Deduplicate UBJSON/BJData length-type error message

The "expected length type specification" parse error was built with an
identical if/else block in both get_ubjson_string() and
get_ubjson_size_value(), each branching on the input format to pick the
marker list. Extract a single unexpected_length_type_message() helper that
selects the markers via a ternary and appends the caller-supplied infix,
removing four near-duplicate message strings and centralizing the marker
list. Error messages are unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tv6SnfYbcx8y3y4PrECcto

.github/workflows/codeql-analysis.yml

@@ -38,14 +38,14 @@ jobs:
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+      uses: github/codeql-action/init@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
       with:
         languages: c-cpp
 
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+      uses: github/codeql-action/autobuild@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+      uses: github/codeql-action/analyze@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0

.github/workflows/flawfinder.yml

@@ -43,6 +43,6 @@ jobs:
           output: 'flawfinder_results.sarif'
 
       - name: Upload analysis results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+        uses: github/codeql-action/upload-sarif@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
         with:
           sarif_file: ${{github.workspace}}/flawfinder_results.sarif

.github/workflows/scorecards.yml

@@ -76,6 +76,6 @@ jobs:
 
       # Upload the results to GitHub's code scanning dashboard.
       - name: "Upload to code-scanning"
-        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+        uses: github/codeql-action/upload-sarif@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
         with:
           sarif_file: results.sarif

.github/workflows/semgrep.yml

@@ -61,7 +61,7 @@ jobs:
 
       # Upload SARIF file generated in previous step
       - name: Upload SARIF file
-        uses: github/codeql-action/upload-sarif@54f647b7e1bb85c95cddabcd46b0c578ec92bc1a # v4.36.3
+        uses: github/codeql-action/upload-sarif@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
         with:
           sarif_file: semgrep.sarif
         if: always()

.github/workflows/stale.yml

@@ -20,7 +20,7 @@ jobs:
         with:
           egress-policy: audit
 
-      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10.3.0
+      - uses: actions/stale@1e223db275d687790206a7acac4d1a11bd6fe629 # v10.4.0
         with:
           stale-issue-label: 'state: stale'
           stale-pr-label: 'state: stale'

docs/mkdocs/docs/api/basic_json/accept.md

@@ -49,7 +49,7 @@ Unlike the [`parse()`](parse.md) function, this function neither throws an excep
 :   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
 
     - a custom sentinel type for C++20 ranges
-    - `std::counted_iterator` with a different sentinel type
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/from_bjdata.md

@@ -36,8 +36,10 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
-    custom sentinel type for C++20 ranges
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/from_bson.md

@@ -36,8 +36,10 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
-    custom sentinel type for C++20 ranges
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/from_cbor.md

@@ -39,8 +39,10 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
-    custom sentinel type for C++20 ranges
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/from_msgpack.md

@@ -36,8 +36,10 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
-    custom sentinel type for C++20 ranges
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/from_ubjson.md

@@ -36,8 +36,10 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   a compatible iterator type
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance a
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
-    custom sentinel type for C++20 ranges
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/parse.md

@@ -48,7 +48,7 @@ static basic_json parse(IteratorType first, SentinelType last,
 :   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for instance.
 
     - a custom sentinel type for C++20 ranges
-    - `std::counted_iterator` with a different sentinel type
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 ## Parameters
 

docs/mkdocs/docs/api/basic_json/sax_parse.md

@@ -48,7 +48,10 @@ The SAX event lister must follow the interface of [`json_sax`](../json_sax/index
     with a size of 1, 2, or 4 bytes (interpreted respectively as UTF-8, UTF-16, and UTF-32)
 
 `SentinelType`
-:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for overload (2)
+:   defaults to `IteratorType`; may be a different type comparable to `IteratorType` via `operator!=`, for overload (2), for instance.
+
+    - a custom sentinel type for C++20 ranges
+    - `std::default_sentinel_t`, when `IteratorType` is `std::counted_iterator`
 
 `SAX`
 :   a class fulfilling the SAX event listener interface; see [`json_sax`](../json_sax/index.md)

docs/mkdocs/docs/api/macros/json_diagnostics.md

@@ -38,7 +38,8 @@ When the macro is not defined, the library will define it to its default value.
 
