| #include <iostream> |
| #include <nlohmann/json.hpp> |
| |
| using json = nlohmann::json; |
| |
| namespace ns |
| { |
| // a simple struct to model a person (not default constructible) |
| struct person |
| { |
| person(std::string n, std::string a, int aa) |
| : name(std::move(n)), address(std::move(a)), age(aa) |
| {} |
| |
| std::string name; |
| std::string address; |
| int age; |
| }; |
| } // namespace ns |
| |
| namespace nlohmann |
| { |
| template <> |
| struct adl_serializer<ns::person> |
| { |
| static ns::person from_json(const json& j) |
| { |
| return {j.at("name"), j.at("address"), j.at("age")}; |
| } |
| |
| // Here's the catch! You must provide a to_json method! Otherwise, you |
| // will not be able to convert person to json, since you fully |
| // specialized adl_serializer on that type |
| static void to_json(json& j, ns::person p) |
| { |
| j["name"] = p.name; |
| j["address"] = p.address; |
| j["age"] = p.age; |
| } |
| }; |
| } // namespace nlohmann |
| |
| int main() |
| { |
| json j; |
| j["name"] = "Ned Flanders"; |
| j["address"] = "744 Evergreen Terrace"; |
| j["age"] = 60; |
| |
| auto p = j.template get<ns::person>(); |
| |
| std::cout << p.name << " (" << p.age << ") lives in " << p.address << std::endl; |
| } |