How to use

unsafeFastSwap

method

in

us.ihmc.robotics.lists.RecyclingArrayList

protected void unsafeSwap(int i, int j)
{
 if (i == j)
   return;
 unsafeFastSwap(i, j);
}

/**
* Removes the element at the specified position in this list.
* This method is faster than {@link RecyclingArrayList#remove(int)} but the ith element is swapped with the last element changing the ordering of the list.
*
* @param index the index of the element to be removed
*/
public void fastRemove(int index)
{
 if (index == size - 1)
 {
   size--;
   return;
 }
 rangeCheck(index);
 unsafeFastSwap(index, --size);
}

/**
* Inserts a new element at the specified position in this
* list. Shifts the element currently at that position (if any) and
* any subsequent elements to the right (adds one to their indices).
*
* @param index index at which the new element is to be inserted
* @return the new inserted element
* @throws IndexOutOfBoundsException if the index is out of range
*         (<tt>index &lt; 0 || index &gt;= size()</tt>)
*/
public T insertAtIndex(int index)
{
 rangeCheckForInsert(index);
 // First add new element at last index
 T ret = add();
 // Then go trough the list by swapping elements two by two to reach the desired index
 for (int i = size - 1; i > index; i--)
   unsafeFastSwap(i, i - 1);
 return ret;
}