how does ofstream or ostream type cast all types to string?

Question

any system defined user type past to ostream object is converted to a string or char* ?

like cout<<4<<\"Hello World\";

works perfectly fine, how

Answer 1

an i have just one overloaded operator method with one parameter(like void*) and then decide inside that method how to typecast integer to char*

No, you can't. A void * carries no type information, so there is no way of working out what type it actually points to.