Function sref 

pub fn sref<'a, Pos: StringPosition, MS: STeXModuleStore>(
    sref: Macro<'a, Pos>,
    p: &mut LaTeXParser<'a, Pos, STeXToken<Pos>, STeXParseState<'a, Pos, MS>>,
) -> MacroResult<'a, Pos, STeXToken<Pos>>

Panics