raw_constructor.hpp

#ifndef RAW_CONSTRUCTOR_HPP
#define RAW_CONSTRUCTOR_HPP

#include <memory>
#include <functional>
#include <initializer_list>

#include <patchlevel.h>
#include <boost/version.hpp>
#pragma GCC diagnostic push
#if PY_VERSION_HEX < 0x030400A2
#pragma GCC diagnostic ignored "-Wregister"
#endif
#if PY_VERSION_HEX >= 0x03090000 && BOOST_VERSION < 107500
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
#include "boost/python.hpp"
#include "boost/python/detail/api_placeholder.hpp"
#pragma GCC diagnostic pop

namespace boost { namespace python {

namespace detail {

  template <class F>
  struct raw_constructor_dispatcher
  {
      raw_constructor_dispatcher(F f)
     : f(make_constructor(f)) {}

      PyObject* operator()(PyObject* args, PyObject* keywords)
      {
          borrowed_reference_t* ra = borrowed_reference(args);
          object a(ra);
          return incref(
              object(
                  f(
                      object(a[0])
                    , object(a.slice(1, len(a)))
                    , keywords ? dict(borrowed_reference(keywords)) : dict()
                  )
              ).ptr()
          );
      }

   private:
      object f;
  };

} // namespace detail

template <class F>
object raw_constructor(F f, std::size_t min_args = 0)
{
    return detail::make_raw_function(
        objects::py_function(
            detail::raw_constructor_dispatcher<F>(f)
          , mpl::vector2<void, object>()
          , min_args+1
          , (std::numeric_limits<unsigned>::max)()
        )
    );
}

}} // namespace boost::python

#endif //RAW_CONSTRUCTOR_HPP