What's Next

By now, you should have a good idea about what happens behind the scenes in C++. You are slightly at the mercy of the system until you appreciate what C++ does for you silently and why it is sometimes wrongheaded. One good way to get a feeling for what C++ does is to single-step through you first C++ programs with a debugger, looking at all the functions you went through. It's a good idea to play with C++ to learn more about it, and UnderC makes that less painful. You can learn a lot by tracing all function calls. In UnderC, you do this as follows, by using the #opt command to switch on t (for trace) and v (for verbose):

;> #opt t+ v+
;> s
						=
						"hello";
*sig:   void operator=(char*)
*match: string& operator=(char*)
*TRACE <temp>
*TRACE =
*TRACE copy
*TRACE strlen
*TRACE resize
*TRACE _new_vect
*TRACE strcpy
*TRACE strcpy
(string&) 'hello'
;> #opt t- v-
					

If you repeat this with string s = "hello", you will indeed see that __C__ (that is, the constructor) is called instead of operator=.

Chapter 10, “Templates,” deals with templates. You have already begun using templates because all the standard containers are template classes. Templates offer a powerful way to reuse code because they enable you to generate functions and classes automatically for each specified type.