Use the with_*_t aliases in the remaining tests and docs

#5787 missed the instantiations spelled as `basic_json <` (astyle's
formatting) or ending in the CustomBaseClass argument. Convert them,
including the binary_t.md example pointed out in review.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json/binary_t.md

@@ -64,18 +64,7 @@ values of that type directly to a `basic_json` instance, and they will automatic
 rather than arrays:
 
 ```cpp
-using custom_json = nlohmann::basic_json<
-    nlohmann::ordered_map,  // ObjectType
-    std::vector,            // ArrayType
-    std::string,            // StringType
-    bool,                   // BooleanType
-    std::int64_t,           // NumberIntegerType
-    std::uint64_t,          // NumberUnsignedType
-    double,                 // NumberFloatType
-    std::allocator,         // AllocatorType
-    nlohmann::adl_serializer,
-    std::vector<std::byte>  // Custom BinaryType
->;
+using custom_json = nlohmann::ordered_json::with_binary_t<std::vector<std::byte>>;
 
 std::vector<std::byte> data{std::byte{1}, std::byte{2}, std::byte{3}};
 custom_json j = data;  // Creates a binary value, not an array

docs/mkdocs/docs/examples/as_base_class.cpp

@@ -15,19 +15,7 @@ class base_class_with_hidden_members
     }
 };
 
-using json = nlohmann::basic_json <
-             std::map,
-             std::vector,
-             std::string,
-             bool,
-             std::int64_t,
-             std::uint64_t,
-             double,
-             std::allocator,
-             nlohmann::adl_serializer,
-             std::vector<std::uint8_t>,
-             base_class_with_hidden_members
-             >;
+using json = nlohmann::json::with_base_class_t<base_class_with_hidden_members>;
 
 int main()
 {

include/nlohmann/detail/json_pointer.hpp

@@ -878,127 +878,64 @@ class json_pointer
     @param[in,out] result        the result object to insert values to
 
     @note Empty objects or arrays are flattened to `null`.
-
-    The value is walked with an explicit stack rather than the call stack, so
-    arbitrarily deeply nested values can be flattened.
-
-    @sa https://github.com/nlohmann/json/issues/5393
     */
     template<typename BasicJsonType>
     static void flatten(const string_t& reference_string,
                         const BasicJsonType& value,
                         BasicJsonType& result)
     {
-        using object_const_iterator = typename BasicJsonType::object_t::const_iterator;
-
-        // an array or object being walked: the container, the array index or
-        // object iterator of the next child, and the length of the path of the
-        // container itself
-        struct frame
+        switch (value.type())
         {
-            const BasicJsonType* container;
-            std::size_t index;
-            object_const_iterator member;
-            std::size_t path_length;
-        };
-
-        // The containers being flattened are kept on an explicit stack, and
-        // every child is flattened completely before the next one, so the
-        // entries come out in the same order as with a recursive walk. The
-        // path of the value being flattened is kept in one buffer that grows
-        // and shrinks with the stack, rather than in a new string per level.
-        std::vector<frame> stack;
-        string_t path = reference_string;
-
-        // flatten `v`, whose path is `path`: primitives and empty containers
-        // are added to the result right away; other containers get a frame
-        const auto enter = [&stack, &path, &result](const BasicJsonType & v)
-        {
-            switch (v.type())
+            case detail::value_t::array:
             {
-                case detail::value_t::array:
+                if (value.m_data.m_value.array->empty())
                 {
-                    if (v.m_data.m_value.array->empty())
-                    {
-                        // flatten empty array as null
-                        result[path] = nullptr;
-                    }
-                    else
-                    {
-                        stack.push_back({&v, 0, object_const_iterator(), path.size()});
-                    }
-                    return;
+                    // flatten empty array as null
+                    result[reference_string] = nullptr;
                 }
-
-                case detail::value_t::object:
+                else
                 {
-                    if (v.m_data.m_value.object->empty())
+                    // iterate array and use index as a reference string
+                    for (std::size_t i = 0; i < value.m_data.m_value.array->size(); ++i)
                     {
-                        // flatten empty object as null
-                        result[path] = nullptr;
+                        flatten(detail::concat<string_t>(reference_string, '/', std::to_string(i)),
+                                value.m_data.m_value.array->operator[](i), result);
                     }
-                    else
