> On 17 May 2019, at 21:12, Giuseppe D'Angelo via Development > <development@qt-project.org> wrote: > > Il 17/05/19 16:46, Bernhard Lindner ha scritto: >>> I've done this experiment for QMap / QHash / QSet, where keeping COW at >>> the cost of an extra indirection (dptr -> [refcount + std:: class] -> >>> actual data) is more acceptable since these classes jump all over the >>> memory anyhow. Basically "it worked", still requiring a few changes >>> though, e.g. std::unordered_map iterators are forward, QHash ones are >>> bidirectional. If the SIC is acceptable, something to consider for Qt 6. >> Are there any plans/discussions how to procede with that experiment? > > It was worth a try after we discussed this possibility a couple of years ago > at QtCS. I don't know if it's still interesting to pursue.
I’ve tried the same thing and it seems possible to implement this in a more or less source compatible way. One problem with QMap/QHash is the insertMulti() functionality and the fact that hash and multi_hash are not two separate types. But that is something I would very much like to deprecate in Qt 5.15 already (by deprecating insertMulti()). Cheers, Lars _______________________________________________ Development mailing list Development@qt-project.org https://lists.qt-project.org/listinfo/development
