Re: Runtime Error for virtual derived class destructor
On 7/13/2012 8:09 AM, pritesh kadam wrote:
I declared derived class destructor as virtual.
CODE:
#include<iostream>
using namespace std;
class Base{ //Base class
int x; public:
Base()
{cout<<"Base Constructed\n";}
~Fred() //Base destructor not virtual
I think you meant
~Base()
{cout<<"Base Destructed\n";}
};
class Der: public Base //Derived
{
public:
Der(){cout<<"Derived Constructor"; }
virtual ~Der() //Derived class destructor virtual
{ cout<<"Derived Destructed";}
};
int main()
{
Base *f=new Der();
delete f;
Since 'Base' class destructor is not virtual, deleting a derived object
via the base class pointer has undefined behavior. A "run-time error"
is totally acceptable result since the language does not impose any
particular behavior in this case. Just like absence of any "error"
would be, as well. Or your hard drive formatted. Or nasal demons.
Read up on "undefined behavior".
}
It gets compiled correctly. But on execution, following is o/p :
O/p
Base Constructed
Derived Constructor
Base Destructed
*** glibc detected *** ./trial: free(): invalid pointer: 0x0957b00c ***
[...]
V
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