SfxItemSet shows up in perf profiles frequently,
and the hottest part is the malloc of the two arrays we need.
But most of the time, one of those arrays is a compile-time
constant.
So this change introduces
(*) WhichRangesContainer, which manages whether the SfxItemSet
owns the array it points at or not.
(*) a static const member in svl::Items (idea from mkaganski)
to store the data.
Change-Id: Icb8cdbc4d54fd76739565c575e16a744515e5355
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/118703
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
5d0a231b29