At some point in 2016 the
xparse package changed its
k-type argument to the better
e-type one. Then, shortly after, the behavior of the
e-type arg was changed again to improve its usability.
This is described in this question.
Now, I'm writing a class that defines some commands using
e-type args and I would like to be compatible with whichever version of
xparse one might have. Notably, arXiv runs TeXLive 2016 with a version of
xparse that seems to support the old behavior of
e-type args, so this is an important case to consider.
Thus I would like to use
\@ifpackagelater in my code to detect which kind of arguments I have to use and define my macros accordingly. However, I have troubles finding the exact versions (i.e. the date to give to
\@ifpackagelater) to discriminate the two changes, i.e. from
e-type, and from the old to the new behavior of
Which are the dates of those changes, suitable to give to
\@ifpackagelate for this purpose?
UPDATE: To clarify my need. What I want to do is to write class code supporting TeXLive 2016 onward, because that's what arXiv runs, and this means I have to:
- gracefully exit if the xparse package is too old (by providing the correct date to
- discriminate between the two behaviors of
e-type to support both (by providing the correct date to
So I need the dates of the two changes.