Marius
Mon Mar 01 15:42:29 CST 2004
"Bonj" <a@b.com> wrote in message
news:eo$#bb8$DHA.2180@TK2MSFTNGP09.phx.gbl...
> also could cause issue if member functions / data were accessed after
> 'delete this'
>
> ??
Yes... That's why delete this should be the 'last' thing called and at a
point where you know the object(s) are not needed anymore... once the delete
this has been called, all the virtual destructors will be called..
In fact, I had a discussion about this some while ago in some other forum
and I posted there a test-case for a few scenarios.
Here are the results:
class A
{
public:
A() {};
virtual ~A() { cout << "Destructor of A called...\n"; };
virtual Method() {};
};
class B : public A
{
public:
B() {};
virtual ~B() { cout << "Destructor of B called...\n"; }
virtual Method() {delete this;};
};
class C : public B
{
public:
C() {};
virtual ~C() { cout << "Destructor of C called...\n"; }
virtual Method() {B::Method();}
};
then,
A* TheObject = new C;
TheObject->Method();
Output is:
Destructor of C called...
Destructor of B called...
Destructor of A called...
Press any key to continue
Removing the B::Method from the Method's implementation in class C, yields
that no destructors are called at all.
Doing a "delete this" in the Method implementation in class C [w/ nothing
written for the implementation of Method in A and B] yields:
Destructor of C called...
Destructor of B called...
Destructor of A called...
Press any key to continue
Marius