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       #Post#: 7--------------------------------------------------
       Constructors/Destructors and virtual
       By: avinash.srin Date: August 25, 2011, 9:43 am
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       Can you make constructors and destructors virtual? Explain the
       background in each case.
       #Post#: 18--------------------------------------------------
       Re: Constructors/Destructors and virtual
       By: avinash.srin Date: August 26, 2011, 5:27 am
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       No we cant make virtual constructors. It's illegal and not
       required as well. A constructor is invoked at the time of object
       creation. Only after that a vtable and virtual pointer are
       created. Hence, there wont be any use of having a virtual
       constructor.
       However, it's possible to have virtual destructors and advisable
       to be used in classes with at least one virtual function. Having
       virtual functions indicate that a class is meant to act as an
       interface to derived classes, and when it is, an object of a
       derived class may be destroyed through a pointer to the base.
       For example:
       [code]
       class Base {
       // ...
       virtual ~Base();
       };
       class Derived : public Base {
       // ...
       ~Derived();
       };
       void f()
       {
       Base* p = new Derived;
       delete p;
       is called
       }
       [/code]
       Had Base's destructor not been virtual, Derived's destructor
       would not have been called - with likely bad effects, such as
       resources owned by Derived not being freed. Note that a base
       type pointer is pointing to a derived type object in the
       example.
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