74b875641f
I'm not entirely sure why function_ref_base declares its destructor. I guess it's declared in order to make it protected, because the class is non-polymorphic and inherited by function_ref, and one may want to avoid slicing. On the other hand, function_ref_base is an implementation detail, living in a `detail` namespace; so that sounds very unlikely. In any case, the class is clearly meant to be copiable, so add back (as protected) the missing special members. Pick-to: 6.9 6.8 6.5 Change-Id: Ibf909e1746e65eecf8b8990839a6e4c9eb56ca13 Reviewed-by: Marc Mutz <marc.mutz@qt.io>