/* __ _____ _____ _____ __| | __| | | | JSON for Modern C++ (test suite) | | |__ | | | | | | version 3.9.1 |_____|_____|_____|_|___| https://github.com/nlohmann/json Licensed under the MIT License <http://opensource.org/licenses/MIT>. SPDX-License-Identifier: MIT Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include "doctest_compatibility.h" DOCTEST_GCC_SUPPRESS_WARNING("-Wfloat-equal") #include <nlohmann/json.hpp> using nlohmann::json; #include <deque> #include <forward_list> #include <list> #include <set> #include <unordered_map> #include <unordered_set> #include <iostream> #include <sstream> #include <iomanip> #if defined(_MSC_VER) #pragma warning (push) #pragma warning (disable : 4189) // local variable is initialized but not referenced #endif TEST_CASE("README" * doctest::skip()) { { // redirect std::cout for the README file auto old_cout_buffer = std::cout.rdbuf(); std::ostringstream new_stream; std::cout.rdbuf(new_stream.rdbuf()); { // create an empty structure (null) json j; // add a number that is stored as double (note the implicit conversion of j to an object) j["pi"] = 3.141; // add a Boolean that is stored as bool j["happy"] = true; // add a string that is stored as std::string j["name"] = "Niels"; // add another null object by passing nullptr j["nothing"] = nullptr; // add an object inside the object j["answer"]["everything"] = 42; // add an array that is stored as std::vector (using an initializer list) j["list"] = { 1, 0, 2 }; // add another object (using an initializer list of pairs) j["object"] = { {"currency", "USD"}, {"value", 42.99} }; // instead, you could also write (which looks very similar to the JSON above) json j2 = { {"pi", 3.141}, {"happy", true}, {"name", "Niels"}, {"nothing", nullptr}, { "answer", { {"everything", 42} } }, {"list", {1, 0, 2}}, { "object", { {"currency", "USD"}, {"value", 42.99} } } }; } { // ways to express the empty array [] json empty_array_implicit = {{}}; CHECK(empty_array_implicit.is_array()); json empty_array_explicit = json::array(); CHECK(empty_array_explicit.is_array()); // a way to express the empty object {} json empty_object_explicit = json::object(); CHECK(empty_object_explicit.is_object()); // a way to express an _array_ of key/value pairs [["currency", "USD"], ["value", 42.99]] json array_not_object = json::array({ {"currency", "USD"}, {"value", 42.99} }); CHECK(array_not_object.is_array()); CHECK(array_not_object.size() == 2); CHECK(array_not_object[0].is_array()); CHECK(array_not_object[1].is_array()); } { // create object from string literal json j = "{ \"happy\": true, \"pi\": 3.141 }"_json; // or even nicer with a raw string literal auto j2 = R"( { "happy": true, "pi": 3.141 } )"_json; // or explicitly auto j3 = json::parse("{ \"happy\": true, \"pi\": 3.141 }"); // explicit conversion to string std::string s = j.dump(); // {\"happy\":true,\"pi\":3.141} // serialization with pretty printing // pass in the amount of spaces to indent std::cout << j.dump(4) << std::endl; // { // "happy": true, // "pi": 3.141 // } std::cout << std::setw(2) << j << std::endl; } { // create an array using push_back json j; j.push_back("foo"); j.push_back(1); j.push_back(true); // comparison bool x = (j == "[\"foo\", 1, true]"_json); // true CHECK(x == true); // iterate the array for (json::iterator it = j.begin(); it != j.end(); ++it) { std::cout << *it << '\n'; } // range-based for for (auto element : j) { std::cout << element << '\n'; } // getter/setter const auto tmp = j[0].get<std::string>(); j[1] = 42; bool foo{j.at(2)}; CHECK(foo == true); // other stuff j.size(); // 3 entries j.empty(); // false j.type(); // json::value_t::array j.clear(); // the array is empty again // create an object json o; o["foo"] = 23; o["bar"] = false; o["baz"] = 3.141; // find an entry if (o.find("foo") != o.end()) { // there is an entry with key "foo" } } { std::vector<int> c_vector {1, 2, 3, 4}; json j_vec(c_vector); // [1, 2, 3, 4] std::deque<float> c_deque {1.2f, 2.3f, 3.4f, 5.6f}; json j_deque(c_deque); // [1.2, 2.3, 3.4, 5.6] std::list<bool> c_list {true, true, false, true}; json j_list(c_list); // [true, true, false, true] std::forward_list<int64_t> c_flist {12345678909876, 23456789098765, 34567890987654, 45678909876543}; json j_flist(c_flist); // [12345678909876, 23456789098765, 34567890987654, 45678909876543] std::array<unsigned long, 4> c_array {{1, 2, 3, 4}}; json j_array(c_array); // [1, 2, 3, 4] std::set<std::string> c_set {"one", "two", "three", "four", "one"}; json j_set(c_set); // only one entry for "one" is used // ["four", "one", "three", "two"] std::unordered_set<std::string> c_uset {"one", "two", "three", "four", "one"}; json j_uset(c_uset); // only one entry for "one" is used // maybe ["two", "three", "four", "one"] std::multiset<std::string> c_mset {"one", "two", "one", "four"}; json j_mset(c_mset); // both entries for "one" are used // maybe ["one", "two", "one", "four"] std::unordered_multiset<std::string> c_umset {"one", "two", "one", "four"}; json j_umset(c_umset); // both entries for "one" are used // maybe ["one", "two", "one", "four"] } { std::map<std::string, int> c_map { {"one", 1}, {"two", 2}, {"three", 3} }; json j_map(c_map); // {"one": 1, "two": 2, "three": 3} std::unordered_map<const char*, float> c_umap { {"one", 1.2f}, {"two", 2.3f}, {"three", 3.4f} }; json j_umap(c_umap); // {"one": 1.2, "two": 2.3, "three": 3.4} std::multimap<std::string, bool> c_mmap { {"one", true}, {"two", true}, {"three", false}, {"three", true} }; json j_mmap(c_mmap); // only one entry for key "three" is used // maybe {"one": true, "two": true, "three": true} std::unordered_multimap<std::string, bool> c_ummap { {"one", true}, {"two", true}, {"three", false}, {"three", true} }; json j_ummap(c_ummap); // only one entry for key "three" is used // maybe {"one": true, "two": true, "three": true} } { // strings std::string s1 = "Hello, world!"; json js = s1; auto s2 = js.get<std::string>(); // Booleans bool b1 = true; json jb = b1; bool b2{jb}; CHECK(b2 == true); // numbers int i = 42; json jn = i; double f{jn}; CHECK(f == 42); // etc. std::string vs = js.get<std::string>(); bool vb = jb.get<bool>(); CHECK(vb == true); int vi = jn.get<int>(); CHECK(vi == 42); // etc. } { // a JSON value json j_original = R"({ "baz": ["one", "two", "three"], "foo": "bar" })"_json; // access members with a JSON pointer (RFC 6901) j_original["/baz/1"_json_pointer]; // "two" // a JSON patch (RFC 6902) json j_patch = R"([ { "op": "replace", "path": "/baz", "value": "boo" }, { "op": "add", "path": "/hello", "value": ["world"] }, { "op": "remove", "path": "/foo"} ])"_json; // apply the patch json j_result = j_original.patch(j_patch); // { // "baz": "boo", // "hello": ["world"] // } // calculate a JSON patch from two JSON values auto res = json::diff(j_result, j_original); // [ // { "op":" replace", "path": "/baz", "value": ["one", "two", "three"] }, // { "op":"remove","path":"/hello" }, // { "op":"add","path":"/foo","value":"bar" } // ] } // restore old std::cout std::cout.rdbuf(old_cout_buffer); } } #if defined(_MSC_VER) #pragma warning (pop) #endif