That is, insert() doesn't overwrite an existing entry, and range
insert inserts the first of equivalent keys' values, not the last.
This allowed this author to optimize the implementation of
makeUnique() to a O(N) algorithm (was: O(N²)). Said optimization would
have been possible with the old semantics, too, but I wrote the
algorithm first and only then noticed the broken insert() behavior is
present on QFlatMap, too, so I decided not to let good code go to
waste and to fix both problems at the same time.
In order to give users a hint of the changed semantics, make the new
API opt-in until Qt 6.5, so Qt 6.4 ships with the both the old and the
new semantics disabled, where they contradict.
Fixes: QTBUG-100092
Change-Id: Ic96d8bfe6bed9068dbe8c0d7171bd8921050fd95
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
1977c922e9