f64/d2/rect.go
func (r Rectangle) Eq(s Rectangle) bool {
	return r == s || r.Empty() && s.Empty()
}
func (r Rectangle) Eq(s Rectangle) bool {
	return r == s || r.Empty() && s.Empty()
}
// Eq reports whether r and s contain the same set of points. All empty
// rectangles are considered equal.