Most Concert Technology entities are implemented by means of two classes: a handle class and an implementation class, where an object of the handle class contains a data member (the handle pointer) that points to an object (its implementation object) of the corresponding implementation class. As a Concert Technology user, you will be working primarily with handles.

As handles, these objects should be passed in either of these ways:

• as const by value (when no change is involved);
• by reference (when the function to which the handle is passed changes the implementation of that handle).

They should be created as automatic objects, where "automatic" has the usual C++ meaning.

Member functions of a handle class correspond to member functions of the same name in the implementation class.