LinuxQuestions.org - fun with templates, typedefs, and ,

Hello, everyone! I thought I'd share this bit of obscure C++ I came up with because it entertained me.

Code:

#include <iostream>





struct empty_struct

{

        typedef void print_type() const;

        virtual print_type printme = 0;

};





template <class Type>

void print_it(const Type &oObject, typename Type::print_type Type:: *mMembers[])

{ if (mMembers) while (*mMembers) (oObject.**mMembers++)(); }





class derived_struct : public empty_struct

{

public:

        print_type derived_struct:: *operator , (bool rReally) const

        { return rReally? &derived_struct::showme : NULL; }



private:

        void showme() const

        { std::cout << "showed!\n"; }



        void printme() const

        { std::cout << "printed!\n"; }

};





int main()

{

        derived_struct object;



        empty_struct::print_type derived_struct:: *members[] =

          { &empty_struct::printme, (object, true), (object, false) };



        print_it(object, members);

}

I personally think it's silly that this can be done, but I also appreciate that it can be done in principle. If only I could figure out how to define printme and showme using the typedef!
Kevin Barry