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<FONT COLOR="#AOAO99">Smart Pointers and other Pointer classes</FONT></H3></CENTER>

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<p>This article was contributed by <A HREF="mailto:Poul@wizsoft.com">Poul Costinsky</A>. You can also
find this and other articles at his web site at <A HREF="http://www.wizsoft.com/%7epoul/srs/">http://www.wizsoft.com/~poul/srs/</A>

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Because copy has different meaning with different classes, there are several pointer
classes here. 
  <li><a name="SmartPointersClasses"></a><b>Smart pointers classes</b>. Replace the now
    obsolete CWizPtr, BaseMultiRefPtr, and MultiRefPtr.(I don't remove them for convenience
    only). <b><font size="+1">No plain C/C++ pointers again!</font></b> <br>
    File <a href="SmartPointers.h" tppabs="http://www.codeguru.com/cpp_mfc/SmartPointers.h">SmartPointers.h</a> defines the following classes: <ul>
      <li>CWizSmartPtr - trivial base class for all others;</li>
      <li>CWizSafePtr - smart pointer class which basic garbage collections (i.e. knows to<br>
        delete the pointer in destructor). <b><i>From here and later every pointer class must hold</i></b>
        <b><i>a pointer allocated from heap only</i></b>! Copy operator attaches the object to the
        pointer and then detaches it from previous pointer - &quot;pessimistic shadow copy&quot;. </li>
      <li>CWizSafeArray - simple array of objects.</li>
      <li>CWizDuplPtr - implements deep copy semantics for copy constructor/operator.<br>
        Requires from an object to have a copy constructor. No polymorphism. </li>
      <li>CWizClonePtr - implements deep copy semantics for copy constructor/operator, with
        support for polymorphism in pointed object. Requires from an object to have a Clone()
        function. In the case of polymorphism a Clone() function must be virtual function
        returning pointer to the root of hierarchy. <br>
        An example: <p><tt>class A</tt> <br>
        <tt>{</tt> <br>
        <tt>A(const A&amp; a);</tt> <br>
        <tt>virtual A* Clone() const { return new A(*this); }</tt> <br>
        <tt>};</tt> </p>
        <p><tt>class B</tt> <br>
        <tt>{</tt> <br>
        <tt>B(const B&amp; a);</tt> <br>
        <tt>virtual A* Clone() const { return new B(*this); }</tt> <br>
        <tt>};</tt> </p>
      </li>
      <li>CWizBaseMultiRefPtr - <b>Multiply pointer</b> classes with <b>reference counting</b> and
        polymorphism.<br>
        Class implements basic machinery of reference counting, but doesn't implement a counter. <br>
        Class CWizMultiRefPtr uses <b>int</b> as counter (the simplest solution). <br>
        Implement garbage collection with reference counting, shadow copy, polymorphism. </li>
      <li>CWizCounterMultiRefPtr - optimized <b>Multiply pointer</b> classes with <b>reference
        counting</b> and polymorphism. Differs from CWizBaseMultiRefPtr in implementing reference
        counting,<br>
        which shifted to the managed class itself. It minimizes memory fragmentation, but requires
        access to the managed classes, which is not always possible. <br>
        &nbsp;</li>
    </ul>
    <p>File <a href="SmartPointersSerialize.h.htm" tppabs="http://www.codeguru.com/cpp_mfc/SmartPointersSerialize.h">SmartPointersSerialize.h</a> defines <b>StoreSmartPtr()</b>
    and <b>LoadSmartPtr()</b> functions for serializing to/from MFC CArchive.<br>
    File <a href="SmartPointerArrays.h.htm" tppabs="http://www.codeguru.com/cpp_mfc/SmartPointerArrays.h">SmartPointerArrays.h </a>defines arrays of smart
    pointers. All arrays are derived from CArray of MFC.<br>
    File <a href="SmartPointerArraysSerialize.h.htm" tppabs="http://www.codeguru.com/cpp_mfc/SmartPointerArraysSerialize.h">SmartPointerArraysSerialize.h</a> defines
    template function <b>SerializeArray() </b>for serializing to/from MFC CArchive.<br>
    File <a href="SmartPointerArraysSort.h.htm" tppabs="http://www.codeguru.com/cpp_mfc/SmartPointerArraysSort.h">SmartPointerArraysSort.h</a> defines template
    function <b>SerializeArray() </b>for serializing to/from MFC CArchive.<br>
    File <a href="SerializeVersion.h.htm" tppabs="http://www.codeguru.com/cpp_mfc/SerializeVersion.h">SerializeVersion.h</a> defines function
    SortSmartPrtArray(). </p>
  </li>
<P>
  <li><b>Multiply pointer</b> class with <b>reference counting</b> CWizMultiPtr.<br>
    Designed to hold objects of one class (no polymorphism). Several pointers can point to the
    same object; the object deleted when destroying the last pointer to it. By the nature uses
    shallow copy. <br>
    File <a href="MULTIPTR.H.htm" tppabs="http://www.codeguru.com/cpp_mfc/MULTIPTR.H">MULTIPTR.H</a> . </li>


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