peerplays-fc/include/fc/container/flat_fwd.hpp

#pragma once 
#include <boost/container/flat_map.hpp>
#include <boost/container/flat_set.hpp>

namespace fc {

   using boost::container::flat_map;
   using boost::container::flat_set;

   namespace raw {
       template<typename Stream, typename T>
       void pack( Stream& s, const flat_set<T>& value );
       template<typename Stream, typename T>
       void unpack( Stream& s, flat_set<T>& value );
       template<typename Stream, typename K, typename... V>
       void pack( Stream& s, const flat_map<K,V...>& value );
       template<typename Stream, typename K, typename... V>
       void unpack( Stream& s, flat_map<K,V...>& value ) ;
   } // namespace raw

} // fc