Functions outside classes

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Lecture 3 - Page 4 : 36

Notes about C++
Abstraction Mechanisms, Part 1

Functions outside classes

In contrast to similar object-oriented languages, C++ allows functions and variables outside classes

Helper functions are typically wrapped in a namespace together with one or more classes.

In the simple case they are placed in the global name space together with the classes

The C++ Programming Language: Page 240

Effective C++, Third edition: Item 23

Functions outside classes:
- Which function should be defined outside classes - possible answers:
  - Functions that do not need to access the encapsulated state
  - Functions that we want to use without the dot operator
    - f(obj, ...) instead of obj.f(...)
    - Or instead of Class::f(...) where f is a static member
  - Other functions, such as the entry function main

Variables outside classes:
- Global variables and variables in namespaces

Seen from the C perspective: funtions and variables outside classes represent backward compatibility

Compared with Java and C#: Less emphasis on static variables and methods