694 lines
18 KiB
C++
694 lines
18 KiB
C++
/*
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__ _____ _____ _____
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__| | __| | | | JSON for Modern C++ (test suite)
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| | |__ | | | | | | version 2.1.1
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|_____|_____|_____|_|___| https://github.com/nlohmann/json
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Licensed under the MIT License <http://opensource.org/licenses/MIT>.
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Copyright (c) 2013-2016 Niels Lohmann <http://nlohmann.me>.
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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*/
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#include "catch.hpp"
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#include "json.hpp"
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using nlohmann::json;
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#include <array>
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#include <map>
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#include <string>
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#include <memory>
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namespace udt
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{
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enum class country
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{
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china,
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france,
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russia
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};
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struct age
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{
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int m_val;
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age(int rhs = 0) : m_val(rhs) {}
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};
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struct name
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{
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std::string m_val;
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name(const std::string rhs = "") : m_val(rhs) {}
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};
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struct address
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{
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std::string m_val;
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address(const std::string rhs = "") : m_val(rhs) {}
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};
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struct person
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{
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age m_age;
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name m_name;
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country m_country;
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person() : m_age(), m_name(), m_country() {}
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person(const age& a, const name& n, const country& c) : m_age(a), m_name(n), m_country(c) {}
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};
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struct contact
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{
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person m_person;
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address m_address;
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contact() : m_person(), m_address() {}
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contact(const person& p, const address& a) : m_person(p), m_address(a) {}
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};
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struct contact_book
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{
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name m_book_name;
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std::vector<contact> m_contacts;
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contact_book() : m_book_name(), m_contacts() {}
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contact_book(const name& n, const std::vector<contact>& c) : m_book_name(n), m_contacts(c) {}
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};
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}
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// to_json methods
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namespace udt
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{
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// templates because of the custom_json tests (see below)
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template <typename BasicJsonType>
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void to_json(BasicJsonType& j, age a)
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{
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j = a.m_val;
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}
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template <typename BasicJsonType>
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void to_json(BasicJsonType& j, const name& n)
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{
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j = n.m_val;
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}
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template <typename BasicJsonType>
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void to_json(BasicJsonType& j, country c)
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{
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switch (c)
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{
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case country::china:
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j = u8"中华人民共和国";
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return;
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case country::france:
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j = "France";
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return;
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case country::russia:
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j = u8"Российская Федерация";
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return;
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}
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}
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template <typename BasicJsonType>
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void to_json(BasicJsonType& j, const person& p)
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{
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j = BasicJsonType{{"age", p.m_age}, {"name", p.m_name}, {"country", p.m_country}};
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}
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void to_json(nlohmann::json& j, const address& a)
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{
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j = a.m_val;
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}
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void to_json(nlohmann::json& j, const contact& c)
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{
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j = json{{"person", c.m_person}, {"address", c.m_address}};
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}
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void to_json(nlohmann::json& j, const contact_book& cb)
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{
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j = json{{"name", cb.m_book_name}, {"contacts", cb.m_contacts}};
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}
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// operators
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bool operator==(age lhs, age rhs)
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{
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return lhs.m_val == rhs.m_val;
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}
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bool operator==(const address& lhs, const address& rhs)
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{
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return lhs.m_val == rhs.m_val;
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}
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bool operator==(const name& lhs, const name& rhs)
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{
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return lhs.m_val == rhs.m_val;
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}
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bool operator==(const person& lhs, const person& rhs)
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{
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return std::tie(lhs.m_name, lhs.m_age) == std::tie(rhs.m_name, rhs.m_age);
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}
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bool operator==(const contact& lhs, const contact& rhs)
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{
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return std::tie(lhs.m_person, lhs.m_address) ==
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std::tie(rhs.m_person, rhs.m_address);
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}
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bool operator==(const contact_book& lhs, const contact_book& rhs)
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{
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return std::tie(lhs.m_book_name, lhs.m_contacts) ==
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std::tie(rhs.m_book_name, rhs.m_contacts);
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}
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}
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// from_json methods
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namespace udt
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{
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template <typename BasicJsonType>
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void from_json(const BasicJsonType& j, age& a)
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{
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a.m_val = j.template get<int>();
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}
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template <typename BasicJsonType>
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void from_json(const BasicJsonType& j, name& n)
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{
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n.m_val = j.template get<std::string>();
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}
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template <typename BasicJsonType>
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void from_json(const BasicJsonType& j, country& c)
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{
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const auto str = j.template get<std::string>();
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static const std::map<std::string, country> m =
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{
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{u8"中华人民共和国", country::china},
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{"France", country::france},
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{"Российская Федерация", country::russia}
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};
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const auto it = m.find(str);
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// TODO test exceptions
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c = it->second;
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}
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template <typename BasicJsonType>
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void from_json(const BasicJsonType& j, person& p)
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{
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p.m_age = j["age"].template get<age>();
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p.m_name = j["name"].template get<name>();
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p.m_country = j["country"].template get<country>();
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}
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void from_json(const nlohmann::json& j, address& a)
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{
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a.m_val = j.get<std::string>();
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}
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void from_json(const nlohmann::json& j, contact& c)
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{
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c.m_person = j["person"].get<person>();
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c.m_address = j["address"].get<address>();
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}
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void from_json(const nlohmann::json& j, contact_book& cb)
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{
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cb.m_book_name = j["name"].get<name>();
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cb.m_contacts = j["contacts"].get<std::vector<contact>>();
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}
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}
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TEST_CASE("basic usage", "[udt]")
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{
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// a bit narcissic maybe :) ?
