This book is not a book of learning to use the STL, which would read from beginning to end. Rather, it is a reference book, that is to say a book that contains all the specifications of the STL, and in which we will draw when needed. This is typically the kind of book that is kept on hand for years and is the best investment we can make for a book.
The genius of this book, in my opinion, is that besides being a reference book going around about it, this book avoids eccueil aridity and manages to inject over its nearly 800 pages a good dose of pedagogy. Thus, far from being a catalog of objects and methods, this book contains much of the text, as well as concrete examples of using the STL, stressing the need difficulties or possible optimizations.
In short, unlike other reference books, this is not an intimidating book, quite the contrary: it makes the STL affordable, pleasant and almost friendly.
