[acqq]

It can be that _ for any is less expected than a star or a dot would be. We're used to the star in shells and the dot in regexps for decades already.

(0, *) seems more obvious in that example than (0, _) but at least we are used to ____ in the forms printed on paper too.

[chrismorgan]

Just as a point of interest: in these cases, (0, ..) would also work, where .. means “any number of elements”.

[dbaupp]

`..` doesn't work with tuples (yet?).