Instead of copying a list, sorting it just to check it's sorted, and
making a QSet out of it just to check the size is the same as that of
the list (thereby checking there were no duplicates), simply apply
adjacent_find with greater_equal. If none of the elements is ≥ their
successor, that means all elements are < their successor, and _that_
means the range is sorted and has no duplicates. q.e.d.
Pick-to: 6.6 6.5
Change-Id: Id73c674ad4e29117370e8fc6af9fdfc690a3fba9
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>