//     __ _____ _____ _____
//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
// |  |  |__   |  |  | | | |  version 3.11.3
// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2023 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT

// cmake/test.cmake selects the C++ standard versions with which to build a
// unit test based on the presence of JSON_HAS_CPP_<VERSION> macros.
// When using macros that are only defined for particular versions of the standard
// (e.g., JSON_HAS_FILESYSTEM for C++17 and up), please mention the corresponding
// version macro in a comment close by, like this:
// JSON_HAS_CPP_<VERSION> (do not remove; see note at top of file)

#include "doctest_compatibility.h"

#include <azure/core/internal/json/json.hpp>
using Azure::Core::Json::_internal::json;

#if _azure_JSON_HAS_RANGES
#include <algorithm>
#include <ranges>
#endif

TEST_CASE("iterators 2")
{
  SECTION("iterator comparisons")
  {
    json j_values = {
        nullptr, true, 42, 42u, 23.23, {{"one", 1}, {"two", 2}}, {1, 2, 3, 4, 5}, "Hello, world"};

    for (json& j : j_values)
    {
      auto it1 = j.begin();
      auto it2 = j.begin();
      auto it3 = j.begin();
      ++it2;
      ++it3;
      ++it3;
      auto it1_c = j.cbegin();
      auto it2_c = j.cbegin();
      auto it3_c = j.cbegin();
      ++it2_c;
      ++it3_c;
      ++it3_c;

      // comparison: equal
      {
        CHECK(it1 == it1);
        CHECK(!(it1 == it2));
        CHECK(!(it1 == it3));
        CHECK(!(it2 == it3));
        CHECK(it1_c == it1_c);
        CHECK(!(it1_c == it2_c));
        CHECK(!(it1_c == it3_c));
        CHECK(!(it2_c == it3_c));
      }

      // comparison: not equal
      {
        // check definition
        CHECK((it1 != it1) == !(it1 == it1));
        CHECK((it1 != it2) == !(it1 == it2));
        CHECK((it1 != it3) == !(it1 == it3));
        CHECK((it2 != it3) == !(it2 == it3));
        CHECK((it1_c != it1_c) == !(it1_c == it1_c));
        CHECK((it1_c != it2_c) == !(it1_c == it2_c));
        CHECK((it1_c != it3_c) == !(it1_c == it3_c));
        CHECK((it2_c != it3_c) == !(it2_c == it3_c));
      }

      // comparison: smaller
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 < it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 < it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c < it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 < it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 < it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c < it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          CHECK(!(it1 < it1));
          CHECK(it1 < it2);
          CHECK(it1 < it3);
          CHECK(it2 < it3);
          CHECK(!(it1_c < it1_c));
          CHECK(it1_c < it2_c);
          CHECK(it1_c < it3_c);
          CHECK(it2_c < it3_c);
        }
      }

      // comparison: less than or equal
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 <= it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 <= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c <= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 <= it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 <= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c <= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 <= it1) == !(it1 < it1));
          CHECK((it1 <= it2) == !(it2 < it1));
          CHECK((it1 <= it3) == !(it3 < it1));
          CHECK((it2 <= it3) == !(it3 < it2));
          CHECK((it1_c <= it1_c) == !(it1_c < it1_c));
          CHECK((it1_c <= it2_c) == !(it2_c < it1_c));
          CHECK((it1_c <= it3_c) == !(it3_c < it1_c));
          CHECK((it2_c <= it3_c) == !(it3_c < it2_c));
        }
      }

      // comparison: greater than
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 > it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 > it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c > it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 > it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 > it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c > it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 > it1) == (it1 < it1));
          CHECK((it1 > it2) == (it2 < it1));
          CHECK((it1 > it3) == (it3 < it1));
          CHECK((it2 > it3) == (it3 < it2));
          CHECK((it1_c > it1_c) == (it1_c < it1_c));
          CHECK((it1_c > it2_c) == (it2_c < it1_c));
          CHECK((it1_c > it3_c) == (it3_c < it1_c));
          CHECK((it2_c > it3_c) == (it3_c < it2_c));
        }
      }

