170 lines
4 KiB
C++
170 lines
4 KiB
C++
/////////////////////////////////////////////////////////////////////////////
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// Name: wx/sharedptr.h
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// Purpose: Shared pointer based on the counted_ptr<> template, which
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// is in the public domain
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// Author: Robert Roebling, Yonat Sharon
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// Copyright: Robert Roebling
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// Licence: wxWindows licence
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/////////////////////////////////////////////////////////////////////////////
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#ifndef _WX_SHAREDPTR_H_
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#define _WX_SHAREDPTR_H_
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#include "wx/defs.h"
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#include "wx/atomic.h"
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// ----------------------------------------------------------------------------
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// wxSharedPtr: A smart pointer with non-intrusive reference counting.
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// ----------------------------------------------------------------------------
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template <class T>
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class wxSharedPtr
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{
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public:
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typedef T element_type;
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wxEXPLICIT wxSharedPtr( T* ptr = NULL )
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: m_ref(NULL)
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{
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if (ptr)
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m_ref = new reftype(ptr);
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}
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template<typename Deleter>
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wxEXPLICIT wxSharedPtr(T* ptr, Deleter d)
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: m_ref(NULL)
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{
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if (ptr)
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m_ref = new reftype_with_deleter<Deleter>(ptr, d);
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}
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~wxSharedPtr() { Release(); }
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wxSharedPtr(const wxSharedPtr& tocopy) { Acquire(tocopy.m_ref); }
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wxSharedPtr& operator=( const wxSharedPtr& tocopy )
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{
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if (this != &tocopy)
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{
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Release();
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Acquire(tocopy.m_ref);
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}
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return *this;
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}
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wxSharedPtr& operator=( T* ptr )
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{
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if (get() != ptr)
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{
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Release();
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if (ptr)
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m_ref = new reftype(ptr);
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}
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return *this;
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}
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// test for pointer validity: defining conversion to unspecified_bool_type
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// and not more obvious bool to avoid implicit conversions to integer types
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typedef T *(wxSharedPtr<T>::*unspecified_bool_type)() const;
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operator unspecified_bool_type() const
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{
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if (m_ref && m_ref->m_ptr)
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return &wxSharedPtr<T>::get;
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else
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return NULL;
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}
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T& operator*() const
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{
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wxASSERT(m_ref != NULL);
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wxASSERT(m_ref->m_ptr != NULL);
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return *(m_ref->m_ptr);
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}
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T* operator->() const
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{
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wxASSERT(m_ref != NULL);
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wxASSERT(m_ref->m_ptr != NULL);
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return m_ref->m_ptr;
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}
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T* get() const
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{
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return m_ref ? m_ref->m_ptr : NULL;
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}
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void reset( T* ptr = NULL )
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{
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Release();
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if (ptr)
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m_ref = new reftype(ptr);
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}
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template<typename Deleter>
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void reset(T* ptr, Deleter d)
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{
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Release();
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if (ptr)
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m_ref = new reftype_with_deleter<Deleter>(ptr, d);
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}
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bool unique() const { return (m_ref ? m_ref->m_count == 1 : true); }
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long use_count() const { return (m_ref ? (long)m_ref->m_count : 0); }
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private:
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struct reftype
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{
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reftype(T* ptr) : m_ptr(ptr), m_count(1) {}
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virtual ~reftype() {}
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virtual void delete_ptr() { delete m_ptr; }
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T* m_ptr;
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wxAtomicInt m_count;
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};
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template<typename Deleter>
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struct reftype_with_deleter : public reftype
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{
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reftype_with_deleter(T* ptr, Deleter d) : reftype(ptr), m_deleter(d) {}
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virtual void delete_ptr() { m_deleter(this->m_ptr); }
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Deleter m_deleter;
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};
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reftype* m_ref;
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void Acquire(reftype* ref)
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{
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m_ref = ref;
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if (ref)
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wxAtomicInc( ref->m_count );
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}
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void Release()
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{
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if (m_ref)
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{
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if (!wxAtomicDec( m_ref->m_count ))
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{
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m_ref->delete_ptr();
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delete m_ref;
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}
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m_ref = NULL;
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}
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}
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};
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template <class T, class U>
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bool operator == (wxSharedPtr<T> const &a, wxSharedPtr<U> const &b )
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{
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return a.get() == b.get();
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}
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template <class T, class U>
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bool operator != (wxSharedPtr<T> const &a, wxSharedPtr<U> const &b )
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{
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return a.get() != b.get();
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}
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#endif // _WX_SHAREDPTR_H_
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