Function ratio_to_f64 

pub(crate) fn ratio_to_f64<T: Bits + Clone + Integer + Signed + ShlAssign<usize> + ToPrimitive>(
    numer: T,
    denom: T,
) -> f64

Converts a ratio of T to an f64.

In addition to stated trait bounds, T must be able to hold numbers 56 bits larger than the largest of numer and denom. This is automatically true if T is BigInt.