$ git grep --recurse-submodules -we Q_DECLARE_METATYPE | grep .h: | cut -d/ -f1 | uniq -c | sort -n
      1 qt5compat
      1 qtcanvas3d
      1 qtspeech
      1 qtwebview
      2 qtdoc
      2 qtlottie
      2 qtnetworkauth
      2 qtwayland*
      3 qtgamepad
      3 qtsensors
      3 qtwebchannel
      5 qtxmlpatterns
      6 qtactiveqt*
      6 qtscxml
      6 qtsystems
      7 qtmqtt
     10 qtserialbus*
     10 qtvirtualkeyboard*
     10 qtwebengine*
     11 qtpim
     12 qtmultimedia*
     13 qtcoap