I am very glad to see something like this is finally reaching mainstream consciousness. Not being able to do this on Linux (and it unfortunately looks like this is also Windows only) has been a major source of frustration for me when writing C++, especially given that something like it (edit and continue) has been available in Visual C++ for near on 20 years.
I would really like to make Live++ available for Linux one day - it's been asked for a few times already.