json/tests/src/unit-element_access2.cpp

//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
// |  |  |__   |  |  | | | |  version 3.11.2
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// Copyright (c) 2013-2022 Niels Lohmann <http://nlohmann.me>.
// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT

#include "doctest_compatibility.h"

#include <nlohmann/json.hpp>
#ifdef JSON_TEST_NO_GLOBAL_UDLS
    using namespace nlohmann::literals; // NOLINT(google-build-using-namespace)
#endif

// build test with C++14
// JSON_HAS_CPP_14

TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_json)
{
    SECTION("object")
    {
        Json j = {{"integer", 1}, {"unsigned", 1u}, {"floating", 42.23}, {"null", nullptr}, {"string", "hello world"}, {"boolean", true}, {"object", Json::object()}, {"array", {1, 2, 3}}};
        const Json j_const = j;

        SECTION("access specified element with bounds checking")
        {
            SECTION("access within bounds")
            {
                CHECK(j.at("integer") == Json(1));
                CHECK(j.at("unsigned") == Json(1u));
                CHECK(j.at("boolean") == Json(true));
                CHECK(j.at("null") == Json(nullptr));
                CHECK(j.at("string") == Json("hello world"));
                CHECK(j.at("floating") == Json(42.23));
                CHECK(j.at("object") == Json::object());
                CHECK(j.at("array") == Json({1, 2, 3}));

                CHECK(j_const.at("integer") == Json(1));
                CHECK(j_const.at("unsigned") == Json(1u));
                CHECK(j_const.at("boolean") == Json(true));
                CHECK(j_const.at("null") == Json(nullptr));
                CHECK(j_const.at("string") == Json("hello world"));
                CHECK(j_const.at("floating") == Json(42.23));
                CHECK(j_const.at("object") == Json::object());
                CHECK(j_const.at("array") == Json({1, 2, 3}));

#ifdef JSON_HAS_CPP_17
                CHECK(j.at(std::string_view("integer")) == Json(1));
                CHECK(j.at(std::string_view("unsigned")) == Json(1u));
                CHECK(j.at(std::string_view("boolean")) == Json(true));
                CHECK(j.at(std::string_view("null")) == Json(nullptr));
                CHECK(j.at(std::string_view("string")) == Json("hello world"));
                CHECK(j.at(std::string_view("floating")) == Json(42.23));
                CHECK(j.at(std::string_view("object")) == Json::object());
                CHECK(j.at(std::string_view("array")) == Json({1, 2, 3}));

                CHECK(j_const.at(std::string_view("integer")) == Json(1));
                CHECK(j_const.at(std::string_view("unsigned")) == Json(1u));
                CHECK(j_const.at(std::string_view("boolean")) == Json(true));
                CHECK(j_const.at(std::string_view("null")) == Json(nullptr));
                CHECK(j_const.at(std::string_view("string")) == Json("hello world"));
                CHECK(j_const.at(std::string_view("floating")) == Json(42.23));
                CHECK(j_const.at(std::string_view("object")) == Json::object());
                CHECK(j_const.at(std::string_view("array")) == Json({1, 2, 3}));
#endif
            }

            SECTION("access outside bounds")
            {
                CHECK_THROWS_WITH_AS(j.at("foo"), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
                CHECK_THROWS_WITH_AS(j_const.at("foo"), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);


#ifdef JSON_HAS_CPP_17
                CHECK_THROWS_WITH_AS(j.at(std::string_view("foo")), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
                CHECK_THROWS_WITH_AS(j_const.at(std::string_view("foo")), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
#endif
            }

            SECTION("access on non-object type")
            {
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view(std::string_view("foo"))), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view(std::string_view("foo"))), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);
#endif
                }

                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);
#endif
                }

                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
#endif
                }

                SECTION("number (unsigned)")
                {
                    Json j_nonobject(Json::value_t::number_unsigned);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
                    const Json j_nonobject_const(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at(std::string_view("foo")), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
#endif
                }
            }
        }

        SECTION("access specified element with default value")
        {
            SECTION("given a key")
            {
                SECTION("access existing value")
                {
                    CHECK(j.value("integer", 2) == 1);
                    CHECK(j.value("integer", 1.0) == Approx(1));
                    CHECK(j.value("unsigned", 2) == 1u);
                    CHECK(j.value("unsigned", 1.0) == Approx(1u));
                    CHECK(j.value("null", Json(1)) == Json());
                    CHECK(j.value("boolean", false) == true);
                    CHECK(j.value("string", "bar") == "hello world");
                    CHECK(j.value("string", std::string("bar")) == "hello world");
                    CHECK(j.value("floating", 12.34) == Approx(42.23));
                    CHECK(j.value("floating", 12) == 42);
                    CHECK(j.value("object", Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j.value("array", Json({10, 100})) == Json({1, 2, 3}));

                    CHECK(j_const.value("integer", 2) == 1);
                    CHECK(j_const.value("integer", 1.0) == Approx(1));
                    CHECK(j_const.value("unsigned", 2) == 1u);
                    CHECK(j_const.value("unsigned", 1.0) == Approx(1u));
                    CHECK(j_const.value("boolean", false) == true);
                    CHECK(j_const.value("string", "bar") == "hello world");
                    CHECK(j_const.value("string", std::string("bar")) == "hello world");
                    CHECK(j_const.value("floating", 12.34) == Approx(42.23));
                    CHECK(j_const.value("floating", 12) == 42);
                    CHECK(j_const.value("object", Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j_const.value("array", Json({10, 100})) == Json({1, 2, 3}));

#ifdef JSON_HAS_CPP_17
                    CHECK(j.value(std::string_view("integer"), 2) == 1);
                    CHECK(j.value(std::string_view("integer"), 1.0) == Approx(1));
                    CHECK(j.value(std::string_view("unsigned"), 2) == 1u);
                    CHECK(j.value(std::string_view("unsigned"), 1.0) == Approx(1u));
                    CHECK(j.value(std::string_view("null"), Json(1)) == Json());
                    CHECK(j.value(std::string_view("boolean"), false) == true);
                    CHECK(j.value(std::string_view("string"), "bar") == "hello world");
                    CHECK(j.value(std::string_view("string"), std::string("bar")) == "hello world");
                    CHECK(j.value(std::string_view("floating"), 12.34) == Approx(42.23));
                    CHECK(j.value(std::string_view("floating"), 12) == 42);
                    CHECK(j.value(std::string_view("object"), Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j.value(std::string_view("array"), Json({10, 100})) == Json({1, 2, 3}));

