Note 67: An interposer class is a class with the same name of the class it wants to change (using inheritance). By adding its unit after the unit of its base class in a uses statement, a unit will use the modified version of the class rather than the original. Interposer classes are not a terribly neat technique, rather a hack. But they can be very handy, indeed!
This blog post is part of my "113 Delphi 2007 Handbook Notes" blogging project, to promote my new Delphi book.