template <class Object>
void BinaryHeap<Comparable>::
insert (const Comparable & x)
{
   if ( isFull ( ) )
      throw OverFlow ( );

   // percolate up
   int hole = ++currentSize;
   for (; hole > 1 && x < array[ x / 2 ]; hole /= 2)
      array [ hole ] = array [ hole / 2 ];

   array [ hole ] = x;

}