BitIndex

A little-endian zero-indexed bitstring representation.

Internally represented by the primitive unsigned integer types. Use the appropriate BitIndex depending on the number of indices that need to be tracked.

• u8 -> BitIndex8
• u16 -> BitIndex16
• u32 -> BitIndex32
• u64 -> BitIndex64
• u128 -> BitIndex128

Usage

A BitIndex is initialized with ones for the requested availables indices. A BitIndex can be unwrapped to return a copy of the internal representation.

let bi_res = BitIndex8::new(5) // -> Ok(BitIndex8)
let bi = bi_res.unwrap() // -> BitIndex8
assert_eq!(0b11111, bi.unwrap());

Bits can be directly set and unset. BitIndex is zero-indexed.

let mut bi = BitIndex8::new(5).unwrap() // -> BitIndex8
bi.unset(0);
assert_eq!(0b11110, bi.unwrap());
bi.set(0);
assert_eq!(0b11111, bi.unwrap());

Smallest and largest availables indices can be queried.

let mut bi = BitIndex8::new(5).unwrap() // -> BitIndex8
assert_eq!(Some(4), bi.largest());
bi.unset(4);
bi.unset(3);
assert_eq!(Some(2), bi.largest());
bi.clear();
assert_eq!(None, bi.largest());
bi.restore();
assert_eq!(Some(4), bi.largest());

assert_eq!(Some(0), bi.smallest());
bi.unset(1);
bi.unset(2);
assert_eq!(Some(2), bi.smallest());
bi.clear();
assert_eq!(None, bi.smallest());
bi.restore();
assert_eq!(Some(0), bi.smallest());

Popping the smallest/largest returns the value, and unsets it

let mut bi = BitIndex8::new(5).unwrap() // -> BitIndex8
assert_eq!(Some(4), bi.pop_largest());
assert_eq!(Some(3), bi.largest());
assert_eq!(Some(3), bi.pop_largest());
assert_eq!(Some(2), bi.pop_largest());
assert_eq!(Some(1), bi.pop_largest());
assert_eq!(Some(0), bi.pop_largest());
assert_eq!(None, bi.pop_largest());

bi.restore();
assert_eq!(Some(0), bi.pop_smallest());
assert_eq!(Some(1), bi.smallest());