I am looking at How to use A4 instead of letterpaper? and wondering how I can create a custom documentclass like \documentclass{foo}, and then have another function like \foosetsize{a4paper} right after that somehow, rather than putting the paper dimensions inside documentclass options. How can I do that?
So instead of:
\documentclass[a4paper]{foo}
It would be something like:
\documentclass{foo}
\setpapersize{a4paper}
\usepackage[paperwidth=10cm, paperheight=10cm]{geometry}– Fran Dec 22 '19 at 10:33