-                    {
-                        stack.push_back({&v, 0, v.m_data.m_value.object->begin(), path.size()});
-                    }
-                    return;
-                }
-
-                case detail::value_t::null:
-                case detail::value_t::string:
-                case detail::value_t::boolean:
-                case detail::value_t::number_integer:
-                case detail::value_t::number_unsigned:
-                case detail::value_t::number_float:
-                case detail::value_t::binary:
-                case detail::value_t::discarded:
-                default:
-                {
-                    // add a primitive value with its reference string
-                    result[path] = v;
-                    return;
                 }
+                break;
             }
-        };
 
-        enter(value);
-        while (!stack.empty())
-        {
-            // the frame is changed through stack.back(): enter() may push a
-            // frame, which would invalidate a reference to it
-            const BasicJsonType* const container = stack.back().container;
-
-            // drop the path of the previous child
-            path.resize(stack.back().path_length);
-
-            if (container->is_array())
+            case detail::value_t::object:
             {
-                const auto& array = *container->m_data.m_value.array;
-                const std::size_t i = stack.back().index;
-                if (i == array.size())
+                if (value.m_data.m_value.object->empty())
                 {
-                    stack.pop_back();
-                    continue;
+                    // flatten empty object as null
+                    result[reference_string] = nullptr;
                 }
-
-                // iterate array and use index as a reference string
-                ++stack.back().index;
-                detail::concat_into(path, '/', detail::to_string<string_t>(i));
-                enter(array[i]);
+                else
+                {
+                    // iterate object and use keys as reference string
+                    for (const auto& element : *value.m_data.m_value.object)
+                    {
+                        flatten(detail::concat<string_t>(reference_string, '/', detail::escape(element.first)), element.second, result);
+                    }
+                }
+                break;
             }
-            else
-            {
-                const object_const_iterator it = stack.back().member;
-                if (it == container->m_data.m_value.object->end())
-                {
-                    stack.pop_back();
-                    continue;
-                }
 
-                // iterate object and use keys as reference string
-                ++stack.back().member;
-                detail::concat_into(path, '/', detail::escape(it->first));
-                enter(it->second);
+            case detail::value_t::null:
+            case detail::value_t::string:
+            case detail::value_t::boolean:
+            case detail::value_t::number_integer:
+            case detail::value_t::number_unsigned:
+            case detail::value_t::number_float:
+            case detail::value_t::binary:
+            case detail::value_t::discarded:
+            default:
+            {
+                // add a primitive value with its reference string
+                result[reference_string] = value;
+                break;
             }
         }
     }

single_include/nlohmann/json.hpp

@@ -20796,127 +20796,64 @@ class json_pointer
     @param[in,out] result        the result object to insert values to
 
     @note Empty objects or arrays are flattened to `null`.
-
-    The value is walked with an explicit stack rather than the call stack, so
-    arbitrarily deeply nested values can be flattened.
-
-    @sa https://github.com/nlohmann/json/issues/5393
     */
     template<typename BasicJsonType>
     static void flatten(const string_t& reference_string,
                         const BasicJsonType& value,
                         BasicJsonType& result)
     {
-        using object_const_iterator = typename BasicJsonType::object_t::const_iterator;
-
-        // an array or object being walked: the container, the array index or
-        // object iterator of the next child, and the length of the path of the
-        // container itself
-        struct frame
+        switch (value.type())
         {
-            const BasicJsonType* container;
-            std::size_t index;
-            object_const_iterator member;
-            std::size_t path_length;
-        };
-
-        // The containers being flattened are kept on an explicit stack, and
-        // every child is flattened completely before the next one, so the
-        // entries come out in the same order as with a recursive walk. The
-        // path of the value being flattened is kept in one buffer that grows
-        // and shrinks with the stack, rather than in a new string per level.
