(gdb) p *iface
$4 = {revision = 0, alignment = 4, size = 16, flags = 7, typeId = {_q_value = std::atomic<int> = { 4099 }}, metaObjectFn = 0x0, 
  name = 0x7ffff3c666f4 <QMetaTypeId2<QColor>::nameAsArray> "QColor", 
  defaultCtr = 0x7ffff3c4f040 <QtPrivate::QMetaTypeForType<QColor>::getDefaultCtr()::{lambda(QtPrivate::QMetaTypeInterface const*, void*)#1}::_FUN(QtPrivate::QMetaTypeInterface const*, void*)>, 
  copyCtr = 0x7ffff3c4f060 <QtPrivate::QMetaTypeForType<QColor>::getCopyCtr()::{lambda(QtPrivate::QMetaTypeInterface const*, void*, void const*)#1}::_FUN(QtPrivate::QMetaTypeInterface const*, void*, void const*)>, 
  moveCtr = 0x7ffff3c4f070 <QtPrivate::QMetaTypeForType<QColor>::getMoveCtr()::{lambda(QtPrivate::QMetaTypeInterface const*, void*, void*)#1}::_FUN(QtPrivate::QMetaTypeInterface const*, void*, void*)>, dtor = 0x0, 
  equals = 0x7ffff3c4f120 <QtPrivate::QEqualityOperatorForType<QColor, true>::equals(QtPrivate::QMetaTypeInterface const*, void const*, void const*)>, lessThan = 0x0, 
  debugStream = 0x7ffff3c4f0b0 <QtPrivate::QDebugStreamOperatorForType<QColor, true>::debugStream(QtPrivate::QMetaTypeInterface const*, QDebug&, void const*)>, 
  dataStreamOut = 0x7ffff3c4f0a0 <QtPrivate::QDataStreamOperatorForType<QColor, true>::dataStreamOut(QtPrivate::QMetaTypeInterface const*, QDataStream&, void const*)>, 
  dataStreamIn = 0x7ffff3c4f090 <QtPrivate::QDataStreamOperatorForType<QColor, true>::dataStreamIn(QtPrivate::QMetaTypeInterface const*, QDataStream&, void*)>, legacyRegisterOp = 0x0}