and you're now able to use all the commands. There's only a small number of major functions in the Wire library, which is handy if you're getting started with Arduino. Below are some of the most ...

A good case in point is [Mirko’s] all band radio which you can see ... The radio takes serial (I2C) commands, and the Arduino converts the user interface so that you can control it.

Although Arduino's programming language is based on C++, you won't be able to use all of its commands. But, you can still use objects in Arduino's IDE, which are a fundamental aspect of C++.