Function mpi::ffi::MPI_Win_create_keyval

pub unsafe extern fn MPI_Win_create_keyval(win_copy_attr_fn: MPI_Win_copy_attr_function,
                                           win_delete_attr_fn: MPI_Win_delete_attr_function,
                                           win_keyval: *mut c_int,
                                           extra_state: *mut c_void)
                                           -> c_int