The approach in RCC++ is somewhat different from what I'm aware other teams have used in the past, as rather than simply allowing shared libraries (DLLs on Windows) to be reloaded dynamically RCC++ detects changes in files and compiles the minimal set of source files needed into a shared library then links this in. This gives a quicker turn around at the cost of some developer effort in code markup using macros.
Having instant reload of shared libraries isn't that simple, it's already the same job of having interfaces/macros and lot of tricky stuff... Depends if this is just some plugin system with init/exit method (as standard plugin systems) or full Objects creation/refresh handling (which is what "Runtime C++" means) I guess. Thats not the same, sure you know it, but I wanted to make it clear for others.
. Having full source files change detection is nice, but you loose IDE ability to have output/error reporting (double click to go to the error), not sure about debugging abilities, if some part is failing, what happens?
. Automatically separate the whole project in libs: I thought about it as well, but in Coffee's component based system it makes no point, it's already clearly separated. Rebuilding a simple component takes 1s, and build system already figure out which files need to be rebuilt.
. Coffee already have assets changes detection, that's why I may have extended it to source files as well, but I choose to only take built DLLs into account for the upper reasons.
RCC++ is a nice idea, but it seems hard to integrate it into an existing engine (with the usual existing custom build system, reflection and so on...), but for starting a new project from scratch it seriously looks like a great idea.
But, indeed, that's the future and some nice reason to stick to only one langage for the whole thing...