wxWidgets/include/wx/ptr_shrd.h
Robert Roebling 5200ca361e Added wxSharedPtr<T>
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51102 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2008-01-08 10:51:28 +00:00

134 lines
3.1 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/ptr_shrd.h
// Purpose: Shared pointer based on the counted_ptr<> template, which
// is in the public domain
// Author: Robert Roebling, Yonat Sharon
// RCS-ID: $Id: object.h 47254 2007-07-09 10:09:52Z VS $
// Copyright: Robert Roebling
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_SHARED_PTRH__
#define _WX_SHARED_PTRH__
#include "wx/defs.h"
#include "wx/atomic.h"
// ----------------------------------------------------------------------------
// wxSharedPtr: A smart pointer with non-intrusive reference counting.
// ----------------------------------------------------------------------------
template <class T>
class wxSharedPtr
{
public:
typedef T element_type;
wxEXPLICIT wxSharedPtr( T* ptr = NULL )
: m_ref(NULL)
{
if (ptr)
m_ref = new reftype(ptr);
}
~wxSharedPtr() { Release(); }
wxSharedPtr(const wxSharedPtr& tocopy) { Acquire(tocopy.m_ref); }
wxSharedPtr& operator=( const wxSharedPtr& tocopy )
{
if (this != &tocopy)
{
Release();
Acquire(tocopy.m_ref);
}
return *this;
}
wxSharedPtr& operator=( T* ptr )
{
if (get() != ptr)
{
Release();
if (ptr)
m_ref = new reftype(ptr);
}
return *this;
}
T& operator*() const
{
wxASSERT(m_ref != NULL);
wxASSERT(m_ref->m_ptr != NULL);
return *(m_ref->m_ptr);
}
T* operator->() const
{
wxASSERT(m_ref != NULL);
wxASSERT(m_ref->m_ptr != NULL);
return m_ref->m_ptr;
}
T* get() const
{
return m_ref ? m_ref->m_ptr : NULL;
}
void reset( T* ptr = NULL )
{
Release();
if (ptr)
m_ref = new reftype(ptr);
}
bool unique() const { return (m_ref ? m_ref->m_count == 1 : true); }
long use_count() const { return (m_ref ? (long)m_ref->m_count : 0); }
operator bool() const { return (get() != NULL); }
private:
struct reftype
{
reftype( T* ptr = NULL, unsigned count = 1 ) : m_ptr(ptr), m_count(count) {}
T* m_ptr;
wxAtomicInt m_count;
}* m_ref;
void Acquire(reftype* ref)
{
m_ref = ref;
if (ref)
wxAtomicInc( ref->m_count );
}
void Release()
{
if (m_ref)
{
wxAtomicDec( m_ref->m_count );
if (m_ref->m_count == 0)
{
delete m_ref->m_ptr;
delete m_ref;
}
m_ref = NULL;
}
}
};
template <class T, class U>
bool operator == (wxSharedPtr<T> const &a, wxSharedPtr<U> const &b )
{
return a.get() == b.get();
}
template <class T, class U>
bool operator != (wxSharedPtr<T> const &a, wxSharedPtr<U> const &b )
{
return a.get() != b.get();
}
#endif // _WX_SHARED_PTRH__