                    CHECK(j_const.value(std::string_view("integer"), 2) == 1);
                    CHECK(j_const.value(std::string_view("integer"), 1.0) == Approx(1));
                    CHECK(j_const.value(std::string_view("unsigned"), 2) == 1u);
                    CHECK(j_const.value(std::string_view("unsigned"), 1.0) == Approx(1u));
                    CHECK(j_const.value(std::string_view("boolean"), false) == true);
                    CHECK(j_const.value(std::string_view("string"), "bar") == "hello world");
                    CHECK(j_const.value(std::string_view("string"), std::string("bar")) == "hello world");
                    CHECK(j_const.value(std::string_view("floating"), 12.34) == Approx(42.23));
                    CHECK(j_const.value(std::string_view("floating"), 12) == 42);
                    CHECK(j_const.value(std::string_view("object"), Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j_const.value(std::string_view("array"), Json({10, 100})) == Json({1, 2, 3}));
#endif
                }

                SECTION("access non-existing value")
                {
                    CHECK(j.value("_", 2) == 2);
                    CHECK(j.value("_", 2u) == 2u);
                    CHECK(j.value("_", false) == false);
                    CHECK(j.value("_", "bar") == "bar");
                    CHECK(j.value("_", 12.34) == Approx(12.34));
                    CHECK(j.value("_", Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j.value("_", Json({10, 100})) == Json({10, 100}));

                    CHECK(j_const.value("_", 2) == 2);
                    CHECK(j_const.value("_", 2u) == 2u);
                    CHECK(j_const.value("_", false) == false);
                    CHECK(j_const.value("_", "bar") == "bar");
                    CHECK(j_const.value("_", 12.34) == Approx(12.34));
                    CHECK(j_const.value("_", Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j_const.value("_", Json({10, 100})) == Json({10, 100}));

#ifdef JSON_HAS_CPP_17
                    CHECK(j.value(std::string_view("_"), 2) == 2);
                    CHECK(j.value(std::string_view("_"), 2u) == 2u);
                    CHECK(j.value(std::string_view("_"), false) == false);
                    CHECK(j.value(std::string_view("_"), "bar") == "bar");
                    CHECK(j.value(std::string_view("_"), 12.34) == Approx(12.34));
                    CHECK(j.value(std::string_view("_"), Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j.value(std::string_view("_"), Json({10, 100})) == Json({10, 100}));

                    CHECK(j_const.value(std::string_view("_"), 2) == 2);
                    CHECK(j_const.value(std::string_view("_"), 2u) == 2u);
                    CHECK(j_const.value(std::string_view("_"), false) == false);
                    CHECK(j_const.value(std::string_view("_"), "bar") == "bar");
                    CHECK(j_const.value(std::string_view("_"), 12.34) == Approx(12.34));
                    CHECK(j_const.value(std::string_view("_"), Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j_const.value(std::string_view("_"), Json({10, 100})) == Json({10, 100}));
#endif
                }

                SECTION("access on non-object type")
                {
                    SECTION("null")
                    {
                        Json j_nonobject(Json::value_t::null);
                        const Json j_nonobject_const(Json::value_t::null);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
#endif
                    }

                    SECTION("boolean")
                    {
                        Json j_nonobject(Json::value_t::boolean);
                        const Json j_nonobject_const(Json::value_t::boolean);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);
#endif
                    }

                    SECTION("string")
                    {
                        Json j_nonobject(Json::value_t::string);
                        const Json j_nonobject_const(Json::value_t::string);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);
#endif
                    }

                    SECTION("array")
                    {
                        Json j_nonobject(Json::value_t::array);
                        const Json j_nonobject_const(Json::value_t::array);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);
#endif
                    }

                    SECTION("number (integer)")
                    {
                        Json j_nonobject(Json::value_t::number_integer);
                        const Json j_nonobject_const(Json::value_t::number_integer);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
#endif
                    }

                    SECTION("number (unsigned)")
                    {
                        Json j_nonobject(Json::value_t::number_unsigned);
                        const Json j_nonobject_const(Json::value_t::number_unsigned);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
#endif
                    }

                    SECTION("number (floating-point)")
                    {
                        Json j_nonobject(Json::value_t::number_float);
                        const Json j_nonobject_const(Json::value_t::number_float);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("foo", 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                        CHECK_THROWS_WITH_AS(j_nonobject.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value(std::string_view("foo"), 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
#endif
                    }
                }
            }

            SECTION("given a JSON pointer")
            {
                SECTION("access existing value")
                {
                    CHECK(j.value("/integer"_json_pointer, 2) == 1);
                    CHECK(j.value("/integer"_json_pointer, 1.0) == Approx(1));
                    CHECK(j.value("/unsigned"_json_pointer, 2) == 1u);
                    CHECK(j.value("/unsigned"_json_pointer, 1.0) == Approx(1u));
                    CHECK(j.value("/null"_json_pointer, Json(1)) == Json());
                    CHECK(j.value("/boolean"_json_pointer, false) == true);
                    CHECK(j.value("/string"_json_pointer, "bar") == "hello world");
                    CHECK(j.value("/string"_json_pointer, std::string("bar")) == "hello world");
                    CHECK(j.value("/floating"_json_pointer, 12.34) == Approx(42.23));
                    CHECK(j.value("/floating"_json_pointer, 12) == 42);
                    CHECK(j.value("/object"_json_pointer, Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j.value("/array"_json_pointer, Json({10, 100})) == Json({1, 2, 3}));

