Just a little clarification...
As Behnaz said, after you handle the file extensions thing, compiling should be fine as GCC supports C++.
And programming should be no problem, because the source language makes no difference for programming. (it's just data in the end)
However, you should expect problems during debugging: watching classes, class variables, following execution path during exceptions try/catch/throw, etc. are not validated yet. (and maybe not implemented) For this reason Ride does not officially support C++ for now. We plan to correct this but we have no date to announce.