Using Pybind11 to wrap NESTKernel

[med-ayssar]

Is your feature request related to a problem? Please describe.

• PyNEST uses the SLIEngine API to communicate with the C++ code, and removing this intermediate interface might have huge consquences for the interface design between C++ and Python.
• For each exported class from C++ to Python, a Wrapper class in required to encapsulate the C++ implemention and redirect to the correct function, and sli_pop, sli_push and sli_run, all those help functions must be replaced and might require alot of efforts.

Describe the solution you'd like
Pybind: provides an interesting interface to handle the binding between both languages, without to manually implement a Wrapper for the export class.

Example

From the Pybind documentation

#include <pybind11/pybind11.h>

namespace py = pybind11;

struct Pet {
    Pet(const std::string &name) : name(name) { }
    void setName(const std::string &name_) { name = name_; }
    const std::string &getName() const { return name; }

    std::string name;
};

PYBIND11_MODULE(example, m) {
    py::class_<Pet>(m, "Pet")
        .def(py::init<const std::string &>())
        .def("setName", &Pet::setName)
        .def("getName", &Pet::getName);
}

Just like that, we will have the Pet class also available in python in the exmaple module.

import example
p = example.Pet("RandomName")