Structures

A type that uses a fixed width, unsigned integer as storage for an array of bits. The number of bits is fixed and by default are set to zero.

Using fixed width arrays of bits can be used to implement bitfield like data structures.
As an example, consider an 8-bit value that represents the following data

+---------+---------+-------+-------+
| b7:4    | b2:3    | b1    | b0    |
| Value 2 | Value 1 | Flag2 | Flag1 |
+---------+---------+-------+-------+

struct Data {
    private var bits: BitField8

    var flag1: Bool {
        get { bits[0] }
        set { bits[0] = newValue }

    var flag2: Bool { bits[1] }

    var value1: Int { bits[2...3] }

    var value2: Int {
        get { bits[4...7] }
        set { buts[4...7] = newValue }
    }
}

An allocator that uses an UnsignedInteger to store the allocated entries allowing upto .bitWidth entries to be allocated.

An allocator that uses 2 UnsignedIntegers to store the allocated entries allowing upto 2x .bitWidth entries to be allocated.

Undocumented

Undocumented

NumberSet uses a specified unsigned FixedWidthInteger as the storage for a Set containing the numbers 0…bitWidth. eg a UInt8 can contain the numbers 0...7, a UInt64 can store 0...63. The storage uses a bit per number where bit[x] is used to store x. This gives an ordering of the set from lowest to highest. The rawValue property represents the underlying storage and can be easily interpreted.

rawValue = 0b1001_0001  [0, 4, 7]

An Iterator that return the elements of a NumberSet.