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const udt::age a
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{
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23
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};
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const udt::name n{"theo"};
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const udt::country c{udt::country::france};
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const udt::person sfinae_addict{a, n, c};
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const udt::person senior_programmer{{42}, {u8"王芳"}, udt::country::china};
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const udt::address addr{"Paris"};
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const udt::contact cpp_programmer{sfinae_addict, addr};
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const udt::contact_book book{{"C++"}, {cpp_programmer, {senior_programmer, addr}}};
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SECTION("conversion to json via free-functions")
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{
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CHECK(json(a) == json(23));
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CHECK(json(n) == json("theo"));
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CHECK(json(c) == json("France"));
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CHECK(json(sfinae_addict) == R"({"name":"theo", "age":23, "country":"France"})"_json);
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CHECK(json("Paris") == json(addr));
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CHECK(json(cpp_programmer) ==
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R"({"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"})"_json);
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CHECK(
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json(book) ==
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u8R"({"name":"C++", "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json);
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}
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SECTION("conversion from json via free-functions")
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{
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const auto big_json =
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u8R"({"name":"C++", "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json;
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SECTION("via explicit calls to get")
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{
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const auto parsed_book = big_json.get<udt::contact_book>();
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const auto book_name = big_json["name"].get<udt::name>();
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const auto contacts =
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big_json["contacts"].get<std::vector<udt::contact>>();
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const auto contact_json = big_json["contacts"].at(0);
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const auto contact = contact_json.get<udt::contact>();
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const auto person = contact_json["person"].get<udt::person>();
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const auto address = contact_json["address"].get<udt::address>();
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const auto age = contact_json["person"]["age"].get<udt::age>();
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const auto country =
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contact_json["person"]["country"].get<udt::country>();
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const auto name = contact_json["person"]["name"].get<udt::name>();
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CHECK(age == a);
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CHECK(name == n);
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CHECK(country == c);
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CHECK(address == addr);
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CHECK(person == sfinae_addict);
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CHECK(contact == cpp_programmer);
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CHECK(contacts == book.m_contacts);
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CHECK(book_name == udt::name{"C++"});
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CHECK(book == parsed_book);
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}
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SECTION("implicit conversions")
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{
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const udt::contact_book parsed_book = big_json;
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const udt::name book_name = big_json["name"];
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const std::vector<udt::contact> contacts = big_json["contacts"];
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const auto contact_json = big_json["contacts"].at(0);
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const udt::contact contact = contact_json;
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const udt::person person = contact_json["person"];
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const udt::address address = contact_json["address"];
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const udt::age age = contact_json["person"]["age"];
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const udt::country country = contact_json["person"]["country"];
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const udt::name name = contact_json["person"]["name"];
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CHECK(age == a);
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CHECK(name == n);
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CHECK(country == c);
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CHECK(address == addr);
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CHECK(person == sfinae_addict);
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CHECK(contact == cpp_programmer);
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CHECK(contacts == book.m_contacts);
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CHECK(book_name == udt::name{"C++"});
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CHECK(book == parsed_book);
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}
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}
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}
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namespace udt
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{
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struct legacy_type
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{
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std::string number;
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legacy_type() : number() {}
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legacy_type(const std::string& n) : number(n) {}
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};
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}
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namespace nlohmann
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{
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template <typename T>
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struct adl_serializer<std::shared_ptr<T>>
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{
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static void to_json(json& j, const std::shared_ptr<T>& opt)
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{
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if (opt)
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{
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j = *opt;
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}
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else
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{
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j = nullptr;
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}
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}
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static void from_json(const json& j, std::shared_ptr<T>& opt)
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{
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if (j.is_null())
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{
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opt = nullptr;
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}
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else
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{
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opt.reset(new T(j.get<T>()));
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}
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}
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};
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template <>
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struct adl_serializer<udt::legacy_type>
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{
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static void to_json(json& j, const udt::legacy_type& l)
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{
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j = std::stoi(l.number);
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}
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static void from_json(const json& j, udt::legacy_type& l)
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{
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l.number = std::to_string(j.get<int>());
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}
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};
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}
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TEST_CASE("adl_serializer specialization", "[udt]")
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{
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SECTION("partial specialization")
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{
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SECTION("to_json")
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{
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std::shared_ptr<udt::person> optPerson;
