Introduction to OOP
Chapter 4: Classes and Methods:
Considerations in Method Definitions
In C++ you have a choice to define a method in the class interface, or separately in an implementation file. How do you decide?
Readability. Only put very small methods in the class definition, so that it is easier to read.
Semantics. Methods defined in class interface
(at the descretion of the compiler) be expanded in-line. Another reason for only defining very small methods this way.
, Slide 25