in C++, can I derive a class from a struct

Question

The question says it all really. Am I allowed derive a class from a struct, or should I create a class that embeds my struct and defines copy constructors and an = operator

Answer 1

In C++ struct is (almost) synonymous to a class (except of different default access level), so yes, you can.

struct A {
// fields are public by default
};

class B: public A {
// fields are private by default
};

I'm not familiar with MFC, but it looks like an attempt to maintain both C and C++ APIs.