     Diagnostic messages can also be controlled with the CMake option
     [`JSON_Diagnostics`](../../integration/cmake.md#json_diagnostics) (`OFF` by default)
-    which defines `JSON_DIAGNOSTICS` accordingly.
+    which defines `JSON_DIAGNOSTICS` accordingly. Note this only applies when building the
+    library from source — see the pre-installed-package caveat on that page.
 
 ## Examples
 

docs/mkdocs/docs/api/macros/nlohmann_define_derived_type.md

@@ -57,8 +57,7 @@ Summary:
 :   name of the base type (class, struct) `type` is derived from
 
 `member` (in)
-:   name of the member variable to serialize/deserialize; up to 63 members can be given as a comma-separated
+:   name of the member variable to serialize/deserialize; up to 63 members can be given as a comma-separated list
-    list, which may also be empty
 
 ## Default definition
 
@@ -128,20 +127,6 @@ void to_json(BasicJsonType& j, const B& b) {
     - Macros 4, 5, and 6 have the same prerequisites of [NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE](nlohmann_define_type_non_intrusive.md).
     - Serialization/deserialization of base types must be defined.
 
-!!! info "Derived types without own members"
-
-    The member list may be empty. The macro then generates a `to_json`/`from_json` pair that only delegates to
-    the base type, so `type` serializes exactly like `base_type`:
-
-    ```cpp
-    struct derived : base
-    {
-        NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(derived, base)
-    };
-    ```
-
-    The `WITH_NAMES` variants do not support this.
-
 !!! warning "Implementation limits"
 
     See Implementation limits for [NLOHMANN_DEFINE_TYPE_INTRUSIVE](nlohmann_define_type_intrusive.md) and

docs/mkdocs/docs/api/macros/nlohmann_define_type_intrusive.md

@@ -33,8 +33,7 @@ Summary:
 :   name of the type (class, struct) to serialize/deserialize
 
 `member` (in)
-:   name of the member variable to serialize/deserialize; up to 63 members can be given as a comma-separated
+:   name of the member variable to serialize/deserialize; up to 63 members can be given as a comma-separated list
-    list, which may also be empty
 
 ## Default definition
 
@@ -59,20 +58,6 @@ See the examples below for the concrete generated code.
 
 [GetNonDefNonCopy]: ../../features/arbitrary_types.md#how-can-i-use-get-for-non-default-constructiblenon-copyable-types
 
-!!! info "Types without members"
-
-    The member list may be empty. The macro then generates a `to_json` that produces an empty JSON object
-    `#!json {}`, and a `from_json` that reads no members:
-
-    ```cpp
-    struct marker
-    {
-        NLOHMANN_DEFINE_TYPE_INTRUSIVE(marker)
-    };
-    ```
-
-    The `WITH_NAMES` variants do not support this.
-
 !!! warning "Implementation limits"
 
     - The current implementation is limited to at most 63 member variables. If you want to serialize/deserialize types

docs/mkdocs/docs/api/macros/nlohmann_define_type_non_intrusive.md

@@ -33,8 +33,7 @@ Summary:
 :   name of the type (class, struct) to serialize/deserialize
 
 `member` (in)
-:   name of the (public) member variable to serialize/deserialize; up to 63 members can be given as a
+:   name of the (public) member variable to serialize/deserialize; up to 63 members can be given as a comma-separated list
-    comma-separated list, which may also be empty
 
 ## Default definition
 
@@ -60,18 +59,6 @@ See the examples below for the concrete generated code.
 
