Function rustfmt_nightly::items::rewrite_type_alias

pub(crate) fn rewrite_type_alias(
    ident: Ident, 
    ty_opt: Option<&P<Ty>>, 
    generics: &Generics, 
    generic_bounds_opt: Option<&GenericBounds>, 
    context: &RewriteContext<'_>, 
    indent: Indent, 
    vis: &Visibility, 
    span: Span
) -> Option<String>