Programming Reference:Cpp Coding Style

Line Formatting

• No tab characters (please configure your editor to insert spaces instead).
• Indentation in steps of 2 or 3 space characters.
• Opening braces have their own line, aligned with the previous line; corresponding closing braces are placed on their own lines, at the same character position as the opening brace.
• For function definitions, return types appear on their own line, such that the function name is first in its line.

Naming

• ALL_UPPERCASE_NAMES are reserved for preprocessor macros.
• CamelCase (uppercase letters inside words) is used to indicate word boundaries.
• Class names and namespaces begin with uppercase letters: MyNameSpace, TheClass.
• Local variables and function arguments begin with lowercase letters: theCounter, inSomeInput.
• Data members of true classes are private, and accessed via Accessor Functions.
  • Setters use the prefix "Set" followed by the property's name, or directly the name of the property: SetValue(). Setter functions should also return a non-const reference to the data object itself rather than void, this allows for chaining as in
    float result = MyComputation().SetOrder( 5 ).SetDepth( 10 ).EvaluateAt( 4 );
  • Getters use the name of the property: Value(). Omitting the "Get" prefix allows the programmer to treat getters and reference accessors identically, as far as read access is concerned.
  • Reference Accessors use the name of the property, and are provided in a doubly const and a non-const version. This is important to allow const access from const object references, and to discriminate between read and write accesses (note the mPossiblyChanged flag):
    const int& Value() const { return mValue; }
int& Value() { mPossiblyChanged = true; return mValue; }

Name prefixes

Prefixes should carry information about the scope and usage of a variable but not its type.

• m for class data members,
• s for static class members and static variables,
• g for globals,
• c for constants,
• p for pointers,
• fp for function pointers,
• in for function input arguments,
• out for function output arguments,
• io for function arguments used for input and output.

Variable Declaration

• Always use the narrowest possible scope for a name to avoid side effects.
• Always initialize variables (at declaration resp. constructor).

Memory Allocation

• Allocate from the stack rather than the heap unless there is a good reason to use the new operator. This avoids memory leaks.
• Use STL containers rather than allocating arrays with new[]. This eliminates a number of possible errors (initialization, allocation, deallocation).

Pointers and References

• Use references rather than pointers wherever possible.

Control Flow

• Avoid goto, break outside switch-case blocks, and multiple return statements.

Example Function

void
MyClass::MyFunction( const SomeClass& inTheInput, int& outTheResult )
{
  outTheResult = mSomeDataMember;
  for( int i = 0; i < inTheInput.NumIterations(); ++i )
  {
    int k = 4;
    while( --k > 0 )
      outTheResult -= k;
  }
}