If I have \documentclass[twoside]{report} and I change it to \documentclass[oneside]{report}, \usepackage{fancyhdr} automatically prints the left page header and footer. Is there a way to tell fancyhdr/LaTeX to apply the rightside header/footer if oneside is used?
... maybe with an if ... else statement?
I tried \@ifclasswith{report}{oneside}{True}{False} which yields You can't use \spacefactor in vertical mode. \@.
\makeatletter ... \makeatotheraround the if statement. Does doing that at least get rid of that particular error? (There;s not enough information to say whether there isn't some other problem.) – barbara beeton Dec 30 '22 at 17:31