#include #include using json = nlohmann::json; using namespace nlohmann::literals; namespace ns { class person { private: std::string name = "John Doe"; std::string address = "123 Fake St"; int age = -1; public: person() = default; person(std::string name_, std::string address_, int age_) : name(std::move(name_)), address(std::move(address_)), age(age_) {} friend void to_json(nlohmann::json& nlohmann_json_j, const person& nlohmann_json_t) { nlohmann_json_j["name"] = nlohmann_json_t.name; nlohmann_json_j["address"] = nlohmann_json_t.address; nlohmann_json_j["age"] = nlohmann_json_t.age; } friend void from_json(const nlohmann::json& nlohmann_json_j, person& nlohmann_json_t) { nlohmann_json_t.name = nlohmann_json_j.at("name"); nlohmann_json_t.address = nlohmann_json_j.at("address"); nlohmann_json_t.age = nlohmann_json_j.at("age"); } }; } // namespace ns int main() { ns::person p = {"Ned Flanders", "744 Evergreen Terrace", 60}; // serialization: person -> json json j = p; std::cout << "serialization: " << j << std::endl; // deserialization: json -> person json j2 = R"({"address": "742 Evergreen Terrace", "age": 40, "name": "Homer Simpson"})"_json; auto p2 = j2.template get(); // incomplete deserialization: json j3 = R"({"address": "742 Evergreen Terrace", "name": "Maggie Simpson"})"_json; try { auto p3 = j3.template get(); } catch (json::exception& e) { std::cout << "deserialization failed: " << e.what() << std::endl; } }