                    CHECK(j_const.value("/integer"_json_pointer, 2) == 1);
                    CHECK(j_const.value("/integer"_json_pointer, 1.0) == Approx(1));
                    CHECK(j_const.value("/unsigned"_json_pointer, 2) == 1u);
                    CHECK(j_const.value("/unsigned"_json_pointer, 1.0) == Approx(1u));
                    CHECK(j_const.value("/boolean"_json_pointer, false) == true);
                    CHECK(j_const.value("/string"_json_pointer, "bar") == "hello world");
                    CHECK(j_const.value("/string"_json_pointer, std::string("bar")) == "hello world");
                    CHECK(j_const.value("/floating"_json_pointer, 12.34) == Approx(42.23));
                    CHECK(j_const.value("/floating"_json_pointer, 12) == 42);
                    CHECK(j_const.value("/object"_json_pointer, Json({{"foo", "bar"}})) == Json::object());
                    CHECK(j_const.value("/array"_json_pointer, Json({10, 100})) == Json({1, 2, 3}));
                }

                SECTION("access on non-object type")
                {
                    SECTION("null")
                    {
                        Json j_nonobject(Json::value_t::null);
                        const Json j_nonobject_const(Json::value_t::null);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
                    }

                    SECTION("boolean")
                    {
                        Json j_nonobject(Json::value_t::boolean);
                        const Json j_nonobject_const(Json::value_t::boolean);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with boolean", typename Json::type_error&);
                    }

                    SECTION("string")
                    {
                        Json j_nonobject(Json::value_t::string);
                        const Json j_nonobject_const(Json::value_t::string);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with string", typename Json::type_error&);
                    }

                    SECTION("array")
                    {
                        Json j_nonobject(Json::value_t::array);
                        const Json j_nonobject_const(Json::value_t::array);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with array", typename Json::type_error&);
                    }

                    SECTION("number (integer)")
                    {
                        Json j_nonobject(Json::value_t::number_integer);
                        const Json j_nonobject_const(Json::value_t::number_integer);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                    }

                    SECTION("number (unsigned)")
                    {
                        Json j_nonobject(Json::value_t::number_unsigned);
                        const Json j_nonobject_const(Json::value_t::number_unsigned);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                    }

                    SECTION("number (floating-point)")
                    {
                        Json j_nonobject(Json::value_t::number_float);
                        const Json j_nonobject_const(Json::value_t::number_float);
                        CHECK_THROWS_WITH_AS(j_nonobject.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                        CHECK_THROWS_WITH_AS(j_nonobject_const.value("/foo"_json_pointer, 1), "[json.exception.type_error.306] cannot use value() with number", typename Json::type_error&);
                    }
                }
            }
        }

        SECTION("non-const operator[]")
        {
            {
                Json j_null;
                CHECK(j_null.is_null());
                j_null["key"] = 1;
                CHECK(j_null.is_object());
                CHECK(j_null.size() == 1);
                j_null["key"] = 2;
                CHECK(j_null.size() == 1);
            }
#ifdef JSON_HAS_CPP_17
            {
                std::string_view const key = "key";
                Json j_null;
                CHECK(j_null.is_null());
                j_null[key] = 1;
                CHECK(j_null.is_object());
                CHECK(j_null.size() == 1);
                j_null[key] = 2;
                CHECK(j_null.size() == 1);
            }
#endif
        }

        SECTION("front and back")
        {
            if (std::is_same<Json, nlohmann::ordered_json>::value)
            {
                // "integer" is the first key
                CHECK(j.front() == Json(1));
                CHECK(j_const.front() == Json(1));
                // "array" is last key
                CHECK(j.back() == Json({1, 2, 3}));
                CHECK(j_const.back() == Json({1, 2, 3}));
            }
            else
            {
                // "array" is the smallest key
                CHECK(j.front() == Json({1, 2, 3}));
                CHECK(j_const.front() == Json({1, 2, 3}));
                // "unsigned" is the largest key
                CHECK(j.back() == Json(1u));
                CHECK(j_const.back() == Json(1u));
            }
        }

        SECTION("access specified element")
        {
            SECTION("access within bounds")
            {
                CHECK(j["integer"] == Json(1));
                CHECK(j[typename Json::object_t::key_type("integer")] == j["integer"]);

                CHECK(j["unsigned"] == Json(1u));
                CHECK(j[typename Json::object_t::key_type("unsigned")] == j["unsigned"]);

                CHECK(j["boolean"] == Json(true));
                CHECK(j[typename Json::object_t::key_type("boolean")] == j["boolean"]);

                CHECK(j["null"] == Json(nullptr));
                CHECK(j[typename Json::object_t::key_type("null")] == j["null"]);

                CHECK(j["string"] == Json("hello world"));
                CHECK(j[typename Json::object_t::key_type("string")] == j["string"]);

                CHECK(j["floating"] == Json(42.23));
                CHECK(j[typename Json::object_t::key_type("floating")] == j["floating"]);

                CHECK(j["object"] == Json::object());
                CHECK(j[typename Json::object_t::key_type("object")] == j["object"]);

                CHECK(j["array"] == Json({1, 2, 3}));
                CHECK(j[typename Json::object_t::key_type("array")] == j["array"]);

                CHECK(j_const["integer"] == Json(1));
                CHECK(j_const[typename Json::object_t::key_type("integer")] == j["integer"]);

                CHECK(j_const["boolean"] == Json(true));
                CHECK(j_const[typename Json::object_t::key_type("boolean")] == j["boolean"]);

                CHECK(j_const["null"] == Json(nullptr));
                CHECK(j_const[typename Json::object_t::key_type("null")] == j["null"]);

                CHECK(j_const["string"] == Json("hello world"));
                CHECK(j_const[typename Json::object_t::key_type("string")] == j["string"]);

                CHECK(j_const["floating"] == Json(42.23));
                CHECK(j_const[typename Json::object_t::key_type("floating")] == j["floating"]);

                CHECK(j_const["object"] == Json::object());
                CHECK(j_const[typename Json::object_t::key_type("object")] == j["object"]);

                CHECK(j_const["array"] == Json({1, 2, 3}));
                CHECK(j_const[typename Json::object_t::key_type("array")] == j["array"]);
            }

#ifdef JSON_HAS_CPP_17
            SECTION("access within bounds (string_view)")
            {
                CHECK(j["integer"] == Json(1));
                CHECK(j[std::string_view("integer")] == j["integer"]);

                CHECK(j["unsigned"] == Json(1u));
                CHECK(j[std::string_view("unsigned")] == j["unsigned"]);

