a/libstdc++-v3/include/ext/cast.h b/libstdc++-v3/include/ext/cast.h new file mode 100644 index 0000000..02aedf1 --- /dev/null +++ b/libstdc++-v3/include/ext/cast.h @@ -0,0 +1,121 @@ +// -*- C++ -*- + +// Copyright (C) 2008 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 2, 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. + +// You should have received a copy of the GNU General Public License +// along with this library; see the file COPYING. If not, write to +// the Free Software Foundation, 51 Franklin Street, Fifth Floor, +// Boston, MA 02110-1301, USA. + +// As a special exception, you may use this file as part of a free software +// library without restriction. Specifically, if other files instantiate +// templates or use macros or inline functions from this file, or you compile +// this file and link it with other files to produce an executable, this +// file does not by itself cause the resulting executable to be covered by +// the GNU General Public License. This exception does not however +// invalidate any other reasons why the executable file might be covered by +// the GNU General Public License. + +#ifndef _EXT_CAST_ +#define _EXT_CAST_ 1 + +_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx); + + /** + * 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 apprpriate 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 + struct _Caster + { + typedef typename _ToType::element_type* type; + }; + template + 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 + inline _ToType + __static_pointer_cast(const _FromType& __arg) + { return _ToType(static_cast:: + type>(__arg.get())); } + + template + inline _ToType + __dynamic_pointer_cast(const _FromType& __arg) + { return _ToType(dynamic_cast:: + type>(__arg.get())); } + + template + inline _ToType + __const_pointer_cast(const _FromType& __arg) + { return _ToType(const_cast:: + type>(__arg.get())); } + + template + inline _ToType + __reinterpret_pointer_cast(const _FromType& __arg) + { return _ToType(reinterpret_cast:: + type>(__arg.get())); } + + /** + * Casting operations for cases where _FromType is a standard pointer. + * _ToType can be a standard or non-standard pointer. + */ + template + inline _ToType + __static_pointer_cast(_FromType* __arg) + { return _ToType(static_cast:: + type>(__arg)); } + + template + inline _ToType + __dynamic_pointer_cast(_FromType* __arg) + { return _ToType(dynamic_cast:: + type>(__arg)); } + + template + inline _ToType + __const_pointer_cast(_FromType* __arg) + { return _ToType(const_cast:: + type>(__arg)); } + + template + inline _ToType + __reinterpret_pointer_cast(_FromType* __arg) + { return _ToType(reinterpret_cast:: + type>(__arg)); } + +_GLIBCXX_END_NAMESPACE + +#endif -- 2.7.4