/// <summary>
/// Searches for an item by traversing all cells up to AppendIndex.
/// The reads are volatile, the comparison Object.Equals().
/// </summary>
/// <param name="item">The object ref</param>
/// <returns>A positive value if the item is found, -1 otherwise.</returns>
public int IndexOf(T item)
{
int result = -1;
int aIdx = AppendIndex;
var p = new TesseractPos(0);
for (var i = 0; i <= aIdx; i++)
{
p.Set(i);
var r = Volatile.Read(ref blocks[p.D0][p.D1][p.D2][p.D3]);
if (r != null && r.Equals(item))
{
result = i;
break;
}
}
return(result);
}
/// <summary>
/// Iterates all cells from 0 up to AppendIndex and yields each item
/// if it's not null at the time of the check.
/// </summary>
/// <param name="assertGear">If true volatile-reads the Drive at each iteration. False by default. </param>
/// <returns>A not null item.</returns>
/// <exception cref="InvalidOperationException">If the Drive is P</exception>
public IEnumerable <T> NotNullItems(bool assertGear = false, bool allSlots = false)
{
T item = null;
var j = allSlots ? AllocatedSlots - 1 : AppendIndex;
var p = new TesseractPos(j);
for (int i = 0; i <= j; i++)
{
if (assertGear && Drive == TesseractGear.P)
{
throw new InvalidOperationException("Wrong drive");
}
p.Set(i);
item = Volatile.Read(ref blocks[p.D0][p.D1][p.D2][p.D3]);
if (item != null)
{
yield return(item);
}
}
}