                CHECK(j["boolean"] == Json(true));
                CHECK(j[std::string_view("boolean")] == j["boolean"]);

                CHECK(j["null"] == Json(nullptr));
                CHECK(j[std::string_view("null")] == j["null"]);

                CHECK(j["string"] == Json("hello world"));
                CHECK(j[std::string_view("string")] == j["string"]);

                CHECK(j["floating"] == Json(42.23));
                CHECK(j[std::string_view("floating")] == j["floating"]);

                CHECK(j["object"] == Json::object());
                CHECK(j[std::string_view("object")] == j["object"]);

                CHECK(j["array"] == Json({1, 2, 3}));
                CHECK(j[std::string_view("array")] == j["array"]);

                CHECK(j_const["integer"] == Json(1));
                CHECK(j_const[std::string_view("integer")] == j["integer"]);

                CHECK(j_const["boolean"] == Json(true));
                CHECK(j_const[std::string_view("boolean")] == j["boolean"]);

                CHECK(j_const["null"] == Json(nullptr));
                CHECK(j_const[std::string_view("null")] == j["null"]);

                CHECK(j_const["string"] == Json("hello world"));
                CHECK(j_const[std::string_view("string")] == j["string"]);

                CHECK(j_const["floating"] == Json(42.23));
                CHECK(j_const[std::string_view("floating")] == j["floating"]);

                CHECK(j_const["object"] == Json::object());
                CHECK(j_const[std::string_view("object")] == j["object"]);

                CHECK(j_const["array"] == Json({1, 2, 3}));
                CHECK(j_const[std::string_view("array")] == j["array"]);
            }
#endif

            SECTION("access on non-object type")
            {
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
                    Json j_nonobject2(Json::value_t::null);
                    const Json j_const_nonobject(j_nonobject);

                    CHECK_NOTHROW(j_nonobject["foo"]);
                    CHECK_NOTHROW(j_nonobject2[typename Json::object_t::key_type("foo")]);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"], "[json.exception.type_error.305] cannot use operator[] with a string argument with null", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with null", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_NOTHROW(j_nonobject2[std::string_view("foo")]);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with null", typename Json::type_error&);
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with boolean", typename Json::type_error&);
#endif
                }

                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with string", typename Json::type_error&);
#endif
                }

                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with array", typename Json::type_error&);
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
#endif
                }

                SECTION("number (unsigned)")
                {
                    Json j_nonobject(Json::value_t::number_unsigned);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
                    const Json j_const_nonobject(j_nonobject);
                    CHECK_THROWS_WITH_AS(j_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject["foo"],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[typename Json::object_t::key_type("foo")],
                                         "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_const_nonobject[std::string_view("foo")], "[json.exception.type_error.305] cannot use operator[] with a string argument with number", typename Json::type_error&);
#endif
                }
            }
        }

        SECTION("remove specified element")
        {
            SECTION("remove element by key")
            {
                CHECK(j.find("integer") != j.end());
                CHECK(j.erase("integer") == 1);
                CHECK(j.find("integer") == j.end());
                CHECK(j.erase("integer") == 0);

                CHECK(j.find("unsigned") != j.end());
                CHECK(j.erase("unsigned") == 1);
                CHECK(j.find("unsigned") == j.end());
                CHECK(j.erase("unsigned") == 0);

                CHECK(j.find("boolean") != j.end());
                CHECK(j.erase("boolean") == 1);
                CHECK(j.find("boolean") == j.end());
                CHECK(j.erase("boolean") == 0);

                CHECK(j.find("null") != j.end());
                CHECK(j.erase("null") == 1);
                CHECK(j.find("null") == j.end());
                CHECK(j.erase("null") == 0);

                CHECK(j.find("string") != j.end());
                CHECK(j.erase("string") == 1);
                CHECK(j.find("string") == j.end());
                CHECK(j.erase("string") == 0);

                CHECK(j.find("floating") != j.end());
                CHECK(j.erase("floating") == 1);
                CHECK(j.find("floating") == j.end());
                CHECK(j.erase("floating") == 0);

                CHECK(j.find("object") != j.end());
                CHECK(j.erase("object") == 1);
                CHECK(j.find("object") == j.end());
                CHECK(j.erase("object") == 0);

                CHECK(j.find("array") != j.end());
                CHECK(j.erase("array") == 1);
                CHECK(j.find("array") == j.end());
                CHECK(j.erase("array") == 0);
            }

#ifdef JSON_HAS_CPP_17
            SECTION("remove element by key (string_view)")
            {
                CHECK(j.find(std::string_view("integer")) != j.end());
                CHECK(j.erase(std::string_view("integer")) == 1);
                CHECK(j.find(std::string_view("integer")) == j.end());
                CHECK(j.erase(std::string_view("integer")) == 0);

                CHECK(j.find(std::string_view("unsigned")) != j.end());
                CHECK(j.erase(std::string_view("unsigned")) == 1);
                CHECK(j.find(std::string_view("unsigned")) == j.end());
                CHECK(j.erase(std::string_view("unsigned")) == 0);

                CHECK(j.find(std::string_view("boolean")) != j.end());
                CHECK(j.erase(std::string_view("boolean")) == 1);
                CHECK(j.find(std::string_view("boolean")) == j.end());
                CHECK(j.erase(std::string_view("boolean")) == 0);

                CHECK(j.find(std::string_view("null")) != j.end());
                CHECK(j.erase(std::string_view("null")) == 1);
                CHECK(j.find(std::string_view("null")) == j.end());
                CHECK(j.erase(std::string_view("null")) == 0);

                CHECK(j.find(std::string_view("string")) != j.end());
                CHECK(j.erase(std::string_view("string")) == 1);
                CHECK(j.find(std::string_view("string")) == j.end());
                CHECK(j.erase(std::string_view("string")) == 0);

                CHECK(j.find(std::string_view("floating")) != j.end());
                CHECK(j.erase(std::string_view("floating")) == 1);
                CHECK(j.find(std::string_view("floating")) == j.end());
                CHECK(j.erase(std::string_view("floating")) == 0);

                CHECK(j.find(std::string_view("object")) != j.end());
                CHECK(j.erase(std::string_view("object")) == 1);
                CHECK(j.find(std::string_view("object")) == j.end());
                CHECK(j.erase(std::string_view("object")) == 0);

