//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
// |  |  |__   |  |  | | | |  version 3.12.0
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT

#include "doctest_compatibility.h"

#define JSON_TESTS_PRIVATE
// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
// line *before* including json.hpp, since the library #undefs it once the header
// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
// tests of deprecated functions are skipped if these functions are deleted
#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
#endif

#include <nlohmann/json.hpp>
using nlohmann::json;
using nlohmann::ordered_json;

#include <algorithm>
#include <climits>
#include <limits>
#include <iostream>
#include <fstream>
#include <set>
#include "make_test_data_available.hpp"
#include "test_utils.hpp"
#include "sax_countdown.hpp"
using utils::SaxCountdown;


// trait_test_arg and the "value_in_range_of trait" TEST_CASE_TEMPLATE_DEFINE
// are shared with unit-32bit.cpp
#include "value_in_range_of_test.hpp"

// NOLINTNEXTLINE(bugprone-throwing-static-initialization)
TEST_CASE_TEMPLATE_INVOKE(value_in_range_of_test, \
                          trait_test_arg<std::int32_t, std::int32_t, true, true>, \
                          trait_test_arg<std::int32_t, std::uint32_t, true, false>, \
                          trait_test_arg<std::uint32_t, std::int32_t, false, true>, \
                          trait_test_arg<std::uint32_t, std::uint32_t, true, true>, \
                          trait_test_arg<std::int32_t, std::int64_t, false, false>, \
                          trait_test_arg<std::int32_t, std::uint64_t, true, false>, \
                          trait_test_arg<std::uint32_t, std::int64_t, false, false>, \
                          trait_test_arg<std::uint32_t, std::uint64_t, true, false>, \
                          trait_test_arg<std::int64_t, std::int32_t, true, true>, \
                          trait_test_arg<std::int64_t, std::uint32_t, true, true>, \
                          trait_test_arg<std::uint64_t, std::int32_t, false, true>, \
                          trait_test_arg<std::uint64_t, std::uint32_t, true, true>, \
                          trait_test_arg<std::int64_t, std::int64_t, true, true>, \
                          trait_test_arg<std::int64_t, std::uint64_t, true, false>, \
                          trait_test_arg<std::uint64_t, std::int64_t, false, true>, \
                          trait_test_arg<std::uint64_t, std::uint64_t, true, true>);

#if SIZE_MAX == 0xffffffff
TEST_CASE_TEMPLATE_INVOKE(value_in_range_of_test, \
                          trait_test_arg<std::size_t, std::int32_t, false, true>, \
                          trait_test_arg<std::size_t, std::uint32_t, true, true>, \
                          trait_test_arg<std::size_t, std::int64_t, false, false>, \
                          trait_test_arg<std::size_t, std::uint64_t, true, false>);
#else
// NOLINTNEXTLINE(bugprone-throwing-static-initialization)
TEST_CASE_TEMPLATE_INVOKE(value_in_range_of_test, \
                          trait_test_arg<std::size_t, std::int32_t, false, true>, \
                          trait_test_arg<std::size_t, std::uint32_t, true, true>, \
                          trait_test_arg<std::size_t, std::int64_t, false, true>, \
                          trait_test_arg<std::size_t, std::uint64_t, true, true>);
#endif

TEST_CASE("BJData")
{
    SECTION("binary_reader BJData lookup tables")
    {
        // both lookups are static member functions
        std::vector<std::uint8_t> const data;
        using reader_t = nlohmann::detail::binary_reader<json, decltype(nlohmann::detail::input_adapter(data))>;

        // the excluded optimized-type markers must match binary_writer's
        // is_bjdata_excluded_type_marker(), which encodes the same 8 markers
        for (const char marker :
                {'[', '{', 'S', 'H', 'T', 'F', 'N', 'Z'
                })
        {
            CHECK(reader_t::is_bjd_excluded_optimized_type(static_cast<unsigned char>(marker)));
        }
        for (const char marker :
                {'U', 'i', 'u', 'I', 'm', 'l', 'M', 'L', 'd', 'D', 'C', 'B', 'x'
                })
        {
            CHECK(!reader_t::is_bjd_excluded_optimized_type(static_cast<unsigned char>(marker)));
        }

        // every dtype marker must round-trip to its ND-array type name
        const std::vector<std::pair<char, std::string>> types
        {
            {'B', "byte"}, {'C', "char"}, {'D', "double"}, {'I', "int16"},
            {'L', "int64"}, {'M', "uint64"}, {'U', "uint8"}, {'d', "single"},
            {'i', "int8"}, {'l', "int32"}, {'m', "uint32"}, {'u', "uint16"}
        };
        for (const auto& type : types)
        {
            const char* name = reader_t::bjd_type_name(static_cast<unsigned char>(type.first));
            REQUIRE(name != nullptr);
            CHECK(std::string(name) == type.second);
        }
        CHECK(reader_t::bjd_type_name(static_cast<unsigned char>('x')) == nullptr);
    }

    SECTION("individual values")
    {
        SECTION("discarded")
        {
            // a discarded value cannot be serialized to BJData
            json const j = json::value_t::discarded;
            CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
        }

        SECTION("discarded values nested in a container")
        {
            json const discarded = json::value_t::discarded;

            SECTION("in an array")
            {
                json const j = {1, discarded, 2};
#if JSON_DIAGNOSTICS
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/1) cannot serialize discarded value to BJData", json::type_error&);
#else
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
#endif
            }

            SECTION("as an object value")
            {
                json j;
                j["a"] = 1;
                j["b"] = discarded;
#if JSON_DIAGNOSTICS
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to BJData", json::type_error&);
#else
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
#endif
            }

            SECTION("nested deeper (array in object in array)")
            {
                json inner_array = {1, discarded};
                json middle_object;
                middle_object["x"] = inner_array;
                json const j = {middle_object};
#if JSON_DIAGNOSTICS
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/0/x/1) cannot serialize discarded value to BJData", json::type_error&);
#else
                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
#endif
            }

            SECTION("optimized array of all-discarded elements")
            {
                json const j = {discarded, discarded};
#if JSON_DIAGNOSTICS
                CHECK_THROWS_WITH_AS(json::to_bjdata(j, true, true), "[json.exception.type_error.321] (/0) cannot serialize discarded value to BJData", json::type_error&);
#else
                CHECK_THROWS_WITH_AS(json::to_bjdata(j, true, true), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
#endif
            }
        }

        SECTION("null")
        {
            json const j = nullptr;
            std::vector<uint8_t> const expected = {'Z'};
            const auto result = json::to_bjdata(j);
            CHECK(result == expected);

            // roundtrip
            CHECK(json::from_bjdata(result) == j);
            CHECK(json::from_bjdata(result, true, false) == j);
        }

        SECTION("boolean")
        {
            SECTION("true")
            {
                json const j = true;
                std::vector<uint8_t> const expected = {'T'};
                const auto result = json::to_bjdata(j);
                CHECK(result == expected);

                // roundtrip
                CHECK(json::from_bjdata(result) == j);
                CHECK(json::from_bjdata(result, true, false) == j);
            }

            SECTION("false")
            {
                json const j = false;
                std::vector<uint8_t> const expected = {'F'};
                const auto result = json::to_bjdata(j);
                CHECK(result == expected);

                // roundtrip
                CHECK(json::from_bjdata(result) == j);
                CHECK(json::from_bjdata(result, true, false) == j);
            }
        }

        SECTION("byte")
        {
            SECTION("0..255 (uint8)")
            {
                for (size_t i = 0; i <= 255; ++i)
                {
                    CAPTURE(i)

                    // create JSON value with integer number (no byte type in JSON)
                    json j = -1;
                    j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                    // check type
                    CHECK(j.is_number_integer());

                    // create byte vector
                    std::vector<uint8_t> const value
                    {
                        static_cast<uint8_t>('B'),
                        static_cast<uint8_t>(i),
                    };

                    // compare value
                    CHECK(json::from_bjdata(value) == j);
                }
            }
        }

        SECTION("number")
        {
            SECTION("signed")
            {
                SECTION("-9223372036854775808..-2147483649 (int64)")
                {
                    std::vector<int64_t> const numbers
                    {
                        (std::numeric_limits<int64_t>::min)(),
                        -1000000000000000000LL,
                        -100000000000000000LL,
                        -10000000000000000LL,
                        -1000000000000000LL,
                        -100000000000000LL,
                        -10000000000000LL,
                        -1000000000000LL,
                        -100000000000LL,
                        -10000000000LL,
                        -2147483649LL,
                    };
                    for (const auto i : numbers)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('L'),
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                            static_cast<uint8_t>((i >> 32) & 0xff),
                            static_cast<uint8_t>((i >> 40) & 0xff),
                            static_cast<uint8_t>((i >> 48) & 0xff),
                            static_cast<uint8_t>((i >> 56) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 9);

                        // check individual bytes
                        CHECK(result[0] == 'L');
                        int64_t const restored = (static_cast<int64_t>(result[8]) << 070) +
                                                 (static_cast<int64_t>(result[7]) << 060) +
                                                 (static_cast<int64_t>(result[6]) << 050) +
                                                 (static_cast<int64_t>(result[5]) << 040) +
                                                 (static_cast<int64_t>(result[4]) << 030) +
                                                 (static_cast<int64_t>(result[3]) << 020) +
                                                 (static_cast<int64_t>(result[2]) << 010) +
                                                 static_cast<int64_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("-2147483648..-32769 (int32)")
                {
                    std::vector<int32_t> const numbers
                    {
                        -32769,
                        -100000,
                        -1000000,
                        -10000000,
                        -100000000,
                        -1000000000,
                        -2147483647 - 1, // https://stackoverflow.com/a/29356002/266378
                    };
                    for (const auto i : numbers)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('l'),
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 5);

                        // check individual bytes
                        CHECK(result[0] == 'l');
                        int32_t const restored = (static_cast<int32_t>(result[4]) << 030) +
                                                 (static_cast<int32_t>(result[3]) << 020) +
                                                 (static_cast<int32_t>(result[2]) << 010) +
                                                 static_cast<int32_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("-32768..-129 (int16)")
                {
                    for (int32_t i = -32768; i <= -129; i = utils::next_integer_sample(i, -129, 7))
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('I'),
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 3);

                        // check individual bytes
                        CHECK(result[0] == 'I');
                        auto const restored = static_cast<int16_t>(((result[2] << 8) + result[1]));
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("-9263 (int16)")
                {
                    json const j = -9263;
                    std::vector<uint8_t> const expected = {'I', 0xd1, 0xdb};

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == 3);

                    // check individual bytes
                    CHECK(result[0] == 'I');
                    auto const restored = static_cast<int16_t>(((result[2] << 8) + result[1]));
                    CHECK(restored == -9263);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("-128..-1 (int8)")
                {
                    for (auto i = -128; i <= -1; ++i)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'i',
                            static_cast<uint8_t>(i),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 2);

                        // check individual bytes
                        CHECK(result[0] == 'i');
                        CHECK(static_cast<int8_t>(result[1]) == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("0..127 (int8)")
                {
                    for (size_t i = 0; i <= 127; ++i)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('i'),
                            static_cast<uint8_t>(i),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 2);

                        // check individual bytes
                        CHECK(result[0] == 'i');
                        CHECK(result[1] == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("128..255 (uint8)")
                {
                    for (size_t i = 128; i <= 255; ++i)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('U'),
                            static_cast<uint8_t>(i),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 2);

                        // check individual bytes
                        CHECK(result[0] == 'U');
                        CHECK(result[1] == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("256..32767 (int16)")
                {
                    for (size_t i = 256; i <= 32767; i = utils::next_integer_sample(i, static_cast<size_t>(32767), static_cast<size_t>(7)))
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('I'),
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 3);

                        // check individual bytes
                        CHECK(result[0] == 'I');
                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("32768..65535 (uint16)")
                {
                    for (const uint32_t i :
                            {
                                32768u, 55555u, 65535u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            static_cast<uint8_t>('u'),
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 3);

                        // check individual bytes
                        CHECK(result[0] == 'u');
                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("65536..2147483647 (int32)")
                {
                    for (const uint32_t i :
                            {
                                65536u, 77777u, 2147483647u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'l',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 5);

                        // check individual bytes
                        CHECK(result[0] == 'l');
                        uint32_t const restored = (static_cast<uint32_t>(result[4]) << 030) +
                                                  (static_cast<uint32_t>(result[3]) << 020) +
                                                  (static_cast<uint32_t>(result[2]) << 010) +
                                                  static_cast<uint32_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("2147483648..4294967295 (uint32)")
                {
                    for (const uint32_t i :
                            {
                                2147483648u, 3333333333u, 4294967295u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'm',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 5);

                        // check individual bytes
                        CHECK(result[0] == 'm');
                        uint32_t const restored = (static_cast<uint32_t>(result[4]) << 030) +
                                                  (static_cast<uint32_t>(result[3]) << 020) +
                                                  (static_cast<uint32_t>(result[2]) << 010) +
                                                  static_cast<uint32_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("4294967296..9223372036854775807 (int64)")
                {
                    std::vector<uint64_t> const v = {4294967296LU, 9223372036854775807LU};
                    for (const uint64_t i : v)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json j = -1;
                        j.get_ref<json::number_integer_t&>() = static_cast<json::number_integer_t>(i);

                        // check type
                        CHECK(j.is_number_integer());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'L',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 010) & 0xff),
                            static_cast<uint8_t>((i >> 020) & 0xff),
                            static_cast<uint8_t>((i >> 030) & 0xff),
                            static_cast<uint8_t>((i >> 040) & 0xff),
                            static_cast<uint8_t>((i >> 050) & 0xff),
                            static_cast<uint8_t>((i >> 060) & 0xff),
                            static_cast<uint8_t>((i >> 070) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 9);

                        // check individual bytes
                        CHECK(result[0] == 'L');
                        uint64_t const restored = (static_cast<uint64_t>(result[8]) << 070) +
                                                  (static_cast<uint64_t>(result[7]) << 060) +
                                                  (static_cast<uint64_t>(result[6]) << 050) +
                                                  (static_cast<uint64_t>(result[5]) << 040) +
                                                  (static_cast<uint64_t>(result[4]) << 030) +
                                                  (static_cast<uint64_t>(result[3]) << 020) +
                                                  (static_cast<uint64_t>(result[2]) << 010) +
                                                  static_cast<uint64_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("9223372036854775808..18446744073709551615 (uint64)")
                {
                    std::vector<uint64_t> const v = {9223372036854775808ull, 18446744073709551615ull};
                    for (const uint64_t i : v)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'M',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 010) & 0xff),
                            static_cast<uint8_t>((i >> 020) & 0xff),
                            static_cast<uint8_t>((i >> 030) & 0xff),
                            static_cast<uint8_t>((i >> 040) & 0xff),
                            static_cast<uint8_t>((i >> 050) & 0xff),
                            static_cast<uint8_t>((i >> 060) & 0xff),
                            static_cast<uint8_t>((i >> 070) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 9);

                        // check individual bytes
                        CHECK(result[0] == 'M');
                        uint64_t const restored = (static_cast<uint64_t>(result[8]) << 070) +
                                                  (static_cast<uint64_t>(result[7]) << 060) +
                                                  (static_cast<uint64_t>(result[6]) << 050) +
                                                  (static_cast<uint64_t>(result[5]) << 040) +
                                                  (static_cast<uint64_t>(result[4]) << 030) +
                                                  (static_cast<uint64_t>(result[3]) << 020) +
                                                  (static_cast<uint64_t>(result[2]) << 010) +
                                                  static_cast<uint64_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }
            }

            SECTION("unsigned")
            {
                SECTION("0..127 (int8)")
                {
                    for (size_t i = 0; i <= 127; ++i)
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected{'i', static_cast<uint8_t>(i)};

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 2);

                        // check individual bytes
                        CHECK(result[0] == 'i');
                        auto const restored = static_cast<uint8_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("128..255 (uint8)")
                {
                    for (size_t i = 128; i <= 255; ++i)
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected{'U', static_cast<uint8_t>(i)};

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 2);

                        // check individual bytes
                        CHECK(result[0] == 'U');
                        auto const restored = static_cast<uint8_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("256..32767 (int16)")
                {
                    for (size_t i = 256; i <= 32767; i = utils::next_integer_sample(i, static_cast<size_t>(32767), static_cast<size_t>(7)))
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'I',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 3);

                        // check individual bytes
                        CHECK(result[0] == 'I');
                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("32768..65535 (uint16)")
                {
                    for (const uint32_t i :
                            {
                                32768u, 55555u, 65535u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'u',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 3);

                        // check individual bytes
                        CHECK(result[0] == 'u');
                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }
                SECTION("65536..2147483647 (int32)")
                {
                    for (const uint32_t i :
                            {
                                65536u, 77777u, 2147483647u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'l',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 5);

                        // check individual bytes
                        CHECK(result[0] == 'l');
                        uint32_t const restored = (static_cast<uint32_t>(result[4]) << 030) +
                                                  (static_cast<uint32_t>(result[3]) << 020) +
                                                  (static_cast<uint32_t>(result[2]) << 010) +
                                                  static_cast<uint32_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("2147483648..4294967295 (uint32)")
                {
                    for (const uint32_t i :
                            {
                                2147483648u, 3333333333u, 4294967295u
                            })
                    {
                        CAPTURE(i)

                        // create JSON value with unsigned integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'm',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 8) & 0xff),
                            static_cast<uint8_t>((i >> 16) & 0xff),
                            static_cast<uint8_t>((i >> 24) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 5);

                        // check individual bytes
                        CHECK(result[0] == 'm');
                        uint32_t const restored = (static_cast<uint32_t>(result[4]) << 030) +
                                                  (static_cast<uint32_t>(result[3]) << 020) +
                                                  (static_cast<uint32_t>(result[2]) << 010) +
                                                  static_cast<uint32_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("4294967296..9223372036854775807 (int64)")
                {
                    std::vector<uint64_t> const v = {4294967296ul, 9223372036854775807ul};
                    for (const uint64_t i : v)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'L',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 010) & 0xff),
                            static_cast<uint8_t>((i >> 020) & 0xff),
                            static_cast<uint8_t>((i >> 030) & 0xff),
                            static_cast<uint8_t>((i >> 040) & 0xff),
                            static_cast<uint8_t>((i >> 050) & 0xff),
                            static_cast<uint8_t>((i >> 060) & 0xff),
                            static_cast<uint8_t>((i >> 070) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 9);

                        // check individual bytes
                        CHECK(result[0] == 'L');
                        uint64_t const restored = (static_cast<uint64_t>(result[8]) << 070) +
                                                  (static_cast<uint64_t>(result[7]) << 060) +
                                                  (static_cast<uint64_t>(result[6]) << 050) +
                                                  (static_cast<uint64_t>(result[5]) << 040) +
                                                  (static_cast<uint64_t>(result[4]) << 030) +
                                                  (static_cast<uint64_t>(result[3]) << 020) +
                                                  (static_cast<uint64_t>(result[2]) << 010) +
                                                  static_cast<uint64_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }

                SECTION("9223372036854775808..18446744073709551615 (uint64)")
                {
                    std::vector<uint64_t> const v = {9223372036854775808ull, 18446744073709551615ull};
                    for (const uint64_t i : v)
                    {
                        CAPTURE(i)

                        // create JSON value with integer number
                        json const j = i;

                        // check type
                        CHECK(j.is_number_unsigned());

                        // create expected byte vector
                        std::vector<uint8_t> const expected
                        {
                            'M',
                            static_cast<uint8_t>(i & 0xff),
                            static_cast<uint8_t>((i >> 010) & 0xff),
                            static_cast<uint8_t>((i >> 020) & 0xff),
                            static_cast<uint8_t>((i >> 030) & 0xff),
                            static_cast<uint8_t>((i >> 040) & 0xff),
                            static_cast<uint8_t>((i >> 050) & 0xff),
                            static_cast<uint8_t>((i >> 060) & 0xff),
                            static_cast<uint8_t>((i >> 070) & 0xff),
                        };

                        // compare result + size
                        const auto result = json::to_bjdata(j);
                        CHECK(result == expected);
                        CHECK(result.size() == 9);

                        // check individual bytes
                        CHECK(result[0] == 'M');
                        uint64_t const restored = (static_cast<uint64_t>(result[8]) << 070) +
                                                  (static_cast<uint64_t>(result[7]) << 060) +
                                                  (static_cast<uint64_t>(result[6]) << 050) +
                                                  (static_cast<uint64_t>(result[5]) << 040) +
                                                  (static_cast<uint64_t>(result[4]) << 030) +
                                                  (static_cast<uint64_t>(result[3]) << 020) +
                                                  (static_cast<uint64_t>(result[2]) << 010) +
                                                  static_cast<uint64_t>(result[1]);
                        CHECK(restored == i);

