c++boostboost-uuidcereal

How to serialize a boost::uuid with cereal


Trying to serialize this simple class:

class Data
{
public:
    Data();
    Data(boost::uuids::uuid id);

    Data(const Data&) = delete;
    Data& operator=(const Data&) = delete;

    inline boost::uuids::uuid getGuid() { return guid; }

    template <class Archive>
    void serialize(Archive & ar)
    {
        ar(guid);
    }

private:
    boost::uuids::uuid guid;
};

But I get this error message

error C2338: Trying to serialize an unserializable type with an output archive. 

Poiting to the uuid. The boost serialization way to enable this would be to add

#include <boost/uuid/uuid_serialize.hpp>

but this doesn't work for cereal out of the box. Cereal documentation says

cereal archives operate on either an std::ostream or std::istream object.

so I tried adding the header where there are defined but no luck

#include <boost/uuid/uuid_io.hpp>

Solution

  • This worked with cereal JSON archives. I also included in comment a way to do it for a binary archive.

    #ifndef CEREAL_TYPES_BOOST_UUID_
    #define CEREAL_TYPES_BOOST_UUID_
    
    #include <boost/uuid/uuid.hpp>
    #include <boost/uuid/uuid_io.hpp>
    #include <boost/lexical_cast.hpp>
    
    namespace cereal
    {
        template <class Archive> inline
            void save(Archive& ar, boost::uuids::uuid const& uuid)
        {
            std::string val = boost::lexical_cast<std::string>(uuid);
    
            ar(val);
    
            // Other approach, probably better for binary
            //ar(make_size_tag(static_cast<size_type>(uuid.size())));
            //for (auto it = uuid.begin(), end = uuid.end(); it != end; ++it)
            //  ar(*it);
        }
    
        template <class Archive> inline
            void load(Archive& ar, boost::uuids::uuid& uuid)
        {
            std::string val;
    
            ar(val);
            uuid = boost::lexical_cast<boost::uuids::uuid>(val);
    
            // Other approach, probably better for binary
            //size_type size;
            //ar(make_size_tag(size));
    
            //for (auto it = uuid.begin(), end = uuid.end(); it != end; ++it) {
            //  uint8_t val;
            //  ar(val);
            //  *it = val;
            //}
        }
    } // namespace cereal
    
    #endif // CEREAL_TYPES_BOOST_UUID_