public static void DoTest(string[] args)
    {
        using (new MPI.Environment(ref args))
        {
            Intracommunicator world = Communicator.world;

            world.Barrier();

            // Test addition of integers
            if (world.Rank == 0)
            {
                System.Console.Write("Testing exclusive scan of strings...");
            }
            int partial_sum = world.ExclusiveScan(world.Rank, addInts);
            int expected    = world.Rank * (world.Rank - 1) / 2;
            MPIDebug.Assert(partial_sum == expected);
            if (world.Rank == 0)
            {
                System.Console.WriteLine(" done.");
            }

            // Test addition of integer points
            if (world.Rank == 0)
            {
                System.Console.Write("Testing exclusive scan of strings...");
            }
            Point point_sum = world.ExclusiveScan(new Point(world.Rank, 1), Point.Plus);
            MPIDebug.Assert(point_sum.x == partial_sum && point_sum.y == world.Rank);
            if (world.Rank == 0)
            {
                System.Console.WriteLine(" done.");
            }

            // Test addition of integer arrays
            if (world.Rank == 0)
            {
                System.Console.Write("Testing exclusive scan of integer arrays...");
            }
            int[] arraySum = world.ExclusiveScan(new int[] { world.Rank, 1 }, Operation <int> .Add);
            MPIDebug.Assert((world.Rank == 0 && arraySum == null) ||
                            (world.Rank != 0 && arraySum[0] == partial_sum && arraySum[1] == world.Rank));
            if (world.Rank == 0)
            {
                System.Console.WriteLine(" done.");
            }

            // Test concatenation of strings
            if (world.Rank == 0)
            {
                System.Console.Write("Testing exclusive scan of strings...");
            }
            string str         = world.ExclusiveScan(world.Rank.ToString(), Operation <string> .Add);
            string expectedStr = null;
            if (world.Rank != 0)
            {
                expectedStr = "";
                for (int p = 0; p < world.Rank; ++p)
                {
                    expectedStr += p.ToString();
                }
            }
            MPIDebug.Assert(expectedStr == str);

            if (world.Rank == 0)
            {
                System.Console.WriteLine(" done.");
            }

            // Test concatenation of string arrays
            if (world.Rank == 0)
            {
                System.Console.Write("Testing exclusive scan of string arrays...");
            }
            string[] strArray     = world.ExclusiveScan(new string[] { world.Rank.ToString(), "World" }, Operation <string> .Add);
            string[] expectedStrs = null;
            if (world.Rank != 0)
            {
                expectedStrs = new string[2] {
                    "", ""
                };
                for (int p = 0; p < world.Rank; ++p)
                {
                    expectedStrs[0] += p.ToString();
                    expectedStrs[1] += "World";
                }
                MPIDebug.Assert(expectedStrs[0] == strArray[0]);
                MPIDebug.Assert(expectedStrs[1] == strArray[1]);
            }
            else
            {
                MPIDebug.Assert(expectedStrs == null);
            }

            if (world.Rank == 0)
            {
                System.Console.WriteLine(" done.");
            }
        }
    }