The only time an overloaded function name can be used or assigned without actually calling the function is when a variable or parameter of the correct function pointer type is initialized or assigned the address of the overload function. 

In this case, an overloaded function name has been used in some other context, for example, the following code will generate this error:

class A{
   A(){myex;}           //calling the function
   void myex(int) {}    //or taking its address?
   void myex(float){}
};