76 struct contact  struct
80     contact() : m_person(), m_address() {}  in contact()  function
81     contact(const person& p, const address& a) : m_person(p), m_address(a) {}  in contact()  argument
87     std::vector<contact> m_contacts;
89     contact_book(const name& n, const std::vector<contact>& c) : m_book_name(n), m_contacts(c) {}  in contact_book()
139 static void to_json(nlohmann::json& j, const contact& c)  in to_json()
170 static bool operator==(const contact& lhs, const contact& rhs)  in operator ==()
227 static void from_json(const nlohmann::json& j, contact& c)  in from_json()
236     cb.m_contacts = j["contacts"].get<std::vector<contact>>();  in from_json()
253     const udt::contact cpp_programmer{sfinae_addict, addr};
281                 big_json["contacts"].get<std::vector<udt::contact>>();
283             const auto contact = contact_json.get<udt::contact>();  variable
296             CHECK(contact == cpp_programmer);
320             const std::vector<udt::contact> contacts = big_json["contacts"];
322             const udt::contact contact = contact_json;  variable
334             CHECK(contact == cpp_programmer);