Re: Placement new and destructor
dragoncoder wrote:
int main() {
Foo *pb = new (buf) Foo;
if ( pb.val() == 0 )
cout << "new expression worked!" << endl;
delete[] buf;
return 0;
}
Looking at the above code, I feel it is incorrect at 2 places.
1. Since pb is a pointer to a Foo object, the expression inside the if
condition should have been pb->val() instead of pb.val(), okay that may
be a printing mistake.
2. The second error is not a typographical error. I see at no place in
the code the destructor of the Foo object is called. Instead delete[]
buf calls the destructors of 16 char objects which is fine but I feel
there should be a call to Foo's destructor before the delete[] buf.
Shouldn't there be a call to pb->~Foo() before delete[] ?
I think you are correct.
int main() {
Foo *pb = new (buf) Foo;
//if ( pb.val() == 0 ) // the new above will throw if failed
// so this test always yields false
cout << "new expression worked!" << endl;
pb->~Foo() // yes, destruct *pb
delete[] buf;
return 0;
}