(Questions live in the main forum, or the SDK/Lua sub-forum if very code specific, the Tutorials and Refs sub-forum is for completed works - as are most of the other sub-forums. I've asked the mods to move this.)
There are no events within the C++ code in the same way that events get fired for Lua to hook into, but most of the major classes have a DoTurn() method which can be added to depending on what you need to achieve. (Do a case-insensitive search for ::doturn in the .cpp files to locate these as Firaxis are inconsistent in their coding style.)