A tiny but useful algorithm for getting the bits from n to k off a integer.

bit_slice.rs

fn main() {
  let num = slice(0b1101001, 3, 7);
  
  println!("num = {:#b}", num); // "num = 0b1101"
}


// since all this is just some basic arithmetic
// the function should have a big O of 1.
fn slice(bits: i32, start: i32, end: i32) -> i32 {
  assert!(end > start, "end bit is smaller or equal to the start!");
  
  let diff = end - start;
  let mask = (1 << diff) - 1;
  (bits >> start) & mask
}