Well, this is quite a simple solution to implement yourself as to why there isn’t a built in one I guess. At least make the thing a map of cocos2d::EventKeyboard::KeyCode and bool so you can actualy look up what keys are pressed if you need to.
For reference (as this is “code-sharing”) I have a similar solution built inside my CCX library that you can just attach to any node and capture any keyboard events. You can find it in the input section.