 [GetNonDefNonCopy]: ../../features/arbitrary_types.md#how-can-i-use-get-for-non-default-constructiblenon-copyable-types
 
-!!! info "Types without members"
-
-    The member list may be empty. The macro then generates a `to_json` that produces an empty JSON object
-    `#!json {}`, and a `from_json` that reads no members:
-
-    ```cpp
-    struct marker {};
-    NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(marker)
-    ```
-
-    The `WITH_NAMES` variants do not support this.
-
 !!! warning "Implementation limits"
 
     - The current implementation is limited to at most 63 member variables. If you want to serialize/deserialize types

docs/mkdocs/docs/features/arbitrary_types.md

@@ -215,24 +215,6 @@ For _derived_ classes and structs, use the following macros
     nlohmann::ordered_json j = p; // keys appear in declaration order: name, address, age
     ```
 
-!!! note "Zero-member types"
-
-    All 12 `NLOHMANN_DEFINE_TYPE_*`/`NLOHMANN_DEFINE_DERIVED_TYPE_*` macros (excluding the `WITH_NAMES` variants)
-    also accept types with no member variables to serialize, producing/accepting an empty JSON object `{}`
-    (or, for the derived-type macros, just the base class's own JSON representation):
-
-    ```cpp
-    namespace ns {
-        struct marker {
-            bool operator==(const marker&) const { return true; }
-            NLOHMANN_DEFINE_TYPE_INTRUSIVE(marker)
-        };
-    }
-
-    ns::marker m{};
-    nlohmann::json j = m; // {}
-    ```
-
 !!! note "No macro for non-default-constructible types"
 
     There is currently no `NLOHMANN_DEFINE_TYPE_*`-style macro for types that are not

docs/mkdocs/docs/features/conversions.md

@@ -47,6 +47,28 @@ json j = {{"one", 1}, {"two", 2}};
 auto m = j.get<std::map<std::string, int>>();  // {{"one", 1}, {"two", 2}}
 ```
 
+`#!cpp std::pair` and `#!cpp std::tuple` are also supported, converting positionally to and from a JSON array:
+
+```cpp
+json j = {1.0, "hello", 42};
+auto t = j.get<std::tuple<double, std::string, int>>();  // {1.0, "hello", 42}
+```
+
+!!! info "Extracting references into a tuple"
+
+    A tuple type may also hold references (e.g. `#!cpp std::tuple<double&, std::string&>`) to avoid copying: `get`
+    then returns a tuple of references pointing directly at the elements stored inside the `basic_json` array,
+    rather than a tuple of copies:
+
+    ```cpp
+    json j = {1.0, "hello"};
+    auto refs = j.get<std::tuple<double&, std::string&>>();
+    std::get<1>(refs) = "world";  // modifies j[1] in place
+    ```
+
+    A referenced type must be one the library actually stores (or an arithmetic type it can convert to/from);
+    otherwise this is a compile error.
+
 ## Implicit conversions
 
 By default, a JSON value implicitly converts to a compatible C++ type, so the explicit `get` call can often be omitted:
@@ -136,6 +158,20 @@ std::vector<int> numbers = {1, 2, 3};
 json j = numbers;   // [1,2,3]
 ```
 
+!!! info "Constructing from a C++20 range view"
+
+    A `json` array can also be constructed directly from a C++20 range view (`std::ranges::view`), such as the result
+    of `std::views::filter` or `std::views::transform` -- no intermediate container is needed:
+
+    ```cpp
+    std::vector<int> nums{1, 2, 37, 42, 21};
+    auto filtered = nums | std::views::filter([](int i) { return i > 10; });
+    json j(filtered);   // [37,42,21]
+    ```
+
+    This requires [`JSON_HAS_RANGES`](../api/macros/json_has_ranges.md) to be enabled and is unavailable on MinGW due
+    to incomplete C++20 ranges support there.
+
 ## Your own types
 
 The conversions above are built in for standard types. To make the same syntax work for **your own** types, provide

docs/mkdocs/docs/integration/cmake.md

@@ -135,6 +135,31 @@ Enable CI build targets. The exact targets are used during the several CI steps
 
 Enable [extended diagnostic messages](../home/exceptions.md#extended-diagnostic-messages) by defining macro [`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md). This option is `OFF` by default.
 
