Re: If a class has a virtual destructor

Try this one
#include "stdafx.h"
#include <iostream>

// class that has to be tested for
// virtual destructor
class CVirtualDtor
{
public:

    virtual ~CVirtualDtor ()
    {
        std::cout << "virtual ~CVirtualDtor ()\n";
    };
};

// class that has to be tested for
// virtual destructor
class CNoVirtualDtor
{
public:

    ~CNoVirtualDtor ()
    {
        std::cout << "~CNoVirtualDtor ()\n";
    };
};

// this is the template function
//****************FUNCTION STARTS*******************//

template<typename T>
bool HasVirtualDtor ()
{
    // a boolean return
    static bool bRet = false;

    // since CDerived has no member objects
    // there is no harm if its destructor is skipped
    // during this test
    class CDerived : public T
    {
    public:
        CDerived () {bRet = false;}
        ~CDerived () {bRet = true;}
    };

    // we shall call virtual mechanism to play here
    // and the virtual d-tor will be revealed !
    // assume success of new
    T* oDerived = new CDerived ();
    delete oDerived;

    return bRet;
};

//****************FUNCTION ENDS*******************//

int _tmain(int argc, _TCHAR* argv[])
{
    std::cout << "CNoVirtualDtor has a virtual d-tor ? : " <<
HasVirtualDtor<CNoVirtualDtor>() << std::endl;
    std::cout << "CVirtualDtor has a virtual d-tor ? : " <<
HasVirtualDtor<CVirtualDtor>() << std::endl;
    return 0;
}

--
      [ See http://www.gotw.ca/resources/clcm.htm for info about ]
      [ comp.lang.c++.moderated. First time posters: Do this! ]