-        std::vector<frame> stack;
-        string_t path = reference_string;
-
-        // flatten `v`, whose path is `path`: primitives and empty containers
-        // are added to the result right away; other containers get a frame
-        const auto enter = [&stack, &path, &result](const BasicJsonType & v)
-        {
-            switch (v.type())
+            case detail::value_t::array:
             {
-                case detail::value_t::array:
+                if (value.m_data.m_value.array->empty())
                 {
-                    if (v.m_data.m_value.array->empty())
-                    {
-                        // flatten empty array as null
-                        result[path] = nullptr;
-                    }
-                    else
-                    {
-                        stack.push_back({&v, 0, object_const_iterator(), path.size()});
-                    }
-                    return;
+                    // flatten empty array as null
+                    result[reference_string] = nullptr;
                 }
-
-                case detail::value_t::object:
+                else
                 {
-                    if (v.m_data.m_value.object->empty())
+                    // iterate array and use index as a reference string
+                    for (std::size_t i = 0; i < value.m_data.m_value.array->size(); ++i)
                     {
-                        // flatten empty object as null
-                        result[path] = nullptr;
+                        flatten(detail::concat<string_t>(reference_string, '/', std::to_string(i)),
+                                value.m_data.m_value.array->operator[](i), result);
                     }
-                    else
-                    {
-                        stack.push_back({&v, 0, v.m_data.m_value.object->begin(), path.size()});
-                    }
-                    return;
-                }
-
-                case detail::value_t::null:
-                case detail::value_t::string:
-                case detail::value_t::boolean:
-                case detail::value_t::number_integer:
-                case detail::value_t::number_unsigned:
-                case detail::value_t::number_float:
-                case detail::value_t::binary:
-                case detail::value_t::discarded:
-                default:
-                {
-                    // add a primitive value with its reference string
-                    result[path] = v;
-                    return;
                 }
+                break;
             }
-        };
 
-        enter(value);
-        while (!stack.empty())
-        {
-            // the frame is changed through stack.back(): enter() may push a
-            // frame, which would invalidate a reference to it
-            const BasicJsonType* const container = stack.back().container;
-
-            // drop the path of the previous child
-            path.resize(stack.back().path_length);
-
-            if (container->is_array())
+            case detail::value_t::object:
             {
-                const auto& array = *container->m_data.m_value.array;
-                const std::size_t i = stack.back().index;
-                if (i == array.size())
+                if (value.m_data.m_value.object->empty())
                 {
-                    stack.pop_back();
-                    continue;
+                    // flatten empty object as null
+                    result[reference_string] = nullptr;
                 }
-
-                // iterate array and use index as a reference string
-                ++stack.back().index;
-                detail::concat_into(path, '/', detail::to_string<string_t>(i));
-                enter(array[i]);
+                else
+                {
+                    // iterate object and use keys as reference string
+                    for (const auto& element : *value.m_data.m_value.object)
+                    {
+                        flatten(detail::concat<string_t>(reference_string, '/', detail::escape(element.first)), element.second, result);
+                    }
+                }
+                break;
             }
-            else
-            {
-                const object_const_iterator it = stack.back().member;
-                if (it == container->m_data.m_value.object->end())
-                {
-                    stack.pop_back();
-                    continue;
-                }
 
-                // iterate object and use keys as reference string
-                ++stack.back().member;
-                detail::concat_into(path, '/', detail::escape(it->first));
-                enter(it->second);
+            case detail::value_t::null:
+            case detail::value_t::string:
+            case detail::value_t::boolean:
+            case detail::value_t::number_integer:
+            case detail::value_t::number_unsigned:
+            case detail::value_t::number_float:
+            case detail::value_t::binary:
+            case detail::value_t::discarded:
+            default:
+            {
+                // add a primitive value with its reference string
+                result[reference_string] = value;
+                break;
             }
         }