+!!! warning "Does not apply to a pre-installed package"
+
+    This option only takes effect when building nlohmann/json from source as part of your own
+    CMake project (e.g. via [`FetchContent`](#fetchcontent) or [`add_subdirectory`](#external)).
+    It has **no effect** on a package that was already built and installed elsewhere (Homebrew,
+    vcpkg, a system package, etc.) — the resulting compile definition is baked into the exported
+    `nlohmann_jsonTargets.cmake` at install time, and `set(JSON_Diagnostics ON)` before
+    `find_package()` does not change it (verified against the Homebrew-installed package: the
+    exported target still carries a fixed `$<$<BOOL:OFF>:JSON_DIAGNOSTICS=1>`, regardless of any
+    variable set in the consuming project).
+
+    To enable extended diagnostics for a pre-installed package, override the imported target's
+    property directly after `find_package()`:
+
+    ```cmake
+    find_package(nlohmann_json REQUIRED)
+    set_target_properties(nlohmann_json::nlohmann_json PROPERTIES
+        INTERFACE_COMPILE_DEFINITIONS "JSON_DIAGNOSTICS=1")
+    ```
+
+    This only works cleanly when your project is the sole consumer of that imported target. If
+    nlohmann_json is pulled in from more than one place in your dependency graph with different
+    `JSON_DIAGNOSTICS` values, you may see a `"JSON_DIAGNOSTICS" redefined` compiler error, since
+    conflicting `-D` flags can end up on the same compile command line.
+
 ### `JSON_Diagnostic_Positions`
 
 Enable position diagnostics by defining macro [`JSON_DIAGNOSTIC_POSITIONS`](../api/macros/json_diagnostic_positions.md). This option is `OFF` by default.

include/nlohmann/detail/input/binary_reader.hpp

@@ -1846,6 +1846,47 @@ class binary_reader
         return get_ubjson_value(get_char ? get_ignore_noop() : current);
     }
 
+    /*!
+    @brief reject a negative UBJSON/BJData string length
+
+    String and key lengths are written with signed integer markers (i, I, l,
+    L). A negative value is malformed; without this check get_string() would
+    silently treat it as an empty string and leave the following bytes to be
+    misread as the next value. This mirrors the non-negative check the
+    optimized-container count path already performs in get_ubjson_size_value.
+
+    @param[in] len  the string length read from the input
+    @return whether the length is valid (non-negative)
+    */
+    template<typename NumberType>
+    bool check_ubjson_string_length(const NumberType len)
+    {
+        if (JSON_HEDLEY_UNLIKELY(len < 0))
+        {
+            return sax->parse_error(chars_read, get_token_string(), parse_error::create(113, chars_read,
+                                    exception_message(input_format, "string length must not be negative", "string"), nullptr));
+        }
+        return true;
+    }
+
+    /*!
+    @brief create the error message for a missing/invalid length-type marker
+
+    Used both when reading a UBJSON/BJData string and when reading an optimized
+    container size. The accepted markers depend on the input format, and the
+    size variant appends " after '#'" via @a infix.
+
+    @param[in] last_token  the offending byte as returned by get_token_string()
+    @param[in] infix       extra context inserted after the marker list
+    @return the formatted error message
+    */
+    std::string unexpected_length_type_message(const std::string& last_token, const char* infix) const
+    {
+        return concat("expected length type specification (",
+                      input_format == input_format_t::bjdata ? "U, i, u, I, m, l, M, L" : "U, i, I, l, L",
+                      ")", infix, "; last byte: 0x", last_token);
+    }
+
     /*!
     @brief reads a UBJSON string
 
@@ -1883,25 +1924,25 @@ class binary_reader
             case 'i':
             {
                 std::int8_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'I':
             {
                 std::int16_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'l':
             {
                 std::int32_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'L':
             {
                 std::int64_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'u':
@@ -1938,17 +1979,8 @@ class binary_reader
                 break;
         }
         auto last_token = get_token_string();
-        std::string message;
+        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read,
-
+                                exception_message(input_format, unexpected_length_type_message(last_token, ""), "string"), nullptr));
-        if (input_format != input_format_t::bjdata)
-        {
-            message = "expected length type specification (U, i, I, l, L); last byte: 0x" + last_token;
-        }
-        else
-        {
-            message = "expected length type specification (U, i, u, I, m, l, M, L); last byte: 0x" + last_token;
-        }
-        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format, message, "string"), nullptr));
     }
 
