A prototype 2D array implementation

IntArray2d.kt

class IntArray2D: Cloneable
{
    val xsize:Int
    val ysize:Int
    val _array:IntArray
    constructor(xsize:Int, ysize:Int){
        this.xsize=xsize
        this.ysize=ysize
        _array = IntArray(xsize*ysize)
    }
    constructor(src:IntArray2D) {
        this.xsize=src.xsize
        this.ysize=src.ysize
        this._array = src._array.clone()
    }
    /** Returns the array element at the given [index]. This method can be called using the index operator. */
    public operator fun get(index: Int): Int = _array[index]

    /** Returns the array element at the given [xIndex],[yIndex] position. This method can be called using the index operator. */
    public operator fun get(xIndex: Int, yIndex:Int): Int = _array[xIndex *ysize+yIndex]

    /** Sets the element at the given [index] to the given [value]. This method can be called using the index operator. */
    public operator fun set(index: Int, value: Int): Unit {
        _array[index]=value
    }
    /** Sets the element at the given [index] to the given [value]. This method can be called using the index operator. */
    public operator fun set(xIndex: Int, yIndex: Int, value: Int): Unit {
        _array[xIndex *ysize+yIndex]=value
    }

    /** Returns the number of elements in the array. */
    public val size: Int
        get() =_array.size

    /** Creates an iterator over the elements of the array. */
    public operator fun iterator(): IntIterator = _array.iterator()

    public override fun clone(): IntArray2D {
        return IntArray2D(this)
    }
}