                        // roundtrip
                        CHECK(json::from_bjdata(result) == j);
                        CHECK(json::from_bjdata(result, true, false) == j);
                    }
                }
            }
            SECTION("float64")
            {
                SECTION("3.1415925")
                {
                    double v = 3.1415925;
                    json const j = v;
                    std::vector<uint8_t> const expected =
                    {
                        'D', 0xfc, 0xde, 0xa6, 0x3f, 0xfb, 0x21, 0x09, 0x40
                    };
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result) == v);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("half-precision float")
            {
                SECTION("simple half floats")
                {
                    CHECK(json::parse("0.0") == json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x00})));
                    CHECK(json::parse("-0.0") == json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x80})));
                    CHECK(json::parse("1.0") == json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x3c})));
                    CHECK(json::parse("1.5") == json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x3e})));
                    CHECK(json::parse("65504.0") == json::from_bjdata(std::vector<uint8_t>({'h', 0xff, 0x7b})));
                }

                SECTION("errors")
                {
                    SECTION("no byte follows")
                    {
                        json _;
                        std::vector<uint8_t> const vec0 = {'h'};
                        CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec0), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
                        CHECK(json::from_bjdata(vec0, true, false).is_discarded());
                    }

                    SECTION("only one byte follows")
                    {
                        json _;
                        std::vector<uint8_t> const vec1 = {'h', 0x00};
                        CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec1), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
                        CHECK(json::from_bjdata(vec1, true, false).is_discarded());
                    }
                }
            }

            SECTION("half-precision float (edge cases)")
            {
                SECTION("exp = 0b00000")
                {
                    SECTION("0 (0 00000 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x00}));
                        const json::number_float_t d{j};
                        CHECK(d == 0.0);
                    }

                    SECTION("-0 (1 00000 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x80}));
                        const json::number_float_t d{j};
                        CHECK(d == -0.0);
                    }

                    SECTION("2**-24 (0 00000 0000000001)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x01, 0x00}));
                        const json::number_float_t d{j};
                        CHECK(d == std::pow(2.0, -24.0));
                    }
                }

                SECTION("exp = 0b11111")
                {
                    SECTION("infinity (0 11111 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x7c}));
                        const json::number_float_t d{j};
                        CHECK(d == std::numeric_limits<json::number_float_t>::infinity());
                        CHECK(j.dump() == "null");
                    }

                    SECTION("-infinity (1 11111 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0xfc}));
                        const json::number_float_t d{j};
                        CHECK(d == -std::numeric_limits<json::number_float_t>::infinity());
                        CHECK(j.dump() == "null");
                    }
                }

                SECTION("other values from https://en.wikipedia.org/wiki/Half-precision_floating-point_format")
                {
                    SECTION("1 (0 01111 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x3c}));
                        const json::number_float_t d{j};
                        CHECK(d == 1);
                    }

                    SECTION("-2 (1 10000 0000000000)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0xc0}));
                        const json::number_float_t d{j};
                        CHECK(d == -2);
                    }

                    SECTION("65504 (0 11110 1111111111)")
                    {
                        json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0xff, 0x7b}));
                        const json::number_float_t d{j};
                        CHECK(d == 65504);
                    }
                }

                SECTION("infinity")
                {
                    json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x7c}));
                    json::number_float_t const d{j};
                    CHECK_FALSE(std::isfinite(d));
                    CHECK(j.dump() == "null");
                }

                SECTION("NaN")
                {
                    json const j = json::from_bjdata(std::vector<uint8_t>({'h', 0x00, 0x7e }));
                    json::number_float_t const d{j};
                    CHECK(std::isnan(d));
                    CHECK(j.dump() == "null");
                }
            }

            SECTION("high-precision number")
            {
                SECTION("unsigned integer number")
                {
                    std::vector<uint8_t> const vec = {'H', 'i', 0x14, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0'};
                    const auto j = json::from_bjdata(vec);
                    CHECK(j.is_number_unsigned());
                    CHECK(j.dump() == "12345678901234567890");
                }

                SECTION("signed integer number")
                {
                    std::vector<uint8_t> const vec = {'H', 'i', 0x13, '-', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8'};
                    const auto j = json::from_bjdata(vec);
                    CHECK(j.is_number_integer());
                    CHECK(j.dump() == "-123456789012345678");
                }

                SECTION("floating-point number")
                {
                    std::vector<uint8_t> const vec = {'H', 'i', 0x16, '3', '.', '1', '4', '1', '5', '9',  '2', '6', '5', '3', '5', '8', '9',  '7', '9', '3', '2', '3', '8', '4',  '6'};
                    const auto j = json::from_bjdata(vec);
                    CHECK(j.is_number_float());
                    CHECK(j.dump() == "3.141592653589793");
                }

                SECTION("errors")
                {
                    // error while parsing length
                    std::vector<uint8_t> const vec0 = {'H', 'i'};
                    CHECK(json::from_bjdata(vec0, true, false).is_discarded());
                    // error while parsing string
                    std::vector<uint8_t> const vec1 = {'H', 'i', '1'};
                    CHECK(json::from_bjdata(vec1, true, false).is_discarded());

                    json _;
                    std::vector<uint8_t> const vec2 = {'H', 'i', 2, '1', 'A', '3'};
                    CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec2), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing BJData high-precision number: invalid number text: 1A", json::parse_error);
                    std::vector<uint8_t> const vec3 = {'H', 'i', 2, '1', '.'};
                    CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec3), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing BJData high-precision number: invalid number text: 1.", json::parse_error);
                    // Reject NULs where they are read, including trailing NULs and payloads cut off after one.
                    SECTION("NUL in high-precision number (issue #5753)")
                    {
                        for (const auto& vec : std::vector<std::vector<uint8_t>>
                    {
                        {'H', 'i', 3, '1', 0, 'x'},
                        {'H', 'i', 2, '1', 0},
                        {'H', 'i', 3, '1', 0}
                    })
                        {
                            CAPTURE(vec)
                            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec), "[json.exception.parse_error.115] parse error at byte 5: syntax error while parsing BJData high-precision number: invalid number text; last byte: 0x00", json::parse_error);
                            CHECK(json::from_bjdata(vec, true, false).is_discarded());
                            CHECK(json::from_bjdata(vec, false, false).is_discarded());
                        }

                        std::vector<uint8_t> const nested = {'[', 'H', 'i', 3, '1', 0, 'x', ']'};
                        CHECK_THROWS_WITH_AS(_ = json::from_bjdata(nested), "[json.exception.parse_error.115] parse error at byte 6: syntax error while parsing BJData high-precision number: invalid number text; last byte: 0x00", json::parse_error);
                        CHECK(json::from_bjdata(nested, true, false).is_discarded());

                        std::vector<uint8_t> const valid = {'H', 'i', 1, '1'};
                        const auto j = json::from_bjdata(valid);
                        CHECK(j.is_number_unsigned());
                        CHECK(j == json(1));
                    }

                    std::vector<uint8_t> const vec_overflow = {'H', 'i', 5, '1', 'e', '4', '0', '0'};
                    CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec_overflow), "[json.exception.out_of_range.406] number overflow parsing '1e400'", json::out_of_range);
                    std::vector<uint8_t> const vec4 = {'H', 2, '1', '0'};
                    CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec4), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x02", json::parse_error);
                }
            }
        }

        SECTION("string")
        {
            SECTION("N = 0..127")
            {
                for (size_t N = 0; N <= 127; ++N)
                {
                    CAPTURE(N)

                    // create JSON value with string containing of N * 'x'
                    const auto s = std::string(N, 'x');
                    json const j = s;

                    // create expected byte vector
                    std::vector<uint8_t> expected;
                    expected.push_back('S');
                    expected.push_back('i');
                    expected.push_back(static_cast<uint8_t>(N));
                    for (size_t i = 0; i < N; ++i)
                    {
                        expected.push_back('x');
                    }

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == N + 3);
                    // check that no null byte is appended
                    if (N > 0)
                    {
                        CHECK(result.back() != '\x00');
                    }

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("N = 128..255")
            {
                for (size_t N = 128; N <= 255; ++N)
                {
                    CAPTURE(N)

                    // create JSON value with string containing of N * 'x'
                    const auto s = std::string(N, 'x');
                    json const j = s;

                    // create expected byte vector
                    std::vector<uint8_t> expected;
                    expected.push_back('S');
                    expected.push_back('U');
                    expected.push_back(static_cast<uint8_t>(N));
                    for (size_t i = 0; i < N; ++i)
                    {
                        expected.push_back('x');
                    }

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == N + 3);
                    // check that no null byte is appended
                    CHECK(result.back() != '\x00');

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("N = 256..32767")
            {
                for (const size_t N :
                        {
                            256u, 999u, 1025u, 3333u, 2048u, 32767u
                        })
                {
                    CAPTURE(N)

                    // create JSON value with string containing of N * 'x'
                    const auto s = std::string(N, 'x');
                    json const j = s;

                    // create expected byte vector (hack: create string first)
                    std::vector<uint8_t> expected(N, 'x');
                    // reverse order of commands, because we insert at begin()
                    expected.insert(expected.begin(), static_cast<uint8_t>((N >> 8) & 0xff));
                    expected.insert(expected.begin(), static_cast<uint8_t>(N & 0xff));
                    expected.insert(expected.begin(), 'I');
                    expected.insert(expected.begin(), 'S');

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == N + 4);
                    // check that no null byte is appended
                    CHECK(result.back() != '\x00');

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("N = 32768..65535")
            {
                for (const size_t N :
                        {
                            32768u, 55555u, 65535u
                        })
                {
                    CAPTURE(N)

                    // create JSON value with string containing of N * 'x'
                    const auto s = std::string(N, 'x');
                    json const j = s;

                    // create expected byte vector (hack: create string first)
                    std::vector<uint8_t> expected(N, 'x');
                    // reverse order of commands, because we insert at begin()
                    expected.insert(expected.begin(), static_cast<uint8_t>((N >> 8) & 0xff));
                    expected.insert(expected.begin(), static_cast<uint8_t>(N & 0xff));
                    expected.insert(expected.begin(), 'u');
                    expected.insert(expected.begin(), 'S');

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == N + 4);
                    // check that no null byte is appended
                    CHECK(result.back() != '\x00');

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("N = 65536..2147483647")
            {
                for (const size_t N :
                        {
                            65536u, 77777u, 1048576u
                        })
                {
                    CAPTURE(N)

                    // create JSON value with string containing of N * 'x'
                    const auto s = std::string(N, 'x');
                    json const j = s;

                    // create expected byte vector (hack: create string first)
                    std::vector<uint8_t> expected(N, 'x');
                    // reverse order of commands, because we insert at begin()
                    expected.insert(expected.begin(), static_cast<uint8_t>((N >> 24) & 0xff));
                    expected.insert(expected.begin(), static_cast<uint8_t>((N >> 16) & 0xff));
                    expected.insert(expected.begin(), static_cast<uint8_t>((N >> 8) & 0xff));
                    expected.insert(expected.begin(), static_cast<uint8_t>(N & 0xff));
                    expected.insert(expected.begin(), 'l');
                    expected.insert(expected.begin(), 'S');

                    // compare result + size
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);
                    CHECK(result.size() == N + 6);
                    // check that no null byte is appended
                    CHECK(result.back() != '\x00');

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }
        }

        SECTION("binary")
        {
            for (json::bjdata_version_t bjdata_version :
                    {
                        json::bjdata_version_t::draft2, json::bjdata_version_t::draft3
                    })
            {
                CAPTURE(bjdata_version)
                const bool draft3 = (bjdata_version == json::bjdata_version_t::draft3);

                SECTION("N = 0..127")
                {
                    for (std::size_t N = 0; N <= 127; ++N)
                    {
                        CAPTURE(N)

                        // create JSON value with byte array containing of N * 'x'
                        const auto s = std::vector<std::uint8_t>(N, 'x');
                        json const j = json::binary(s);

                        // create expected byte vector
                        std::vector<std::uint8_t> expected;
                        expected.push_back(static_cast<std::uint8_t>('['));
                        if (draft3 || N != 0)
                        {
                            expected.push_back(static_cast<std::uint8_t>('$'));
                            expected.push_back(static_cast<std::uint8_t>(draft3 ? 'B' : 'U'));
                        }
                        expected.push_back(static_cast<std::uint8_t>('#'));
                        expected.push_back(static_cast<std::uint8_t>('i'));
                        expected.push_back(static_cast<std::uint8_t>(N));
                        for (size_t i = 0; i < N; ++i)
                        {
                            expected.push_back(0x78);
                        }

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, true, bjdata_version);
                        CHECK(result == expected);
                        if (!draft3 && N == 0)
                        {
                            CHECK(result.size() == N + 4);
                        }
                        else
                        {
                            CHECK(result.size() == N + 6);
                        }

                        // check that no null byte is appended
                        if (N > 0)
                        {
                            CHECK(result.back() != '\x00');
                        }

                        if (draft3)
                        {
                            // roundtrip
                            CHECK(json::from_bjdata(result) == j);
                            CHECK(json::from_bjdata(result, true, false) == j);
                        }
                        else
                        {
                            // roundtrip only works to an array of numbers
                            json j_out = s;
                            CHECK(json::from_bjdata(result) == j_out);
                            CHECK(json::from_bjdata(result, true, false) == j_out);
                        }
                    }
                }

                SECTION("N = 128..255")
                {
                    for (std::size_t N = 128; N <= 255; ++N)
                    {
                        CAPTURE(N)

                        // create JSON value with byte array containing of N * 'x'
                        const auto s = std::vector<std::uint8_t>(N, 'x');
                        json const j = json::binary(s);

                        // create expected byte vector
                        std::vector<uint8_t> expected;
                        expected.push_back(static_cast<std::uint8_t>('['));
                        expected.push_back(static_cast<std::uint8_t>('$'));
                        expected.push_back(static_cast<std::uint8_t>(draft3 ? 'B' : 'U'));
                        expected.push_back(static_cast<std::uint8_t>('#'));
                        expected.push_back(static_cast<std::uint8_t>('U'));
                        expected.push_back(static_cast<std::uint8_t>(N));
                        for (size_t i = 0; i < N; ++i)
                        {
                            expected.push_back(0x78);
                        }

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, true, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 6);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        if (draft3)
                        {
                            // roundtrip
                            CHECK(json::from_bjdata(result) == j);
                            CHECK(json::from_bjdata(result, true, false) == j);
                        }
                        else
                        {
                            // roundtrip only works to an array of numbers
                            json j_out = s;
                            CHECK(json::from_bjdata(result) == j_out);
                            CHECK(json::from_bjdata(result, true, false) == j_out);
                        }
                    }
                }

                SECTION("N = 256..32767")
                {
                    for (const std::size_t N :
                            {
                                256u, 999u, 1025u, 3333u, 2048u, 32767u
                            })
                    {
                        CAPTURE(N)

                        // create JSON value with byte array containing of N * 'x'
                        const auto s = std::vector<std::uint8_t>(N, 'x');
                        json const j = json::binary(s);

                        // create expected byte vector
                        std::vector<std::uint8_t> expected(N + 7, 'x');
                        expected[0] = '[';
                        expected[1] = '$';
                        expected[2] = draft3 ? 'B' : 'U';
                        expected[3] = '#';
                        expected[4] = 'I';
                        expected[5] = static_cast<std::uint8_t>(N & 0xFF);
                        expected[6] = static_cast<std::uint8_t>((N >> 8) & 0xFF);

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, true, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 7);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        if (draft3)
                        {
                            // roundtrip
                            CHECK(json::from_bjdata(result) == j);
                            CHECK(json::from_bjdata(result, true, false) == j);
                        }
                        else
                        {
                            // roundtrip only works to an array of numbers
                            json j_out = s;
                            CHECK(json::from_bjdata(result) == j_out);
                            CHECK(json::from_bjdata(result, true, false) == j_out);
                        }
                    }
                }

                SECTION("N = 32768..65535")
                {
                    for (const std::size_t N :
                            {
                                32768u, 55555u, 65535u
                            })
                    {
                        CAPTURE(N)

                        // create JSON value with byte array containing of N * 'x'
                        const auto s = std::vector<std::uint8_t>(N, 'x');
                        json const j = json::binary(s);

                        // create expected byte vector
                        std::vector<std::uint8_t> expected(N + 7, 'x');
                        expected[0] = '[';
                        expected[1] = '$';
                        expected[2] = draft3 ? 'B' : 'U';
                        expected[3] = '#';
                        expected[4] = 'u';
                        expected[5] = static_cast<std::uint8_t>(N & 0xFF);
                        expected[6] = static_cast<std::uint8_t>((N >> 8) & 0xFF);

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, true, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 7);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        if (draft3)
                        {
                            // roundtrip
                            CHECK(json::from_bjdata(result) == j);
                            CHECK(json::from_bjdata(result, true, false) == j);
                        }
                        else
                        {
                            // roundtrip only works to an array of numbers
                            json j_out = s;
                            CHECK(json::from_bjdata(result) == j_out);
                            CHECK(json::from_bjdata(result, true, false) == j_out);
                        }
                    }
                }

                SECTION("N = 65536..2147483647")
                {
                    for (const std::size_t N :
                            {
                                65536u, 77777u, 1048576u
                            })
                    {
                        CAPTURE(N)

                        // create JSON value with byte array containing of N * 'x'
                        const auto s = std::vector<std::uint8_t>(N, 'x');
                        json const j = json::binary(s);

                        // create expected byte vector
                        std::vector<std::uint8_t> expected(N + 9, 'x');
                        expected[0] = '[';
                        expected[1] = '$';
                        expected[2] = draft3 ? 'B' : 'U';
                        expected[3] = '#';
                        expected[4] = 'l';
                        expected[5] = static_cast<std::uint8_t>(N & 0xFF);
                        expected[6] = static_cast<std::uint8_t>((N >> 8) & 0xFF);
                        expected[7] = static_cast<std::uint8_t>((N >> 16) & 0xFF);
                        expected[8] = static_cast<std::uint8_t>((N >> 24) & 0xFF);

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, true, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 9);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        if (draft3)
                        {
                            // roundtrip
                            CHECK(json::from_bjdata(result) == j);
                            CHECK(json::from_bjdata(result, true, false) == j);
                        }
                        else
                        {
                            // roundtrip only works to an array of numbers
                            json j_out = s;
                            CHECK(json::from_bjdata(result) == j_out);
                            CHECK(json::from_bjdata(result, true, false) == j_out);
                        }
                    }
                }

                SECTION("Other Serializations")
                {
                    const std::size_t N = 10;
                    const auto s = std::vector<std::uint8_t>(N, 'x');
                    json const j = json::binary(s);

                    SECTION("No Count No Type")
                    {
                        std::vector<uint8_t> expected;
                        expected.push_back(static_cast<std::uint8_t>('['));
                        for (std::size_t i = 0; i < N; ++i)
                        {
                            expected.push_back(static_cast<std::uint8_t>(draft3 ? 'B' : 'U'));
                            expected.push_back(static_cast<std::uint8_t>(0x78));
                        }
                        expected.push_back(static_cast<std::uint8_t>(']'));

                        // compare result + size
                        const auto result = json::to_bjdata(j, false, false, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 12);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        // roundtrip only works to an array of numbers
                        json j_out = s;
                        CHECK(json::from_bjdata(result) == j_out);
                        CHECK(json::from_bjdata(result, true, false) == j_out);
                    }

                    SECTION("Yes Count No Type")
                    {
                        std::vector<std::uint8_t> expected;
                        expected.push_back(static_cast<std::uint8_t>('['));
                        expected.push_back(static_cast<std::uint8_t>('#'));
                        expected.push_back(static_cast<std::uint8_t>('i'));
                        expected.push_back(static_cast<std::uint8_t>(N));

                        for (size_t i = 0; i < N; ++i)
                        {
                            expected.push_back(static_cast<std::uint8_t>(draft3 ? 'B' : 'U'));
                            expected.push_back(static_cast<std::uint8_t>(0x78));
                        }

                        // compare result + size
                        const auto result = json::to_bjdata(j, true, false, bjdata_version);
                        CHECK(result == expected);
                        CHECK(result.size() == N + 14);
                        // check that no null byte is appended
                        CHECK(result.back() != '\x00');

