Question

1.So I have:

Class A;

Class B : public A;

Class C : public B;

2.And a vector of pointers of type B:

vector<B*> vec;

3.Then:

C* ptr = new C();

vec.push_back(ptr);

So the question is, it is reliable to use std::find like this?

std::find(vec.begin(), vec.end(), prt);

Also, is it fine to do search using this-> pointer?

std::find(vec.begin(), vec.end(), this); //inside of a type C object

Thanks in advance.

Answer 1

Yes, this is safe since there is a well-defined comparison (==) between pointers to objects in a type hierarchy. Even though the actual value of the pointers may differ after a conversion to a base class type (often the case with multiple inheritance), the runtime is required to adjust for that so that comparisons between those pointers still yield the correct result.