I would really like to hear your opinion about the problems of FRP (for GUIs, in case there are other popular uses). I use C++ and QML, a "declarative" (it's a

I would really like to hear your opinion about the problems of FRP (for GUIs, in case there are other popular uses). I use C++ and QML, a "declarative" (it's a somewhat fuzzy concept) language, for GUI programming daily. I have a bunch of techniques in C++ to tame mutable state, including use of a quasi-functional style where possible. More... "functionality" seems like a good idea in general, hence my curiosity what doesn't work.