                        // roundtrip only works to an array of numbers
                        json j_out = s;
                        CHECK(json::from_bjdata(result) == j_out);
                        CHECK(json::from_bjdata(result, true, false) == j_out);
                    }
                }
            }
        }
        SECTION("array")
        {
            SECTION("empty")
            {
                SECTION("size=false type=false")
                {
                    json const j = json::array();
                    std::vector<uint8_t> const expected = {'[', ']'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = json::array();
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true")
                {
                    json const j = json::array();
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("[null]")
            {
                SECTION("size=false type=false")
                {
                    json const j = {nullptr};
                    std::vector<uint8_t> const expected = {'[', 'Z', ']'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = {nullptr};
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 1, 'Z'};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true")
                {
                    json const j = {nullptr};
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 1, 'Z'};
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("[1,2,3,4,5]")
            {
                SECTION("size=false type=false")
                {
                    json const j = json::parse("[1,2,3,4,5]");
                    std::vector<uint8_t> const expected = {'[', 'i', 1, 'i', 2, 'i', 3, 'i', 4, 'i', 5, ']'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = json::parse("[1,2,3,4,5]");
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 5, 'i', 1, 'i', 2, 'i', 3, 'i', 4, 'i', 5};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true")
                {
                    json const j = json::parse("[1,2,3,4,5]");
                    std::vector<uint8_t> const expected = {'[', '$', 'i', '#', 'i', 5, 1, 2, 3, 4, 5};
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("[[[[]]]]")
            {
                SECTION("size=false type=false")
                {
                    json const j = json::parse("[[[[]]]]");
                    std::vector<uint8_t> const expected = {'[', '[', '[', '[', ']', ']', ']', ']'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = json::parse("[[[[]]]]");
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 1, '[', '#', 'i', 1, '[', '#', 'i', 1, '[', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true")
                {
                    json const j = json::parse("[[[[]]]]");
                    std::vector<uint8_t> const expected = {'[', '#', 'i', 1, '[', '#', 'i', 1, '[', '#', 'i', 1, '[', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("array with int16_t elements")
            {
                SECTION("size=false type=false")
                {
                    json j(257, nullptr);
                    std::vector<uint8_t> expected(j.size() + 2, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[258] = ']'; // closing array
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json j(257, nullptr);
                    std::vector<uint8_t> expected(j.size() + 5, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[1] = '#'; // array size
                    expected[2] = 'I'; // int16
                    expected[3] = 0x01; // 0x0101, first byte
                    expected[4] = 0x01; // 0x0101, second byte
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("array with uint16_t elements")
            {
                SECTION("size=false type=false")
                {
                    json j(32768, nullptr);
                    std::vector<uint8_t> expected(j.size() + 2, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[32769] = ']'; // closing array
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json j(32768, nullptr);
                    std::vector<uint8_t> expected(j.size() + 5, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[1] = '#'; // array size
                    expected[2] = 'u'; // int16
                    expected[3] = 0x00; // 0x0101, first byte
                    expected[4] = 0x80; // 0x0101, second byte
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("array with int32_t elements")
            {
                SECTION("size=false type=false")
                {
                    json j(65793, nullptr);
                    std::vector<uint8_t> expected(j.size() + 2, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[65794] = ']'; // closing array
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json j(65793, nullptr);
                    std::vector<uint8_t> expected(j.size() + 7, 'Z'); // all null
                    expected[0] = '['; // opening array
                    expected[1] = '#'; // array size
                    expected[2] = 'l'; // int32
                    expected[3] = 0x01; // 0x00010101, fourth byte
                    expected[4] = 0x01; // 0x00010101, third byte
                    expected[5] = 0x01; // 0x00010101, second byte
                    expected[6] = 0x00; // 0x00010101, first byte
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }
        }

        SECTION("object")
        {
            SECTION("empty")
            {
                SECTION("size=false type=false")
                {
                    json const j = json::object();
                    std::vector<uint8_t> const expected = {'{', '}'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = json::object();
                    std::vector<uint8_t> const expected = {'{', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true")
                {
                    json const j = json::object();
                    std::vector<uint8_t> const expected = {'{', '#', 'i', 0};
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("{\"\":null}")
            {
                SECTION("size=false type=false")
                {
                    json const j = {{"", nullptr}};
                    std::vector<uint8_t> const expected = {'{', 'i', 0, 'Z', '}'};
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = {{"", nullptr}};
                    std::vector<uint8_t> const expected = {'{', '#', 'i', 1, 'i', 0, 'Z'};
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }

            SECTION("{\"a\": {\"b\": {\"c\": {}}}}")
            {
                SECTION("size=false type=false")
                {
                    json const j = json::parse(R"({"a": {"b": {"c": {}}}})");
                    std::vector<uint8_t> const expected =
                    {
                        '{', 'i', 1, 'a', '{', 'i', 1, 'b', '{', 'i', 1, 'c', '{', '}', '}', '}', '}'
                    };
                    const auto result = json::to_bjdata(j);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=false")
                {
                    json const j = json::parse(R"({"a": {"b": {"c": {}}}})");
                    std::vector<uint8_t> const expected =
                    {
                        '{', '#', 'i', 1, 'i', 1, 'a', '{', '#', 'i', 1, 'i', 1, 'b', '{', '#', 'i', 1, 'i', 1, 'c', '{', '#', 'i', 0
                    };
                    const auto result = json::to_bjdata(j, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }

                SECTION("size=true type=true ignore object type marker")
                {
                    json const j = json::parse(R"({"a": {"b": {"c": {}}}})");
                    std::vector<uint8_t> const expected =
                    {
                        '{', '#', 'i', 1, 'i', 1, 'a', '{', '#', 'i', 1, 'i', 1, 'b', '{', '#', 'i', 1, 'i', 1, 'c', '{', '#', 'i', 0
                    };
                    const auto result = json::to_bjdata(j, true, true);
                    CHECK(result == expected);

                    // roundtrip
                    CHECK(json::from_bjdata(result) == j);
                    CHECK(json::from_bjdata(result, true, false) == j);
                }
            }
        }
    }

    SECTION("errors")
    {
        SECTION("strict mode")
        {
            std::vector<uint8_t> const vec = {'Z', 'Z'};
            SECTION("non-strict mode")
            {
                const auto result = json::from_bjdata(vec, false);
                CHECK(result == json());
            }

            SECTION("strict mode")
            {
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vec),
                                     "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData value: expected end of input; last byte: 0x5A", json::parse_error&);
            }
        }
    }

    SECTION("SAX aborts")
    {
        SECTION("start_array()")
        {
            std::vector<uint8_t> const v = {'[', 'T', 'F', ']'};
            SaxCountdown scp(0);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("start_object()")
        {
            std::vector<uint8_t> const v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
            SaxCountdown scp(0);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("key() in object")
        {
            std::vector<uint8_t> const v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
            SaxCountdown scp(1);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("start_array(len)")
        {
            std::vector<uint8_t> const v = {'[', '#', 'i', '2', 'T', 'F'};
            SaxCountdown scp(0);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("start_object(len)")
        {
            std::vector<uint8_t> const v = {'{', '#', 'i', '1', 3, 'f', 'o', 'o', 'F'};
            SaxCountdown scp(0);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("key() in object with length")
        {
            std::vector<uint8_t> const v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
            SaxCountdown scp(1);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("start_array() in ndarray _ArraySize_")
        {
            // _ArrayType_ (2 events: key + string) is now emitted before
            // _ArraySize_ (see GitHub issue #5661), which shifts the events
            // below later by the same 2 events
            std::vector<uint8_t> const v = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 2, 2, 1, 1, 2};
            SaxCountdown scp(4);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("number_integer() in ndarray _ArraySize_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 2, 1, 1, 2};
            SaxCountdown scp(5);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("key() in ndarray _ArrayType_")
        {
            // _ArrayType_ is emitted right after start_object(), before _ArraySize_
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'U', '#', 'i', 2, 2, 2, 1, 2, 3, 4};
            SaxCountdown scp(1);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("string() in ndarray _ArrayType_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'U', '#', 'i', 2, 2, 2, 1, 2, 3, 4};
            SaxCountdown scp(2);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("key() in ndarray _ArrayData_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'U', '#', 'i', 2, 2, 2, 1, 2, 3, 4};
            SaxCountdown scp(8);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("string() in ndarray _ArrayData_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'U', '#', 'i', 2, 2, 2, 1, 2, 3, 4};
            SaxCountdown scp(9);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("string() in ndarray _ArrayType_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 3, 2, 6, 5, 4, 3, 2, 1};
            SaxCountdown scp(11);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }

        SECTION("start_array() in ndarray _ArrayData_")
        {
            std::vector<uint8_t> const v = {'[', '$', 'U', '#', '[', 'i', 2, 'i', 3, ']', 6, 5, 4, 3, 2, 1};
            SaxCountdown scp(13);
            CHECK_FALSE(json::sax_parse(v, &scp, json::input_format_t::bjdata));
        }
    }

    SECTION("parsing values")
    {
        SECTION("strings")
        {
            // create a single-character string for all number types
            std::vector<uint8_t> s_i = {'S', 'i', 1, 'a'};
            std::vector<uint8_t> const s_U = {'S', 'U', 1, 'a'};
            std::vector<uint8_t> const s_I = {'S', 'I', 1, 0, 'a'};
            std::vector<uint8_t> const s_u = {'S', 'u', 1, 0, 'a'};
            std::vector<uint8_t> const s_l = {'S', 'l', 1, 0, 0, 0, 'a'};
            std::vector<uint8_t> const s_m = {'S', 'm', 1, 0, 0, 0, 'a'};
            std::vector<uint8_t> const s_L = {'S', 'L', 1, 0, 0, 0, 0, 0, 0, 0, 'a'};
            std::vector<uint8_t> const s_M = {'S', 'M', 1, 0, 0, 0, 0, 0, 0, 0, 'a'};

            // check if string is parsed correctly to "a"
            CHECK(json::from_bjdata(s_i) == "a");
            CHECK(json::from_bjdata(s_U) == "a");
            CHECK(json::from_bjdata(s_I) == "a");
            CHECK(json::from_bjdata(s_u) == "a");
            CHECK(json::from_bjdata(s_l) == "a");
            CHECK(json::from_bjdata(s_m) == "a");
            CHECK(json::from_bjdata(s_L) == "a");
            CHECK(json::from_bjdata(s_M) == "a");

            // roundtrip: output should be optimized
            CHECK(json::to_bjdata(json::from_bjdata(s_i)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_U)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_I)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_u)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_l)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_m)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_L)) == s_i);
            CHECK(json::to_bjdata(json::from_bjdata(s_M)) == s_i);
        }

        SECTION("number")
        {
            SECTION("float")
            {
                // float32
                std::vector<uint8_t> const v_d = {'d', 0xd0, 0x0f, 0x49, 0x40};
                CHECK(json::from_bjdata(v_d) == 3.14159f);

                // float64
                std::vector<uint8_t> const v_D = {'D', 0x6e, 0x86, 0x1b, 0xf0, 0xf9, 0x21, 0x09, 0x40};
                CHECK(json::from_bjdata(v_D) == 3.14159);

                // float32 is serialized as float64 as the library does not support float32
                CHECK(json::to_bjdata(json::from_bjdata(v_d)) == json::to_bjdata(3.14159f));
            }
        }

        SECTION("array")
        {
            SECTION("optimized version (length only)")
            {
                // create vector with two elements of the same type
                std::vector<uint8_t> const v_TU = {'[', '#', 'U', 2, 'T', 'T'};
                std::vector<uint8_t> const v_T = {'[', '#', 'i', 2, 'T', 'T'};
                std::vector<uint8_t> const v_F = {'[', '#', 'i', 2, 'F', 'F'};
                std::vector<uint8_t> const v_Z = {'[', '#', 'i', 2, 'Z', 'Z'};
                std::vector<uint8_t> const v_i = {'[', '#', 'i', 2, 'i', 0x7F, 'i', 0x7F};
                std::vector<uint8_t> const v_U = {'[', '#', 'i', 2, 'U', 0xFF, 'U', 0xFF};
                std::vector<uint8_t> const v_I = {'[', '#', 'i', 2, 'I', 0xFF, 0x7F, 'I', 0xFF, 0x7F};
                std::vector<uint8_t> const v_u = {'[', '#', 'i', 2, 'u', 0x0F, 0xA7, 'u', 0x0F, 0xA7};
                std::vector<uint8_t> const v_l = {'[', '#', 'i', 2, 'l', 0xFF, 0xFF, 0xFF, 0x7F, 'l', 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_m = {'[', '#', 'i', 2, 'm', 0xFF, 0xC9, 0x9A, 0xBB, 'm', 0xFF, 0xC9, 0x9A, 0xBB};
                std::vector<uint8_t> const v_L = {'[', '#', 'i', 2, 'L', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 'L', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_M = {'[', '#', 'i', 2, 'M', 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 'M', 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const v_D = {'[', '#', 'i', 2, 'D', 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40, 'D', 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40};
                std::vector<uint8_t> const v_S = {'[', '#', 'i', 2, 'S', 'i', 1, 'a', 'S', 'i', 1, 'a'};
                std::vector<uint8_t> const v_C = {'[', '#', 'i', 2, 'C', 'a', 'C', 'a'};
                std::vector<uint8_t> const v_B = {'[', '#', 'i', 2, 'B', 0xFF, 'B', 0xFF};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_TU) == json({true, true}));
                CHECK(json::from_bjdata(v_T) == json({true, true}));
                CHECK(json::from_bjdata(v_F) == json({false, false}));
                CHECK(json::from_bjdata(v_Z) == json({nullptr, nullptr}));
                CHECK(json::from_bjdata(v_i) == json({127, 127}));
                CHECK(json::from_bjdata(v_U) == json({255, 255}));
                CHECK(json::from_bjdata(v_I) == json({32767, 32767}));
                CHECK(json::from_bjdata(v_u) == json({42767, 42767}));
                CHECK(json::from_bjdata(v_l) == json({2147483647, 2147483647}));
                CHECK(json::from_bjdata(v_m) == json({3147483647, 3147483647}));
                CHECK(json::from_bjdata(v_L) == json({9223372036854775807, 9223372036854775807}));
                CHECK(json::from_bjdata(v_M) == json({10223372036854775807ull, 10223372036854775807ull}));
                CHECK(json::from_bjdata(v_D) == json({3.1415926, 3.1415926}));
                CHECK(json::from_bjdata(v_S) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_C) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_B) == json({255, 255}));

                // roundtrip: output should be optimized
                CHECK(json::to_bjdata(json::from_bjdata(v_T), true) == v_T);
                CHECK(json::to_bjdata(json::from_bjdata(v_F), true) == v_F);
                CHECK(json::to_bjdata(json::from_bjdata(v_Z), true) == v_Z);
                CHECK(json::to_bjdata(json::from_bjdata(v_i), true) == v_i);
                CHECK(json::to_bjdata(json::from_bjdata(v_U), true) == v_U);
                CHECK(json::to_bjdata(json::from_bjdata(v_I), true) == v_I);
                CHECK(json::to_bjdata(json::from_bjdata(v_u), true) == v_u);
                CHECK(json::to_bjdata(json::from_bjdata(v_l), true) == v_l);
                CHECK(json::to_bjdata(json::from_bjdata(v_m), true) == v_m);
                CHECK(json::to_bjdata(json::from_bjdata(v_L), true) == v_L);
                CHECK(json::to_bjdata(json::from_bjdata(v_M), true) == v_M);
                CHECK(json::to_bjdata(json::from_bjdata(v_D), true) == v_D);
                CHECK(json::to_bjdata(json::from_bjdata(v_S), true) == v_S);
                CHECK(json::to_bjdata(json::from_bjdata(v_C), true) == v_S); // char is serialized to string
                CHECK(json::to_bjdata(json::from_bjdata(v_B), true) == v_U); // byte is serialized to uint8
            }

            SECTION("optimized version (type and length)")
            {
                // create vector with two elements of the same type
                std::vector<uint8_t> const v_i = {'[', '$', 'i', '#', 'i', 2, 0x7F, 0x7F};
                std::vector<uint8_t> const v_U = {'[', '$', 'U', '#', 'i', 2, 0xFF, 0xFF};
                std::vector<uint8_t> const v_I = {'[', '$', 'I', '#', 'i', 2, 0xFF, 0x7F, 0xFF, 0x7F};
                std::vector<uint8_t> const v_u = {'[', '$', 'u', '#', 'i', 2, 0x0F, 0xA7, 0x0F, 0xA7};
                std::vector<uint8_t> const v_l = {'[', '$', 'l', '#', 'i', 2, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_m = {'[', '$', 'm', '#', 'i', 2, 0xFF, 0xC9, 0x9A, 0xBB, 0xFF, 0xC9, 0x9A, 0xBB};
                std::vector<uint8_t> const v_L = {'[', '$', 'L', '#', 'i', 2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_M = {'[', '$', 'M', '#', 'i', 2, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const v_D = {'[', '$', 'D', '#', 'i', 2, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40};
                std::vector<uint8_t> const v_S = {'[', '#', 'i', 2, 'S', 'i', 1, 'a', 'S', 'i', 1, 'a'};
                std::vector<uint8_t> const v_C = {'[', '$', 'C', '#', 'i', 2, 'a', 'a'};
                std::vector<uint8_t> const v_B = {'[', '$', 'B', '#', 'i', 2, 0xFF, 0xFF};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_i) == json({127, 127}));
                CHECK(json::from_bjdata(v_U) == json({255, 255}));
                CHECK(json::from_bjdata(v_I) == json({32767, 32767}));
                CHECK(json::from_bjdata(v_u) == json({42767, 42767}));
                CHECK(json::from_bjdata(v_l) == json({2147483647, 2147483647}));
                CHECK(json::from_bjdata(v_m) == json({3147483647, 3147483647}));
                CHECK(json::from_bjdata(v_L) == json({9223372036854775807, 9223372036854775807}));
                CHECK(json::from_bjdata(v_M) == json({10223372036854775807ull, 10223372036854775807ull}));
                CHECK(json::from_bjdata(v_D) == json({3.1415926, 3.1415926}));
                CHECK(json::from_bjdata(v_S) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_C) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_B) == json::binary(std::vector<uint8_t>({static_cast<uint8_t>(255), static_cast<uint8_t>(255)})));

                // roundtrip: output should be optimized
                std::vector<uint8_t> const v_empty = {'[', '#', 'i', 0};
                CHECK(json::to_bjdata(json::from_bjdata(v_i), true, true) == v_i);
                CHECK(json::to_bjdata(json::from_bjdata(v_U), true, true) == v_U);
                CHECK(json::to_bjdata(json::from_bjdata(v_I), true, true) == v_I);
                CHECK(json::to_bjdata(json::from_bjdata(v_u), true, true) == v_u);
                CHECK(json::to_bjdata(json::from_bjdata(v_l), true, true) == v_l);
                CHECK(json::to_bjdata(json::from_bjdata(v_m), true, true) == v_m);
                CHECK(json::to_bjdata(json::from_bjdata(v_L), true, true) == v_L);
                CHECK(json::to_bjdata(json::from_bjdata(v_M), true, true) == v_M);
                CHECK(json::to_bjdata(json::from_bjdata(v_D), true, true) == v_D);
                CHECK(json::to_bjdata(json::from_bjdata(v_S), true, true) == v_S);
                CHECK(json::to_bjdata(json::from_bjdata(v_C), true, true) == v_S); // char is serialized to string
                CHECK(json::to_bjdata(json::from_bjdata(v_B), true, true, json::bjdata_version_t::draft2) == v_U);
                CHECK(json::to_bjdata(json::from_bjdata(v_B), true, true, json::bjdata_version_t::draft3) == v_B);
            }

            SECTION("optimized ndarray (type and vector-size as optimized 1D array)")
            {
                // create vector with two elements of the same type
                std::vector<uint8_t> const v_0 = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 1, 0};
                std::vector<uint8_t> const v_1 = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 1, 2, 0x7F, 0x7F};
                std::vector<uint8_t> const v_i = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0x7F, 0x7F};
                std::vector<uint8_t> const v_U = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xFF};
                std::vector<uint8_t> const v_I = {'[', '$', 'I', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0x7F, 0xFF, 0x7F};
                std::vector<uint8_t> const v_u = {'[', '$', 'u', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0x0F, 0xA7, 0x0F, 0xA7};
                std::vector<uint8_t> const v_l = {'[', '$', 'l', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_m = {'[', '$', 'm', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xC9, 0x9A, 0xBB, 0xFF, 0xC9, 0x9A, 0xBB};
                std::vector<uint8_t> const v_L = {'[', '$', 'L', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_M = {'[', '$', 'M', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const v_D = {'[', '$', 'D', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40};
                std::vector<uint8_t> const v_S = {'[', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 'S', 'i', 1, 'a', 'S', 'i', 1, 'a'};
                std::vector<uint8_t> const v_C = {'[', '$', 'C', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 'a', 'a'};
                std::vector<uint8_t> const v_B = {'[', '$', 'B', '#', '[', '$', 'i', '#', 'i', 2, 1, 2, 0xFF, 0xFF};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_0) == json::array());
                CHECK(json::from_bjdata(v_1) == json({127, 127}));
                CHECK(json::from_bjdata(v_i) == json({127, 127}));
                CHECK(json::from_bjdata(v_U) == json({255, 255}));
                CHECK(json::from_bjdata(v_I) == json({32767, 32767}));
                CHECK(json::from_bjdata(v_u) == json({42767, 42767}));
                CHECK(json::from_bjdata(v_l) == json({2147483647, 2147483647}));
                CHECK(json::from_bjdata(v_m) == json({3147483647, 3147483647}));
                CHECK(json::from_bjdata(v_L) == json({9223372036854775807, 9223372036854775807}));
                CHECK(json::from_bjdata(v_M) == json({10223372036854775807ull, 10223372036854775807ull}));
                CHECK(json::from_bjdata(v_D) == json({3.1415926, 3.1415926}));
                CHECK(json::from_bjdata(v_S) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_C) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_B) == json::binary(std::vector<uint8_t>({static_cast<uint8_t>(255), static_cast<uint8_t>(255)})));
            }

