Macro gcollections::forward_all_binop

macro_rules! forward_all_binop {
    (impl < $($bn : ident : $(+ $bs : ident) *), * > $imp : ident for $res : ty,
 $method : ident, $arg : ty) => { ... };
    (impl < $($bn : ident : $(+ $bs : ident) *), * > $imp : ident for $res : ty,
 $method : ident) => { ... };
}