.. _program_listing_file_dx2_beam_io.cxx:

Program Listing for File beam_io.cxx
====================================

|exhale_lsh| :ref:`Return to documentation for file <file_dx2_beam_io.cxx>` (``dx2/beam_io.cxx``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   
   #include <dx2/beam_io.hpp>
   
   namespace beam_io {
   
   json to_json(const Beam &beam) {
     return std::visit([](const auto &b) { return b.to_json(); }, beam);
   }
   
   Beam from_json(const json &beam_data) {
     std::string type = beam_data["__id__"];
   
     if (type == "monochromatic") {
       return MonochromaticBeam(beam_data);
     } else if (type == "polychromatic") {
       return PolychromaticBeam(beam_data);
     } else {
       throw std::runtime_error("Unknown beam id: " + type);
     }
   }
   
   } // namespace beam_io