pub fn bits(&self) -> usize {
		for i in 1..N {
			if self.0[N - i] > 0 {
				return (0x40 * (N - i + 1))
					- self.0[N - i].leading_zeros() as usize;
			}
		}

		0x40 - self.0[0].leading_zeros() as usize
	}
Return the least number of bits needed to represent the number
stacks-core/src/uint.rs