Layout conventions

Similarly to the naming conventions, Symbian OS code is laid out in a standard way. Developers and organisations usually have existing preferences for these issues. This information is provided to help you to read Symbian OS code, even if you do not choose to adopt the same layout yourself.

• the number of headers included is minimised, forward references being preferred where possible.

• the standard anti-nesting method is used to avoid multiple inclusion of headers: for example,

// EG.H
//
// Copyright notice
//

#ifndef _EG_H_
#define _EG_H_
//...include files and declarations
#endif

Symbian OS code uses the following conventions for laying out class declarations:

• access control specifiers are always given for readability

• class members are declared in the following order: public member functions, protected member functions, private member functions, protected data, private data, public data. The appropriate access specifier is given at the start of each group.

• for readability, function arguments are named in the function declaration as well as the definition

• virtual functions that replace inherited behaviour are grouped together in the header, with a comment documenting from which class the behaviour is inherited

• the virtual keyword is not given for these functions

• virtual functions are not made inline, as it is difficult to know exactly how a compiler treats these. The exception to this are virtual inline destructors, which are allowed.

• specify inline explicitly for inline functions.

• do not provide the implementation in the class declaration. Instead, implementations are provided at the bottom of the header or in a separate inl file.