pub trait NumOrd<Other> {
fn num_partial_cmp(&self, other: &Other) -> Option<Ordering>;
fn num_eq(&self, other: &Other) -> bool { ... }
fn num_ne(&self, other: &Other) -> bool { ... }
fn num_lt(&self, other: &Other) -> bool { ... }
fn num_le(&self, other: &Other) -> bool { ... }
fn num_gt(&self, other: &Other) -> bool { ... }
fn num_ge(&self, other: &Other) -> bool { ... }
fn num_cmp(&self, other: &Other) -> Ordering { ... }
}