Как получить перечисление от?boost::property_tree

Это мое "нерабочий" пример.

config.xml

  EMISSION::EMIT1
  42

main.cpp

#include 
#include 
#include 

int main()
{
  enum class EMISSION { EMIT1, EMIT2 } ;
  enum EMISSION myEmission;

  //Initialize the XML file into property_tree
  boost::property_tree::ptree pt;
  read_xml("config.xml", pt);

  //test enum (SUCCESS)
  myEmission = EMISSION::EMIT1;
  std::cout < (myEmission == EMISSION::EMIT1) < "\n";

  //test basic ptree interpreting capability (SUCCESS)
  const double fooDouble = pt.get