Why is flush() in Stream and not in Print?

[JAndrassy]

Why is in Stream.h virtual void flush() = 0;?
flush() is output related and should be in Print as it is in AVR core.

[matthijskooijman]

Hm, it surprises me that it is. In the AVR and SAM cores, this method was moved to Print a long time ago: arduino/Arduino#2387

I wonder what version this API was based on, or if it was maybe moved back for some reason?

[PaulStoffregen]

This repository also seem to still pre-date the addition of availableForWrite(), which has been a part of the core library for a very long time. I mentioned this ~4 years ago. #64 (comment) Maybe it should be its own issue? But frankly, I've having a hard time taking this repository seriously. :(

[JAndrassy]

This repository also seem to still pre-date the addition of availableForWrite(), which has been a part of the core library for a very long time. I mentioned this ~4 years ago. #64 (comment) Maybe it should be its own issue? But frankly, I've having a hard time taking this repository seriously. :(

but it is used in megaavr core and in mbed core

[bxparks]

It is even more confusing that:

• the ESP32 core defines flush() in its Stream.h, while
• the ESP8266 core defines flush() in its Print.h.

I had to use #if conditional macros to create code that worked across AVR, ESP8266, ESP32, etc. I would have thought that something as fundamental as Print would have a consistent API across all the Arduino platforms.

[JAndrassy]

It is even more confusing that:

* the ESP32 core defines `flush()` in its [Stream.h](https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/Stream.h#L51), while

* the ESP8266 core defines `flush()` in its [Print.h](https://github.com/esp8266/Arduino/blob/master/cores/esp8266/Print.h#L103).

I had to use #if conditional macros to create code that worked across AVR, ESP8266, ESP32, etc. I would have thought that something as fundamental as Print would have a consistent API across all the Arduino platforms.

espressif/arduino-esp32#943

[JAndrassy]

and in the namespace arduino branch for mbed core?

[facchinm]

I'm rebasing it there too