     /*!
@@ -2227,17 +2259,8 @@ class binary_reader
                 break;
         }
         auto last_token = get_token_string();
-        std::string message;
+        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read,
-
+                                exception_message(input_format, unexpected_length_type_message(last_token, " after '#'"), "size"), nullptr));
-        if (input_format != input_format_t::bjdata)
-        {
-            message = "expected length type specification (U, i, I, l, L) after '#'; last byte: 0x" + last_token;
-        }
-        else
-        {
-            message = "expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x" + last_token;
-        }
-        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format, message, "size"), nullptr));
     }
 
     /*!

include/nlohmann/detail/input/input_adapters.hpp

@@ -220,20 +220,29 @@ class iterator_input_adapter
     // whether IteratorType refers to a contiguous range and therefore supports
     // a std::memcpy fast path (pointers always do; in C++20 we can also detect
     // library iterators such as those of std::vector and std::string).
-    // The fast path also requires SentinelType == IteratorType so std::distance works.
+    // Computing the available element count needs either same-type iterators
+    // (plain std::distance) or, in C++20, a sized sentinel (std::ranges::distance),
+    // e.g. std::counted_iterator paired with std::default_sentinel_t.
     static constexpr bool iterator_is_contiguous =
-        std::is_same<IteratorType, SentinelType>::value && (
 #if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
-            std::contiguous_iterator<IteratorType> ||
+        (std::is_same<IteratorType, SentinelType>::value || std::sized_sentinel_for<SentinelType, IteratorType>)
+        && (std::contiguous_iterator<IteratorType> || std::is_pointer<IteratorType>::value);
+#else
+        std::is_same<IteratorType, SentinelType>::value && std::is_pointer<IteratorType>::value;
 #endif
-            std::is_pointer<IteratorType>::value);
 
     // contiguous fast path: bulk copy the remaining range with std::memcpy
     template<class T>
     std::size_t get_elements_impl(T* dest, std::size_t count, std::true_type /*contiguous*/)
     {
         const std::size_t wanted = count * sizeof(T);
+#if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
+        // std::ranges::distance also supports sized sentinels of a different
+        // type (e.g. std::counted_iterator + std::default_sentinel_t)
+        const std::size_t available = static_cast<std::size_t>(std::ranges::distance(current, end)) * sizeof(char_type);
+#else
         const std::size_t available = static_cast<std::size_t>(std::distance(current, end)) * sizeof(char_type);
+#endif
         const std::size_t copied = (std::min)(wanted, available);
         if (JSON_HEDLEY_LIKELY(copied != 0))
         {
@@ -386,17 +395,30 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             }
             else
             {
-                if (JSON_HEDLEY_UNLIKELY(!input.empty()))
+                // A supplementary code point is a high surrogate (0xD800..0xDBFF)
+                // followed by a low surrogate (0xDC00..0xDFFF). A lone low
+                // surrogate, a high surrogate at the end of the input, or a high
+                // surrogate followed by any other unit is malformed UTF-16. In
+                // that case the offending unit is passed through unchanged so the
+                // UTF-8 decoder rejects it, matching how \uXXXX surrogate escapes
+                // are handled in the lexer.
+                bool valid_pair = false;
+                if (wc <= 0xDBFF && JSON_HEDLEY_UNLIKELY(!input.empty()))
                 {
                     const auto wc2 = static_cast<unsigned int>(input.get_character());
-                    const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
+                    if (0xDC00 <= wc2 && wc2 <= 0xDFFF)
-                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
+                    {
-                    utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
+                        const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
-                    utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                        utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
-                    utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                        utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
-                    utf8_bytes_filled = 4;
+                        utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                        utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                        utf8_bytes_filled = 4;
+                        valid_pair = true;
+                    }
                 }
-                else
+
+                if (!valid_pair)
                 {
                     utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
                     utf8_bytes_filled = 1;

include/nlohmann/detail/macro_scope.hpp

@@ -587,59 +587,16 @@ void templated_json_throw(ExceptionType exception)
 
