inline bool operator==(const OfferID& left, const std::string& right) { return left.value() == right; }
inline bool operator<(const OfferID& left, const OfferID& right) { return left.value() < right.value(); }
inline std::size_t hash_value(const OfferID& offerId) { size_t seed = 0; boost::hash_combine(seed, offerId.value()); return seed; }