CRTP to avoid virtual member function overhead

Question

In CRTP to avoid dynamic polymorphism, the following solution is proposed to avoid the overhead of virtual member functions and impose a specific interface:

temp         


        

Answer 1

No, imagine the following situation:

template 
void bar(base obj) {
   obj.foo();
}

base my_obj;
bar(my_obj);

Base's foo will be called instead of my_type's...

Do this, and you will get your erro message:

template 
struct base {
  void foo() {
    sizeof(Derived::foo);
    static_cast(this)->foo();
  };
};

But I must confess I am not sure how this will work in compilers other than GCC, tested only with GCC.