Equivalent of pybind11's dynamic_attr: desired?

[inducer]

In putting together inducer/pyopencl#546, I find that I'm lacking pybind11's dynamic_attr. I've taken a look around, and it doesn't seem like it'd be tricky to add. I'd be happy to give that a shot, unless that's one of the actively undesired features of pybind11---please let me know. Also, if there are any un-obvious gotchas to look out for, I'd be happy to know about them.

[wjakob]

Yes, this is currently missing. It should be relatively easy to add - you'll need to add dynamic_attr to nb_attr.h) allocate an extra flag in type_flags (nb_class.h) and then handle it in nb_type_new (nb_type.cpp)

[inducer]

#22