D0 CODING CONVENTIONS
A Short Summary

Gustaaf Brooijmans
gusbroo@fnal.gov

Summary of D0 coding standards

Note:

This document summarizes the essential features of the coding standards - which I think are most important (I've tried to keep this short), please read http://www-d0.fnal.gov/computing/docs/d0cppsty.html for more complete information.
(Gustaaf Brooijmans 10/22/98)

• Files
  • Header files (.hpp) should start with
    #ifndef _XXX_,
    followed by
    #define _XXX_
    and therefore need to be closed by
    #endif
  • All #include's should be conditioned by using this convention:
    

    
     #ifndef _YYY_
       #include "yyy.hpp"
     #endif
     

    (this is for reducing compilation times)
  • minimize the use of global variables
  • a comment block should indicate file name, purpose, author, date, comments, etc.
• Classes
  • a comment block should give purpose, author, comments, states, etc.
  • only public inheritance is allowed.
  • classes should start with the public section, finish with the private section
  • comment non-obvious features/fields
  • no inlines in the class declarations
    (no void set() {n=0;})
    instead, below the class declaration, add inline void yyy::set(){n=0;}
    do-nothing inlines {} are ok.
  • all data fields should be private and start with an underscore
  • don't omit argument names of member functions in declarations
    (don't: void get_pt(float, float, float);)
• Operations and functions
  • comment all operations and functions - explain all inputs and outputs!
  • accessors should be const
  • parameters should be explicit, and declared as const when they are
    (i.e. use: void add(const float cell_energy);)
• Variables
  • declare variables when using them
    (this also allows you to initialize them with a useful value),
    in the block in which they are used.
  • avoid global variables
• Constants
  • no hard-coded constants in the code please
• Flow Control
  • do not use weird constructs that take 20 minutes to understand
    (even though they make it look like you really understand c++)
  • don't use break (except in switch), continue and goto
• Lexicalities
  • all variables, functions should be in lower case
    (occasional uppercase in the middle is allowed)
  • all #defined stuff is in uppercase only
    (underscores allowed)
  • typedefs, structures, classes start with uppercase and are followed with lowercase
  • names should be explicit (avoid the popular drppng f vwls)
  • indent by 2 or 3 columns (not 8 at a time)
  • use a blank space around every binary operator
  • fit each line on 80 columns