Function min_step 

pub const fn min_step(radix: u32, bits: usize, is_signed: bool) -> usize

Get the number of digits that can be always processed without overflowing.

Calculate the number of digits that can always be processed without overflowing for a given type, that is, it can process every (positive) value in the range [0, radix^N) where N is the number of digits.

For example, with u8 with radix 10, we have a maximum value of 255, so we have a min step of 2: that is, we can always process values from [0, 10^2) (or [0, 100)).