[LAD] Jack API c++ example/tutorial?

Old dog here; trying to learn a new trick. I've found QProcess in Qt5 very useful and Qt Creator helps by immediately complaining about my mistakes. I found a line in QJackCtl like '#include <jack/jack.h>' and was surprised there were no complaints when I pasted it in. 'locate jack.h' found these two, amongst many others, in a familiar folder and it all begins to make sense: /usr/include/jack/jack.h /usr/include/jack/weakjack.h I've used 'jack_transport' via QProcess successfully, but I feel like there's a giant leap in my understanding ahead and a simple basic example, or tutorial, would help. -- Long time ago I 'typed in' a whole 1kB on a hexadecimal keypad and got to play space invaders on my Tangerine Microtan 65 :)