29 #ifdef NDN_CXX_HAVE_STACKTRACE 
   33   if (x.value().empty())
 
   36   std::ostringstream out;
 
   37   out << 
"===== Stacktrace =====\n" 
   39       << 
"======================\n";
 
std::string to_string(const errinfo_stacktrace &x)
 
boost::error_info< struct stacktrace, boost::stacktrace::stacktrace > errinfo_stacktrace