Before, it was implemented as a private no-op(!). This looks overly dangerous. The typical pattern in C++98 was to declare it private, but _not_ implement it, so one would get a linker error at least. This, OTOH, will just compile and fail to work. Picking to all active branches to ensure it's not inadvertently used. Pick-to: 6.10 6.8 6.5 Change-Id: I6c2223a605665f1f0bade488fe9794d62ee335c6 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Ivan Solovev <ivan.solovev@qt.io> Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>