It's also worth understanding whether +0.0 and -0.0 are equivalent in your environment:

* Do they compare equal?

* If they're convertible to boolean, do they both evaluate to false?

* If you serialize/deserialize the value (e.g., to JSON and back), does it maintain the distinction?

* If you send this value to a database (esp. one with stored procedures), how does its behavior compare to your language?