Chief Delphi - Cannot allocate an object of type 'Command'

Guys,

I think I understand why this is throwing an error, but I am looking for the correct way to do this. In Brad Miller's last Robot Builder video on youtube he writes the following java code:

Code:

autonomousCommand = (Command) autonomousModes->GetSelected();

Unfortunately, if you write the same code in C++ you get the following error:

C:/WindRiver/workspace/TestProject/Robot.cpp: In member function `virtual void Robot::AutonomousInit()':
C:/WindRiver/workspace/TestProject/Robot.cpp:40: error: cannot allocate an object of type `Command'
C:/WindRiver/workspace/TestProject/Robot.cpp:40: error: because the following virtual functions are abstract:
C:/WindRiver/vxworks-6.3/target/h/WPILib/Commands/Command.h:79: error: virtual void Command::Initialize()
C:/WindRiver/vxworks-6.3/target/h/WPILib/Commands/Command.h:84: error: virtual void Command::Execute()
C:/WindRiver/vxworks-6.3/target/h/WPILib/Commands/Command.h:95: error: virtual bool Command::IsFinished()
C:/WindRiver/vxworks-6.3/target/h/WPILib/Commands/Command.h:101: error: virtual void Command::End()
C:/WindRiver/vxworks-6.3/target/h/WPILib/Commands/Command.h:114: error: virtual void Command::Interrupted()
C:\WindRiver\vxworks-6.3\host\x86-win32\bin\make.exe: *** [CommandBasedRobotTemplate/Debug/Objects/TestProject/Robot.o] Error 1

The idea is to cast to the "Command" type in order to be able to set autonomousCommand equal to the output of a SelectableChooser object (which is set by the user clicking on the desired command on the Smartdashboard) - which is then the command that gets run in autonomous.

Any thoughts? Thanks in advance.

- Bryce

P.S. Here's the complete code in Robot.cpp

Code:

void Robot::RobotInit() {

        RobotMap::init();

        // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS

        driveTrain = new DriveTrain();

        elevator = new Elevator();

        wrist = new Wrist();

        claw = new Claw();

    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=CONSTRUCTORS

        // This MUST be here. If the OI creates Commands (which it very likely

        // will), constructing it during the construction of CommandBase (from

        // which commands extend), subsystems are not guaranteed to be

        // yet. Thus, their requires() statements may grab null pointers. Bad

        // news. Don't move it.

        oi = new OI();

        lw = LiveWindow::GetInstance();

        // instantiate the command used for the autonomous period

        autonomousModes = new SendableChooser();

        autonomousModes->AddDefault("Deliver Cylinder", new DeliverCylinder());

        autonomousModes->AddObject("Awesome Autonomous", new AutonomousCommand());

        smartDashboard->PutData("Autonomous Modes", autonomousModes);

  }

        

void Robot::AutonomousInit() {

        autonomousCommand = (Command) autonomousModes->GetSelected();

        if (autonomousCommand != NULL) autonomousCommand->Start();

        

}