AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QModelIndex: improve qHash

Browse Source 
QModelIndex's qHash is really bad. It was retained from Qt 5, but ends
up producing poor results in large hashes.

This can't be fixed in Qt 6.

Task-number: QTBUG-113613
Change-Id: I5f7f427ded124479baa6fffd175f7810e1dc2580
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
This commit is contained in:
Thiago Macieira 2023-05-15 17:26:39 -07:00
parent e1c3083dad
commit 9cef9df822
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/corelib/itemmodels/qabstractitemmodel.h
View File

@ -499,7 +499,13 @@ inline Qt::ItemFlags QModelIndex::flags() const
{ return m ? m->flags(*this) : Qt::ItemFlags(); }
inline size_t qHash(const QModelIndex &index, size_t seed = 0) noexcept
{ return size_t((size_t(index.row()) << 4) + size_t(index.column()) + index.internalId()) ^ seed; }
{
#if QT_VERSION >= QT_VERSION_CHECK(7, 0, 0)
return qHashMulti(seed, index.row(), index.column(), index.internalId());
#else
return size_t((size_t(index.row()) << 4) + size_t(index.column()) + index.internalId()) ^ seed;
#endif
}
QT_END_NAMESPACE