Function num_traits::sign::signum

pub fn signum<T>(value: T) -> T where
    T: Signed, 

Returns the sign of the number.

For f32 and f64:

• 1.0 if the number is positive, +0.0 or INFINITY
• -1.0 if the number is negative, -0.0 or NEG_INFINITY
• NaN if the number is NaN

For signed integers:

• 0 if the number is zero
• 1 if the number is positive
• -1 if the number is negative