Edward Diener writes: >I know that I am missing how the mechanism works which links > the property_map concept to the get(), put(), and operator[] functions.
A property map is something which relates "keys" to "values", where there "keys" are the "names" of the properties. Given a property map, you can get and/or set the "value" associated with each "key" using the get() and put() functions. You can build a property map out of anything at all, just by defining the necessary interface. For example, you could build a property map that returned the values of class members by name, or one that returned the n-th number in a mathematical sequence, given n. The idea is that in your generic code, you say "give me a property map which I can use with the following keys to return values of type T", and it is then up to the client code how they implement that property map --- _anything_ which provides the necessary interface will do. operator[] is essentially just syntactic sugar for get()/put(), where the values are real, discernable objects, for which you can obtain a reference. Returning a reference means that you can store the reference for later use, or pass it to another function, and is actually the key benefit of using operator[] rather than plain get()/put(). Anthony -- Anthony Williams Senior Software Engineer, Beran Instruments Ltd. Remove NOSPAM when replying, for timely response. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
