How to Create a reference to an External Print object

Question

Right now I have an object:

class Dog
{
 public:
 Dog(uint8_t I2c, Stream& feedback);
 void Speak();
 private:
 uint8_t _I2c;
 Stream& _output;
};
Dog::Dog(uint8_t I2c, Stream& feedback):_output(feedback),_I2c(I2c){}
Dog::Speak(){
_output.println("Hi There.");
}

That is currently constructed in my sketch via:

Dog Dug([I2cPort], Serial);

How can I modify my class so that to be compatible with taking either a Serial object or an LCD display (using Adafruit's RGB LCD library )?

Eg:

Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();
Dog Dug([I2cPort], Serial);
Dog Sam([I2cPort], lcd);

Additional info:

The LCD in question is mostly used as a UI display in its own library this library refreshes the display every 1.5 sec. As information from speak(); and the UI have similar priority, it is acceptable if one instantly overwrites the other.

I am open to solutions that involve modifying the construction of Dog the only requirement is that I need to be able to indicate print("[something]"); in the Dog.cpp

I'm interested in asking this question on the Arduino SE as I believe there are differences in how you would approach this if the problem was on a traditional computer.

• Juraj: it is not a buffer. only a reference
• ATE-ENGE: Noted, edited the question for clarity.
• Juraj: nice. now you put the answer into the questions title :-)
• ATE-ENGE: And just like that, it works. Thanks for the magic.

Answer 1

If your class is only writing to the stream you probably want to have your class take a Print object instead of a Stream object.

The Adafruit library inherits from Print.

• ATE-ENGE: That can change, I only need this line for feedback to either my COM port (Serial) or to the LCD.
• Juraj: both are derived from Print class. arduino.stackexchange.com/questions/52563/…