      // comparison: greater than or equal
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 >= it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 >= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c >= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 >= it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 >= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c >= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 >= it1) == !(it1 < it1));
          CHECK((it1 >= it2) == !(it1 < it2));
          CHECK((it1 >= it3) == !(it1 < it3));
          CHECK((it2 >= it3) == !(it2 < it3));
          CHECK((it1_c >= it1_c) == !(it1_c < it1_c));
          CHECK((it1_c >= it2_c) == !(it1_c < it2_c));
          CHECK((it1_c >= it3_c) == !(it1_c < it3_c));
          CHECK((it2_c >= it3_c) == !(it2_c < it3_c));
        }
      }
    }

    // check exceptions if different objects are compared
    for (auto j : j_values)
    {
      for (auto k : j_values)
      {
        if (j != k)
        {
#if JSON_DIAGNOSTICS
          // the output differs in each loop, so we cannot fix a string for the expected exception
#else
          CHECK_THROWS_WITH_AS(
              j.begin() == k.begin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.cbegin() == k.cbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.begin() < k.begin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.cbegin() < k.cbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
#endif
        }
      }
    }
  }

  SECTION("iterator arithmetic")
  {
    json j_object = {{"one", 1}, {"two", 2}, {"three", 3}};
    json j_array = {1, 2, 3, 4, 5, 6};
    json j_null = nullptr;
    json j_value = 42;

    SECTION("addition and subtraction")
    {
      SECTION("object")
      {
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it += 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it += 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it + 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it + 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              1 + it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              1 + it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it -= 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it -= 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it - 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it - 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it - it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it - it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
      }

      SECTION("array")
      {
        {
          auto it = j_array.begin();
          it += 3;
          CHECK((j_array.begin() + 3) == it);
          CHECK((3 + j_array.begin()) == it);
          CHECK((it - 3) == j_array.begin());
          CHECK((it - j_array.begin()) == 3);
          CHECK(*it == json(4));
          it -= 2;
          CHECK(*it == json(2));
        }
        {
          auto it = j_array.cbegin();
          it += 3;
          CHECK((j_array.cbegin() + 3) == it);
          CHECK((3 + j_array.cbegin()) == it);
          CHECK((it - 3) == j_array.cbegin());
          CHECK((it - j_array.cbegin()) == 3);
          CHECK(*it == json(4));
          it -= 2;
          CHECK(*it == json(2));
        }
      }

      SECTION("null")
      {
        {
          auto it = j_null.begin();
          it += 3;
          CHECK((j_null.begin() + 3) == it);
          CHECK((3 + j_null.begin()) == it);
          CHECK((it - 3) == j_null.begin());
          CHECK((it - j_null.begin()) == 3);
          CHECK(it != j_null.end());
          it -= 3;
          CHECK(it == j_null.end());
        }
        {
          auto it = j_null.cbegin();
          it += 3;
          CHECK((j_null.cbegin() + 3) == it);
          CHECK((3 + j_null.cbegin()) == it);
          CHECK((it - 3) == j_null.cbegin());
          CHECK((it - j_null.cbegin()) == 3);
          CHECK(it != j_null.cend());
          it -= 3;
          CHECK(it == j_null.cend());
        }
      }

      SECTION("value")
      {
        {
          auto it = j_value.begin();
          it += 3;
          CHECK((j_value.begin() + 3) == it);
          CHECK((3 + j_value.begin()) == it);
          CHECK((it - 3) == j_value.begin());
          CHECK((it - j_value.begin()) == 3);
          CHECK(it != j_value.end());
          it -= 3;
          CHECK(*it == json(42));
        }
        {
          auto it = j_value.cbegin();
          it += 3;
          CHECK((j_value.cbegin() + 3) == it);
          CHECK((3 + j_value.cbegin()) == it);
          CHECK((it - 3) == j_value.cbegin());
          CHECK((it - j_value.cbegin()) == 3);
          CHECK(it != j_value.cend());
          it -= 3;
          CHECK(*it == json(42));
        }
      }
    }

    SECTION("subscript operator")
    {
      SECTION("object")
      {
        {
          auto it = j_object.begin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.cbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators",
              json::invalid_iterator&);
        }
      }

      SECTION("array")
      {
        {
          auto it = j_array.begin();
          CHECK(it[0] == json(1));
          CHECK(it[1] == json(2));
          CHECK(it[2] == json(3));
          CHECK(it[3] == json(4));
          CHECK(it[4] == json(5));
          CHECK(it[5] == json(6));
        }
        {
          auto it = j_array.cbegin();
          CHECK(it[0] == json(1));
          CHECK(it[1] == json(2));
          CHECK(it[2] == json(3));
          CHECK(it[3] == json(4));
          CHECK(it[4] == json(5));
          CHECK(it[5] == json(6));
        }
      }

