Make it working with modern gcc

[dwrobel]

• fixes lack of overrides keyword and correct wrong prototypes (caused compilation errors),
• removes size_t SoftwareWire::write(char* data) as it caused compilation errors.

[Koepel]

The goal is not to be modern, but to be a drop-in replacement for the Arduino Wire library.

I see that the function parameters of Arduino Wire library for the AVR microcontrollers differs from SoftwareWire. Some changes might be needed, but I'm not sure about the "override" keyword. I rather add the inline functions from the Arduino Wire.h file. I agree that the write(char* data) has to go.

Arduino AVR Wire library: https://github.com/arduino/ArduinoCore-avr/tree/master/libraries/Wire/src

[dwrobel]

The goal is not to be modern, but to be a drop-in replacement for the Arduino Wire library.

FYI, I'm using it as a replacement of Wire for Adafruit-MCP23017-Arduino-Library (see: https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library/pull/26).

I'm not sure about the "override" keyword.

Basically it's a must if you intent to correctly override a virtual method, if you omit it, you can simply end up creating a new method instead of overwriting the existing one (see example here: https://github.com/Testato/SoftwareWire/pull/20/files#diff-aa9086e443c0537f539acb314ad36cfeR326).

[Koepel]

Let's wait a few days for Testato.

The Arduino AVR Wire library and the Arduino SAMD Wire library use virtual. So I prefer to use virtual and add also the extra inline functions. Your changes adds override, that could make the SoftwareWire behave different from the Arduino Wire library.

If you use the official Arduino Wire library with the modified Adafruit library, will a new method be created? Perhaps Adafruit and/or Arduino has to fix that to prevent it. Then we can follow.

[Testato]

Override seems that do not change the behavior of the method, so if can compile with arduino official ide and confirm that there is no problem, for me this PR is acceptable

[Koepel]

Okay. Testato, I leave it up to you if the version should be increased.

dwrobel, thank you for your contribution to this library.

[Testato]

Thanks @dwrobel