Chunks

typedef void(*FileChunkCaseFunc)(od::StreamData&);
template<unsigned Magic, FileChunkCaseFunc Func>
struct FileChunkCase
{
    static constexpr std::pair<unsigned, FileChunkCaseFunc> pair = std::make_pair(Magic, Func);
};

template<class...Args>
class FileChunkReader
{
public:
    void operator()(od::StreamData & s);
};

template<class...Args>
void FileChunkReader<Args...>::operator()(od::StreamData & s)
{
    unsigned chunk, len;
    do
    {
        s >> chunk >> len;

        for(auto& pair: {Args::pair...})
        {
            if(pair.first == chunk) {
                pair.second(s);
                break;
            }
        }

        s.seek(len-4, od::StreamData::Cursor);
    }
    while(!s.eof());
}

void readBiom(od::StreamData & s)
{
    printf("Biom\n");
}
void readBloc(od::StreamData & s)
{
    printf("Bloc\n");
}

void SerializeWorld::load(const std::string & fname)
{
    od::StreamData s;
    s.load(fname);

    FileChunkReader<
        FileChunkCase<stringMagic("BIOM"), readBiom>,
        FileChunkCase<stringMagic("BLOC"), readBloc>
    >()(s);
}