pub fn read_optional_angled(default: Option<Tokens>) -> Result<Option<Tokens>>Expand description
The angle-bracket twin of read_optional.
Perl beamer.cls.ltxml L50-57 readBeamerAngled (backing its
BeamerAngled / OptionalBeamerAngled parameter types) does exactly this.
The angle-bracket optional is not beamer-specific — apacite spells its
citation pre-note that way (\cite<see>[p.5]{key}, apacite.sty L313
\def\@cite<#1>), so it lives here beside read_optional.