                CHECK(j.find(std::string_view("array")) != j.end());
                CHECK(j.erase(std::string_view("array")) == 1);
                CHECK(j.find(std::string_view("array")) == j.end());
                CHECK(j.erase(std::string_view("array")) == 0);
            }
#endif

            SECTION("remove element by iterator")
            {
                SECTION("erase(begin())")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::iterator const it2 = jobject.erase(jobject.begin());
                        CHECK(jobject == Json({{"b", 1}, {"c", 17u}}));
                        CHECK(*it2 == Json(1));
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::const_iterator const it2 = jobject.erase(jobject.cbegin());
                        CHECK(jobject == Json({{"b", 1}, {"c", 17u}}));
                        CHECK(*it2 == Json(1));
                    }
                }

                SECTION("erase(begin(), end())")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::iterator it2 = jobject.erase(jobject.begin(), jobject.end());
                        CHECK(jobject == Json::object());
                        CHECK(it2 == jobject.end());
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::const_iterator it2 = jobject.erase(jobject.cbegin(), jobject.cend());
                        CHECK(jobject == Json::object());
                        CHECK(it2 == jobject.cend());
                    }
                }

                SECTION("erase(begin(), begin())")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::iterator const it2 = jobject.erase(jobject.begin(), jobject.begin());
                        CHECK(jobject == Json({{"a", "a"}, {"b", 1}, {"c", 17u}}));
                        CHECK(*it2 == Json("a"));
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::const_iterator const it2 = jobject.erase(jobject.cbegin(), jobject.cbegin());
                        CHECK(jobject == Json({{"a", "a"}, {"b", 1}, {"c", 17u}}));
                        CHECK(*it2 == Json("a"));
                    }
                }

                SECTION("erase at offset")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::iterator const it = jobject.find("b");
                        typename Json::iterator const it2 = jobject.erase(it);
                        CHECK(jobject == Json({{"a", "a"}, {"c", 17u}}));
                        CHECK(*it2 == Json(17));
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        typename Json::const_iterator const it = jobject.find("b");
                        typename Json::const_iterator const it2 = jobject.erase(it);
                        CHECK(jobject == Json({{"a", "a"}, {"c", 17u}}));
                        CHECK(*it2 == Json(17));
                    }
                }

                SECTION("erase subrange")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}, {"d", false}, {"e", true}};
                        typename Json::iterator const it2 = jobject.erase(jobject.find("b"), jobject.find("e"));
                        CHECK(jobject == Json({{"a", "a"}, {"e", true}}));
                        CHECK(*it2 == Json(true));
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}, {"d", false}, {"e", true}};
                        typename Json::const_iterator const it2 = jobject.erase(jobject.find("b"), jobject.find("e"));
                        CHECK(jobject == Json({{"a", "a"}, {"e", true}}));
                        CHECK(*it2 == Json(true));
                    }
                }

                SECTION("different objects")
                {
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}, {"d", false}, {"e", true}};
                        Json jobject2 = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.begin()),
                                             "[json.exception.invalid_iterator.202] iterator does not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject.begin(), jobject2.end()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.begin(), jobject.end()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.begin(), jobject2.end()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                    }
                    {
                        Json jobject = {{"a", "a"}, {"b", 1}, {"c", 17u}, {"d", false}, {"e", true}};
                        Json jobject2 = {{"a", "a"}, {"b", 1}, {"c", 17u}};
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.cbegin()),
                                             "[json.exception.invalid_iterator.202] iterator does not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject.cbegin(), jobject2.cend()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.cbegin(), jobject.cend()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                        CHECK_THROWS_WITH_AS(jobject.erase(jobject2.cbegin(), jobject2.cend()),
                                             "[json.exception.invalid_iterator.203] iterators do not fit current value", typename Json::invalid_iterator&);
                    }
                }
            }

            SECTION("remove element by key in non-object type")
            {
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with null", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with null", typename Json::type_error&);
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with boolean", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with boolean", typename Json::type_error&);
#endif
                }

                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with string", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with string", typename Json::type_error&);
#endif
                }

                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with array", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with array", typename Json::type_error&);
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with number", typename Json::type_error&);
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
                    CHECK_THROWS_WITH_AS(j_nonobject.erase("foo"), "[json.exception.type_error.307] cannot use erase() with number", typename Json::type_error&);

#ifdef JSON_HAS_CPP_17
                    CHECK_THROWS_WITH_AS(j_nonobject.erase(std::string_view("foo")), "[json.exception.type_error.307] cannot use erase() with number", typename Json::type_error&);
#endif
                }
            }
        }

        SECTION("find an element in an object")
        {
            SECTION("existing element")
            {
                for (const auto* key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.find(key) != j.end());
                    CHECK(*j.find(key) == j.at(key));
                    CHECK(j_const.find(key) != j_const.end());
                    CHECK(*j_const.find(key) == j_const.at(key));
                }
#ifdef JSON_HAS_CPP_17
                for (const std::string_view key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.find(key) != j.end());
                    CHECK(*j.find(key) == j.at(key));
                    CHECK(j_const.find(key) != j_const.end());
                    CHECK(*j_const.find(key) == j_const.at(key));
                }
#endif
            }

            SECTION("nonexisting element")
            {
                CHECK(j.find("foo") == j.end());
                CHECK(j_const.find("foo") == j_const.end());

#ifdef JSON_HAS_CPP_17
                CHECK(j.find(std::string_view("foo")) == j.end());
                CHECK(j_const.find(std::string_view("foo")) == j_const.end());
#endif
            }

            SECTION("all types")
            {
                SECTION("null")
                {
                    Json j_nonarray(Json::value_t::null);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("string")
                {
                    Json j_nonarray(Json::value_t::string);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("object")
                {
                    Json j_nonarray(Json::value_t::object);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("array")
                {
                    Json j_nonarray(Json::value_t::array);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonarray(Json::value_t::boolean);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonarray(Json::value_t::number_integer);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("number (unsigned)")
                {
                    Json j_nonarray(Json::value_t::number_unsigned);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonarray(Json::value_t::number_float);
                    const Json j_nonarray_const(j_nonarray);

