.. _env_drcf_version:

1.3.2 DRCF Version Compatibility
--------------------------------

The DRFL headers require C++11 or later and cannot be compiled as C. To use DRFL from C, write a small C++ wrapper with ``extern "C"`` functions. The underscore-prefixed functions take a handle: the TCP functions use the handle from _CreateRobotControl (released with _DestroyRobotControl), and the RT functions use the handle from _create_robot_control_udp (released with _destroy_robot_control_udp). CDRFLEx creates both handles.

Some functions may have different interface usage depending on the controller version. 
Set **DRCF_VERSION** to 2 or 3 according to the controller version. DRCF_VERSION must have the same value in every source file that includes the DRFL header. Set it once for the whole project as a compiler definition (for example ``-DDRCF_VERSION=2`` or ``target_compile_definitions(<target> PRIVATE DRCF_VERSION=2)``) rather than with ``#define`` in individual files. If DRCF_VERSION is not defined, DRFLEx.h uses 3.

.. code-block:: cpp
   :linenos:
   :caption: Example of including and initializing DRFLEx in C++

   // DRCF_VERSION is set as a compiler definition, for example -DDRCF_VERSION=3
   #include "../../include/DRFLEx.h"
   #include "util.hpp"

   const std::string IP_ADDRESS = "192.168.137.100";

   using namespace DRAFramework;
   CDRFLEx robot;

   bool g_bHasControlAuthority = FALSE;
   bool g_TpInitailizingComplted = FALSE;
   bool control_authority_granted = FALSE;