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json j = optPerson;
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CHECK(j.is_null());
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optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia});
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j = optPerson;
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CHECK_FALSE(j.is_null());
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CHECK(j.get<udt::person>() == *optPerson);
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}
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SECTION("from_json")
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{
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auto person = udt::person{{42}, {"John Doe"}, udt::country::russia};
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json j = person;
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auto optPerson = j.get<std::shared_ptr<udt::person>>();
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REQUIRE(optPerson);
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CHECK(*optPerson == person);
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j = nullptr;
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optPerson = j.get<std::shared_ptr<udt::person>>();
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CHECK(!optPerson);
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}
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}
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SECTION("total specialization")
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{
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SECTION("to_json")
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{
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udt::legacy_type lt{"4242"};
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json j = lt;
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CHECK(j.get<int>() == 4242);
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}
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SECTION("from_json")
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{
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json j = 4242;
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auto lt = j.get<udt::legacy_type>();
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CHECK(lt.number == "4242");
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}
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}
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}
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namespace nlohmann
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{
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template <>
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struct adl_serializer<std::vector<float>>
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{
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using type = std::vector<float>;
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static void to_json(json& j, const type&)
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{
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j = "hijacked!";
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}
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static void from_json(const json&, type& opt)
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{
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opt = {42.0, 42.0, 42.0};
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}
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// preferred version
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static type from_json(const json&)
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{
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return {4.0, 5.0, 6.0};
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}
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};
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}
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TEST_CASE("even supported types can be specialized", "[udt]")
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{
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json j = std::vector<float> {1.0, 2.0, 3.0};
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CHECK(j.dump() == R"("hijacked!")");
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auto f = j.get<std::vector<float>>();
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// the single argument from_json method is preferred
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CHECK((f == std::vector<float> {4.0, 5.0, 6.0}));
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}
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namespace nlohmann
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{
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template <typename T>
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struct adl_serializer<std::unique_ptr<T>>
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{
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static void to_json(json& j, const std::unique_ptr<T>& opt)
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{
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if (opt)
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{
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j = *opt;
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}
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else
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{
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j = nullptr;
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}
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}
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// this is the overload needed for non-copyable types,
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static std::unique_ptr<T> from_json(const json& j)
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{
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if (j.is_null())
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{
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return nullptr;
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}
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else
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{
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return std::unique_ptr<T>(new T(j.get<T>()));
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}
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}
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};
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}
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TEST_CASE("Non-copyable types", "[udt]")
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{
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SECTION("to_json")
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{
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std::unique_ptr<udt::person> optPerson;
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json j = optPerson;
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CHECK(j.is_null());
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optPerson.reset(new udt::person{{42}, {"John Doe"}, udt::country::russia});
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j = optPerson;
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CHECK_FALSE(j.is_null());
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CHECK(j.get<udt::person>() == *optPerson);
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}
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SECTION("from_json")
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{
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auto person = udt::person{{42}, {"John Doe"}, udt::country::russia};
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json j = person;
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auto optPerson = j.get<std::unique_ptr<udt::person>>();
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REQUIRE(optPerson);
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CHECK(*optPerson == person);
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j = nullptr;
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optPerson = j.get<std::unique_ptr<udt::person>>();
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CHECK(!optPerson);
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}
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}
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// custom serializer - advanced usage
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// pack structs that are pod-types (but not scalar types)
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// relies on adl for any other type
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template <typename T, typename = void>
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struct pod_serializer
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{
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// use adl for non-pods, or scalar types
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template <
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typename BasicJsonType, typename U = T,
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typename std::enable_if <
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not(std::is_pod<U>::value and std::is_class<U>::value), int >::type = 0 >
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static void from_json(const BasicJsonType& j, U& t)
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{
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using nlohmann::from_json;
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from_json(j, t);
|
|
}
|
|
|
|
// special behaviour for pods
|
|
template <typename BasicJsonType, typename U = T,
|
|
typename std::enable_if<
|
|
std::is_pod<U>::value and std::is_class<U>::value, int>::type = 0>
|
|
static void from_json(const BasicJsonType& j, U& t)
|
|
{
|
|
std::uint64_t value;
|
|
// TODO The following block is no longer relevant in this serializer, make another one that shows the issue
|
|
// the problem arises only when one from_json method is defined without any constraint
|
|
//
|
|
// Why cannot we simply use: j.get<std::uint64_t>() ?
|
|
// Well, with the current experiment, the get method looks for a from_json
|
|
// function, which we are currently defining!
|
|
// This would end up in a stack overflow. Calling nlohmann::from_json is a
|
|
// workaround (is it?).
