Direct calls to member functions

[RiccardoRossi]

Dear Developers,
we have a code with a large python api and lots of classes exposed to python.

and we would like to speed up ( a lot) codes of the type

for elem in Elements:
     LHS = elem.Calculate()

where elem, Elements and elem.Calculate() are all exposed from c++

we would like to do something on the line of

vectorizer(Container& Elements, std::function<return_type()> func)
       return_type .ret .. //here allocated correctly
       std::for_each(std::execution::part, Elements.begin(), Elements.end(), [](auto& it{
          ret[i] = it.Calculate(); //admittedly pseudo code
      }

we need this for perfomance so

1. we need to avoid overheads in func
2. we need to be threadsafe
3. we would need the performance to be the same as wrapping the entire function in a "ParallelizedFunc"

is there any way of achieving this with the current versions of pybind?
thank you in advance for any hint