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CnC_Renegade/Code/WWOnline/RefPtr.h

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/*
** Command & Conquer Renegade(tm)
** Copyright 2025 Electronic Arts Inc.
**
** This program 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 of the License, or
** (at your option) any later version.
**
** 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/******************************************************************************
*
* FILE
* $Archive: /Commando/Code/WWOnline/RefPtr.h $
*
* DESCRIPTION
* RefPtr<> and RefPtrConst<> are const-friendly, polymorphic reference
* counting smart pointers.
*
* The pointed-to class must be derived from RefCount.
*
* RefPtr<X> replaces X*
* RefPtrConst<X> replaces const X*
*
* Dynamic_Cast<X> replaces dynamic_cast<X*> and dynamic_cast<X&>
* Reinterpret_Cast<X> replaces reinterpret_cast<X*> and reinterpret_cast<X&>
* Const_Cast<X> replaces const_cast<X*> and const_cast<X&>
*
* IsValid() replaces (x != NULL)
*
* Member function Attach() or assigning RefPtr<X>() will NULL a pointer.
*
* Generally, RefPtr<> and RefPtrConst<> behave like their raw pointer
* counterparts, except of course they are reference counted and will delete
* the pointed-to object when the last reference is lost. The major
* syntatical differences are the use of RefPtrConst<> to represent a pointer
* to a constant object (I found it impossible to represent this within rc_ptr)
* and the use of the upper-case cast functions (it is not possible to overload
* these built-in functions).
*
* An explicit goal of this class is to completely avoid the "new" and "delete"
* operators in client code. The constructors for these pointers are private;
* they are friends of the pointed-to class. This forces the use of Factory
* Method functions (or similar) in the pointed-to class. Pointed-to classes
* should make the constructor protected or private to disallow clients from
* creating an instance with "new". If this is done, it becomes very difficult
* for the client to accidentally leak objects and/or misuse the pointed-to
* class or the reference counting pointers.
*
* PROGRAMMER
* Steven Clinard
* $Author: Denzil_l $
*
* VERSION INFO
* $Modtime: 7/06/01 4:23p $
* $Revision: 1 $
*
******************************************************************************/
#ifndef __REFPTR_H__
#define __REFPTR_H__
#include "RefCounted.h"
#include <stddef.h>
#include <assert.h>
template<typename Type> class RefPtr;
template<typename Type> class RefPtrConst;
class RefPtrBase
{
public:
inline bool operator==(const RefPtrBase& rhs) const
{return (mRefObject == rhs.mRefObject);}
inline bool operator!=(const RefPtrBase& rhs) const
{return !operator==(rhs);}
inline bool IsValid(void) const
{return (mRefObject != NULL);}
inline void Release(void)
{
if (IsValid())
{
mRefObject->ReleaseReference();
mRefObject = NULL;
}
}
protected:
RefPtrBase() :
mRefObject(NULL)
{}
RefPtrBase(RefCounted* object) :
mRefObject(object)
{
assert((mRefObject == NULL) || (mRefObject->ReferenceCount() == 0));
if (IsValid())
{
mRefObject->AddReference();
}
}
RefPtrBase(const RefPtrBase& object) :
mRefObject(object.mRefObject)
{
assert(!"RefPtrBase(const RefPtrBase&) - Why is this being called?");
if (IsValid())
{
mRefObject->AddReference();
}
}
virtual ~RefPtrBase()
{Release();}
const RefPtrBase& operator=(const RefPtrBase&);
inline RefCounted* const GetRefObject(void)
{return mRefObject;}
inline const RefCounted* const GetRefObject(void) const
{return mRefObject;}
inline void Attach(RefCounted* object)
{
// If objects are different
if (object != mRefObject)
{
// Add reference to new object
if (object != NULL)
{
object->AddReference();
}
// Release reference to old object
Release();
// Assign new object
mRefObject = object;
}
}
private:
RefCounted* mRefObject;
template<typename Derived>
friend RefPtr<Derived> Dynamic_Cast(RefPtrBase&);
template<typename Type>
friend RefPtr<Type> Reinterpret_Cast(RefPtrBase&);
};
template<typename Type> class RefPtr :
public RefPtrBase
{
public:
RefPtr() :
RefPtrBase()
{}
template<typename Derived>