|
|
// I shall find a good way to avoid this once all constructors are converted
|
|
// to free methods
|
|
//
|
|
// In short, constructing a json by constructor calls to_json
|
|
// calling get calls from_json, for now, we cannot do this in custom
|
|
// serializers
|
|
nlohmann::from_json(j, value);
|
|
auto bytes = static_cast<char*>(static_cast<void*>(&value));
|
|
std::memcpy(&t, bytes, sizeof(value));
|
|
}
|
|
|
|
template <
|
|
typename BasicJsonType, typename U = T,
|
|
typename std::enable_if <
|
|
not(std::is_pod<U>::value and std::is_class<U>::value), int >::type = 0 >
|
|
static void to_json(BasicJsonType& j, const T& t)
|
|
{
|
|
using nlohmann::to_json;
|
|
to_json(j, t);
|
|
}
|
|
|
|
template <typename BasicJsonType, typename U = T,
|
|
typename std::enable_if<
|
|
std::is_pod<U>::value and std::is_class<U>::value, int>::type = 0>
|
|
static void to_json(BasicJsonType& j, const T& t) noexcept
|
|
{
|
|
auto bytes = static_cast< const unsigned char*>(static_cast<const void*>(&t));
|
|
std::uint64_t value = bytes[0];
|
|
for (auto i = 1; i < 8; ++i)
|
|
value |= std::uint64_t{bytes[i]} << 8 * i;
|
|
nlohmann::to_json(j, value);
|
|
}
|
|
};
|
|
|
|
namespace udt
|
|
{
|
|
struct small_pod
|
|
{
|
|
int begin;
|
|
char middle;
|
|
short end;
|
|
};
|
|
|
|
struct non_pod
|
|
{
|
|
std::string s;
|
|
non_pod() : s() {}
|
|
non_pod(const std::string& S) : s(S) {}
|
|
};
|
|
|
|
template <typename BasicJsonType>
|
|
void to_json(BasicJsonType& j, const non_pod& np)
|
|
{
|
|
j = np.s;
|
|
}
|
|
|
|
template <typename BasicJsonType>
|
|
void from_json(const BasicJsonType& j, non_pod& np)
|
|
{
|
|
np.s = j.template get<std::string>();
|
|
}
|
|
|
|
bool operator==(small_pod lhs, small_pod rhs) noexcept
|
|
{
|
|
return std::tie(lhs.begin, lhs.middle, lhs.end) ==
|
|
std::tie(rhs.begin, rhs.middle, rhs.end);
|
|
}
|
|
|
|
bool operator==(const non_pod& lhs, const non_pod& rhs) noexcept
|
|
{
|
|
return lhs.s == rhs.s;
|
|
}
|
|
|
|
std::ostream& operator<<(std::ostream& os, small_pod l)
|
|
{
|
|
return os << "begin: " << l.begin << ", middle: " << l.middle << ", end: " << l.end;
|
|
}
|
|
}
|
|
|
|
TEST_CASE("custom serializer for pods", "[udt]")
|
|
{
|
|
using custom_json =
|
|
nlohmann::basic_json<std::map, std::vector, std::string, bool,
|
|
std::int64_t, std::uint64_t, double, std::allocator,
|
|
pod_serializer>;
|
|
|
|
auto p = udt::small_pod{42, '/', 42};
|
|
custom_json j = p;
|
|
|
|
auto p2 = j.get<udt::small_pod>();
|
|
|
|
CHECK(p == p2);
|
|
|
|
auto np = udt::non_pod{{"non-pod"}};
|
|
custom_json j2 = np;
|
|
auto np2 = j2.get<udt::non_pod>();
|
|
CHECK(np == np2);
|
|
}
|
|
|
|
template <typename T, typename>
|
|
struct another_adl_serializer;
|
|
|
|
using custom_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, double, std::allocator, another_adl_serializer>;
|
|
|
|
template <typename T, typename>
|
|
struct another_adl_serializer
|
|
{
|
|
static void from_json(const custom_json& j, T& t)
|
|
{
|
|
using nlohmann::from_json;
|
|
from_json(j, t);
|
|
}
|
|
|
|
static void to_json(custom_json& j, const T& t)
|
|
{
|
|
using nlohmann::to_json;
|
|
to_json(j, t);
|
|
}
|
|
};
|
|
|
|
TEST_CASE("custom serializer that does adl by default", "[udt]")
|
|
{
|
|
using json = nlohmann::json;
|
|
|
|
auto me = udt::person{{23}, {"theo"}, udt::country::france};
|
|
|
|
json j = me;
|
|
custom_json cj = me;
|
|
|
|
CHECK(j.dump() == cj.dump());
|
|
|
|
CHECK(me == j.get<udt::person>());
|
|
CHECK(me == cj.get<udt::person>());
|
|
}
|