Undefined References

Hi,

I am trying to compile C++ code based on the example code "i2c_without_internal_address.c"

However I keep getting erros when compiling such as: 

```
undefined reference to `i2c_open'
undefined reference to `i2c_ioctl_write'
undefined reference to `i2c_close'
```

Is ther a proper way to compile perhaps? I'm using g++  my_code.cpp -o output