Robotbuilder c++ code dies in Test Mode

[Joe Ross]

I've duplicated this. It has to do with the way the SpeedController object is cast to the

Here's the code that causes the crash:

lw->AddActuator("Subsystem 1", "Speed Controller 1", (Talon&)subsystem1SpeedController1);

Here's code that works:

lw->AddActuator("Subsystem 1", "Speed Controller 1", std::static_pointer_cast<Talon>(subsystem1SpeedController1));

I'm not a C++ guru, so I'm not sure if that's the right method to cast the shared_pointer from a SpeedController to Talon or other class that implements a SpeedController.

[calcmogul]

Originally Posted by Joe Ross

Here's code that works:

lw->AddActuator("Subsystem 1", "Speed Controller 1",  std::static_pointer_cast<Talon>(subsystem1SpeedController1));

I'm not a C++ guru, so I'm not sure if that's the right method to cast the shared_pointer from a SpeedController to Talon or other class that implements a SpeedController.

I think std::static_pointer_cast will work here. The type is definitely a Talon, so std::dynamic_pointer_cast isn't necessary. Note that the pointer passed in can't be that of a stack allocated object or a double-free would occur later.

Originally Posted by Joe Ross

Here's the code that causes the crash:

lw->AddActuator("Subsystem 1", "Speed Controller 1",  (Talon&)subsystem1SpeedController1);

Is subsystem1SpeedController1 an object or pointer to an object? If the suggested code is correct, then subsystem1SpeedController1 is a pointer and casting to Talon& seems strange to me anyway.

[Joe Ross]

Originally Posted by mathmogul

Is subsystem1SpeedController1 an object or pointer to an object? If the suggested code is correct, then subsystem1SpeedController1 is a pointer and casting to Talon& seems strange to me anyway.

Here's the full code as RobotBuilder generated (minus the comments)

#include "RobotMap.h"
#include "LiveWindow/LiveWindow.h"

std::shared_ptr<SpeedController> RobotMap::subsystem1SpeedController1;
void RobotMap::init() {

    LiveWindow *lw = LiveWindow::GetInstance();

    subsystem1SpeedController1.reset(new Talon(0));
    lw->AddActuator("Subsystem 1", "Speed Controller 1", (Talon&) subsystem1SpeedController1);
}

[rod@3711]

Thanks, that worked for me.