qdebug.h includes many Qt and STL headers, so if you include a Qt header you get all those transitive includes, which may affect build time. - Where appropriate use the printf-like syntax of qDebug() and co., these don't need the QDebug streaming operators - qfloat16 is used in an inline member function, so include it explicitly [ChangeLog][Potentially Source Incompatible Changes] Various Qt public headers don't include QDebug any more; if you need QDebug's streaming you'll have to include it in your code. Task-number: QTBUG-132439 Pick-to: 6.9 Change-Id: I750587e17a3b38fa226cd3af8eaccc8da580f436 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>