RefPtr(const RefPtr<Derived>& derived) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(const_cast<Derived*>(derived.ReferencedObject())));
}
RefPtr(const RefPtr<Type>& object) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(const_cast<Type*>(object.ReferencedObject())));
}
virtual ~RefPtr()
{}
template<typename Derived>
inline const RefPtr<Type>& operator=(const RefPtr<Derived>& derived)
{
Attach(static_cast<RefCounted*>(const_cast<Derived*>(derived.ReferencedObject())));
return *this;
}
inline const RefPtr<Type>& operator=(const RefPtr<Type>& object)
{
Attach(static_cast<RefCounted*>(const_cast<Type*>(object.ReferencedObject())));
return *this;
}
inline Type& operator*() const
{
assert(IsValid());
return *const_cast<Type*>(ReferencedObject());
}
inline Type* const operator->() const
{
assert(IsValid());
return const_cast<Type*>(ReferencedObject());
}
// Template function for implicit conversion ops
template<typename NewType>
inline operator RefPtr<NewType>()
{return RefPtr<NewType>(GetRefObject());}
// These are public mostly because I can't seem to declare rc_ptr<Other> as a friend
inline Type* const ReferencedObject(void)
{return reinterpret_cast<Type*>(GetRefObject());}
inline const Type* const ReferencedObject(void) const
{return reinterpret_cast<const Type*>(GetRefObject());}
RefPtr(Type* object) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(object));
}
inline const RefPtr<Type>& operator=(Type* object)
{
Attach(static_cast<RefCounted*>(object));
return *this;
}
private:
friend RefPtr<Type> Dynamic_Cast(RefPtrBase&);
friend RefPtr<Type> Reinterpret_Cast(RefPtrBase&);
friend RefPtr<Type> Const_Cast(RefPtrConst<Type>&);
};
template<typename Type> class RefPtrConst :
public RefPtrBase
{
public:
RefPtrConst() :
RefPtrConst()
{}
template<typename Derived>
RefPtrConst(const RefPtr<Derived>& derived) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(derived.ReferencedObject()));
}
RefPtrConst(const RefPtr<Type>& object) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(const_cast<Type* const >(object.ReferencedObject())));
}
template<typename Derived>
RefPtrConst(const RefPtrConst<Derived>& derived) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(derived.ReferencedObject()));
}
RefPtrConst(const RefPtrConst<Type>& object) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(object.ReferencedObject()));
}
template<typename Derived>
inline const RefPtrConst<Type>& operator=(const RefPtr<Derived>& derived)
{
Attach(static_cast<RefCounted*>(derived.ReferencedObject()));
return *this;
}
inline const RefPtrConst<Type>& operator=(const RefPtr<Type>& object)
{
Attach(static_cast<RefCounted*>(object.ReferencedObject()));
return *this;
}
template<typename Derived>
inline const RefPtrConst<Type>& operator=(const RefPtrConst<Derived>& derived)
{
Attach(static_cast<RefCounted*>(derived.ReferencedObject()));
return *this;
}
inline const RefPtrConst<Type>& operator=(const RefPtrConst<Type>& object)
{
Attach(static_cast<RefCounted*>(object.ReferencedObject()));
return *this;
}
virtual ~RefPtrConst()
{}
inline const Type& operator*() const
{
assert(IsValid());
return *ReferencedObject();
}
inline const Type* const operator->() const
{
assert(IsValid());
return ReferencedObject();
}
// This is public mostly because I can't seem to declare rc_ptr<Other> as a friend
inline const Type* const ReferencedObject() const
{return reinterpret_cast<const Type*>(GetRefObject());}
RefPtrConst(const Type* object) :
RefPtrBase()
{
Attach(static_cast<RefCounted*>(object));
}
const RefPtrConst<Type>& operator=(const Type* object)
{
Attach(static_cast<RefCounted*>(object));
}
};
template<typename Derived>
RefPtr<Derived> Dynamic_Cast(RefPtrBase& base)
{
RefPtr<Derived> derived;
derived.Attach(base.GetRefObject());
return derived;
}
template<typename Type>
RefPtr<Type> Reinterpret_Cast(RefPtrBase& rhs)
{
RefPtr<Type> object;
object.Attach(rhs.GetRefObject());
return object;
}
template<typename Type>
RefPtr<Type> Const_Cast(RefPtrConst<Type>& rhs)
{
RefPtr<Type> object;
object.Attach(static_cast<RefCounted*>(rhs.ReferencedObject()));
return object;
}
#endif // __REFPTR_H__