arangodb/3rdParty/boost/1.61.0/libs/parameter/test/literate/defining-the-keywords1.cpp

#include <boost/parameter/keyword.hpp>
namespace graphs
{
  namespace tag { struct graph; } // keyword tag type

  namespace // unnamed
  {
    // A reference to the keyword object
    boost::parameter::keyword<tag::graph>& _graph
    = boost::parameter::keyword<tag::graph>::get();
  }
}