Function syntex_syntax::ext::deriving::generic::cs_binop

pub fn cs_binop(binop: BinOp_, base: P<Expr>, enum_nonmatch_f: EnumNonMatchCollapsedFunc, cx: &mut ExtCtxt, trait_span: Span, substructure: &Substructure) -> P<Expr>

Use a given binop to combine the result of calling the derived method on all the fields.