ardupilot/libraries/AP_HAL_PX4/AP_HAL_PX4_Namespace.h

#pragma once

namespace PX4 {
    class PX4Scheduler;
    class PX4UARTDriver;
    class PX4Storage;
    class PX4RCInput;
    class PX4RCOutput;
    class PX4AnalogIn;
    class PX4AnalogSource;
    class PX4Util;
    class PX4GPIO;
    class PX4DigitalSource;
    class NSHShellStream;
    class PX4I2CDriver;
    class PX4_I2C;
    class Semaphore;
}