 Could it be possible for a function to pass a series as boolean? If the
 series is provided it can act like a "- - by" flag.

You can pass a pointer-to-series as an optional argument (with
a default of "null").

Suppose that a function contains two (or more) consecutive boolean/int arguments which are provided with a default value.
My point is if it could be possible to skip the first boolean/int argument - by leaving a blank for example - and entering only the successive one(s)?
E.g. if my function is defined as :
my_function(series X, bool tmp1[0], bool tmp2[0])
I'd like to type:
my_function(X, , 1)
Does it make any sense ?
Cheers,
Artur