It used to be "iterator", causing a qdoc warning:
src/corelib/serialization/qjsonobject.cpp:1405: (qdoc) warning: clang found diagnostics parsing \fn int QJsonObject::const_iterator::operator-(const_iterator other) const
error: out-of-line definition of 'operator-' does not match any declaration in 'QJsonObject::const_iterator'
Add a small test.
Change-Id: Id65effffa720ed1e0fb0ee6937dcc4298f3ef363
Reviewed-by: Lars Knoll <lars.knoll@qt.io>