| -rw-r--r-- | microkde/opie2/osmartpointer.h | 149 |
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diff --git a/microkde/opie2/osmartpointer.h b/microkde/opie2/osmartpointer.h new file mode 100644 index 0000000..c7dc9d9 --- a/dev/null +++ b/microkde/opie2/osmartpointer.h @@ -0,0 +1,149 @@ +// -*- Mode: C++; -*- +/* + This file is part of the Opie Project + Copyright (C) 2004 Rajko Albrecht <alwin@handhelds.org> + Copyright (C) The Opie Team <opie-devel@handhelds.org> + =. + .=l. + .>+-= +_;:, .> :=|. This program is free software; you can +.> <`_, > . <= redistribute it and/or modify it under +:`=1 )Y*s>-.-- : the terms of the GNU Library General Public +.="- .-=="i, .._ License as published by the Free Software +- . .-<_> .<> Foundation; either version 2 of the License, + ._= =} : or (at your option) any later version. + .%`+i> _;_. + .i_,=:_. -<s. This program 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 +..}^=.= = ; Library General Public License for more +++= -. .` .: details. +: = ...= . :.=- +-. .:....=;==+<; You should have received a copy of the GNU + -_. . . )=. = Library General Public License along with + -- :-=` this library; see the file COPYING.LIB. + If not, write to the Free Software Foundation, + Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +#ifndef _OSmartPointer_h +#define _OSmartPointer_h + +#include <stddef.h> + +/*! + * \file OSmartPointer.h + * \brief smart pointer and reference counter + * \author Rajko Albrecht + * + */ + +namespace Opie { +namespace Core { + +//! simple reference counter class +class ORefCount { +protected: + //! reference count member + long m_RefCount; +public: + //! first reference must be added after "new" via Pointer() + ORefCount() : m_RefCount(0) + {} + virtual ~ORefCount() {} + //! add a reference + void Incr() { + ++m_RefCount; + } + //! delete a reference + void Decr() { + --m_RefCount; + } + //! is it referenced + bool Shared() { return (m_RefCount > 0); } +}; + +//! reference counting wrapper class +template<class T> class OSmartPointer { + //! pointer to object + /*! + * this object must contain Incr(), Decr() and Shared() + * methode as public members. The best way is, that it will be a child + * class of RefCount + */ + T *ptr; +public: + //! standart constructor + OSmartPointer() { ptr = NULL; } + //! standart destructor + /*! + * release the reference, if it were the last reference, destroys + * ptr + */ + ~OSmartPointer() + { + if (ptr){ + ptr->Decr(); + if (!ptr->Shared()) + delete ptr; + } + } + //! construction + OSmartPointer(T* t) { if (ptr = t) ptr->Incr(); } + //! Pointer copy + OSmartPointer(const OSmartPointer<T>& p) + { if (ptr = p.ptr) ptr->Incr(); } + //! pointer copy by assignment + OSmartPointer<T>& operator= (const OSmartPointer<T>& p) + { + // already same: nothing to do + if (ptr == p.ptr) return *this; + // decouple reference + if (ptr) { ptr->Decr(); if (!ptr->Shared()) delete ptr; } + // establish new reference + if (ptr = p.ptr) ptr->Incr(); + return *this; + } + OSmartPointer<T>& operator= (T*p) + { + if (ptr==p)return *this; + if (ptr) { + ptr->Decr(); + if (!ptr->Shared()) delete ptr; + } + if (ptr=p) ptr->Incr(); + return *this; + } + + //! cast to conventional pointer + operator T* () const { return ptr; } + + //! deref: fails for NULL pointer + T& operator* () {return *ptr; } + //! deref: fails for NULL pointer + const T& operator* ()const {return *ptr; } + + //! deref with method call + T* operator-> () {return ptr; } + //! deref with const method call + const T* operator-> ()const {return ptr; } + + //! supports "if (pointer)" + operator bool () const { return (ptr != NULL); } + //! "if (pointer)" as non const + operator bool () { return ptr != NULL;} + + //! support if (!pointer)" + bool operator! () const { return (ptr == NULL); } + //! support if (!pointer)" as non const + bool operator! () { return (ptr == NULL); } +}; + +} +} + +#endif + |