            SECTION("optimized ndarray (type and vector-size ndarray with JData annotations)")
            {
                // create vector with 0, 1, 2 elements of the same type
                std::vector<uint8_t> const v_e = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 2, 1, 0xFE, 0xFF};
                std::vector<uint8_t> const v_U = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06};
                std::vector<uint8_t> const v_i = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06};
                std::vector<uint8_t> const v_u = {'[', '$', 'u', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00};
                std::vector<uint8_t> const v_I = {'[', '$', 'I', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00};
                std::vector<uint8_t> const v_m = {'[', '$', 'm', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00};
                std::vector<uint8_t> const v_l = {'[', '$', 'l', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00};
                std::vector<uint8_t> const v_M = {'[', '$', 'M', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
                std::vector<uint8_t> const v_L = {'[', '$', 'L', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
                std::vector<uint8_t> const v_d = {'[', '$', 'd', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x00, 0x00, 0x80, 0x3F, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x40, 0x40, 0x00, 0x00, 0x80, 0x40, 0x00, 0x00, 0xA0, 0x40, 0x00, 0x00, 0xC0, 0x40};
                std::vector<uint8_t> const v_D = {'[', '$', 'D', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF0, 0x3F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x14, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x40};
                std::vector<uint8_t> const v_C = {'[', '$', 'C', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 'a', 'b', 'c', 'd', 'e', 'f'};
                std::vector<uint8_t> const v_B = {'[', '$', 'B', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_e) == json({{"_ArrayData_", {254, 255}}, {"_ArraySize_", {2, 1}}, {"_ArrayType_", "uint8"}}));
                CHECK(json::from_bjdata(v_U) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint8"}}));
                CHECK(json::from_bjdata(v_i) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "int8"}}));
                CHECK(json::from_bjdata(v_i) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "int8"}}));
                CHECK(json::from_bjdata(v_u) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint16"}}));
                CHECK(json::from_bjdata(v_I) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "int16"}}));
                CHECK(json::from_bjdata(v_m) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint32"}}));
                CHECK(json::from_bjdata(v_l) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "int32"}}));
                CHECK(json::from_bjdata(v_M) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint64"}}));
                CHECK(json::from_bjdata(v_L) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "int64"}}));
                CHECK(json::from_bjdata(v_d) == json({{"_ArrayData_", {1.f, 2.f, 3.f, 4.f, 5.f, 6.f}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "single"}}));
                CHECK(json::from_bjdata(v_D) == json({{"_ArrayData_", {1., 2., 3., 4., 5., 6.}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "double"}}));
                CHECK(json::from_bjdata(v_C) == json({{"_ArrayData_", {'a', 'b', 'c', 'd', 'e', 'f'}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "char"}}));
                CHECK(json::from_bjdata(v_B) == json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "byte"}}));

                // roundtrip: output should be optimized
                CHECK(json::to_bjdata(json::from_bjdata(v_e), true, true) == v_e);
                CHECK(json::to_bjdata(json::from_bjdata(v_U), true, true) == v_U);
                CHECK(json::to_bjdata(json::from_bjdata(v_i), true, true) == v_i);
                CHECK(json::to_bjdata(json::from_bjdata(v_u), true, true) == v_u);
                CHECK(json::to_bjdata(json::from_bjdata(v_I), true, true) == v_I);
                CHECK(json::to_bjdata(json::from_bjdata(v_m), true, true) == v_m);
                CHECK(json::to_bjdata(json::from_bjdata(v_l), true, true) == v_l);
                CHECK(json::to_bjdata(json::from_bjdata(v_M), true, true) == v_M);
                CHECK(json::to_bjdata(json::from_bjdata(v_L), true, true) == v_L);
                CHECK(json::to_bjdata(json::from_bjdata(v_d), true, true) == v_d);
                CHECK(json::to_bjdata(json::from_bjdata(v_D), true, true) == v_D);
                CHECK(json::to_bjdata(json::from_bjdata(v_C), true, true) == v_C);
                // v_B uses the Draft-3-only 'B' marker, so it round-trips only when
                // Draft 3 is explicitly selected (see GitHub issue #5404); the
                // default Draft 2 falls back to a plain object instead, covered by
                // the "ndarray with _ArrayType_ "byte" is gated by the BJData draft
                // version" section below
                CHECK(json::to_bjdata(json::from_bjdata(v_B), true, true, json::bjdata_version_t::draft3) == v_B);
            }

            SECTION("ndarray with data not matching _ArrayType_ is written as an object")
            {
                // A JData-annotated object is only serialized as an ndarray when
                // its _ArrayData_ elements are actually stored as the number kind
                // named by _ArrayType_. Otherwise the writer would read the wrong
                // union member (e.g. a std::string's heap pointer as a uint64) and
                // emit it, so such an object falls back to a plain object encoding
                // that still round-trips.

                // string data declared as a uint64 array
                json const j_str = json({{"_ArrayType_", "uint64"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {"pointer", "value"}}});
                const auto out_str = json::to_bjdata(j_str);
                CHECK(out_str.at(0) == '{');
                CHECK(json::from_bjdata(out_str) == j_str);

                // integer data declared as a double array
                json const j_float = json({{"_ArrayType_", "double"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1, 2}}});
                const auto out_float = json::to_bjdata(j_float);
                CHECK(out_float.at(0) == '{');
                CHECK(json::from_bjdata(out_float) == j_float);

                // a non-integer shape entry is likewise not treated as an ndarray
                json const j_size = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", {"x", 1}}, {"_ArrayData_", {1}}});
                const auto out_size = json::to_bjdata(j_size);
                CHECK(out_size.at(0) == '{');
                CHECK(json::from_bjdata(out_size) == j_size);

                // a negative shape entry is not a usable dimension either
                json const j_neg = json::parse(R"({"_ArrayType_":"uint8","_ArraySize_":[-1,1],"_ArrayData_":[1]})");
                const auto out_neg = json::to_bjdata(j_neg);
                CHECK(out_neg.at(0) == '{');
                CHECK(json::from_bjdata(out_neg) == j_neg);
            }

            SECTION("ndarray parsed from text is written as a typed array")
            {
                // json::parse stores a non-negative integer as number_unsigned while
                // the C++ API stores an int literal as number_integer, so _ArrayType_
                // names the wire type rather than the storage. Both storages have to
                // produce the same typed array for every type.
                // "byte" is checked separately below since it additionally requires
                // BJData Draft 3 to be selected explicitly (see GitHub issue #5404).
                for (const char* type :
                        {"uint8", "int8", "uint16", "int16", "uint32", "int32", "uint64", "int64", "char"
                        })
                {
                    CAPTURE(type)
                    const std::string text = std::string(R"({"_ArrayType_":")") + type +
                                             R"(","_ArraySize_":[2,3],"_ArrayData_":[1,2,3,4,5,6]})";
                    const auto from_text = json::to_bjdata(json::parse(text));
                    CHECK(from_text.at(0) == '[');
                    CHECK(from_text == json::to_bjdata(json({{"_ArrayType_", type}, {"_ArraySize_", {2, 3}}, {"_ArrayData_", {1, 2, 3, 4, 5, 6}}})));
                }

                {
                    const std::string text = R"({"_ArrayType_":"byte","_ArraySize_":[2,3],"_ArrayData_":[1,2,3,4,5,6]})";
                    const auto from_text = json::to_bjdata(json::parse(text), true, true, json::bjdata_version_t::draft3);
                    CHECK(from_text.at(0) == '[');
                    CHECK(from_text == json::to_bjdata(json({{"_ArrayType_", "byte"}, {"_ArraySize_", {2, 3}}, {"_ArrayData_", {1, 2, 3, 4, 5, 6}}}),
                    true, true, json::bjdata_version_t::draft3));
                }

                // negative values under a signed type behave the same way
                const auto from_neg = json::to_bjdata(json::parse(R"({"_ArrayType_":"int32","_ArraySize_":[2,1],"_ArrayData_":[-5,7]})"));
                CHECK(from_neg.at(0) == '[');
                CHECK(from_neg == json::to_bjdata(json({{"_ArrayType_", "int32"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {-5, 7}}})));

                // and so do the floating point types
                const auto from_float = json::to_bjdata(json::parse(R"({"_ArrayType_":"double","_ArraySize_":[2,1],"_ArrayData_":[1.5,2.5]})"));
                CHECK(from_float.at(0) == '[');
                CHECK(from_float == json::to_bjdata(json({{"_ArrayType_", "double"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5, 2.5}}})));
            }

            SECTION("optimized ndarray (type and vector-size as 1D array)")
            {
                // create vector with two elements of the same type
                std::vector<uint8_t> const v_0 = {'[', '$', 'i', '#', '[', ']'};
                std::vector<uint8_t> const v_E = {'[', '$', 'i', '#', '[', 'i', 2, 'i', 0, ']'};
                std::vector<uint8_t> const v_i = {'[', '$', 'i', '#', '[', 'i', 1, 'i', 2, ']', 0x7F, 0x7F};
                std::vector<uint8_t> const v_U = {'[', '$', 'U', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xFF};
                std::vector<uint8_t> const v_I = {'[', '$', 'I', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0x7F, 0xFF, 0x7F};
                std::vector<uint8_t> const v_u = {'[', '$', 'u', '#', '[', 'i', 1, 'i', 2, ']', 0x0F, 0xA7, 0x0F, 0xA7};
                std::vector<uint8_t> const v_l = {'[', '$', 'l', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_m = {'[', '$', 'm', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xC9, 0x9A, 0xBB, 0xFF, 0xC9, 0x9A, 0xBB};
                std::vector<uint8_t> const v_L = {'[', '$', 'L', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_M = {'[', '$', 'M', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const v_D = {'[', '$', 'D', '#', '[', 'i', 1, 'i', 2, ']', 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40};
                std::vector<uint8_t> const v_S = {'[', '#', '[', 'i', 1, 'i', 2, ']', 'S', 'i', 1, 'a', 'S', 'i', 1, 'a'};
                std::vector<uint8_t> const v_C = {'[', '$', 'C', '#', '[', 'i', 1, 'i', 2, ']', 'a', 'a'};
                std::vector<uint8_t> const v_B = {'[', '$', 'B', '#', '[', 'i', 1, 'i', 2, ']', 0xFF, 0xFF};
                std::vector<uint8_t> const v_R = {'[', '#', '[', 'i', 2, ']', 'i', 6, 'U', 7};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_0) == json::array());
                CHECK(json::from_bjdata(v_E) == json::array());
                CHECK(json::from_bjdata(v_i) == json({127, 127}));
                CHECK(json::from_bjdata(v_U) == json({255, 255}));
                CHECK(json::from_bjdata(v_I) == json({32767, 32767}));
                CHECK(json::from_bjdata(v_u) == json({42767, 42767}));
                CHECK(json::from_bjdata(v_l) == json({2147483647, 2147483647}));
                CHECK(json::from_bjdata(v_m) == json({3147483647, 3147483647}));
                CHECK(json::from_bjdata(v_L) == json({9223372036854775807, 9223372036854775807}));
                CHECK(json::from_bjdata(v_M) == json({10223372036854775807ull, 10223372036854775807ull}));
                CHECK(json::from_bjdata(v_D) == json({3.1415926, 3.1415926}));
                CHECK(json::from_bjdata(v_S) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_C) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_B) == json::binary(std::vector<uint8_t>({static_cast<uint8_t>(255), static_cast<uint8_t>(255)})));
                CHECK(json::from_bjdata(v_R) == json({6, 7}));
            }

            SECTION("optimized ndarray (type and vector-size as size-optimized array)")
            {
                // create vector with two elements of the same type
                std::vector<uint8_t> const v_i = {'[', '$', 'i', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0x7F, 0x7F};
                std::vector<uint8_t> const v_U = {'[', '$', 'U', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xFF};
                std::vector<uint8_t> const v_I = {'[', '$', 'I', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0x7F, 0xFF, 0x7F};
                std::vector<uint8_t> const v_u = {'[', '$', 'u', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0x0F, 0xA7, 0x0F, 0xA7};
                std::vector<uint8_t> const v_l = {'[', '$', 'l', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_m = {'[', '$', 'm', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xC9, 0x9A, 0xBB, 0xFF, 0xC9, 0x9A, 0xBB};
                std::vector<uint8_t> const v_L = {'[', '$', 'L', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F};
                std::vector<uint8_t> const v_M = {'[', '$', 'M', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const v_D = {'[', '$', 'D', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40, 0x4a, 0xd8, 0x12, 0x4d, 0xfb, 0x21, 0x09, 0x40};
                std::vector<uint8_t> const v_S = {'[', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 'S', 'i', 1, 'a', 'S', 'i', 1, 'a'};
                std::vector<uint8_t> const v_C = {'[', '$', 'C', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 'a', 'a'};
                std::vector<uint8_t> const v_B = {'[', '$', 'B', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2, 0xFF, 0xFF};

                // check if vector is parsed correctly
                CHECK(json::from_bjdata(v_i) == json({127, 127}));
                CHECK(json::from_bjdata(v_U) == json({255, 255}));
                CHECK(json::from_bjdata(v_I) == json({32767, 32767}));
                CHECK(json::from_bjdata(v_u) == json({42767, 42767}));
                CHECK(json::from_bjdata(v_l) == json({2147483647, 2147483647}));
                CHECK(json::from_bjdata(v_m) == json({3147483647, 3147483647}));
                CHECK(json::from_bjdata(v_L) == json({9223372036854775807, 9223372036854775807}));
                CHECK(json::from_bjdata(v_M) == json({10223372036854775807ull, 10223372036854775807ull}));
                CHECK(json::from_bjdata(v_D) == json({3.1415926, 3.1415926}));
                CHECK(json::from_bjdata(v_S) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_C) == json({"a", "a"}));
                CHECK(json::from_bjdata(v_B) == json::binary(std::vector<uint8_t>({static_cast<uint8_t>(255), static_cast<uint8_t>(255)})));
            }

            SECTION("invalid ndarray annotations remains as object")
            {
                // check if invalid ND array annotations stay as object
                json j_type = json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "invalidtype"}});
                json j_size = json({{"_ArrayData_", {1, 2, 3, 4, 5}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint8"}});

                // roundtrip: output should stay as object
                CHECK(json::from_bjdata(json::to_bjdata(j_type), true, true) == j_type);
                CHECK(json::from_bjdata(json::to_bjdata(j_size), true, true) == j_size);
            }

            SECTION("ndarray whose _ArrayType_ is not a string stays as object")
            {
                // the type name is looked up as a string below the annotation
                // check; a non-string _ArrayType_ cannot name a known dtype,
                // so calling get<string_t>() on it would throw type_error.302
                // instead of falling back like an unrecognized type name
                // already does (see GitHub issue #5398)
                json const j_number = json({{"_ArrayType_", 1}, {"_ArraySize_", {2}}, {"_ArrayData_", {1, 2}}});
                const auto out_number = json::to_bjdata(j_number);
                CHECK(out_number.at(0) == '{');
                CHECK(json::from_bjdata(out_number) == j_number);

                json const j_null = json({{"_ArrayType_", nullptr}, {"_ArraySize_", {2}}, {"_ArrayData_", {1, 2}}});
                const auto out_null = json::to_bjdata(j_null);
                CHECK(out_null.at(0) == '{');
                CHECK(json::from_bjdata(out_null) == j_null);

                json const j_bool = json({{"_ArrayType_", true}, {"_ArraySize_", {2}}, {"_ArrayData_", {1, 2}}});
                const auto out_bool = json::to_bjdata(j_bool);
                CHECK(out_bool.at(0) == '{');
                CHECK(json::from_bjdata(out_bool) == j_bool);

                json const j_array = json({{"_ArrayType_", {"uint8"}}, {"_ArraySize_", {2}}, {"_ArrayData_", {1, 2}}});
                const auto out_array = json::to_bjdata(j_array);
                CHECK(out_array.at(0) == '{');
                CHECK(json::from_bjdata(out_array) == j_array);

                json const j_object = json({{"_ArrayType_", {{"a", 1}}}, {"_ArraySize_", {2}}, {"_ArrayData_", {1, 2}}});
                const auto out_object = json::to_bjdata(j_object);
                CHECK(out_object.at(0) == '{');
                CHECK(json::from_bjdata(out_object) == j_object);
            }

            SECTION("re-serializing a value containing a plain-array-of-bytes is value-stable but not byte-stable")
            {
                // OSS-Fuzz found this input (an array whose first element is a
                // binary_t byte, followed by an object whose _ArrayType_ is
                // not a string) while exercising the fix for #5398 above: once
                // the fix stops to_bjdata() from throwing type_error.302 for
                // the third element, serialization proceeds far enough to
                // reach a pre-existing, unrelated round-trip quirk in how a
                // single-byte binary_t value is re-encoded.
                std::vector<std::uint8_t> const input
                {
                    0x5b, 0x5b, 0x24, 0x42, 0x23, 0x5b, 0x69, 0x01, 0x5d, 0x5b, 0x5b, 0x5d, 0x7b, 0x55, 0x0b,
                    0x5f, 0x41, 0x72, 0x72, 0x61, 0x79, 0x44, 0x61, 0x74, 0x61, 0x5f, 0x54, 0x55, 0x0b, 0x5f,
                    0x41, 0x72, 0x72, 0x61, 0x79, 0x53, 0x69, 0x7a, 0x65, 0x5f, 0x5a, 0x55, 0x0b, 0x5f, 0x41,
                    0x72, 0x72, 0x61, 0x79, 0x54, 0x79, 0x70, 0x65, 0x5f, 0x54, 0x7d, 0x5d
                };
                json const j1 = json::from_bjdata(input);

                // to_bjdata() must not throw (this is what #5398 fixes)
                std::vector<std::uint8_t> vec2;
                CHECK_NOTHROW(vec2 = json::to_bjdata(j1, false, false));

                // parsing back a plain (non-optimized) array of bytes cannot
                // recover that it used to be a binary_t: from_bjdata() has no
                // way to distinguish "array of uint8 numbers" from "array of
                // bytes" unless the compact "$U#" array header is used, so
                // the binary_t collapses into a plain JSON array
                json const j2 = json::from_bjdata(vec2);
                CHECK(j1 != j2);
                CHECK(j2 == json({{91}, json::array(), {{"_ArrayData_", true}, {"_ArraySize_", nullptr}, {"_ArrayType_", true}}}));

                // re-serializing j2 no longer goes through the dedicated
                // binary_t writer (which always uses the 'U' marker for raw
                // bytes); the now-plain number 91 goes through the generic
                // smallest-type writer instead, which - like the rest of the
                // UBJSON/BJData writer, and unchanged by this fix - prefers
                // the 'i' (int8) marker over 'U' (uint8) for values that fit
                // both. Both markers are valid BJData and both decode back to
                // 91, so this is not byte-for-byte identical to vec2, but it
                // is value-stable: parsing it again reproduces j2 exactly.
                std::vector<std::uint8_t> const vec3 = json::to_bjdata(j2, false, false);
                CHECK(json::from_bjdata(vec3) == j2);
            }

            SECTION("ndarray whose dimensions overflow stays as object")
            {
                // the product of the dimensions wraps around std::size_t to 0
                // and so matches the size of the empty _ArrayData_; writing this
                // as an ndarray would announce an element count no reader can
                // honor, so it has to stay a plain object
                json j_overflow = json({{"_ArrayData_", json::array()}, {"_ArraySize_", {9223372036854775808ull, 2}}, {"_ArrayType_", "uint8"}});
                CHECK(json::from_bjdata(json::to_bjdata(j_overflow), true, true) == j_overflow);

                // a single dimension that does not fit into std::size_t is
                // rejected for the same reason (only observable where
                // std::size_t is narrower than 64 bit)
                json j_huge = json({{"_ArrayData_", json::array()}, {"_ArraySize_", {18446744073709551615ull, 2}}, {"_ArrayType_", "uint8"}});
                CHECK(json::from_bjdata(json::to_bjdata(j_huge), true, true) == j_huge);

                // a well-formed ndarray is still encoded as one
                json j_ok = json({{"_ArrayData_", {1, 2, 3, 4, 5, 6}}, {"_ArraySize_", {2, 3}}, {"_ArrayType_", "uint8"}});
                CHECK(json::to_bjdata(j_ok) == std::vector<uint8_t>({'[', '$', 'U', '#', '[', 'i', 2, 'i', 3, ']', 1, 2, 3, 4, 5, 6}));
                CHECK(json::from_bjdata(json::to_bjdata(j_ok), true, true) == j_ok);
            }

            SECTION("ndarray whose _ArraySize_ is not an array stays as object")
            {
                // the shape is written verbatim as the header length, so a
                // value that is not an array cannot produce a valid one: null
                // would emit 'Z' and an object '{', neither of which a reader
                // accepts after '#'. Both have to stay plain objects.
                json const j_null = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", nullptr}, {"_ArrayData_", json::array()}});
                const auto out_null = json::to_bjdata(j_null);
                CHECK(out_null.at(0) == '{');
                CHECK(json::from_bjdata(out_null) == j_null);