      SECTION("null")
      {
        {
          auto it = j_null.begin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
        {
          auto it = j_null.cbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
      }

      SECTION("value")
      {
        {
          auto it = j_value.begin();
          CHECK(it[0] == json(42));
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
        {
          auto it = j_value.cbegin();
          CHECK(it[0] == json(42));
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
      }
    }
  }

  SECTION("reverse iterator comparisons")
  {
    json j_values = {
        nullptr, true, 42, 42u, 23.23, {{"one", 1}, {"two", 2}}, {1, 2, 3, 4, 5}, "Hello, world"};

    for (json& j : j_values)
    {
      auto it1 = j.rbegin();
      auto it2 = j.rbegin();
      auto it3 = j.rbegin();
      ++it2;
      ++it3;
      ++it3;
      auto it1_c = j.crbegin();
      auto it2_c = j.crbegin();
      auto it3_c = j.crbegin();
      ++it2_c;
      ++it3_c;
      ++it3_c;

      // comparison: equal
      {
        CHECK(it1 == it1);
        CHECK(!(it1 == it2));
        CHECK(!(it1 == it3));
        CHECK(!(it2 == it3));
        CHECK(it1_c == it1_c);
        CHECK(!(it1_c == it2_c));
        CHECK(!(it1_c == it3_c));
        CHECK(!(it2_c == it3_c));
      }

      // comparison: not equal
      {
        // check definition
        CHECK((it1 != it1) == !(it1 == it1));
        CHECK((it1 != it2) == !(it1 == it2));
        CHECK((it1 != it3) == !(it1 == it3));
        CHECK((it2 != it3) == !(it2 == it3));
        CHECK((it1_c != it1_c) == !(it1_c == it1_c));
        CHECK((it1_c != it2_c) == !(it1_c == it2_c));
        CHECK((it1_c != it3_c) == !(it1_c == it3_c));
        CHECK((it2_c != it3_c) == !(it2_c == it3_c));
      }

      // comparison: smaller
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 < it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 < it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c < it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 < it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 < it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 < it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c < it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c < it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          CHECK(!(it1 < it1));
          CHECK(it1 < it2);
          CHECK(it1 < it3);
          CHECK(it2 < it3);
          CHECK(!(it1_c < it1_c));
          CHECK(it1_c < it2_c);
          CHECK(it1_c < it3_c);
          CHECK(it2_c < it3_c);
        }
      }

      // comparison: less than or equal
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 <= it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 <= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c <= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 <= it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 <= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 <= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c <= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c <= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 <= it1) == !(it1 < it1));
          CHECK((it1 <= it2) == !(it2 < it1));
          CHECK((it1 <= it3) == !(it3 < it1));
          CHECK((it2 <= it3) == !(it3 < it2));
          CHECK((it1_c <= it1_c) == !(it1_c < it1_c));
          CHECK((it1_c <= it2_c) == !(it2_c < it1_c));
          CHECK((it1_c <= it3_c) == !(it3_c < it1_c));
          CHECK((it2_c <= it3_c) == !(it3_c < it2_c));
        }
      }

      // comparison: greater than
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 > it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 > it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c > it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 > it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 > it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 > it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c > it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c > it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 > it1) == (it1 < it1));
          CHECK((it1 > it2) == (it2 < it1));
          CHECK((it1 > it3) == (it3 < it1));
          CHECK((it2 > it3) == (it3 < it2));
          CHECK((it1_c > it1_c) == (it1_c < it1_c));
          CHECK((it1_c > it2_c) == (it2_c < it1_c));
          CHECK((it1_c > it3_c) == (it3_c < it1_c));
          CHECK((it2_c > it3_c) == (it3_c < it2_c));
        }
      }

