Well, I think I have all the capabilities of doing any task in C++ either in windows using Visual Studio or Linux/Unix.
My level is advance, I know advance topics like STL, Boost, Threading, Fork processes, Signals to stop process at any time, IPC, Sempahore, Socket for making distributed system.
Few major works are creating SQL type DB, application logger etc.
I am not sure what your bar to judge capability in C++ but I know OOP, Template, Forward declarations and things like that as well.