Function signed 

pub fn signed(bits: &Bits) -> isize

Converts up to the first 64 bits of a bit string to a signed integer.

If the length of the the bit string is less than the length of isize, the result is sign-extended to 64 bits.

Example

let bits = Bits::new([0x10, 0x32, 0x54, 0x76]);
let signed = bits_as::signed(&bits);

assert_eq!(signed, 0x0000000076543210);

let bits = Bits::from([0x10, 0x32, 0x54, 0x76]);
let signed = bits_as::signed(&bits);

assert_eq!(signed, 0xFFFFFFFFF6543210u64 as isize);