renamed wx/ptr_shrd.h to wx/sharedptr.h; split wx/ptr_scpd.h in wx/scopedptr.h and wx/scopedarray.h; extracted common parts into new wx/checkeddelete.h

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/sharedptr.h

@@ -0,0 +1,141 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/sharedptr.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_SHAREDPTR_H_
+#define _WX_SHAREDPTR_H_
+
+#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;
+    }
+
+    // test for pointer validity: defining conversion to unspecified_bool_type
+    // and not more obvious bool to avoid implicit conversions to integer types
+    typedef T *(wxSharedPtr<T>::*unspecified_bool_type)() const;
+    operator unspecified_bool_type() const
+    {
+        if (m_ref && m_ref->m_ptr)
+           return  &wxSharedPtr<T>::get;
+        else
+           return NULL;
+    }
+
+    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); }
+
+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_SHAREDPTR_H_