                    CHECK(j_nonarray.find("foo") == j_nonarray.end());
                    CHECK(j_nonarray_const.find("foo") == j_nonarray_const.end());

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonarray.find(std::string_view("foo")) == j_nonarray.end());
                    CHECK(j_nonarray_const.find(std::string_view("foo")) == j_nonarray_const.end());
#endif
                }
            }
        }

        SECTION("count keys in an object")
        {
            SECTION("existing element")
            {
                for (const auto* key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.count(key) == 1);
                    CHECK(j_const.count(key) == 1);
                }
#ifdef JSON_HAS_CPP_17
                for (const std::string_view key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.count(key) == 1);
                    CHECK(j_const.count(key) == 1);
                }
#endif
            }

            SECTION("nonexisting element")
            {
                CHECK(j.count("foo") == 0);
                CHECK(j_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                CHECK(j.count(std::string_view("foo")) == 0);
                CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
            }

            SECTION("all types")
            {
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
                    const Json j_nonobject_const(Json::value_t::null);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
                    const Json j_nonobject_const(Json::value_t::string);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("object")
                {
                    Json j_nonobject(Json::value_t::object);
                    const Json j_nonobject_const(Json::value_t::object);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
                    const Json j_nonobject_const(Json::value_t::array);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
                    const Json j_nonobject_const(Json::value_t::boolean);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
                    const Json j_nonobject_const(Json::value_t::number_integer);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("number (unsigned)")
                {
                    Json j_nonobject(Json::value_t::number_unsigned);
                    const Json j_nonobject_const(Json::value_t::number_unsigned);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
                    const Json j_nonobject_const(Json::value_t::number_float);

                    CHECK(j_nonobject.count("foo") == 0);
                    CHECK(j_nonobject_const.count("foo") == 0);

#ifdef JSON_HAS_CPP_17
                    CHECK(j.count(std::string_view("foo")) == 0);
                    CHECK(j_const.count(std::string_view("foo")) == 0);
#endif
                }
            }
        }

        SECTION("check existence of key in an object")
        {
            SECTION("existing element")
            {
                for (const auto* key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.contains(key) == true);
                    CHECK(j_const.contains(key) == true);
                }

#ifdef JSON_HAS_CPP_17
                for (const std::string_view key :
                        {"integer", "unsigned", "floating", "null", "string", "boolean", "object", "array"
                        })
                {
                    CHECK(j.contains(key) == true);
                    CHECK(j_const.contains(key) == true);
                }
#endif
            }

            SECTION("nonexisting element")
            {
                CHECK(j.contains("foo") == false);
                CHECK(j_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                CHECK(j.contains(std::string_view("foo")) == false);
                CHECK(j_const.contains(std::string_view("foo")) == false);
#endif
            }

            SECTION("all types")
            {
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
                    const Json j_nonobject_const(Json::value_t::null);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
                    const Json j_nonobject_const(Json::value_t::string);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("object")
                {
                    Json j_nonobject(Json::value_t::object);
                    const Json j_nonobject_const(Json::value_t::object);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
                    const Json j_nonobject_const(Json::value_t::array);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
                    const Json j_nonobject_const(Json::value_t::boolean);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
                    const Json j_nonobject_const(Json::value_t::number_integer);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("number (unsigned)")
                {
                    Json j_nonobject(Json::value_t::number_unsigned);
                    const Json j_nonobject_const(Json::value_t::number_unsigned);

                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);

#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }

                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
                    const Json j_nonobject_const(Json::value_t::number_float);
                    CHECK(j_nonobject.contains("foo") == false);
                    CHECK(j_nonobject_const.contains("foo") == false);
#ifdef JSON_HAS_CPP_17
                    CHECK(j_nonobject.contains(std::string_view("foo")) == false);
                    CHECK(j_nonobject_const.contains(std::string_view("foo")) == false);
#endif
                }
            }
        }
    }
}

#if !defined(JSON_NOEXCEPTION)
TEST_CASE_TEMPLATE("element access 2 (throwing tests)", Json, nlohmann::json, nlohmann::ordered_json)
{
    SECTION("object")
    {
        Json j = {{"integer", 1}, {"unsigned", 1u}, {"floating", 42.23}, {"null", nullptr}, {"string", "hello world"}, {"boolean", true}, {"object", Json::object()}, {"array", {1, 2, 3}}};
        const Json j_const = {{"integer", 1}, {"unsigned", 1u}, {"floating", 42.23}, {"null", nullptr}, {"string", "hello world"}, {"boolean", true}, {"object", Json::object()}, {"array", {1, 2, 3}}};

        SECTION("access specified element with default value")
        {
            SECTION("given a JSON pointer")
            {
                SECTION("access non-existing value")
                {
                    CHECK(j.value("/not/existing"_json_pointer, 2) == 2);
                    CHECK(j.value("/not/existing"_json_pointer, 2u) == 2u);
                    CHECK(j.value("/not/existing"_json_pointer, false) == false);
                    CHECK(j.value("/not/existing"_json_pointer, "bar") == "bar");
                    CHECK(j.value("/not/existing"_json_pointer, 12.34) == Approx(12.34));
                    CHECK(j.value("/not/existing"_json_pointer, Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j.value("/not/existing"_json_pointer, Json({10, 100})) == Json({10, 100}));

                    CHECK(j_const.value("/not/existing"_json_pointer, 2) == 2);
                    CHECK(j_const.value("/not/existing"_json_pointer, 2u) == 2u);
                    CHECK(j_const.value("/not/existing"_json_pointer, false) == false);
                    CHECK(j_const.value("/not/existing"_json_pointer, "bar") == "bar");
                    CHECK(j_const.value("/not/existing"_json_pointer, 12.34) == Approx(12.34));
                    CHECK(j_const.value("/not/existing"_json_pointer, Json({{"foo", "bar"}})) == Json({{"foo", "bar"}}));
                    CHECK(j_const.value("/not/existing"_json_pointer, Json({10, 100})) == Json({10, 100}));
                }
            }
        }
    }
}
#endif

// TODO(falbrechtskirchinger) merge with the other test case; clean up
TEST_CASE_TEMPLATE("element access 2 (additional value() tests)", Json, nlohmann::json, nlohmann::ordered_json)
{
    using string_t = typename Json::string_t;
    using number_integer_t = typename Json::number_integer_t;

