Crate numwit 

Witness types and operations for numbers which are Positive or Negative, but not zero.

Operation	LHS	RHS	Output	Assignable?
Add	Positive	Positive	Positive	Yes
	Negative	Negative	Negative	Yes
	Positive	Negative	?	No
	Negative	Positive	?	No
	Positive	impl Unsigned	Positive	Yes
	Negative	impl Unsigned	?	No
Sub	Positive	Positive	?	No
	Negative	Negative	?	No
	Positive	Negative	Positive	Yes
	Negative	Positive	Negative	Yes
	Positive	impl Unsigned	?	No
	Negative	impl Unsigned	Negative	Yes
Mul	Positive	Positive	Positive	Yes
	Negative	Negative	Positive	No
	Positive	Negative	Negative	No
	Negative	Positive	Negative	Yes
	Positive	impl Unsigned	?	No
	Negative	impl Unsigned	?	No
Div	Positive	Positive	Positive	Yes
	Negative	Negative	Positive	No
	Positive	Negative	Negative	No
	Negative	Positive	Negative	Yes
	Positive	impl Unsigned	Positive	Yes
	Negative	impl Unsigned	Negative	Yes
Neg	Positive		Negative
	Negative		Positive

Structs

Negative

A guarantee that T < 0.

NotNegative

NotPositive

Positive

A guarantee that T > 0.