from abstraction to ADTs to C++ classes


abstract data types consist of...
  data, operations
interface vs. implementation (e.g. TV, car, radio)
client vs. implementer (both programmers)


how to think about classes
  better tool for realizing ADTs 
  structs were formally grouped data, 
    classes also have formally grouped functions
  message-based computing (see lecture slides)


syntactic anatomy of a class 
  header (specification or interface), source (implementation) files
    *strictly speaking, member data in header is part of implementation
  member data
  member functions (methods)
  constructors, can have many different ones
    default (no parameters)


see example code for class SimpleDate