C++: Can I cast a vector to a vector <base_class> during a function call?

Question

I have a existed class and function which look like this:

Class base_class{
    ...
}

void Func(...,vector &vec_b,...){
    // inside          


        

Answer 1

No. Even if an A is a B, a vector is not a vector.

To pass one in place of the other, you can pass a vector of pointers (or use a Boost ptr_vector). Alternatively, you may be able to use a template to allow passing a vector of anything that provides the right interface.

Either of these will require changing your function though -- there's essentially no way to avoid that (and still provide the functionality you want).