                // an object shape passes the per-entry check by iterating its
                // values rather than dimensions, so it needs rejecting too
                json const j_obj = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", {{"a", 1}}}, {"_ArrayData_", {1}}});
                const auto out_obj = json::to_bjdata(j_obj);
                CHECK(out_obj.at(0) == '{');
                CHECK(json::from_bjdata(out_obj) == j_obj);

                // a scalar shape is not a dimension list either
                json const j_num = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", 1}, {"_ArrayData_", {1}}});
                const auto out_num = json::to_bjdata(j_num);
                CHECK(out_num.at(0) == '{');
                CHECK(json::from_bjdata(out_num) == j_num);

                // OSS-Fuzz issue 474400817: an empty object _ArraySize_ was
                // written as the ND-array header length, which from_bjdata()
                // could not read back
                const std::vector<uint8_t> input =
                {
                    '[', '{', 'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'D', 'a', 't', 'a', '_', 'Z',
                    'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'T', 'y', 'p', 'e', '_', 'S', 'i', 5, 'i', 'n', 't', '1', '6',
                    'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'S', 'i', 'z', 'e', '_', '{', '}', '}', ']'
                };
                const json j1 = json::from_bjdata(input);
                CHECK(j1 == json::parse(R"([{"_ArrayType_":"int16","_ArraySize_":{},"_ArrayData_":null}])"));
                json j2;
                CHECK_NOTHROW(j2 = json::from_bjdata(json::to_bjdata(j1, false, false)));
                CHECK(j2 == j1);
            }

            SECTION("ndarray with out-of-range _ArrayData_ elements stays as object")
            {
                // each element is cast to the (possibly narrower) C++ type
                // named by _ArrayType_ before being written; a value that
                // does not fit that type would silently wrap instead of
                // being reported, so such an object falls back to a plain
                // object encoding that still round-trips (see GitHub issue #5403)

                // an unsigned element that does not fit uint8
                json const j_uint8 = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1, 256}}});
                const auto out_uint8 = json::to_bjdata(j_uint8);
                CHECK(out_uint8.at(0) == '{');
                CHECK(json::from_bjdata(out_uint8) == j_uint8);

                // a signed element that does not fit int8
                json const j_int8 = json({{"_ArrayType_", "int8"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1, 200}}});
                const auto out_int8 = json::to_bjdata(j_int8);
                CHECK(out_int8.at(0) == '{');
                CHECK(json::from_bjdata(out_int8) == j_int8);

                // a negative element is likewise out of range for an
                // unsigned _ArrayType_
                json const j_uint16_neg = json({{"_ArrayType_", "uint16"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1, -1}}});
                const auto out_uint16_neg = json::to_bjdata(j_uint16_neg);
                CHECK(out_uint16_neg.at(0) == '{');
                CHECK(json::from_bjdata(out_uint16_neg) == j_uint16_neg);

                // a double element that overflows to infinity when narrowed
                // to the "single" (float) precision named by _ArrayType_
                json const j_single = json({{"_ArrayType_", "single"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5, 1e40}}});
                const auto out_single = json::to_bjdata(j_single);
                CHECK(out_single.at(0) == '{');
                CHECK(json::from_bjdata(out_single) == j_single);

                // a double element that is finite and within the range of "single"
                // but is not exactly representable as a float, so narrowing it would
                // silently round it (0.1 is read back as 0.10000000149011612); this,
                // like the overflow case above, falls back to a plain object (see
                // GitHub issue #5661)
                json const j_single_rounded = json({{"_ArrayType_", "single"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5, 0.1}}});
                const auto out_single_rounded = json::to_bjdata(j_single_rounded);
                CHECK(out_single_rounded.at(0) == '{');
                CHECK(json::from_bjdata(out_single_rounded) == j_single_rounded);

                // a double element that underflows to 0 when narrowed to "single"
                json const j_single_underflow = json({{"_ArrayType_", "single"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5, 1e-300}}});
                const auto out_single_underflow = json::to_bjdata(j_single_underflow);
                CHECK(out_single_underflow.at(0) == '{');
                CHECK(json::from_bjdata(out_single_underflow) == j_single_underflow);

                // in-range boundary values still use the compact ndarray encoding
                json const j_uint8_ok = json({{"_ArrayType_", "uint8"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {0, 255}}});
                CHECK(json::to_bjdata(j_uint8_ok) == std::vector<uint8_t>({'[', '$', 'U', '#', '[', 'i', 2, 'i', 1, ']', 0, 255}));

                json const j_int8_ok = json({{"_ArrayType_", "int8"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {-128, 127}}});
                CHECK(json::to_bjdata(j_int8_ok) == std::vector<uint8_t>({'[', '$', 'i', '#', '[', 'i', 2, 'i', 1, ']', 0x80, 0x7F}));

                json const j_single_ok = json({{"_ArrayType_", "single"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5, -1.5}}});
                const auto out_single_ok = json::to_bjdata(j_single_ok);
                CHECK(out_single_ok.at(0) == '[');
                CHECK(json::from_bjdata(out_single_ok) == json({{"_ArrayType_", "single"}, {"_ArraySize_", {2, 1}}, {"_ArrayData_", {1.5f, -1.5f}}}));
            }

            SECTION("ndarray with _ArrayType_ \"char\" is limited to 0..127")
            {
                // both BJData drafts limit a char to 0..127; larger values must not
                // be written as 'C' elements (the reader rejects them), so such an
                // object stays a plain object that round-trips
                for (const auto version :
                        {
                            json::bjdata_version_t::draft2, json::bjdata_version_t::draft3
                        })
                {
                    json const j_ok = json({{"_ArrayType_", "char"}, {"_ArraySize_", {2, 2}}, {"_ArrayData_", {0, 97, 98, 127}}});
                    const auto out_ok = json::to_bjdata(j_ok, true, true, version);
                    CHECK(out_ok == std::vector<uint8_t>({'[', '$', 'C', '#', '[', '$', 'i', '#', 'i', 2, 2, 2, 0, 97, 98, 127}));
                    CHECK(json::from_bjdata(out_ok) == j_ok);

                    for (const int bad :
                            {
                                128, 200, 255, 256, -1
                            })
                    {
                        CAPTURE(bad)
                        json const j_bad = json({{"_ArrayType_", "char"}, {"_ArraySize_", {2, 2}}, {"_ArrayData_", {97, 98, 99, bad}}});
                        const auto out_bad = json::to_bjdata(j_bad, true, true, version);
                        CHECK(out_bad.at(0) == '{');
                        CHECK(json::from_bjdata(out_bad) == j_bad);
                    }
                }
            }

            SECTION("ndarray annotation keys are read back in the documented order")
            {
                // from_bjdata() must emit the annotation object's keys in the order
                // used throughout the documentation, _ArrayType_, _ArraySize_,
                // _ArrayData_: the type marker precedes the dimension vector on the
                // wire (see get_ubjson_size_type()), so it is known, and emitted,
                // before _ArraySize_. For a plain json this key order is invisible
                // (its comparison ignores it), but for an ordered_json it is not (see
                // GitHub issue #5661).
                const ordered_json o = ordered_json::parse(R"({"_ArrayType_":"uint8","_ArraySize_":[2,2],"_ArrayData_":[1,2,3,4]})");
                const auto packed = ordered_json::to_bjdata(o);
                CHECK(packed.at(0) == '[');
                const ordered_json o_back = ordered_json::from_bjdata(packed);
                CHECK(o_back == o);
                CHECK(o_back.dump() == o.dump());
            }

            SECTION("ndarray that would not be read back as an annotated object stays as object")
            {
                // the reader only restores an annotated object from an ND-array
                // with at least two non-zero dimensions that is not a 1xN row
                // vector; any other shape is read back as a plain array. Writing
                // such an object as an ND-array would drop its annotation, so it
                // falls back to a plain object encoding that round-trips.
                for (const char* text :
                        {
                            R"({"_ArrayType_":"int16","_ArraySize_":[],"_ArrayData_":[]})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[2],"_ArrayData_":[1,2]})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[1,2],"_ArrayData_":[1,2]})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[0],"_ArrayData_":[]})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[2,0],"_ArrayData_":[]})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[0,2],"_ArrayData_":[]})"
                        })
                {
                    CAPTURE(text)
                    const json j = json::parse(text);
                    for (const bool use_size :
                            {
                                false, true
                            })
                    {
                        const auto out = json::to_bjdata(j, use_size, use_size);
                        CHECK(out.at(0) == '{');
                        CHECK(json::from_bjdata(out) == j);
                    }
                }

                // a genuine ND-array still uses the compact encoding and round-trips
                const json j_2d = json::parse(R"({"_ArrayType_":"int16","_ArraySize_":[2,1],"_ArrayData_":[1,2]})");
                const auto out_2d = json::to_bjdata(j_2d);
                CHECK(out_2d.at(0) == '[');
                CHECK(json::from_bjdata(out_2d) == j_2d);
            }

            SECTION("ndarray with non-array _ArrayData_ stays as object")
            {
                // the elements are written from _ArrayData_ as a flat list, so it
                // has to be an array: null has size 0, any other scalar has size 1,
                // and iterating an object visits its values, so each of these could
                // match the dimensions and be encoded as an unrelated ND-array
                for (const char* text :
                        {
                            R"({"_ArrayType_":"int16","_ArraySize_":[2,1],"_ArrayData_":null})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[2,1],"_ArrayData_":{"a":1,"b":2}})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[1],"_ArrayData_":5})",
                            R"({"_ArrayType_":"int16","_ArraySize_":[],"_ArrayData_":null})"
                        })
                {
                    CAPTURE(text)
                    const json j = json::parse(text);
                    const auto out = json::to_bjdata(j);
                    CHECK(out.at(0) == '{');
                    CHECK(json::from_bjdata(out) == j);
                }

                // OSS-Fuzz issue 563659413: an empty binary _ArraySize_ is written
                // as a plain object and read back as an empty array, after which
                // the object with a null _ArrayData_ was encoded as an empty
                // ND-array and re-read as [], so a second round trip lost the value
                const std::vector<uint8_t> input =
                {
                    '{', 'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'D', 'a', 't', 'a', '_', 'Z',
                    'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'T', 'y', 'p', 'e', '_', 'S', 'i', 5, 'i', 'n', 't', '1', '6',
                    'U', 11, '_', 'A', 'r', 'r', 'a', 'y', 'S', 'i', 'z', 'e', '_', '[', '$', 'B', '#', '[', ']', '}'
                };
                const json j1 = json::from_bjdata(input);
                const json j2 = json::from_bjdata(json::to_bjdata(j1, false, false));
                CHECK(j2 == json::parse(R"({"_ArrayType_":"int16","_ArraySize_":[],"_ArrayData_":null})"));
                CHECK(json::from_bjdata(json::to_bjdata(j2, false, false)) == j2);
            }

            SECTION("ndarray with _ArrayType_ \"byte\" is gated by the BJData draft version")
            {
                // the 'B' (byte) marker used by _ArrayType_ "byte" is only defined
                // by BJData Draft 3; Draft 2 (the default) has no such marker, so
                // emitting it unconditionally produced a stream that a Draft 2
                // reader could not parse as intended (see GitHub issue #5404).
                // Two dimensions are used so that a successfully written ndarray
                // round-trips back into the annotated object (a single dimension
                // is, by the BJData ndarray convention, read back as a plain
                // binary value rather than the annotated object, same as every
                // other single-dimension ndarray of a non-"byte" type is read
                // back as a plain array instead of the annotated object).
                json const j_byte = json({{"_ArrayType_", "byte"}, {"_ArraySize_", {2, 3}}, {"_ArrayData_", {1, 2, 3, 4, 5, 6}}});

                // default (Draft 2): falls back to a plain object and round-trips
                const auto out_draft2 = json::to_bjdata(j_byte);
                CHECK(out_draft2.at(0) == '{');
                CHECK(json::from_bjdata(out_draft2) == j_byte);

                // explicit Draft 2: same as the default
                const auto out_draft2_explicit = json::to_bjdata(j_byte, true, true, json::bjdata_version_t::draft2);
                CHECK(out_draft2_explicit.at(0) == '{');
                CHECK(json::from_bjdata(out_draft2_explicit) == j_byte);

                // Draft 3 explicitly selected: still uses the compact 'B' ndarray encoding
                const auto out_draft3 = json::to_bjdata(j_byte, true, true, json::bjdata_version_t::draft3);
                CHECK(out_draft3 == std::vector<uint8_t>({'[', '$', 'B', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 1, 2, 3, 4, 5, 6}));
                CHECK(json::from_bjdata(out_draft3) == j_byte);
            }
        }
    }

    SECTION("parse errors")
    {
        SECTION("empty byte vector")
        {
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(std::vector<uint8_t>()),
                                 "[json.exception.parse_error.110] parse error at byte 1: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
        }

        SECTION("char")
        {
            SECTION("eof after C byte")
            {
                std::vector<uint8_t> const v = {'C'};
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData char: unexpected end of input", json::parse_error&);
            }

            SECTION("byte out of range")
            {
                std::vector<uint8_t> const v = {'C', 130};
                json _;
                CHECK_THROWS_WITH(_ = json::from_bjdata(v), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing BJData char: byte after 'C' must be in range 0x00..0x7F; last byte: 0x82");
            }
        }

        SECTION("byte")
        {
            SECTION("parse bjdata markers in ubjson")
            {
                std::vector<uint8_t> const v = {'B', 1};

                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(v), "[json.exception.parse_error.112] parse error at byte 1: syntax error while parsing UBJSON value: invalid byte: 0x42", json::parse_error&);
            }
        }

        SECTION("strings")
        {
            SECTION("eof after S byte")
            {
                std::vector<uint8_t> const v = {'S'};
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            }

            SECTION("invalid byte")
            {
                std::vector<uint8_t> const v = {'S', '1', 'a'};
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing BJData string: expected length type specification (U, i, u, I, m, l, M, L); last byte: 0x31", json::parse_error&);
            }

            SECTION("negative length")
            {
                json _;

                std::vector<uint8_t> const vi = {'S', 'i', 0xFF};
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vi), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing BJData string: string length must not be negative", json::parse_error&);
                CHECK(json::from_bjdata(vi, true, false).is_discarded());

                std::vector<uint8_t> const vl = {'S', 'l', 0xFF, 0xFF, 0xFF, 0xFF};
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vl), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData string: string length must not be negative", json::parse_error&);
                CHECK(json::from_bjdata(vl, true, false).is_discarded());
            }

            SECTION("parse bjdata markers in ubjson")
            {
                // create a single-character string for all number types
                std::vector<uint8_t> const s_u = {'S', 'u', 1, 0, 'a'};
                std::vector<uint8_t> const s_m = {'S', 'm', 1, 0, 0, 0, 'a'};
                std::vector<uint8_t> const s_M = {'S', 'M', 1, 0, 0, 0, 0, 0, 0, 0, 'a'};

                json _;
                // check if string is parsed correctly to "a"
                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(s_u), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON string: expected length type specification (U, i, I, l, L); last byte: 0x75", json::parse_error&);
                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(s_m), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON string: expected length type specification (U, i, I, l, L); last byte: 0x6D", json::parse_error&);
                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(s_M), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing UBJSON string: expected length type specification (U, i, I, l, L); last byte: 0x4D", json::parse_error&);
            }
        }

        SECTION("array")
        {
            SECTION("optimized array: no size following type")
            {
                std::vector<uint8_t> const v = {'[', '$', 'i', 2};
                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.112] parse error at byte 4: syntax error while parsing BJData size: expected '#' after type information; last byte: 0x02", json::parse_error&);
            }

            SECTION("optimized array: negative size")
            {
                std::vector<uint8_t> const v1 = {'[', '#', 'i', 0xF1};
                std::vector<uint8_t> const v2 = {'[', '$', 'I', '#', 'i', 0xF2};
                std::vector<uint8_t> const v3 = {'[', '$', 'I', '#', '[', 'i', 0xF4, 'i', 0x02, ']'};
                std::vector<uint8_t> const v4 = {'[', '$', 'l', '#', 'i', 0xF7};
                std::vector<uint8_t> const v5 = {'[', '$', 'I', '#', '[', 'i', 0xF5, 'i', 0xF1, ']'};
                std::vector<uint8_t> const v6 = {'[', '#', '[', 'i', 0xF3, 'i', 0x02, ']'};

                std::vector<uint8_t> const vI = {'[', '#', 'I', 0x00, 0xF1};
                std::vector<uint8_t> const vl = {'[', '#', 'l', 0x00, 0x00, 0x00, 0xF2};
                std::vector<uint8_t> const vL = {'[', '#', 'L', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF3};
                std::vector<uint8_t> const vM = {'[', '$', 'M', '#', '[', 'I', 0x00, 0x20, 'M', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0xFF, ']'};
                std::vector<uint8_t> const vMX = {'[', '$', 'U', '#', '[', 'M', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 'U', 0x01, ']'};

                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v1), "[json.exception.parse_error.113] parse error at byte 4: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v1, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v2), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v2, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v3), "[json.exception.parse_error.113] parse error at byte 7: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v3, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v4), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v4, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v5), "[json.exception.parse_error.113] parse error at byte 7: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v5, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v6), "[json.exception.parse_error.113] parse error at byte 5: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(v6, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vI), "[json.exception.parse_error.113] parse error at byte 5: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(vI, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vl), "[json.exception.parse_error.113] parse error at byte 7: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(vl, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vL), "[json.exception.parse_error.113] parse error at byte 11: syntax error while parsing BJData size: count in an optimized container must be positive", json::parse_error&);
                CHECK(json::from_bjdata(vL, true, false).is_discarded());

#if SIZE_MAX != 0xffffffff
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vM), "[json.exception.out_of_range.408] syntax error while parsing BJData size: excessive ndarray size caused overflow", json::out_of_range&);
#else
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vM), "[json.exception.out_of_range.408] syntax error while parsing BJData size: integer value overflow", json::out_of_range&);
#endif
                CHECK(json::from_bjdata(vM, true, false).is_discarded());

#if SIZE_MAX != 0xffffffff
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vMX), "[json.exception.out_of_range.408] syntax error while parsing BJData size: excessive ndarray size caused overflow", json::out_of_range&);
#else
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vMX), "[json.exception.out_of_range.408] syntax error while parsing BJData size: integer value overflow", json::out_of_range&);
#endif
                CHECK(json::from_bjdata(vMX, true, false).is_discarded());
            }

            SECTION("optimized array: integer value overflow")
            {
#if SIZE_MAX == 0xffffffff
                std::vector<uint8_t> const vL = {'[', '#', 'L', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7F};
                std::vector<uint8_t> const vM = {'[', '$', 'M', '#', '[', 'I', 0x00, 0x20, 'M', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0xFF, ']'};

                json _;
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vL), "[json.exception.out_of_range.408] syntax error while parsing BJData size: integer value overflow", json::out_of_range&);
                CHECK(json::from_bjdata(vL, true, false).is_discarded());
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vM), "[json.exception.out_of_range.408] syntax error while parsing BJData size: integer value overflow", json::out_of_range&);
                CHECK(json::from_bjdata(vM, true, false).is_discarded());
#endif
            }

            SECTION("overflow detection in dimension multiplication")
            {
                // Simple SAX handler just to monitor if overflow is detected
                struct SimpleOverflowSaxHandler : public nlohmann::json_sax<json>
                {
                    bool overflow_detected = false;

                    // Implement all required virtual methods with minimal implementation
                    bool null() override
                    {
                        return true;
                    }
                    bool boolean(bool /*val*/) override
                    {
                        return true;
                    }
                    bool number_integer(json::number_integer_t /*val*/) override
                    {
                        return true;
                    }
                    bool number_unsigned(json::number_unsigned_t /*val*/) override
                    {
                        return true;
                    }
                    bool number_float(json::number_float_t /*val*/, const std::string& /*s*/) override
                    {
                        return true;
                    }
                    bool string(std::string& /*val*/) override
                    {
                        return true;
                    }
                    bool binary(json::binary_t& /*val*/) override
                    {
                        return true;
                    }
                    bool start_object(std::size_t /*elements*/) override
                    {
                        return true;
                    }
                    bool key(std::string& /*val*/) override
                    {
                        return true;
                    }
                    bool end_object() override
                    {
                        return true;
                    }
                    bool start_array(std::size_t /*elements*/) override
                    {
                        return true;
                    }
                    bool end_array() override
                    {
                        return true;
                    }

                    // This is the only method we care about - detecting error 408
                    bool parse_error(std::size_t /*position*/, const std::string& /*last_token*/, const json::exception& ex) override
                    {
                        if (ex.id == 408)
                        {
                            overflow_detected = true;
                        }
                        return false;
                    }
                };

                // Create BJData payload with overflow-causing dimensions (2^32+1) × (2^32)
                const std::vector<uint8_t> bjdata_payload =
                {
                    0x5B,                                           // '[' start array
                    0x24, 0x55,                                     // '$', 'U' (type uint8)
                    0x23, 0x5B,                                     // '#', '[' (dimensions array)
                    0x4D,                                           // 'M' (uint64)
                    0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // 2^32 + 1 (4294967297) as little-endian
                    0x4D,                                           // 'M' (uint64)
                    0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, // 2^32 (4294967296) as little-endian
                    0x5D                                            // ']' end dimensions
                    // No data - we don't need it for this test, we just want to hit the overflow check
                };

