Public Default Property Item( _
   ByVal row As Integer, _
   ByVal col As Integer _
) As Double

Dim instance As Matrix
Dim row As Integer
Dim col As Integer
Dim value As Double
 
instance.Item(row, col) = value
 
value = instance.Item(row, col)

public double this( 
   int row,
   int col
) {get; set;}

public:
property double default [int,int] {
   double get(introw, intcol);
   void set (introw, intcol, doublevalue);
}