     }

tests/src/unit-bson.cpp

@@ -46,9 +46,7 @@ class huge_binary_t : public std::vector<std::uint8_t>
     }
 };
 
-using huge_binary_json = nlohmann::basic_json <
-                         std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t,
-                         double, std::allocator, nlohmann::adl_serializer, huge_binary_t, void >;
+using huge_binary_json = nlohmann::json::with_binary_t<huge_binary_t>;
 
 // a string type that can be made to report a size beyond INT32_MAX without
 // allocating that much memory, so BSON length overflow can be tested for
@@ -96,9 +94,7 @@ class huge_string_t : public std::string
     bool pretend_huge = false;
 };
 
-using huge_string_json = nlohmann::basic_json <
-                         std::map, std::vector, huge_string_t, bool, std::int64_t, std::uint64_t,
-                         double, std::allocator, nlohmann::adl_serializer, std::vector<std::uint8_t>, void >;
+using huge_string_json = nlohmann::json::with_string_t<huge_string_t>;
 } // namespace
 
 TEST_CASE("BSON")

tests/src/unit-custom-base-class.cpp

@@ -400,20 +400,7 @@ class base_class_with_hidden_members
     std::size_t m_size = 42;
 };
 
-using json_with_hidden_base_members =
-    nlohmann::basic_json <
-    std::map,
-    std::vector,
-    std::string,
-    bool,
-    std::int64_t,
-    std::uint64_t,
-    double,
-    std::allocator,
-    nlohmann::adl_serializer,
-    std::vector<std::uint8_t>,
-    base_class_with_hidden_members
-    >;
+using json_with_hidden_base_members = nlohmann::json::with_base_class_t<base_class_with_hidden_members>;
 
 TEST_CASE("JSON Node as_base_class")
 {
@@ -459,19 +446,7 @@ struct const_member_base
     const int id = 7; // NOLINT(misc-non-private-member-variables-in-classes)
 };
 
-using json_with_const_base = nlohmann::basic_json <
-                             std::map,
-                             std::vector,
-                             std::string,
-                             bool,
-                             std::int64_t,
-                             std::uint64_t,
-                             double,
-                             std::allocator,
-                             nlohmann::adl_serializer,
-                             std::vector<std::uint8_t>,
-                             const_member_base
-                             >;
+using json_with_const_base = nlohmann::json::with_base_class_t<const_member_base>;
 
 // build an array nested @a depth levels deep, with the innermost value 1;
 // every level is constructed (never assigned), since const_member_base does

tests/src/unit-custom-binary-type.cpp

@@ -26,15 +26,11 @@ namespace
 
 // a BinaryType whose value type is signed: the elements must still be
 // processed as the numbers 0..255
-using char_binary_json = nlohmann::basic_json <
-                         std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t,
-                         double, std::allocator, nlohmann::adl_serializer, std::vector<char>, void >;
+using char_binary_json = nlohmann::json::with_binary_t<std::vector<char>>;
 
 #ifdef JSON_HAS_CPP_17
     // a BinaryType whose value type is not an integer type at all
-    using byte_binary_json = nlohmann::basic_json <
-    std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t,
-    double, std::allocator, nlohmann::adl_serializer, std::vector<std::byte>, void >;
+    using byte_binary_json = nlohmann::json::with_binary_t<std::vector<std::byte>>;
 #endif
 
 } // namespace

tests/src/unit-json_pointer.cpp

@@ -939,81 +939,3 @@ TEST_CASE("unescaping keeps a '~' that does not start an escape sequence")
     nlohmann::detail::unescape(s);
     CHECK(s == "~/~");
 }
-
-TEST_CASE("flatten of structured values")
-{
-    SECTION("values nested too deeply for the call stack (#5393)")
-    {
-        // flatten() used to recurse once per nesting level
-        const std::size_t depth = 100000;
-        for (const bool objects :
-                {
-                    false, true
-                })
-        {
-            CAPTURE(objects)
-            std::string text;
-            std::string path;
-            for (std::size_t i = 0; i < depth; ++i)
-            {
-                text += objects ? "{\"a\":" : "[";
-                path += objects ? "/a" : "/0";
-            }
-            text += "0";
-            text += std::string(depth, objects ? '}' : ']');
-            const auto value = json::parse(text);
-
-            const auto flat = value.flatten();
-            REQUIRE(flat.size() == 1);
-            REQUIRE(flat.begin().key().size() == path.size());
-            CHECK(flat.begin().key() == path);
-            CHECK(flat.begin().value() == 0);
-
-            // unflatten() is not iterative: it takes time and memory
-            // quadratic in the depth, so it is only roundtripped for a
-            // moderate depth
-            std::string small_text;
-            for (std::size_t i = 0; i < 500; ++i)
-            {
-                small_text += objects ? "{\"a\":" : "[";
-            }
-            small_text += "0";
-            small_text += std::string(500, objects ? '}' : ']');
-            const auto small_value = json::parse(small_text);
-            CHECK(small_value.flatten().unflatten() == small_value);