                // Test with overflow dimensions using SAX parser
                {
                    SimpleOverflowSaxHandler handler;
                    const auto result = json::sax_parse(bjdata_payload, &handler,
                                                        nlohmann::detail::input_format_t::bjdata, false);

                    // Should detect overflow
                    CHECK(handler.overflow_detected == true);
                    CHECK(result == false);
                }

                // Test with DOM parser (should throw)
                {
                    json _;
                    CHECK_THROWS_AS(_ = json::from_bjdata(bjdata_payload), json::out_of_range);
                }

                // Test with normal dimensions
                const std::vector<uint8_t> normal_payload =
                {
                    0x5B,                                           // '[' start array
                    0x24, 0x55,                                     // '$', 'U' (type uint8)
                    0x23, 0x5B,                                     // '#', '[' (dimensions array)
                    0x55, 0x02,                                     // 'U', 2 (uint8)
                    0x55, 0x03,                                     // 'U', 3 (uint8)
                    0x5D,                                           // ']' end dimensions
                    // 6 data bytes for a 2×3 array (enough to avoid EOF but not entire array)
                    0x01, 0x02, 0x03, 0x04, 0x05, 0x06
                };

                // For normal dimensions, overflow should not be detected
                {
                    SimpleOverflowSaxHandler handler;
                    const auto result = json::sax_parse(normal_payload, &handler,
                                                        nlohmann::detail::input_format_t::bjdata, false);

                    CHECK(handler.overflow_detected == false);
                    CHECK(result == true);
                }
            }

            SECTION("ndarray of half-precision floats can be read")
            {
                // the 'h' element type is read as _ArrayType_ "half"
                json _;
                const std::vector<uint8_t> half = {'[', '$', 'h', '#', '[', '$', 'U', '#', 'U', 2, 2, 2, 0x00, 0x3C, 0x00, 0x40, 0x00, 0x42, 0x00, 0x44};
                const json j_half = json::parse(R"({"_ArrayType_":"half","_ArraySize_":[2,2],"_ArrayData_":[1.0,2.0,3.0,4.0]})");
                CHECK(json::from_bjdata(half) == j_half);

                // the writer does not pack "half": it writes a plain object that reads back equal
                CHECK(json::from_bjdata(json::to_bjdata(j_half)) == j_half);
                CHECK(json::from_bjdata(json::to_bjdata(j_half, true, true, json::bjdata_version_t::draft3)) == j_half);

                // truncated half data
                CHECK_THROWS_AS(_ = json::from_bjdata(std::vector<uint8_t>(half.begin(), half.end() - 1)), json::parse_error&);
            }

            SECTION("ndarray of char rejects values above 127")
            {
                json _;
                const std::vector<uint8_t> ok = {'[', '$', 'C', '#', '[', '$', 'U', '#', 'U', 2, 2, 2, 'a', 'b', 'c', 0x7F};
                CHECK(json::from_bjdata(ok) == json::parse(R"({"_ArrayType_":"char","_ArraySize_":[2,2],"_ArrayData_":[97,98,99,127]})"));

                std::vector<uint8_t> bad = ok;
                bad.back() = 0xC8;
                CHECK_THROWS_AS(_ = json::from_bjdata(bad), json::parse_error&);
                CHECK(json::from_bjdata(bad, true, false).is_discarded());

                // the same restriction holds for 1-D arrays
                CHECK_THROWS_AS(_ = json::from_bjdata(std::vector<uint8_t>({'[', '$', 'C', '#', 'i', 1, 0xC8})), json::parse_error&);

                // truncated input
                CHECK_THROWS_AS(_ = json::from_bjdata(std::vector<uint8_t>(ok.begin(), ok.end() - 1)), json::parse_error&);

                // 'B' (byte) elements may use the full range
                const std::vector<uint8_t> byte_nd = {'[', '$', 'B', '#', '[', '$', 'U', '#', 'U', 2, 2, 2, 1, 2, 3, 0xC8};
                CHECK(json::from_bjdata(byte_nd) == json::parse(R"({"_ArrayType_":"byte","_ArraySize_":[2,2],"_ArrayData_":[1,2,3,200]})"));
            }

            SECTION("do not accept NTFZ markers in ndarray optimized type (with count)")
            {
                json _;
                std::vector<uint8_t> const v_N = {'[', '$', 'N', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2};
                std::vector<uint8_t> const v_T = {'[', '$', 'T', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2};
                std::vector<uint8_t> const v_F = {'[', '$', 'F', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2};
                std::vector<uint8_t> const v_Z = {'[', '$', 'Z', '#', '[', '#', 'i', 2, 'i', 1, 'i', 2};

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_N), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x4E is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_N, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_T), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x54 is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_T, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_F), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x46 is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_F, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_Z), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x5A is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_Z, true, false).is_discarded());
            }

            SECTION("do not accept NTFZ markers in ndarray optimized type (without count)")
            {
                json _;
                std::vector<uint8_t> const v_N = {'[', '$', 'N', '#', '[', 'i', 1, 'i', 2, ']'};
                std::vector<uint8_t> const v_T = {'[', '$', 'T', '#', '[', 'i', 1, 'i', 2, ']'};
                std::vector<uint8_t> const v_F = {'[', '$', 'F', '#', '[', 'i', 1, 'i', 2, ']'};
                std::vector<uint8_t> const v_Z = {'[', '$', 'Z', '#', '[', 'i', 1, 'i', 2, ']'};

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_N), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x4E is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_N, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_T), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x54 is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_T, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_F), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x46 is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_F, true, false).is_discarded());

                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v_Z), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x5A is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v_Z, true, false).is_discarded());
            }
        }

        SECTION("strings")
        {
            std::vector<uint8_t> const vS = {'S'};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vS), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vS, true, false).is_discarded());

            std::vector<uint8_t> const v = {'S', 'i', '2', 'a'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 5: syntax error while parsing BJData string: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v, true, false).is_discarded());

            std::vector<uint8_t> const vC = {'C'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vC), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing BJData char: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vC, true, false).is_discarded());
        }

        SECTION("sizes")
        {
            std::vector<uint8_t> const vU = {'[', '#', 'U'};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vU), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vU, true, false).is_discarded());

            std::vector<uint8_t> const vi = {'[', '#', 'i'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vi), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vi, true, false).is_discarded());

            std::vector<uint8_t> const vI = {'[', '#', 'I'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vI), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vI, true, false).is_discarded());

            std::vector<uint8_t> const vu = {'[', '#', 'u'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vu), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vu, true, false).is_discarded());

            std::vector<uint8_t> const vl = {'[', '#', 'l'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vl), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vl, true, false).is_discarded());

            std::vector<uint8_t> const vm = {'[', '#', 'm'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vm), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vm, true, false).is_discarded());

            std::vector<uint8_t> const vL = {'[', '#', 'L'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vL), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vL, true, false).is_discarded());

            std::vector<uint8_t> const vM = {'[', '#', 'M'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vM), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vM, true, false).is_discarded());

            std::vector<uint8_t> const v0 = {'[', '#', 'T', ']'};
            CHECK_THROWS_WITH(_ = json::from_bjdata(v0), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x54");
            CHECK(json::from_bjdata(v0, true, false).is_discarded());

            std::vector<uint8_t> const vB = {'[', '#', 'B', ']'};
            CHECK_THROWS_WITH(_ = json::from_bjdata(vB), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x42");
            CHECK(json::from_bjdata(v0, true, false).is_discarded());
        }

        SECTION("parse bjdata markers as array size in ubjson")
        {
            json _;
            std::vector<uint8_t> const vu = {'[', '#', 'u'};
            CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vu), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x75", json::parse_error&);
            CHECK(json::from_ubjson(vu, true, false).is_discarded());

            std::vector<uint8_t> const vm = {'[', '#', 'm'};
            CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vm), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x6D", json::parse_error&);
            CHECK(json::from_ubjson(vm, true, false).is_discarded());

            std::vector<uint8_t> const vM = {'[', '#', 'M'};
            CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vM), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x4D", json::parse_error&);
            CHECK(json::from_ubjson(vM, true, false).is_discarded());

            std::vector<uint8_t> const v0 = {'[', '#', '['};
            CHECK_THROWS_WITH_AS(_ = json::from_ubjson(v0), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON size: expected length type specification (U, i, I, l, L) after '#'; last byte: 0x5B", json::parse_error&);
            CHECK(json::from_ubjson(v0, true, false).is_discarded());
        }

        SECTION("types")
        {
            std::vector<uint8_t> const v0 = {'[', '$'};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v0), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BJData type: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v0, true, false).is_discarded());

            std::vector<uint8_t> const vi = {'[', '$', '#'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vi), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x23 is not a permitted optimized array type", json::parse_error&);
            CHECK(json::from_bjdata(vi, true, false).is_discarded());

            std::vector<uint8_t> const vU = {'[', '$', 'U'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vU), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vU, true, false).is_discarded());

            std::vector<uint8_t> const v1 = {'[', '$', '['};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v1), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x5B is not a permitted optimized array type", json::parse_error&);
            CHECK(json::from_bjdata(v1, true, false).is_discarded());
        }

        SECTION("arrays")
        {
            std::vector<uint8_t> const vST = {'[', '$', 'i', '#', 'i', 2, 1};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vST), "[json.exception.parse_error.110] parse error at byte 8: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vST, true, false).is_discarded());

            std::vector<uint8_t> const vS = {'[', '#', 'i', 2, 'i', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vS), "[json.exception.parse_error.110] parse error at byte 7: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vS, true, false).is_discarded());

            std::vector<uint8_t> const v = {'[', 'i', 2, 'i', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 6: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v, true, false).is_discarded());
        }

        SECTION("ndarrays")
        {
            std::vector<uint8_t> const vST = {'[', '$', 'i', '#', '[', '$', 'i', '#'};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vST), "[json.exception.parse_error.113] parse error at byte 9: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0xFF", json::parse_error&);
            CHECK(json::from_bjdata(vST, true, false).is_discarded());

            std::vector<uint8_t> const v = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 2, 1, 2};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 13: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v, true, false).is_discarded());

            std::vector<uint8_t> const vS0 = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'i', 2, 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vS0), "[json.exception.parse_error.110] parse error at byte 12: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vS0, true, false).is_discarded());

            std::vector<uint8_t> const vS = {'[', '$', 'i', '#', '[', '#', 'i', 2, 1, 2, 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vS), "[json.exception.parse_error.113] parse error at byte 9: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x01", json::parse_error&);
            CHECK(json::from_bjdata(vS, true, false).is_discarded());

            std::vector<uint8_t> const vT = {'[', '$', 'i', '#', '[', 'i', 2, 'i'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vT), "[json.exception.parse_error.110] parse error at byte 9: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vT, true, false).is_discarded());

            std::vector<uint8_t> const vT0 = {'[', '$', 'i', '#', '[', 'i'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vT0), "[json.exception.parse_error.110] parse error at byte 7: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vT0, true, false).is_discarded());

            std::vector<uint8_t> const vu = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'u', 1, 0};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vu), "[json.exception.parse_error.110] parse error at byte 12: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vu, true, false).is_discarded());

            std::vector<uint8_t> const vm = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'm', 1, 0, 0, 0};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vm), "[json.exception.parse_error.110] parse error at byte 14: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vm, true, false).is_discarded());

            std::vector<uint8_t> const vM = {'[', '$', 'i', '#', '[', '$', 'i', '#', 'M', 1, 0, 0, 0, 0, 0, 0, 0};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vM), "[json.exception.parse_error.110] parse error at byte 18: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vM, true, false).is_discarded());

            std::vector<uint8_t> const vU = {'[', '$', 'U', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 1, 2, 3, 4, 5};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vU), "[json.exception.parse_error.110] parse error at byte 18: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vU, true, false).is_discarded());

            std::vector<uint8_t> const vB = {'[', '$', 'B', '#', '[', '$', 'i', '#', 'i', 2, 2, 3, 1, 2, 3, 4, 5};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vU), "[json.exception.parse_error.110] parse error at byte 18: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vU, true, false).is_discarded());

            std::vector<uint8_t> const vT1 = {'[', '$', 'T', '#', '[', '$', 'i', '#', 'i', 2, 2, 3};
            CHECK(json::from_bjdata(vT1, true, false).is_discarded());

            std::vector<uint8_t> const vh = {'[', '$', 'h', '#', '[', '$', 'i', '#', 'i', 2, 2, 3};
            CHECK(json::from_bjdata(vh, true, false).is_discarded());

            std::vector<uint8_t> const vR = {'[', '$', 'i', '#', '[', 'i', 1, '[', ']', ']', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR), "[json.exception.parse_error.113] parse error at byte 8: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR, true, false).is_discarded());

            std::vector<uint8_t> const vRo = {'[', '$', 'i', '#', '[', 'i', 0, '{', '}', ']', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vRo), "[json.exception.parse_error.113] parse error at byte 8: syntax error while parsing BJData size: expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x7B", json::parse_error&);
            CHECK(json::from_bjdata(vRo, true, false).is_discarded());

            std::vector<uint8_t> const vR1 = {'[', '$', 'i', '#', '[', '[', 'i', 1, ']', ']', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR1), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR1, true, false).is_discarded());

            // a dimension vector that opens another one is rejected where the
            // nested '[' is read, rather than after it has been descended into
            std::vector<uint8_t> const vR2 = {'[', '$', 'i', '#', '[', '#', '[', 'i', 1, ']', ']', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR2), "[json.exception.parse_error.113] parse error at byte 7: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR2, true, false).is_discarded());

            std::vector<uint8_t> const vR3 = {'[', '#', '[', 'i', '2', 'i', 2, ']'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR3), "[json.exception.parse_error.112] parse error at byte 8: syntax error while parsing BJData size: ndarray requires both type and size", json::parse_error&);
            CHECK(json::from_bjdata(vR3, true, false).is_discarded());

            std::vector<uint8_t> const vR4 = {'[', '$', 'i', '#', '[', '$', 'i', '#', '[', 'i', 1, ']', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR4), "[json.exception.parse_error.113] parse error at byte 9: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR4, true, false).is_discarded());

            std::vector<uint8_t> const vR5 = {'[', '$', 'i', '#', '[', '[', '[', ']', ']', ']'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR5), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR5, true, false).is_discarded());

            std::vector<uint8_t> const vR6 = {'[', '$', 'i', '#', '[', '$', 'i', '#', '[', 'i', '2', 'i', 2, ']'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vR6), "[json.exception.parse_error.113] parse error at byte 9: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vR6, true, false).is_discarded());

            std::vector<uint8_t> const vH = {'[', 'H', '[', '#', '[', '$', 'i', '#', '[', 'i', '2', 'i', 2, ']'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vH), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vH, true, false).is_discarded());

            // Every "#[" of this chain used to open another dimension vector
            // and cost several stack frames before anything was rejected, so a
            // long enough chain crashed the process (see #5104). The nested
            // vector is refused where it is read, so the length is irrelevant.
            std::vector<uint8_t> vRdeep = {'['};
            for (std::size_t i = 0; i < 100000; ++i)
            {
                vRdeep.push_back('#');
                vRdeep.push_back('[');
            }
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vRdeep), "[json.exception.parse_error.113] parse error at byte 5: syntax error while parsing BJData size: ndarray dimensional vector is not allowed", json::parse_error&);
            CHECK(json::from_bjdata(vRdeep, true, false).is_discarded());
        }

        SECTION("objects")
        {
            std::vector<uint8_t> const vST = {'{', '$', 'i', '#', 'i', 2, 'i', 1, 'a', 1};
            json _;
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vST), "[json.exception.parse_error.110] parse error at byte 11: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vST, true, false).is_discarded());

            std::vector<uint8_t> const vT = {'{', '$', 'i', 'i', 1, 'a', 1};
            CHECK_THROWS_WITH(_ = json::from_bjdata(vT), "[json.exception.parse_error.112] parse error at byte 4: syntax error while parsing BJData size: expected '#' after type information; last byte: 0x69");
            CHECK(json::from_bjdata(vT, true, false).is_discarded());

            std::vector<uint8_t> const vS = {'{', '#', 'i', 2, 'i', 1, 'a', 'i', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vS), "[json.exception.parse_error.110] parse error at byte 10: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vS, true, false).is_discarded());

            std::vector<uint8_t> const v = {'{', 'i', 1, 'a', 'i', 1};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.110] parse error at byte 7: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v, true, false).is_discarded());

            std::vector<uint8_t> const v2 = {'{', 'i', 1, 'a', 'i', 1, 'i'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v2), "[json.exception.parse_error.110] parse error at byte 8: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v2, true, false).is_discarded());

            std::vector<uint8_t> const v3 = {'{', 'i', 1, 'a'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v3), "[json.exception.parse_error.110] parse error at byte 5: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(v3, true, false).is_discarded());

            std::vector<uint8_t> const vST1 = {'{', '$', 'd', '#', 'i', 2, 'i', 1, 'a'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vST1), "[json.exception.parse_error.110] parse error at byte 10: syntax error while parsing BJData number: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vST1, true, false).is_discarded());

            std::vector<uint8_t> const vST2 = {'{', '#', 'i', 2, 'i', 1, 'a'};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vST2), "[json.exception.parse_error.110] parse error at byte 8: syntax error while parsing BJData value: unexpected end of input", json::parse_error&);
            CHECK(json::from_bjdata(vST2, true, false).is_discarded());

            std::vector<uint8_t> const vO = {'{', '#', '[', 'i', 2, 'i', 1, ']', 'i', 1, 'a', 'i', 1, 'i', 1, 'b', 'i', 2};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vO), "[json.exception.parse_error.112] parse error at byte 8: syntax error while parsing BJData size: ndarray requires both type and size", json::parse_error&);
            CHECK(json::from_bjdata(vO, true, false).is_discarded());

            std::vector<uint8_t> const vO2 = {'{', '$', 'i', '#', '[', 'i', 2, 'i', 1, ']', 'i', 1, 'a', 1, 'i', 1, 'b', 2};
            CHECK_THROWS_WITH_AS(_ = json::from_bjdata(vO2), "[json.exception.parse_error.112] parse error at byte 10: syntax error while parsing BJData object: BJData object does not support ND-array size in optimized format", json::parse_error&);
            CHECK(json::from_bjdata(vO2, true, false).is_discarded());
        }
    }

    SECTION("writing optimized values")
    {
        SECTION("integer")
        {
            SECTION("array of i")
            {
                json const j = {1, -1};
                std::vector<uint8_t> const expected = {'[', '$', 'i', '#', 'i', 2, 1, 0xff};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of U")
            {
                json const j = {200, 201};
                std::vector<uint8_t> const expected = {'[', '$', 'U', '#', 'i', 2, 0xC8, 0xC9};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of I")
            {
                json const j = {30000, -30000};
                std::vector<uint8_t> const expected = {'[', '$', 'I', '#', 'i', 2, 0x30, 0x75, 0xd0, 0x8a};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of u")
            {
                json const j = {50000, 50001};
                std::vector<uint8_t> const expected = {'[', '$', 'u', '#', 'i', 2, 0x50, 0xC3, 0x51, 0xC3};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of l")
            {
                json const j = {70000, -70000};
                std::vector<uint8_t> const expected = {'[', '$', 'l', '#', 'i', 2, 0x70, 0x11, 0x01, 0x00, 0x90, 0xEE, 0xFE, 0xFF};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of m")
            {
                json const j = {3147483647, 3147483648};
                std::vector<uint8_t> const expected = {'[', '$', 'm', '#', 'i', 2, 0xFF, 0xC9, 0x9A, 0xBB, 0x00, 0xCA, 0x9A, 0xBB};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }

            SECTION("array of L")
            {
                json const j = {5000000000, -5000000000};
                std::vector<uint8_t> const expected = {'[', '$', 'L', '#', 'i', 2, 0x00, 0xF2, 0x05, 0x2A, 0x01, 0x00, 0x00, 0x00, 0x00, 0x0E, 0xFA, 0xD5, 0xFE, 0xFF, 0xFF, 0xFF};
                CHECK(json::to_bjdata(j, true, true) == expected);
            }
        }