      // comparison: greater than or equal
      {
        if (j.type() == json::value_t::object)
        {
#if JSON_DIAGNOSTICS
          CHECK_THROWS_WITH_AS(
              it1 >= it1,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it2,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 >= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it3,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it1_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it2_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c >= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it3_c,
              "[json.exception.invalid_iterator.213] (/5) cannot compare order of object iterators",
              json::invalid_iterator&);
#else
          CHECK_THROWS_WITH_AS(
              it1 >= it1,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it2,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2 >= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1 >= it3,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it1_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it2_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it2_c >= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it1_c >= it3_c,
              "[json.exception.invalid_iterator.213] cannot compare order of object iterators",
              json::invalid_iterator&);
#endif
        }
        else
        {
          // check definition
          CHECK((it1 >= it1) == !(it1 < it1));
          CHECK((it1 >= it2) == !(it1 < it2));
          CHECK((it1 >= it3) == !(it1 < it3));
          CHECK((it2 >= it3) == !(it2 < it3));
          CHECK((it1_c >= it1_c) == !(it1_c < it1_c));
          CHECK((it1_c >= it2_c) == !(it1_c < it2_c));
          CHECK((it1_c >= it3_c) == !(it1_c < it3_c));
          CHECK((it2_c >= it3_c) == !(it2_c < it3_c));
        }
      }
    }

    // check exceptions if different objects are compared
    for (auto j : j_values)
    {
      for (auto k : j_values)
      {
        if (j != k)
        {
#if JSON_DIAGNOSTICS
          // the output differs in each loop, so we cannot fix a string for the expected exception
#else
          CHECK_THROWS_WITH_AS(
              j.rbegin() == k.rbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.crbegin() == k.crbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.rbegin() < k.rbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              j.crbegin() < k.crbegin(),
              "[json.exception.invalid_iterator.212] cannot compare iterators of different "
              "containers",
              json::invalid_iterator&);
#endif
        }
      }
    }
  }

  SECTION("reverse iterator arithmetic")
  {
    json j_object = {{"one", 1}, {"two", 2}, {"three", 3}};
    json j_array = {1, 2, 3, 4, 5, 6};
    json j_null = nullptr;
    json j_value = 42;

    SECTION("addition and subtraction")
    {
      SECTION("object")
      {
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it += 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it += 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it + 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it + 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              1 + it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              1 + it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it -= 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it -= 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it - 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it - 1,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it - it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it - it,
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
      }

      SECTION("array")
      {
        {
          auto it = j_array.rbegin();
          it += 3;
          CHECK((j_array.rbegin() + 3) == it);
          CHECK(json::reverse_iterator(3 + j_array.rbegin()) == it);
          CHECK((it - 3) == j_array.rbegin());
          CHECK((it - j_array.rbegin()) == 3);
          CHECK(*it == json(3));
          it -= 2;
          CHECK(*it == json(5));
        }
        {
          auto it = j_array.crbegin();
          it += 3;
          CHECK((j_array.crbegin() + 3) == it);
          CHECK(json::const_reverse_iterator(3 + j_array.crbegin()) == it);
          CHECK((it - 3) == j_array.crbegin());
          CHECK((it - j_array.crbegin()) == 3);
          CHECK(*it == json(3));
          it -= 2;
          CHECK(*it == json(5));
        }
      }

      SECTION("null")
      {
        {
          auto it = j_null.rbegin();
          it += 3;
          CHECK((j_null.rbegin() + 3) == it);
          CHECK(json::reverse_iterator(3 + j_null.rbegin()) == it);
          CHECK((it - 3) == j_null.rbegin());
          CHECK((it - j_null.rbegin()) == 3);
          CHECK(it != j_null.rend());
          it -= 3;
          CHECK(it == j_null.rend());
        }
        {
          auto it = j_null.crbegin();
          it += 3;
          CHECK((j_null.crbegin() + 3) == it);
          CHECK(json::const_reverse_iterator(3 + j_null.crbegin()) == it);
          CHECK((it - 3) == j_null.crbegin());
          CHECK((it - j_null.crbegin()) == 3);
          CHECK(it != j_null.crend());
          it -= 3;
          CHECK(it == j_null.crend());
        }
      }

      SECTION("value")
      {
        {
          auto it = j_value.rbegin();
          it += 3;
          CHECK((j_value.rbegin() + 3) == it);
          CHECK(json::reverse_iterator(3 + j_value.rbegin()) == it);
          CHECK((it - 3) == j_value.rbegin());
          CHECK((it - j_value.rbegin()) == 3);
          CHECK(it != j_value.rend());
          it -= 3;
          CHECK(*it == json(42));
        }
        {
          auto it = j_value.crbegin();
          it += 3;
          CHECK((j_value.crbegin() + 3) == it);
          CHECK(json::const_reverse_iterator(3 + j_value.crbegin()) == it);
          CHECK((it - 3) == j_value.crbegin());
          CHECK((it - j_value.crbegin()) == 3);
          CHECK(it != j_value.crend());
          it -= 3;
          CHECK(*it == json(42));
        }
      }
    }