    // test assumes string_t and object_t::key_type are the same
    REQUIRE(std::is_same<string_t, typename Json::object_t::key_type>::value);

    Json j
    {
        {"foo", "bar"},
        {"baz", 42}
    };

    const char* cpstr = "default";
    const char castr[] = "default"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
    string_t const str = "default";

    number_integer_t integer = 69;
    std::size_t size = 69;

    SECTION("deduced ValueType")
    {
        SECTION("literal key")
        {
            CHECK(j.value("foo", "default") == "bar");
            CHECK(j.value("foo", cpstr) == "bar");
            CHECK(j.value("foo", castr) == "bar");
            CHECK(j.value("foo", str) == "bar");
            // this test is in fact different than the one below,
            // because of 0 considering const char * overloads
            // where as any other number does not
            CHECK(j.value("baz", 0) == 42);
            CHECK(j.value("baz", 47) == 42);
            CHECK(j.value("baz", integer) == 42);
            CHECK(j.value("baz", size) == 42);

            CHECK(j.value("bar", "default") == "default");
            CHECK(j.value("bar", 0) == 0);
            CHECK(j.value("bar", 47) == 47);
            CHECK(j.value("bar", integer) == integer);
            CHECK(j.value("bar", size) == size);

            CHECK_THROWS_WITH_AS(Json().value("foo", "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().value("foo", str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("const char * key")
        {
            const char* key = "foo";
            const char* key2 = "baz";
            const char* key_notfound = "bar";

            CHECK(j.value(key, "default") == "bar");
            CHECK(j.value(key, cpstr) == "bar");
            CHECK(j.value(key, castr) == "bar");
            CHECK(j.value(key, str) == "bar");
            CHECK(j.value(key2, 0) == 42);
            CHECK(j.value(key2, 47) == 42);
            CHECK(j.value(key2, integer) == 42);
            CHECK(j.value(key2, size) == 42);

            CHECK(j.value(key_notfound, "default") == "default");
            CHECK(j.value(key_notfound, 0) == 0);
            CHECK(j.value(key_notfound, 47) == 47);
            CHECK(j.value(key_notfound, integer) == integer);
            CHECK(j.value(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().value(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().value(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("const char(&)[] key")
        {
            const char key[] = "foo"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
            const char key2[] = "baz"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
            const char key_notfound[] = "bar"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)

            CHECK(j.value(key, "default") == "bar");
            CHECK(j.value(key, cpstr) == "bar");
            CHECK(j.value(key, castr) == "bar");
            CHECK(j.value(key, str) == "bar");
            CHECK(j.value(key2, 0) == 42);
            CHECK(j.value(key2, 47) == 42);
            CHECK(j.value(key2, integer) == 42);
            CHECK(j.value(key2, size) == 42);

            CHECK(j.value(key_notfound, "default") == "default");
            CHECK(j.value(key_notfound, 0) == 0);
            CHECK(j.value(key_notfound, 47) == 47);
            CHECK(j.value(key_notfound, integer) == integer);
            CHECK(j.value(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().value(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().value(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("string_t/object_t::key_type key")
        {
            string_t const key = "foo";
            string_t const key2 = "baz";
            string_t const key_notfound = "bar";

            CHECK(j.value(key, "default") == "bar");
            CHECK(j.value(key, cpstr) == "bar");
            CHECK(j.value(key, castr) == "bar");
            CHECK(j.value(key, str) == "bar");
            CHECK(j.value(key2, 0) == 42);
            CHECK(j.value(key2, 47) == 42);
            CHECK(j.value(key2, integer) == 42);
            CHECK(j.value(key2, size) == 42);

            CHECK(j.value(key_notfound, "default") == "default");
            CHECK(j.value(key_notfound, 0) == 0);
            CHECK(j.value(key_notfound, 47) == 47);
            CHECK(j.value(key_notfound, integer) == integer);
            CHECK(j.value(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().value(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().value(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

#ifdef JSON_HAS_CPP_17
        SECTION("std::string_view key")
        {
            std::string_view const key = "foo";
            std::string_view const key2 = "baz";
            std::string_view const key_notfound = "bar";

            CHECK(j.value(key, "default") == "bar");
            CHECK(j.value(key, cpstr) == "bar");
            CHECK(j.value(key, castr) == "bar");
            CHECK(j.value(key, str) == "bar");
            CHECK(j.value(key2, 0) == 42);
            CHECK(j.value(key2, 47) == 42);
            CHECK(j.value(key2, integer) == 42);
            CHECK(j.value(key2, size) == 42);

            CHECK(j.value(key_notfound, "default") == "default");
            CHECK(j.value(key_notfound, 0) == 0);
            CHECK(j.value(key_notfound, 47) == 47);
            CHECK(j.value(key_notfound, integer) == integer);
            CHECK(j.value(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().value(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().value(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }
#endif
    }

    SECTION("explicit ValueType")
    {
        SECTION("literal key")
        {
            CHECK(j.template value<string_t>("foo", "default") == "bar");
            CHECK(j.template value<string_t>("foo", cpstr) == "bar");
            CHECK(j.template value<string_t>("foo", castr) == "bar");
            CHECK(j.template value<string_t>("foo", str) == "bar");
            CHECK(j.template value<number_integer_t>("baz", 0) == 42);
            CHECK(j.template value<number_integer_t>("baz", 47) == 42);
            CHECK(j.template value<number_integer_t>("baz", integer) == 42);
            CHECK(j.template value<std::size_t>("baz", 0) == 42);
            CHECK(j.template value<std::size_t>("baz", 47) == 42);
            CHECK(j.template value<std::size_t>("baz", size) == 42);

            CHECK(j.template value<string_t>("bar", "default") == "default");
            CHECK(j.template value<number_integer_t>("bar", 0) == 0);
            CHECK(j.template value<number_integer_t>("bar", 47) == 47);
            CHECK(j.template value<number_integer_t>("bar", integer) == integer);
            CHECK(j.template value<std::size_t>("bar", 0) == 0);
            CHECK(j.template value<std::size_t>("bar", 47) == 47);
            CHECK(j.template value<std::size_t>("bar", size) == size);