        SECTION("unsigned integer")
        {
            SECTION("array of i")
            {
                json const j = {1u, 2u};
                std::vector<uint8_t> const expected = {'[', '$', 'i', '#', 'i', 2, 1, 2};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'i', 1, 'i', 2};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of U")
            {
                json const j = {200u, 201u};
                std::vector<uint8_t> const expected = {'[', '$', 'U', '#', 'i', 2, 0xC8, 0xC9};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'U', 0xC8, 'U', 0xC9};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of I")
            {
                json const j = {30000u, 30001u};
                std::vector<uint8_t> const expected = {'[', '$', 'I', '#', 'i', 2, 0x30, 0x75, 0x31, 0x75};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'I', 0x30, 0x75, 'I', 0x31, 0x75};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of u")
            {
                json const j = {50000u, 50001u};
                std::vector<uint8_t> const expected = {'[', '$', 'u', '#', 'i', 2, 0x50, 0xC3, 0x51, 0xC3};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'u', 0x50, 0xC3, 'u', 0x51, 0xC3};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of l")
            {
                json const j = {70000u, 70001u};
                std::vector<uint8_t> const expected = {'[', '$', 'l', '#', 'i', 2, 0x70, 0x11, 0x01, 0x00, 0x71, 0x11, 0x01, 0x00};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'l', 0x70, 0x11, 0x01, 0x00, 'l', 0x71, 0x11, 0x01, 0x00};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of m")
            {
                json const j = {3147483647u, 3147483648u};
                std::vector<uint8_t> const expected = {'[', '$', 'm', '#', 'i', 2, 0xFF, 0xC9, 0x9A, 0xBB, 0x00, 0xCA, 0x9A, 0xBB};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'm', 0xFF, 0xC9, 0x9A, 0xBB, 'm', 0x00, 0xCA, 0x9A, 0xBB};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of L")
            {
                json const j = {5000000000u, 5000000001u};
                std::vector<uint8_t> const expected = {'[', '$', 'L', '#', 'i', 2, 0x00, 0xF2, 0x05, 0x2A, 0x01, 0x00, 0x00, 0x00, 0x01, 0xF2, 0x05, 0x2A, 0x01, 0x00, 0x00, 0x00};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'L', 0x00, 0xF2, 0x05, 0x2A, 0x01, 0x00, 0x00, 0x00, 'L', 0x01, 0xF2, 0x05, 0x2A, 0x01, 0x00, 0x00, 0x00};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }

            SECTION("array of M")
            {
                json const j = {10223372036854775807ull, 10223372036854775808ull};
                std::vector<uint8_t> const expected = {'[', '$', 'M', '#', 'i', 2, 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 0x00, 0x00, 0x64, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                std::vector<uint8_t> const expected_size = {'[', '#', 'i', 2, 'M', 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D, 'M', 0x00, 0x00, 0x64, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D};
                CHECK(json::to_bjdata(j, true, true) == expected);
                CHECK(json::to_bjdata(j, true) == expected_size);
            }
        }
    }
}

TEST_CASE("BJData input that cannot be read is discarded by every overload")
{
    std::vector<std::uint8_t> input = json::to_bjdata(json({{"a", {1, 2}}}));
    input.pop_back();

    json _;
    CHECK_THROWS_AS(_ = json::from_bjdata(input.begin(), input.end()), json::parse_error&);
    CHECK(json::from_bjdata(input, true, false).is_discarded());
    CHECK(json::from_bjdata(input.begin(), input.end(), true, false).is_discarded());
}

TEST_CASE("BJData SAX parsing stops at every event")
{
    // Containers are opened and closed by the loop that reads them; a SAX
    // handler that rejects any event - including the end of a nested
    // container - must stop the parse right there.
    const auto count_events = [](const std::vector<std::uint8_t>& input)
    {
        int events = 0;
        while (true)
        {
            SaxCountdown scp(events);
            if (json::sax_parse(input, &scp, json::input_format_t::bjdata))
            {
                return events;
            }
            ++events;
            REQUIRE(events < 1000);
        }
    };

    // 20 events: every container kind closes inside another one
    const json j = json::parse(R"({"a": [1, {"b": []}], "c": {"d": [[2]]}})");
    CHECK(count_events(json::to_bjdata(j)) == 20);
    CHECK(count_events(json::to_bjdata(j, true)) == 20);
    CHECK(count_events(json::to_bjdata(j, true, true)) == 20);

    // an ND-array is announced as an annotated object: start_object, then
    // _ArrayType_, _ArraySize_ and _ArrayData_ with its elements
    const json ndarray = json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": [2, 2], "_ArrayData_": [1, 2, 3, 4]})");
    CHECK(count_events(json::to_bjdata(ndarray, true, true)) == 16);
}

TEST_CASE("issue #5405 - array reserve for definite-length BJData arrays")
{
#if !defined(JSON_NOEXCEPTION)
    // this SECTION relies on catching a thrown exception to distinguish
    // which of two acceptable, bounded rejections a hostile header took;
    // under JSON_NOEXCEPTION, JSON_THROW never produces a catchable C++
    // exception (it aborts instead), so this cannot be tested that way here
    SECTION("a huge claimed length with no element data must not over-allocate")
    {
        // optimized form [$type#count: type 'i' (int8), count as a four-byte
        // little-endian 'l' (int32) of 0x7FFFFFFF (2147483647), but no
        // element data at all. max_size() for a std::vector is far larger
        // than this count, so it does not reject the header outright; the
        // (capped) reservation must not attempt to allocate space for
        // billions of elements before the missing data is detected.
        json _;
        const std::vector<uint8_t> input = {'[', '$', 'i', '#', 'l', 0xFF, 0xFF, 0xFF, 0x7F};
        // On a platform where std::vector<json>::max_size() is smaller than
        // the claimed count (e.g. 32-bit, where max_size() is bounded by a
        // 32-bit SIZE_MAX divided by sizeof(json)), the SAX consumer's own
        // check rejects the header outright (out_of_range.408, with the
        // claimed count in the message) instead of accepting it and only
        // finding it short of data once the (capped) reservation looks for
        // element bytes that were never provided (parse_error.110). Either
        // is an acceptable, bounded rejection of the hostile header -- the
        // property under test is that no path attempts to allocate space
        // for billions of elements.
        bool threw = false;
        try
        {
            _ = json::from_bjdata(input);
        }
        catch (const json::parse_error& e)
        {
            threw = true;
            CHECK(e.id == 110);
            CHECK(std::string(e.what()) == "[json.exception.parse_error.110] parse error at byte 10: syntax error while parsing BJData number: unexpected end of input");
        }
        catch (const json::out_of_range& e)
        {
            threw = true;
            CHECK(e.id == 408);
            CHECK(std::string(e.what()).find("excessive array size") != std::string::npos);
        }
        CHECK(threw);

        // json_sax_dom_parser::start_array()'s max_size() check (unlike the
        // scanner's own parse_error path) throws unconditionally via
        // JSON_THROW rather than going through sax->parse_error(), so it is
        // not gated by allow_exceptions=false on a platform where this
        // header hits that check (e.g. 32-bit, see above) -- allow either
        // a discarded result or the same out_of_range it throws with
        // exceptions enabled.
        try
        {
            CHECK(json::from_bjdata(input, true, false).is_discarded());
        }
        catch (const json::out_of_range& e)
        {
            CHECK(e.id == 408);
        }
    }
#endif

    SECTION("arrays of various sizes decode to the same value as before the reserve optimization")
    {
        for (const auto size :
                {
                    std::size_t{0}, std::size_t{1}, std::size_t{5}, // small
                    std::size_t{16384},                             // exactly at the reserve cap
                    std::size_t{20000}                              // above the reserve cap
                })
        {
            CAPTURE(size)
            json j = json::array();
            for (std::size_t i = 0; i < size; ++i)
            {
                j.push_back(static_cast<int>(i % 1000));
            }

            // exercise both the plain and the optimized [$type#count encoding
            const auto packed_plain = json::to_bjdata(j);
            CHECK(json::from_bjdata(packed_plain) == j);

            const auto packed_optimized = json::to_bjdata(j, true, true);
            CHECK(json::from_bjdata(packed_optimized) == j);
        }
    }

    SECTION("a user-defined SAX consumer is unaffected by the internal DOM reserve optimization")
    {
        // the reserve() call is local to json_sax_dom_parser / json_sax_dom_callback_parser;
        // a custom SAX consumer that does not touch a DOM array sees identical events
        json j = json::array();
        for (int i = 0; i < 100; ++i)
        {
            j.push_back(i);
        }
        const auto packed = json::to_bjdata(j, true, true);

        SaxCountdown scp(1000000); // large enough to never trigger an abort
        CHECK(json::sax_parse(packed, &scp, json::input_format_t::bjdata));
    }
}

TEST_CASE("Universal Binary JSON Specification Examples 1")
{
    SECTION("Null Value")
    {
        json const j = {{"passcode", nullptr}};
        std::vector<uint8_t> v = {'{', 'i', 8, 'p', 'a', 's', 's', 'c', 'o', 'd', 'e', 'Z', '}'};
        CHECK(json::to_bjdata(j) == v);
        CHECK(json::from_bjdata(v) == j);
    }

    SECTION("No-Op Value")
    {
        json const j = {"foo", "bar", "baz"};
        std::vector<uint8_t> v = {'[', 'S', 'i', 3, 'f', 'o', 'o',
                                  'S', 'i', 3, 'b', 'a', 'r',
                                  'S', 'i', 3, 'b', 'a', 'z', ']'
                                 };
        std::vector<uint8_t> const v2 = {'[', 'S', 'i', 3, 'f', 'o', 'o', 'N',
                                         'S', 'i', 3, 'b', 'a', 'r', 'N', 'N', 'N',
                                         'S', 'i', 3, 'b', 'a', 'z', 'N', 'N', ']'
                                        };
        CHECK(json::to_bjdata(j) == v);
        CHECK(json::from_bjdata(v) == j);
        CHECK(json::from_bjdata(v2) == j);
    }

    SECTION("Boolean Types")
    {
        json const j = {{"authorized", true}, {"verified", false}};
        std::vector<uint8_t> v = {'{', 'i', 10, 'a', 'u', 't', 'h', 'o', 'r', 'i', 'z', 'e', 'd', 'T',
                                  'i', 8, 'v', 'e', 'r', 'i', 'f', 'i', 'e', 'd', 'F', '}'
                                 };
        CHECK(json::to_bjdata(j) == v);
        CHECK(json::from_bjdata(v) == j);
    }

    SECTION("Numeric Types")
    {
        json j =
        {
            {"int8", 16},
            {"uint8", 255},
            {"int16", 32767},
            {"uint16", 42767},
            {"int32", 2147483647},
            {"uint32", 3147483647},
            {"int64", 9223372036854775807},
            {"uint64", 10223372036854775807ull},
            {"float64", 113243.7863123}
        };
        std::vector<uint8_t> v = {'{',
                                  'i', 7, 'f', 'l', 'o', 'a', 't', '6', '4', 'D', 0xcf, 0x34, 0xbc, 0x94, 0xbc, 0xa5, 0xfb, 0x40,
                                  'i', 5, 'i', 'n', 't', '1', '6', 'I', 0xff, 0x7f,
                                  'i', 5, 'i', 'n', 't', '3', '2', 'l', 0xff, 0xff, 0xff, 0x7f,
                                  'i', 5, 'i', 'n', 't', '6', '4', 'L', 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f,
                                  'i', 4, 'i', 'n', 't', '8', 'i', 16,
                                  'i', 6, 'u', 'i', 'n', 't', '1', '6', 'u', 0x0F, 0xA7,
                                  'i', 6, 'u', 'i', 'n', 't', '3', '2', 'm', 0xFF, 0xC9, 0x9A, 0xBB,
                                  'i', 6, 'u', 'i', 'n', 't', '6', '4', 'M', 0xFF, 0xFF, 0x63, 0xA7, 0xB3, 0xB6, 0xE0, 0x8D,
                                  'i', 5, 'u', 'i', 'n', 't', '8', 'U', 0xff,
                                  '}'
                                 };
        CHECK(json::to_bjdata(j) == v);
        CHECK(json::from_bjdata(v) == j);
    }

    SECTION("Char Type")
    {
        json const j = {{"rolecode", "a"}, {"delim", ";"}};
        std::vector<uint8_t> const v = {'{', 'i', 5, 'd', 'e', 'l', 'i', 'm', 'C', ';', 'i', 8, 'r', 'o', 'l', 'e', 'c', 'o', 'd', 'e', 'C', 'a', '}'};
        //CHECK(json::to_bjdata(j) == v);
        CHECK(json::from_bjdata(v) == j);
    }

    SECTION("Byte Type")
    {
        const auto s = std::vector<std::uint8_t>(
        {
            static_cast<std::uint8_t>(222),
            static_cast<std::uint8_t>(173),
            static_cast<std::uint8_t>(190),
            static_cast<std::uint8_t>(239)
        });
        json const j = {{"binary", json::binary(s)}, {"val", 123}};
        std::vector<uint8_t> const v = {'{', 'i', 6, 'b', 'i', 'n', 'a', 'r', 'y', '[', '$', 'B', '#', 'i', 4, 222, 173, 190, 239, 'i', 3, 'v', 'a', 'l', 'i', 123, '}'};
        //CHECK(json::to_bjdata(j) == v); // 123 value gets encoded as uint8
        CHECK(json::from_bjdata(v) == j);
    }

    SECTION("String Type")
    {
        SECTION("English")
        {
            json const j = "hello";
            std::vector<uint8_t> v = {'S', 'i', 5, 'h', 'e', 'l', 'l', 'o'};
            CHECK(json::to_bjdata(j) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("Russian")
        {
            json const j = "привет";
            std::vector<uint8_t> v = {'S', 'i', 12, 0xD0, 0xBF, 0xD1, 0x80, 0xD0, 0xB8, 0xD0, 0xB2, 0xD0, 0xB5, 0xD1, 0x82};
            CHECK(json::to_bjdata(j) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("Russian")
        {
            json const j = "مرحبا";
            std::vector<uint8_t> v = {'S', 'i', 10, 0xD9, 0x85, 0xD8, 0xB1, 0xD8, 0xAD, 0xD8, 0xA8, 0xD8, 0xA7};
            CHECK(json::to_bjdata(j) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("ill-formed UTF-8 (see #5529, #5651)")
        {
            // none of the binary format specs requires a decoder to reject
            // ill-formed UTF-8 in a text string, so a value whose bytes are
            // not valid UTF-8 (0xC0 0xAE is an overlong encoding of '.')
            // round-trips byte for byte as a string value; to_bjdata() writes
            // the bytes unchanged, as before 3.13.0, unless
            // JSON_STRICT_BINARY_UTF8 is enabled (see
            // unit-binary_utf8_strict.cpp)
            const std::vector<uint8_t> v = {'S', 'i', 2, 0xc0, 0xae};
            json j;
            CHECK_NOTHROW(j = json::from_bjdata(v));
            REQUIRE(j.is_string());
            CHECK(j.get_ref<const json::string_t&>() == std::string("\xc0\xae"));
            CHECK_THROWS_AS(utils::ignore_return_value(j.dump()), json::type_error&);
            CHECK(json::from_bjdata(json::to_bjdata(j)) == j);

            // the same bytes as an object key round-trip as well
            const std::vector<uint8_t> v_key = {'{', 'i', 2, 0xc0, 0xae, 'i', 1, '}'};
            json j_key;
            CHECK_NOTHROW(j_key = json::from_bjdata(v_key));
            REQUIRE(j_key.is_object());
            CHECK(j_key.contains(std::string("\xc0\xae")));
            CHECK(json::from_bjdata(json::to_bjdata(j_key)) == j_key);

            CHECK(json::from_bjdata(json::to_bjdata(json("\xFF"))) == json("\xFF"));
            // a truncated multi-byte sequence
            CHECK(json::from_bjdata(json::to_bjdata(json("\xC3"))) == json("\xC3"));
            // an encoded surrogate half (U+D800)
            CHECK(json::from_bjdata(json::to_bjdata(json("\xED\xA0\x80"))) == json("\xED\xA0\x80"));
            // an overlong encoding of '.'
            CHECK(json::from_bjdata(json::to_bjdata(json("\xC0\xAF"))) == json("\xC0\xAF"));

            // an object key with ill-formed UTF-8 is kept the same way
            CHECK(json::from_bjdata(json::to_bjdata(json{{"\xFF", 1}})) == json{{"\xFF", 1}});
        }
    }

    SECTION("Array Type")
    {
        SECTION("size=false type=false")
        {
            // note the float has been replaced by a double
            json const j = {nullptr, true, false, 4782345193, 153.132, "ham"};
            std::vector<uint8_t> v = {'[', 'Z', 'T', 'F', 'L', 0xE9, 0xCB, 0x0C, 0x1D, 0x01, 0x00, 0x00, 0x00, 'D', 0x4e, 0x62, 0x10, 0x58, 0x39, 0x24, 0x63, 0x40, 'S', 'i', 3, 'h', 'a', 'm', ']'};
            CHECK(json::to_bjdata(j) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("size=true type=false")
        {
            // note the float has been replaced by a double
            json const j = {nullptr, true, false, 4782345193, 153.132, "ham"};
            std::vector<uint8_t> v = {'[', '#', 'i', 6, 'Z', 'T', 'F', 'L', 0xE9, 0xCB, 0x0C, 0x1D, 0x01, 0x00, 0x00, 0x00, 'D', 0x4e, 0x62, 0x10, 0x58, 0x39, 0x24, 0x63, 0x40, 'S', 'i', 3, 'h', 'a', 'm'};
            CHECK(json::to_bjdata(j, true) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("size=true type=true")
        {
            // note the float has been replaced by a double
            json const j = {nullptr, true, false, 4782345193, 153.132, "ham"};
            std::vector<uint8_t> v = {'[', '#', 'i', 6, 'Z', 'T', 'F', 'L', 0xE9, 0xCB, 0x0C, 0x1D, 0x01, 0x00, 0x00, 0x00, 'D', 0x4e, 0x62, 0x10, 0x58, 0x39, 0x24, 0x63, 0x40, 'S', 'i', 3, 'h', 'a', 'm'};
            CHECK(json::to_bjdata(j, true, true) == v);
            CHECK(json::from_bjdata(v) == j);
        }
    }

    SECTION("Object Type")
    {
        SECTION("size=false type=false")
        {
            json j =
            {
                {
                    "post", {
                        {"id", 1137},
                        {"author", "rkalla"},
                        {"timestamp", 1364482090592},
                        {"body", "I totally agree!"}
                    }
                }
            };
            std::vector<uint8_t> v = {'{', 'i', 4, 'p', 'o', 's', 't', '{',
                                      'i', 6, 'a', 'u', 't', 'h', 'o', 'r', 'S', 'i', 6, 'r', 'k', 'a', 'l', 'l', 'a',
                                      'i', 4, 'b', 'o', 'd', 'y', 'S', 'i', 16, 'I', ' ', 't', 'o', 't', 'a', 'l', 'l', 'y', ' ', 'a', 'g', 'r', 'e', 'e', '!',
                                      'i', 2, 'i', 'd', 'I', 0x71, 0x04,
                                      'i', 9, 't', 'i', 'm', 'e', 's', 't', 'a', 'm', 'p', 'L', 0x60, 0x66, 0x78, 0xB1, 0x3D, 0x01, 0x00, 0x00,
                                      '}', '}'
                                     };
            CHECK(json::to_bjdata(j) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("size=true type=false")
        {
            json j =
            {
                {
                    "post", {
                        {"id", 1137},
                        {"author", "rkalla"},
                        {"timestamp", 1364482090592},
                        {"body", "I totally agree!"}
                    }
                }
            };
            std::vector<uint8_t> v = {'{', '#', 'i', 1, 'i', 4, 'p', 'o', 's', 't', '{', '#', 'i', 4,
                                      'i', 6, 'a', 'u', 't', 'h', 'o', 'r', 'S', 'i', 6, 'r', 'k', 'a', 'l', 'l', 'a',
                                      'i', 4, 'b', 'o', 'd', 'y', 'S', 'i', 16, 'I', ' ', 't', 'o', 't', 'a', 'l', 'l', 'y', ' ', 'a', 'g', 'r', 'e', 'e', '!',
                                      'i', 2, 'i', 'd', 'I', 0x71, 0x04,
                                      'i', 9, 't', 'i', 'm', 'e', 's', 't', 'a', 'm', 'p', 'L', 0x60, 0x66, 0x78, 0xB1, 0x3D, 0x01, 0x00, 0x00,
                                     };
            CHECK(json::to_bjdata(j, true) == v);
            CHECK(json::from_bjdata(v) == j);
        }

        SECTION("size=true type=true")
        {
            json j =
            {
                {
                    "post", {
                        {"id", 1137},
                        {"author", "rkalla"},
                        {"timestamp", 1364482090592},
                        {"body", "I totally agree!"}
                    }
                }
            };
            std::vector<uint8_t> v = {'{', '#', 'i', 1, 'i', 4, 'p', 'o', 's', 't', '{', '#', 'i', 4,
                                      'i', 6, 'a', 'u', 't', 'h', 'o', 'r', 'S', 'i', 6, 'r', 'k', 'a', 'l', 'l', 'a',
                                      'i', 4, 'b', 'o', 'd', 'y', 'S', 'i', 16, 'I', ' ', 't', 'o', 't', 'a', 'l', 'l', 'y', ' ', 'a', 'g', 'r', 'e', 'e', '!',
                                      'i', 2, 'i', 'd', 'I', 0x71, 0x04,
                                      'i', 9, 't', 'i', 'm', 'e', 's', 't', 'a', 'm', 'p', 'L', 0x60, 0x66, 0x78, 0xB1, 0x3D, 0x01, 0x00, 0x00,
                                     };
            CHECK(json::to_bjdata(j, true, true) == v);
            CHECK(json::from_bjdata(v) == j);
        }
    }

