Automatically converting an A* into a B*
- by Xavier Nodet
Hi,
Suppose I'm given a class A. I would like to wrap pointers to it into a small class B, some kind of smart pointer, with the constraint that a B* is automatically converted to an A* so that I don't need to rewrite the code that already uses A*.
I would therefore want to modify B so that the following compiles...
struct A {
void foo() {}
};
template <class K>
struct B {
B(K* k) : _k(k) {}
//operator K*() {return _k;}
//K* operator->() {return _k;}
private:
K* _k;
};
void doSomething(A*) {}
void test() {
A a;
A* pointer_to_a (&a);
B<A> b (pointer_to_a);
//b->foo(); // I don't need those two...
//doSomething(b);
B<A>* pointer_to_b (&b);
pointer_to_b->foo(); // 'foo' : is not a member of 'B<K>'
doSomething(pointer_to_b); // 'doSomething' : cannot convert parameter 1 from 'B<K> *' to 'A *'
}
Note that B inheriting from A is not an option (instances of A are created in factories out of my control)...
Is it possible?
Thanks.
