Google C++ style guide

[sclytrack]

> >Function Parameter Ordering: When defining a function, parameter order is:
inputs, then outputs.<
> D may even enforce this, allowing "out" only after "in" arguments.
> -------------------

Function Default Arguments

void foo(int x, int y = 3)
{
   ...
}
...
foo(4);   // same as foo(4, 3)