    SECTION("Optimized Format")
    {
        SECTION("Array Example")
        {
            SECTION("No Optimization")
            {
                // note the floats have been replaced by doubles
                json const j = {29.97, 31.13, 67.0, 2.113, 23.888};
                std::vector<uint8_t> v = {'[',
                                          'D', 0xb8, 0x1e, 0x85, 0xeb, 0x51, 0xf8, 0x3d, 0x40,
                                          'D', 0xe1, 0x7a, 0x14, 0xae, 0x47, 0x21, 0x3f, 0x40,
                                          'D', 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          'D', 0x81, 0x95, 0x43, 0x8b, 0x6c, 0xe7, 0x00, 0x40,
                                          'D', 0x17, 0xd9, 0xce, 0xf7, 0x53, 0xe3, 0x37, 0x40,
                                          ']'
                                         };
                CHECK(json::to_bjdata(j) == v);
                CHECK(json::from_bjdata(v) == j);
            }

            SECTION("Optimized with count")
            {
                // note the floats have been replaced by doubles
                json const j = {29.97, 31.13, 67.0, 2.113, 23.888};
                std::vector<uint8_t> v = {'[', '#', 'i', 5,
                                          'D', 0xb8, 0x1e, 0x85, 0xeb, 0x51, 0xf8, 0x3d, 0x40,
                                          'D', 0xe1, 0x7a, 0x14, 0xae, 0x47, 0x21, 0x3f, 0x40,
                                          'D', 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          'D', 0x81, 0x95, 0x43, 0x8b, 0x6c, 0xe7, 0x00, 0x40,
                                          'D', 0x17, 0xd9, 0xce, 0xf7, 0x53, 0xe3, 0x37, 0x40,
                                         };
                CHECK(json::to_bjdata(j, true) == v);
                CHECK(json::from_bjdata(v) == j);
            }

            SECTION("Optimized with type & count")
            {
                // note the floats have been replaced by doubles
                json const j = {29.97, 31.13, 67.0, 2.113, 23.888};
                std::vector<uint8_t> v = {'[', '$', 'D', '#', 'i', 5,
                                          0xb8, 0x1e, 0x85, 0xeb, 0x51, 0xf8, 0x3d, 0x40,
                                          0xe1, 0x7a, 0x14, 0xae, 0x47, 0x21, 0x3f, 0x40,
                                          0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          0x81, 0x95, 0x43, 0x8b, 0x6c, 0xe7, 0x00, 0x40,
                                          0x17, 0xd9, 0xce, 0xf7, 0x53, 0xe3, 0x37, 0x40,
                                         };
                CHECK(json::to_bjdata(j, true, true) == v);
                CHECK(json::from_bjdata(v) == j);
            }
        }

        SECTION("Object Example")
        {
            SECTION("No Optimization")
            {
                // note the floats have been replaced by doubles
                json const j = { {"lat", 29.976}, {"long", 31.131}, {"alt", 67.0} };
                std::vector<uint8_t> v = {'{',
                                          'i', 3, 'a', 'l', 't', 'D',      0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          'i', 3, 'l', 'a', 't', 'D',      0x60, 0xe5, 0xd0, 0x22, 0xdb, 0xf9, 0x3d, 0x40,
                                          'i', 4, 'l', 'o', 'n', 'g', 'D', 0xa8, 0xc6, 0x4b, 0x37, 0x89, 0x21, 0x3f, 0x40,
                                          '}'
                                         };
                CHECK(json::to_bjdata(j) == v);
                CHECK(json::from_bjdata(v) == j);
            }

            SECTION("Optimized with count")
            {
                // note the floats have been replaced by doubles
                json const j = { {"lat", 29.976}, {"long", 31.131}, {"alt", 67.0} };
                std::vector<uint8_t> v = {'{', '#', 'i', 3,
                                          'i', 3, 'a', 'l', 't', 'D',      0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          'i', 3, 'l', 'a', 't', 'D',      0x60, 0xe5, 0xd0, 0x22, 0xdb, 0xf9, 0x3d, 0x40,
                                          'i', 4, 'l', 'o', 'n', 'g', 'D', 0xa8, 0xc6, 0x4b, 0x37, 0x89, 0x21, 0x3f, 0x40,
                                         };
                CHECK(json::to_bjdata(j, true) == v);
                CHECK(json::from_bjdata(v) == j);
            }

            SECTION("Optimized with type & count")
            {
                // note the floats have been replaced by doubles
                json const j = { {"lat", 29.976}, {"long", 31.131}, {"alt", 67.0} };
                std::vector<uint8_t> v = {'{', '$', 'D', '#', 'i', 3,
                                          'i', 3, 'a', 'l', 't',      0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x50, 0x40,
                                          'i', 3, 'l', 'a', 't',      0x60, 0xe5, 0xd0, 0x22, 0xdb, 0xf9, 0x3d, 0x40,
                                          'i', 4, 'l', 'o', 'n', 'g', 0xa8, 0xc6, 0x4b, 0x37, 0x89, 0x21, 0x3f, 0x40,
                                         };
                CHECK(json::to_bjdata(j, true, true) == v);
                CHECK(json::from_bjdata(v) == j);
            }
        }

        SECTION("Special Cases (Null, No-Op and Boolean)")
        {
            SECTION("Array")
            {
                json _;
                std::vector<uint8_t> const v = {'[', '$', 'N', '#', 'I', 0x00, 0x02};
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x4E is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v, true, false).is_discarded());
            }

            SECTION("Object")
            {
                json _;
                std::vector<uint8_t> const v = {'{', '$', 'Z', '#', 'i', 3, 'i', 4, 'n', 'a', 'm', 'e', 'i', 8, 'p', 'a', 's', 's', 'w', 'o', 'r', 'd', 'i', 5, 'e', 'm', 'a', 'i', 'l'};
                CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x5A is not a permitted optimized array type", json::parse_error&);
                CHECK(json::from_bjdata(v, true, false).is_discarded());
            }
        }
    }
}

TEST_CASE("Parse BJData directly from a file using iterator and sentinel")
{
    std::string const filename = TEST_DATA_DIRECTORY "/json_testsuite/sample.json.bjdata";
    std::ifstream file(filename, std::ios::binary);
    const std::istreambuf_iterator<char> first(file);
    const json parsed = json::from_bjdata(first, utils::istreambuf_sentinel{});
    CHECK((parsed.is_object() || parsed.is_array()));
}

#if !defined(JSON_NOEXCEPTION)
TEST_CASE("all BJData first bytes")
{
    // these bytes will fail immediately with exception parse_error.112
    std::set<uint8_t> supported =
    {
        'T', 'F', 'Z', 'B', 'U', 'i', 'I', 'l', 'L', 'd', 'D', 'C', 'S', '[', '{', 'N', 'H', 'u', 'm', 'M', 'h'
    };

    for (auto i = 0; i < 256; ++i)
    {
        const auto byte = static_cast<uint8_t>(i);
        CAPTURE(byte)

        try
        {
            auto res = json::from_bjdata(std::vector<uint8_t>(1, byte));
        }
        catch (const json::parse_error& e)
        {
            // check that parse_error.112 is only thrown if the
            // first byte is not in the supported set
            INFO_WITH_TEMP(e.what());
            if (supported.find(byte) == supported.end())
            {
                CHECK(e.id == 112);
            }
            else
            {
                CHECK(e.id != 112);
            }
        }
    }
}
#endif

TEST_CASE("BJData and UBJSON can be written to a string")
{
    const std::vector<json> values =
    {
        {{"a", {1, 2.5, "x", nullptr}}, {"b", json::binary({1, 2})}},
        // an annotated ND-array, and objects that only look like one
        json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": [2, 2], "_ArrayData_": [1, 2, 3, 4]})"),
        json::parse(R"({"_ArrayType_": 1, "_ArraySize_": [2, 2], "_ArrayData_": [1, 2, 3, 4]})"),
        json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": 4, "_ArrayData_": [1, 2, 3, 4]})"),
        json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": [2, -2], "_ArrayData_": [1, 2, 3, 4]})"),
        json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": [2, 2], "_ArrayData_": [1, 2, 3]})"),
        json::parse(R"({"_ArrayType_": "uint8", "_ArraySize_": [2, 2], "_ArrayData_": 1})"),
    };

    // compared byte by byte: building a std::string from the bytes would
    // convert them implicitly, which -fsanitize=integer reports for bytes of
    // 0x80 and above
    const auto same_bytes = [](const std::vector<std::uint8_t>& bytes, const std::string & text)
    {
        return bytes.size() == text.size() && std::equal(bytes.begin(), bytes.end(), text.begin(), [](std::uint8_t byte, char c)
        {
            return byte == static_cast<std::uint8_t>(c);
        });
    };

    for (const auto& j : values)
    {
        CAPTURE(j.dump())
        for (const bool use_size :
                {
                    false, true
                })
        {
            for (const bool use_type :
                    {
                        false, true
                    })
            {
                if (use_type && !use_size)
                {
                    continue;
                }
                CAPTURE(use_size)
                CAPTURE(use_type)

                const auto bjdata = json::to_bjdata(j, use_size, use_type);
                std::string bjdata_string;
                json::to_bjdata(j, bjdata_string, use_size, use_type);
                CHECK(same_bytes(bjdata, bjdata_string));

                const auto ubjson = json::to_ubjson(j, use_size, use_type);
                std::string ubjson_string;
                json::to_ubjson(j, ubjson_string, use_size, use_type);
                CHECK(same_bytes(ubjson, ubjson_string));
            }
        }
    }
}

TEST_CASE("BJData use_type requires use_size")
{
    SECTION("non-empty object throws other_error.502")
    {
        const json j = {{"a", 1}, {"b", 2}};
        CHECK_THROWS_WITH_AS(json::to_bjdata(j, false, true),
                             "[json.exception.other_error.502] use_type requires use_size = true",
                             json::other_error&);
    }

    SECTION("non-empty array throws other_error.502")
    {
        const json j = {1, 2, 3};
        CHECK_THROWS_WITH_AS(json::to_bjdata(j, false, true),
                             "[json.exception.other_error.502] use_type requires use_size = true",
                             json::other_error&);
    }

    SECTION("non-empty binary value throws other_error.502")
    {
        const json j = json::binary({1, 2, 3});
        CHECK_THROWS_WITH_AS(json::to_bjdata(j, false, true),
                             "[json.exception.other_error.502] use_type requires use_size = true",
                             json::other_error&);
        CHECK_THROWS_WITH_AS(json::to_ubjson(j, false, true),
                             "[json.exception.other_error.502] use_type requires use_size = true",
                             json::other_error&);
    }

    SECTION("scalars do not throw with use_type=true, use_count=false")
    {
        CHECK_NOTHROW(json::to_bjdata(42, false, true));
        CHECK_NOTHROW(json::to_bjdata(3.14, false, true));
        CHECK_NOTHROW(json::to_bjdata("hello", false, true));
        CHECK_NOTHROW(json::to_bjdata(true, false, true));
        CHECK_NOTHROW(json::to_bjdata(nullptr, false, true));
    }

    SECTION("empty containers do not throw with use_type=true, use_count=false")
    {
        CHECK_NOTHROW(json::to_bjdata(json::array(), false, true));
        CHECK_NOTHROW(json::to_bjdata(json::object(), false, true));
    }

    SECTION("valid combinations on non-empty containers")
    {
        const json j = {{"a", 1}, {"b", 2}};
        CHECK_NOTHROW(json::to_bjdata(j, false, false));
        CHECK_NOTHROW(json::to_bjdata(j, true, false));
        CHECK_NOTHROW(json::to_bjdata(j, true, true));
    }
}

TEST_CASE("BJData round trip of a binary value is value-stable, not byte-stable")
{
    // OSS-Fuzz issue 474480402: a Draft 3 optimized binary array is read as a
    // binary value, which to_bjdata() writes in the default Draft 2 mode as a
    // plain array of uint8 numbers. That is read back as an array of numbers,
    // for which the writer then picks the smallest type marker, int8 ('i'),
    // so re-serializing changes the bytes, but not the value. This is the
    // exception described in the "Round trips" note of the BJData
    // documentation, and why the fuzzer checks value stability (see #5494).
    const std::vector<uint8_t> input = {'[', '$', 'B', '#', 'U', 1, 0x20};
    const json j1 = json::from_bjdata(input);
    CHECK(j1 == json::binary({0x20}));

    const std::vector<uint8_t> vec = json::to_bjdata(j1, false, false);
    CHECK(vec == std::vector<uint8_t>({'[', 'U', 0x20, ']'}));
    const json j2 = json::from_bjdata(vec);
    CHECK(j2 == json::array({0x20}));

    const std::vector<uint8_t> vec2 = json::to_bjdata(j2, false, false);
    CHECK(vec2 == std::vector<uint8_t>({'[', 'i', 0x20, ']'}));
    CHECK(json::from_bjdata(vec2) == j2);
}

TEST_CASE("BJData roundtrips" * doctest::skip())
{
    SECTION("input from self-generated BJData files")
    {
        for (const std::string filename :
                {
                    TEST_DATA_DIRECTORY "/json_nlohmann_tests/all_unicode.json",
                    TEST_DATA_DIRECTORY "/json.org/1.json",
                    TEST_DATA_DIRECTORY "/json.org/2.json",
                    TEST_DATA_DIRECTORY "/json.org/3.json",
                    TEST_DATA_DIRECTORY "/json.org/4.json",
                    TEST_DATA_DIRECTORY "/json.org/5.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip01.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip02.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip03.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip04.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip05.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip06.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip07.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip08.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip09.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip10.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip11.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip12.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip13.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip14.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip15.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip16.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip17.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip18.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip19.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip20.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip21.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip22.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip23.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip24.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip25.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip26.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip27.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip28.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip29.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip30.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip31.json",
                    TEST_DATA_DIRECTORY "/json_roundtrip/roundtrip32.json",
                    TEST_DATA_DIRECTORY "/json_testsuite/sample.json",
                    TEST_DATA_DIRECTORY "/json_tests/pass1.json",
                    TEST_DATA_DIRECTORY "/json_tests/pass2.json",
                    TEST_DATA_DIRECTORY "/json_tests/pass3.json"
                })
        {
            CAPTURE(filename)

            std::ifstream f_json(filename);
            const json j1 = json::parse(f_json);
            auto packed = utils::read_binary_file(filename + ".bjdata");

            {
                INFO_WITH_TEMP(filename + ": std::vector<uint8_t>");
                json j2;
                CHECK_NOTHROW(j2 = json::from_bjdata(packed));
                CHECK(j1 == j2);
            }

            {
                INFO_WITH_TEMP(filename + ": std::ifstream");
                std::ifstream f_bjdata(filename + ".bjdata", std::ios::binary);
                json j2;
                CHECK_NOTHROW(j2 = json::from_bjdata(f_bjdata));
                CHECK(j1 == j2);
            }

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");
                {
                    INFO_WITH_TEMP(filename + ": output adapters: std::vector<uint8_t>");
                    std::vector<uint8_t> vec;
                    json::to_bjdata(j1, vec);
                    CHECK(vec == packed);
                }
            }
        }
    }
}

TEST_CASE("issue #5648 - from_bjdata(ptr, len) must read len bytes, not treat ptr as a C string")
{
    // to_bjdata() encodes the integer 0 as the two bytes 'i' 0x00 (a BJData
    // type marker followed by the value byte 0x00), so the packed data
    // below contains a 0x00 byte before its end.
    const json j = {{"a", 0}};
    const std::vector<std::uint8_t> packed = json::to_bjdata(j);
    bool contains_nul = false;
    for (const auto byte : packed)
    {
        contains_nul |= (byte == 0x00);
    }
    REQUIRE(contains_nul);

#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    // before the fix, from_bjdata had no (ptr, len) overload, so this call
    // bound to from_bjdata(InputType&&, bool strict) instead: ptr was read
    // as a NUL-terminated C string (stopping at the embedded 0x00 byte), and
    // len was silently converted to the strict flag. The deprecated
    // overload added for this issue forwards to from_bjdata(ptr, ptr + len,
    // ...) instead, like from_ubjson's deprecated (ptr, len) overload does.
    json result;
    CHECK_NOTHROW(result = json::from_bjdata(packed.data(), packed.size()));
    CHECK(result == j);

    // len must not collapse into the strict flag either
    CHECK(json::from_bjdata(packed.data(), packed.size(), false) == j);
#endif
}

TEST_CASE("BJData large strings and binaries (chunked reader)")
{
    // Strings share get_ubjson_string() -> get_string() -> get_bytes() with
    // plain UBJSON. Binary values are different: only a Draft 3 optimized
    // array (type marker 'B') is read back as a binary value, through
    // get_binary() -> get_bytes() (see parse_ubjson_internal()'s "If BJData
    // type marker is 'B'" branch); Draft 2 (the default) writes a binary
    // value as a plain array of uint8_t numbers instead (see the "round trip
    // of a binary value is value-stable, not byte-stable" test above), which
    // never reaches get_bytes(). Both reads happen in bounded chunks
    // (binary_reader.hpp, chunk_size == 4096); check lengths around and
    // beyond that size, for both vector (iterator) and pointer inputs.
    for (const std::size_t len :
            {
                std::size_t{0}, std::size_t{1}, std::size_t{4095}, std::size_t{4096},
                std::size_t{4097}, std::size_t{8192}, std::size_t{100000}
            })
    {
        CAPTURE(len)

        // string
        const json j_string = std::string(len, 'x');
        const std::vector<std::uint8_t> v_string = json::to_bjdata(j_string);
        CHECK(json::from_bjdata(v_string) == j_string);
        // pointer input exercises the std::memcpy fast path
        CHECK(json::from_bjdata(reinterpret_cast<const char*>(v_string.data()),
                                reinterpret_cast<const char*>(v_string.data()) + v_string.size()) == j_string);

        // binary, forced into the Draft 3 optimized ('B' marker) encoding
        const json j_binary = json::binary(std::vector<std::uint8_t>(len, 0xCD));
        const std::vector<std::uint8_t> v_binary = json::to_bjdata(j_binary, true, true, json::bjdata_version_t::draft3);
        CHECK(json::from_bjdata(v_binary) == j_binary);
        CHECK(json::from_bjdata(reinterpret_cast<const char*>(v_binary.data()),
                                reinterpret_cast<const char*>(v_binary.data()) + v_binary.size()) == j_binary);

        // a truncated payload must still be reported as an error
        if (len > 16)
        {
            std::vector<std::uint8_t> truncated = v_string;
            truncated.resize(truncated.size() - 8);
            json _;
            CHECK_THROWS_AS(_ = json::from_bjdata(truncated), json::parse_error);
        }
    }
}

TEST_CASE("BJData optimized container type marker is validated for count 0")
{
    // the '$' type marker must be a legal marker even if no element follows
    SECTION("invalid marker")
    {
        // 'Z', 'T', 'F', 'N', 'S', 'H', '[' and '{' are excluded in BJData
        for (const char marker :
                {'x', 'E', 'Z', 'T', 'F', 'N', 'S', 'H', '[', '{'
                })
        {
            for (const char open :
                    {'[', '{'
                    })
            {
                for (const int count :
                        {
                            0, 1
                        })
                {
                    CAPTURE(marker)
                    CAPTURE(open)
                    CAPTURE(count)
                    const std::vector<std::uint8_t> v = {static_cast<std::uint8_t>(open), '$', static_cast<std::uint8_t>(marker), '#', 'i', static_cast<std::uint8_t>(count)};
                    json _;
                    CHECK_THROWS_AS(_ = json::from_bjdata(v), json::parse_error&);
                    CHECK(json::from_bjdata(v, true, false).is_discarded());
                }
            }
        }
    }

    SECTION("error message")
    {
        const std::vector<std::uint8_t> v = {'[', '$', 'x', '#', 'i', 0};
        json _;
        CHECK_THROWS_WITH_AS(_ = json::from_bjdata(v), "[json.exception.parse_error.112] parse error at byte 3: syntax error while parsing BJData type: marker 0x78 is not a permitted optimized array type", json::parse_error&);
    }

    SECTION("valid marker")
    {
        for (const char marker :
                {'i', 'U', 'I', 'u', 'l', 'm', 'L', 'M', 'h', 'd', 'D', 'C'
                })
        {
            CAPTURE(marker)
            const std::vector<std::uint8_t> va = {'[', '$', static_cast<std::uint8_t>(marker), '#', 'i', 0};
            const std::vector<std::uint8_t> vo = {'{', '$', static_cast<std::uint8_t>(marker), '#', 'i', 0};
            CHECK(json::from_bjdata(va) == json::array());
            CHECK(json::from_bjdata(vo) == json::object());
        }

        // an optimized array of bytes is read as a binary value
        const std::vector<std::uint8_t> vb = {'[', '$', 'B', '#', 'i', 0};
        CHECK(json::from_bjdata(vb) == json::binary({}));
    }
}