[Interest] Qt3DRender::QBuffer::dataGenerator() deprecated with no explanation?

[Nyall Dawson]

Hi list,

Building my project on Qt 5.15 ends with a handful of deprecation
warnings coming from Qt3DRender::QBuffer::dataGenerator() and
setDataGenerator():

warning: ‘void Qt3DRender::QBuffer::setDataGenerator(const
QBufferDataGeneratorPtr&)’ is deprecated [-Wdeprecated-declarations]
...
/usr/include/qt5/Qt3DRender/qbuffer.h:110:30: note: declared here
110 | Q3D_DECL_DEPRECATED void setDataGenerator(const
QBufferDataGeneratorPtr &functor);

But there's absolutely no hints anywhere on what to replace this with
-- even the QBuffer docs don't flag these members as obsolete! (see
https://doc.qt.io/qt-5/qt3drender-qbuffer.html#dataGenerator)

How can I resolve these deprecation warnings?

Nyall