Thx for replying. 
In C++, it is easy to create an FSM State class, but it seems there is no way to create a FSM class in C++. My project is mostly implemented by C++, so, it is a little complicated for me to use GC FSM in C++. But GC FSM is doing really good at Buleprints. Try to create a GC FSM in C++ is rare, so this may not be really needed.
An other suggestion, I can’t found the GC FSM C++ API reference docment. I try to read the head file to get the API’s Description. So, if GC FSM can provide the C++ API’s reference and Example Project, that will be perfect.
Final one is, Can GC FSM support “Any State”? Just like the FSM in Unity3D, For example, I made a FSM, it had many states, in every state, if it triggered by event “Cast Spell Failed”, it will trans to the “Idle” state, It’s trouble to add one same event to all the states. So, if FSM support “Any State”, It would be a greate help.
Thx for reading.