Bitmask filtering

Bitmask.kt

class Bitmask(
        mask: Int
) {
    private var bitmask = mask

    val mask: Int
        get() = bitmask

    constructor() : this(0)

    constructor(vararg values: Pair<Int, Boolean>) : this(0) {
        values.forEach { (flag, value) ->
            set(flag, value)
        }
    }

    operator fun get(flag: Int): Boolean = mask.and(flag) != 0

    operator fun set(flag: Int, value: Boolean) {
        bitmask = if (value) {
            bitmask.or(flag)
        } else {
            bitmask.and(flag.inv())
        }
    }

    override fun toString(): String {
        val mask = bitmask.toString(2)

        return "Mask: $mask\nValues:\n" + mask
                .reversed()
                .toCharArray()
                .mapIndexed { i, value ->
                    String.format("\t%1$3d -> %2\$s", Math.pow(2.0, i.toDouble()).toInt(), value != '0')
                }.joinToString(separator = "\n")
    }

    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (javaClass != other?.javaClass) return false

        other as Bitmask

        if (bitmask != other.bitmask) return false

        return true
    }

    override fun hashCode(): Int {
        return bitmask
    }

    companion object {
        fun parse(obj: Any?) = Bitmask(when (obj) {
            is Int -> obj
            is Long -> obj.toInt()
            is String -> obj.toIntOrNull() ?: 0
            else -> 0
        })
    }
}