-        }
-    }
-
-    SECTION("objects and arrays interleaved")
-    {
-        const json value =
-        {
-            {"a", {1, {{"b", json::array()}, {"c", json::object()}}, json::array({{{"x~/", {true, nullptr}}}})}},
-            {"a/b", {{"~", 1}}},
-            {"z", "s"}
-        };
-
-        const json expected =
-        {
-            {"/a/0", 1},
-            {"/a/1/b", nullptr},
-            {"/a/1/c", nullptr},
-            {"/a/2/0/x~0~1/0", true},
-            {"/a/2/0/x~0~1/1", nullptr},
-            {"/a~1b/~0", 1},
-            {"/z", "s"}
-        };
-
-        CHECK(value.flatten() == expected);
-    }
-
-    SECTION("order of the entries of an ordered_json")
-    {
-        const auto value = nlohmann::ordered_json::parse(
-                               R"({"z":"s","a/b":{"~":1,"k":[]},"a":[1,{"c":{},"b":[]},[{"x~/":[true,null],"w":2}]]})");
-
-        const auto flat = value.flatten();
-        CHECK(flat.dump() ==
-              R"({"/z":"s","/a~1b/~0":1,"/a~1b/k":null,"/a/0":1,"/a/1/c":null,"/a/1/b":null,"/a/2/0/x~0~1/0":true,"/a/2/0/x~0~1/1":null,"/a/2/0/w":2})");
-    }
-}

tests/src/unit-msgpack.cpp

@@ -2201,10 +2201,7 @@ struct huge_array : std::vector<T, A>
     }
 };
 
-using huge_array_json = nlohmann::basic_json <
-                        std::map, huge_array, std::string, bool, std::int64_t, std::uint64_t,
-                        double, std::allocator, nlohmann::adl_serializer,
-                        std::vector<std::uint8_t>, void >;
+using huge_array_json = nlohmann::json::with_array_t<huge_array>;
 
 TEST_CASE("MessagePack Size above uint32 for array")
 {
@@ -2249,18 +2246,7 @@ template<typename K, typename V,
     }
 };
 
-using huge_object_json = nlohmann::basic_json <
-                         huge_map,
-                         std::vector,
-                         std::string,
-                         bool,
-                         std::int64_t,
-                         std::uint64_t,
-                         double,
-                         std::allocator,
-                         nlohmann::adl_serializer,
-                         std::vector<std::uint8_t>,
-                         void >;
+using huge_object_json = nlohmann::json::with_object_t<huge_map>;
 
 TEST_CASE("MessagePack Size above uint32 for object")
 {
@@ -2295,18 +2281,7 @@ struct huge_string : std::string
     }
 };
 
-using huge_string_json = nlohmann::basic_json <
-                         std::map,
-                         std::vector,
-                         huge_string,
-                         bool,
-                         std::int64_t,
-                         std::uint64_t,
-                         double,
-                         std::allocator,
-                         nlohmann::adl_serializer,
-                         std::vector<std::uint8_t>,
-                         void >;
+using huge_string_json = nlohmann::json::with_string_t<huge_string>;
 
 TEST_CASE("MessagePack Size above uint32 for string")
 {
@@ -2329,18 +2304,7 @@ struct huge_binary : std::vector<std::uint8_t>
     }
 };
 
-using huge_binary_json = nlohmann::basic_json <
-                         std::map,
-                         std::vector,
-                         std::string,
-                         bool,
-                         std::int64_t,
-                         std::uint64_t,
-                         double,
-                         std::allocator,
-                         nlohmann::adl_serializer,
-                         huge_binary,
-                         void >;
+using huge_binary_json = nlohmann::json::with_binary_t<huge_binary>;
 
 TEST_CASE("MessagePack Size above uint32 for binary")
 {
@@ -2390,14 +2354,10 @@ class beyond_uint32_string_t : public std::string
     }
 };
 
-using beyond_uint32_string_json = nlohmann::basic_json <
-                                  std::map, std::vector, beyond_uint32_string_t, bool, std::int64_t, std::uint64_t,
-                                  double, std::allocator, nlohmann::adl_serializer, std::vector<std::uint8_t>, void >;
+using beyond_uint32_string_json = nlohmann::json::with_string_t<beyond_uint32_string_t>;
 #endif
 
-using beyond_uint32_binary_json = nlohmann::basic_json <
-                                  std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t,
-                                  double, std::allocator, nlohmann::adl_serializer, beyond_uint32_binary_t, void >;
+using beyond_uint32_binary_json = nlohmann::json::with_binary_t<beyond_uint32_binary_t>;
 } // namespace
 
 TEST_CASE("MessagePack lengths beyond UINT32_MAX cannot be serialized")

tests/src/unit-ordered_json2.cpp

@@ -217,16 +217,7 @@ void int_to_string(alt_string& target, std::size_t value)
     target = std::to_string(value).c_str();
 }
 
-using alt_json = nlohmann::basic_json <
-                 std::map,
-                 std::vector,
-                 alt_string,
-                 bool,
-                 std::int64_t,
-                 std::uint64_t,
-                 double,
-                 std::allocator,
-                 nlohmann::adl_serializer >;
+using alt_json = nlohmann::json::with_string_t<alt_string>;
 
 bool operator<(const char* op1, const alt_string& op2) noexcept
 {