    SECTION("subscript operator")
    {
      SECTION("object")
      {
        {
          auto it = j_object.rbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
        {
          auto it = j_object.crbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.209] cannot use offsets with object iterators",
              json::invalid_iterator&);
        }
      }

      SECTION("array")
      {
        {
          auto it = j_array.rbegin();
          CHECK(it[0] == json(6));
          CHECK(it[1] == json(5));
          CHECK(it[2] == json(4));
          CHECK(it[3] == json(3));
          CHECK(it[4] == json(2));
          CHECK(it[5] == json(1));
        }
        {
          auto it = j_array.crbegin();
          CHECK(it[0] == json(6));
          CHECK(it[1] == json(5));
          CHECK(it[2] == json(4));
          CHECK(it[3] == json(3));
          CHECK(it[4] == json(2));
          CHECK(it[5] == json(1));
        }
      }

      SECTION("null")
      {
        {
          auto it = j_null.rbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
        {
          auto it = j_null.crbegin();
          CHECK_THROWS_WITH_AS(
              it[0],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
      }

      SECTION("value")
      {
        {
          auto it = j_value.rbegin();
          CHECK(it[0] == json(42));
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
        {
          auto it = j_value.crbegin();
          CHECK(it[0] == json(42));
          CHECK_THROWS_WITH_AS(
              it[1],
              "[json.exception.invalid_iterator.214] cannot get value",
              json::invalid_iterator&);
        }
      }
    }
  }

#if _azure_JSON_HAS_RANGES
  // JSON_HAS_CPP_20 (do not remove; see note at top of file)
  SECTION("ranges")
  {
    SECTION("concepts")
    {
      using Azure::Core::Json::_internal::detail::iteration_proxy_value;
      CHECK(std::bidirectional_iterator<json::iterator>);
      CHECK(std::input_iterator<iteration_proxy_value<json::iterator>>);

      CHECK(std::is_same<json::iterator, std::ranges::iterator_t<json>>::value);
      CHECK(std::ranges::bidirectional_range<json>);

      using Azure::Core::Json::_internal::detail::iteration_proxy;
      using items_type = decltype(std::declval<json&>().items());
      CHECK(std::is_same<items_type, iteration_proxy<json::iterator>>::value);
      CHECK(
          std::is_same<iteration_proxy_value<json::iterator>, std::ranges::iterator_t<items_type>>::
              value);
      CHECK(std::ranges::input_range<items_type>);
    }

    // libstdc++ algorithms don't work with Clang 15 (04/2022)
#if !DOCTEST_CLANG || (DOCTEST_CLANG && defined(__GLIBCXX__))
    SECTION("algorithms")
    {
      SECTION("copy")
      {
        json j{"foo", "bar"};
        auto j_copied = json::array();

        std::ranges::copy(j, std::back_inserter(j_copied));

        CHECK(j == j_copied);
      }

      SECTION("find_if")
      {
        json j{1, 3, 2, 4};
        auto j_even = json::array();

#if JSON_USE_IMPLICIT_CONVERSIONS
        auto it = std::ranges::find_if(j, [](int v) noexcept { return (v % 2) == 0; });
#else
        auto it = std::ranges::find_if(j, [](const json& j) noexcept {
          int v;
          j.get_to(v);
          return (v % 2) == 0;
        });
#endif

        CHECK(*it == 2);
      }
    }
#endif

    // libstdc++ views don't work with Clang 15 (04/2022)
    // libc++ hides limited ranges implementation behind guard macro
#if !(DOCTEST_CLANG && (defined(__GLIBCXX__) || defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)))
    SECTION("views")
    {
      SECTION("reverse")
      {
        json j{1, 2, 3, 4, 5};
        json j_expected{5, 4, 3, 2, 1};

        auto reversed = j | std::views::reverse;
        CHECK(std::ranges::equal(reversed, j_expected));
      }

      SECTION("transform")
      {
        json j{
            {"a_key", "a_value"},
            {"b_key", "b_value"},
            {"c_key", "c_value"},
        };
        json j_expected{"a_key", "b_key", "c_key"};

        auto transformed
            = j.items() | std::views::transform([](const auto& item) { return item.key(); });
        auto j_transformed = json::array();
        std::ranges::copy(transformed, std::back_inserter(j_transformed));

        CHECK(j_transformed == j_expected);
      }
    }
#endif
  }
#endif
}
