vmap/libs/generic/referencecounted.h
2020-11-17 12:16:16 +01:00

180 lines
4.3 KiB
C++

/*
Copyright (C) 2001-2006, William Joseph.
All Rights Reserved.
This file is part of GtkRadiant.
GtkRadiant 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 of the License, or
(at your option) any later version.
GtkRadiant 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 GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if !defined( INCLUDED_GENERIC_REFERENCECOUNTED_H )
#define INCLUDED_GENERIC_REFERENCECOUNTED_H
/// \file
/// \brief 'smart' pointers and references.
#include <algorithm>
template<typename Type>
class IncRefDecRefCounter
{
public:
void increment( Type& value ){
value.IncRef();
}
void decrement( Type& value ){
value.DecRef();
}
};
/// \brief A smart-pointer that uses a counter stored in the object pointed-to.
template<typename Type, typename Counter = IncRefDecRefCounter<Type> >
class SmartPointer : public Counter
{
Type* m_value;
public:
SmartPointer( const SmartPointer& other )
: m_value( other.m_value ){
Counter::increment( *m_value );
}
explicit SmartPointer( Type* value )
: m_value( value ){
Counter::increment( *m_value );
}
~SmartPointer(){
Counter::decrement( *m_value );
}
SmartPointer& operator=( const SmartPointer& other ){
SmartPointer temp( other );
temp.swap( *this );
return *this;
}
SmartPointer& operator=( Type* value ){
SmartPointer temp( value );
temp.swap( *this );
return *this;
}
void swap( SmartPointer& other ){
std::swap( m_value, other.m_value );
}
operator Type*() const
{
return m_value;
}
Type& operator*() const {
return *m_value;
}
Type* operator->() const {
return m_value;
}
Type* get() const {
return m_value;
}
};
template<typename Type>
inline bool operator<( const SmartPointer<Type>& self, const SmartPointer<Type>& other ){
return self.get() < other.get();
}
template<typename Type>
inline bool operator==( const SmartPointer<Type>& self, const SmartPointer<Type>& other ){
return self.get() == other.get();
}
template<typename Type>
inline bool operator!=( const SmartPointer<Type>& self, const SmartPointer<Type>& other ){
return !::operator==( self, other );
}
namespace std
{
/// \brief Swaps the values of \p self and \p other.
/// Overloads std::swap().
template<typename Type>
inline void swap( SmartPointer<Type>& self, SmartPointer<Type>& other ){
self.swap( other );
}
}
/// \brief A smart-reference that uses a counter stored in the object pointed-to.
template<typename Type, typename Counter = IncRefDecRefCounter<Type> >
class SmartReference : public Counter
{
Type* m_value;
public:
SmartReference( const SmartReference& other )
: m_value( other.m_value ){
Counter::increment( *m_value );
}
explicit SmartReference( Type& value )
: m_value( &value ){
Counter::increment( *m_value );
}
~SmartReference(){
Counter::decrement( *m_value );
}
SmartReference& operator=( const SmartReference& other ){
SmartReference temp( other );
temp.swap( *this );
return *this;
}
SmartReference& operator=( Type& value ){
SmartReference temp( value );
temp.swap( *this );
return *this;
}
void swap( SmartReference& other ){
std::swap( m_value, other.m_value );
}
operator Type&() const
{
return *m_value;
}
Type& get() const {
return *m_value;
}
Type* get_pointer() const {
return m_value;
}
};
template<typename Type>
inline bool operator<( const SmartReference<Type>& self, const SmartReference<Type>& other ){
return self.get() < other.get();
}
template<typename Type>
inline bool operator==( const SmartReference<Type>& self, const SmartReference<Type>& other ){
return self.get() == other.get();
}
template<typename Type>
inline bool operator!=( const SmartReference<Type>& self, const SmartReference<Type>& other ){
return !::operator==( self, other );
}
namespace std
{
/// \brief Swaps the values of \p self and \p other.
/// Overloads std::swap().
template<typename Type>
inline void swap( SmartReference<Type>& self, SmartReference<Type>& other ){
self.swap( other );
}
}
#endif