This book isn‎'‎t an introduction to object‎-oriented technology or design‎.‎ Many books already do a good job of that‎.‎‎.‎‎.‎this isn‎'‎t an advanced treatise either‎.‎ It‎'‎s a book of design patterns that describe simple and elegant solutions to specific problems in object‎-oriented software design‎.‎‎.‎‎.‎‎.‎Once you understand the design patterns and have had an ‎"‎Aha‎!‎‎"‎ ‎(‎and not just a ‎"‎Huh‎?‎‎"‎ experience with them‎,‎ you won‎'‎t ever think about object‎-oriented design in the same way‎.‎ You‎'‎ll have insights that can make your own designs more flexible‎,‎ modular‎,‎ reusable‎,‎ and understandable‎-‎-which is why you‎'‎re interested in object‎-oriented technology in the first place‎,‎ right‎?‎ ‎-‎- From the Preface This is one of the best written and wonderfully insightful books that I have read in a great long while‎.‎‎.‎‎.‎this book establishes the legitimacy of patterns in the best way‎:‎ not by argument‎,‎ but by example‎.‎ ‎-‎- C++ Report‎.‎