            CHECK_THROWS_WITH_AS(Json().template value<string_t>("foo", "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().template value<string_t>("foo", str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("const char * key")
        {
            const char* key = "foo";
            const char* key2 = "baz";
            const char* key_notfound = "bar";

            CHECK(j.template value<string_t>(key, "default") == "bar");
            CHECK(j.template value<string_t>(key, cpstr) == "bar");
            CHECK(j.template value<string_t>(key, castr) == "bar");
            CHECK(j.template value<string_t>(key, str) == "bar");
            CHECK(j.template value<number_integer_t>(key2, 0) == 42);
            CHECK(j.template value<number_integer_t>(key2, 47) == 42);
            CHECK(j.template value<number_integer_t>(key2, integer) == 42);
            CHECK(j.template value<std::size_t>(key2, 0) == 42);
            CHECK(j.template value<std::size_t>(key2, 47) == 42);
            CHECK(j.template value<std::size_t>(key2, size) == 42);

            CHECK(j.template value<string_t>(key_notfound, "default") == "default");
            CHECK(j.template value<number_integer_t>(key_notfound, 0) == 0);
            CHECK(j.template value<number_integer_t>(key_notfound, 47) == 47);
            CHECK(j.template value<number_integer_t>(key_notfound, integer) == integer);
            CHECK(j.template value<std::size_t>(key_notfound, 0) == 0);
            CHECK(j.template value<std::size_t>(key_notfound, 47) == 47);
            CHECK(j.template value<std::size_t>(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("const char(&)[] key")
        {
            const char key[] = "foo"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
            const char key2[] = "baz"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
            const char key_notfound[] = "bar"; // NOLINT(hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)

            CHECK(j.template value<string_t>(key, "default") == "bar");
            CHECK(j.template value<string_t>(key, cpstr) == "bar");
            CHECK(j.template value<string_t>(key, castr) == "bar");
            CHECK(j.template value<string_t>(key, str) == "bar");
            CHECK(j.template value<number_integer_t>(key2, 0) == 42);
            CHECK(j.template value<number_integer_t>(key2, 47) == 42);
            CHECK(j.template value<number_integer_t>(key2, integer) == 42);
            CHECK(j.template value<std::size_t>(key2, 0) == 42);
            CHECK(j.template value<std::size_t>(key2, 47) == 42);
            CHECK(j.template value<std::size_t>(key2, size) == 42);

            CHECK(j.template value<string_t>(key_notfound, "default") == "default");
            CHECK(j.template value<number_integer_t>(key_notfound, 0) == 0);
            CHECK(j.template value<number_integer_t>(key_notfound, 47) == 47);
            CHECK(j.template value<number_integer_t>(key_notfound, integer) == integer);
            CHECK(j.template value<std::size_t>(key_notfound, 0) == 0);
            CHECK(j.template value<std::size_t>(key_notfound, 47) == 47);
            CHECK(j.template value<std::size_t>(key_notfound, size) == size);

            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

        SECTION("string_t/object_t::key_type key")
        {
            string_t const key = "foo";
            string_t const key2 = "baz";
            string_t const key_notfound = "bar";

            CHECK(j.template value<string_t>(key, "default") == "bar");
            CHECK(j.template value<string_t>(key, cpstr) == "bar");
            CHECK(j.template value<string_t>(key, castr) == "bar");
            CHECK(j.template value<string_t>(key, str) == "bar");
            CHECK(j.template value<number_integer_t>(key2, 0) == 42);
            CHECK(j.template value<number_integer_t>(key2, 47) == 42);
            CHECK(j.template value<std::size_t>(key2, 0) == 42);
            CHECK(j.template value<std::size_t>(key2, 47) == 42);

            CHECK(j.template value<string_t>(key_notfound, "default") == "default");
            CHECK(j.template value<number_integer_t>(key_notfound, 0) == 0);
            CHECK(j.template value<number_integer_t>(key_notfound, 47) == 47);
            CHECK(j.template value<std::size_t>(key_notfound, 0) == 0);
            CHECK(j.template value<std::size_t>(key_notfound, 47) == 47);

            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }

#ifdef JSON_HAS_CPP_17
        SECTION("std::string_view key")
        {
            std::string_view const key = "foo";
            std::string_view const key2 = "baz";
            std::string_view const key_notfound = "bar";

            CHECK(j.template value<string_t>(key, "default") == "bar");
            CHECK(j.template value<string_t>(key, cpstr) == "bar");
            CHECK(j.template value<string_t>(key, castr) == "bar");
            CHECK(j.template value<string_t>(key, str) == "bar");
            CHECK(j.template value<number_integer_t>(key2, 0) == 42);
            CHECK(j.template value<number_integer_t>(key2, 47) == 42);
            CHECK(j.template value<number_integer_t>(key2, integer) == 42);
            CHECK(j.template value<std::size_t>(key2, 0) == 42);
            CHECK(j.template value<std::size_t>(key2, 47) == 42);
            CHECK(j.template value<std::size_t>(key2, size) == 42);

            CHECK(j.template value<string_t>(key_notfound, "default") == "default");
            CHECK(j.template value<number_integer_t>(key_notfound, 0) == 0);
            CHECK(j.template value<number_integer_t>(key_notfound, 47) == 47);
            CHECK(j.template value<number_integer_t>(key_notfound, integer) == integer);
            CHECK(j.template value<std::size_t>(key_notfound, 0) == 0);
            CHECK(j.template value<std::size_t>(key_notfound, 47) == 47);
            CHECK(j.template value<std::size_t>(key_notfound, size) == size);

            CHECK(j.template value<std::string_view>(key, "default") == "bar");
            CHECK(j.template value<std::string_view>(key, cpstr) == "bar");
            CHECK(j.template value<std::string_view>(key, castr) == "bar");
            CHECK(j.template value<std::string_view>(key, str) == "bar");

            CHECK(j.template value<std::string_view>(key_notfound, "default") == "default");

            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, "default"), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
            CHECK_THROWS_WITH_AS(Json().template value<string_t>(key, str), "[json.exception.type_error.306] cannot use value() with null", typename Json::type_error&);
        }
#endif
    }
}