Trailing commas in function calls
It would be very useful to be able to write code like this:
some_function (
parameter_a,
parameter_b,
parameter_c, // trailing comma
);
Instead of this:
some_function (
parameter_a,
parameter_b,
parameter_c // no trailing comma
);
Firstly, because it looks more consistent, but also, because it would make it easier to swap the arguments around, which is especially helpful in the early development stage of a project