 #define NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(...) template<typename BasicJsonType, nlohmann::detail::enable_if_t<nlohmann::detail::is_basic_json<BasicJsonType>::value, int> = 0> __VA_ARGS__
 
-// Tags used to dispatch the NLOHMANN_DEFINE_TYPE_*/NLOHMANN_DEFINE_DERIVED_TYPE_*
-// macros below between a zero-member and a one-or-more-member implementation
-// (issue #4041, e.g. NLOHMANN_DEFINE_TYPE_INTRUSIVE(Type) with no further
-// arguments). NLOHMANN_JSON_TYPE_TAG(...) expands to the token EMPTY when
-// __VA_ARGS__ is a single token (Type alone) and to MEMBERS for two or more
-// (Type, member...), naming the body the public macro dispatches to. It
-// reuses the existing 64-slot NLOHMANN_JSON_GET_MACRO dispatch with one extra
-// trailing sentinel token appended so its own trailing "..." is never left
-// completely empty at the lowest supported argument count --
-// invoking a variadic macro so that "..." matches nothing is only granted
-// unconditionally by the standard since C++20, and pre-C++20 compilers may
-// reject it under -pedantic regardless of what the macro body does.
-//
-// NLOHMANN_JSON_DERIVED_TYPE_TAG(...) answers the same question for the
-// derived-type macros, whose fixed prefix is Type,BaseType. It drops the
-// leading Type and defers to NLOHMANN_JSON_TYPE_TAG rather than shifting the
-// slot table by one: NLOHMANN_JSON_GET_MACRO only resolves 64 positional
-// arguments, so tagging Type,BaseType,member... directly would run out one
-// slot early and cap the derived-type macros at 62 members instead of the 63
-// that NLOHMANN_JSON_PASTE supports.
-#define NLOHMANN_JSON_CAT_(x, y) x ## y
-#define NLOHMANN_JSON_CAT(x, y) NLOHMANN_JSON_CAT_(x, y)
-
-#define NLOHMANN_JSON_TYPE_TAG(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_GET_MACRO(__VA_ARGS__, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, EMPTY, \
-        NLOHMANN_JSON_TYPE_TAG_SENTINEL))
-
-#define NLOHMANN_JSON_DERIVED_TYPE_TAG_(Type, ...) NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__)
-#define NLOHMANN_JSON_DERIVED_TYPE_TAG(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DERIVED_TYPE_TAG_(__VA_ARGS__))
-
 /*!
 @brief macro
 @def NLOHMANN_DEFINE_TYPE_INTRUSIVE
 @since version 3.9.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type is used as a declarator type, not in an expression */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType&, Type&) noexcept { })
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -650,15 +607,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_EMPTY(Type) NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY(Type)
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -669,14 +621,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.3
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); })
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -686,17 +633,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.9.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type is used as a declarator type, not in an expression */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType&, Type&) noexcept { })
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -707,15 +647,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_EMPTY(Type) NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY(Type)
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -726,14 +661,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.3
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); })
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -743,17 +673,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type/BaseType are used as declarator types, not in expressions */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -764,15 +687,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_EMPTY(Type, BaseType) NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY(Type, BaseType)
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -783,14 +701,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -801,17 +714,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type/BaseType are used as declarator types, not in expressions */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -822,15 +728,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_EMPTY(Type, BaseType) NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY(Type, BaseType)
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -841,14 +742,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 

single_include/nlohmann/json.hpp

@@ -2962,59 +2962,16 @@ void templated_json_throw(ExceptionType exception)
 
 #define NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(...) template<typename BasicJsonType, nlohmann::detail::enable_if_t<nlohmann::detail::is_basic_json<BasicJsonType>::value, int> = 0> __VA_ARGS__
 
-// Tags used to dispatch the NLOHMANN_DEFINE_TYPE_*/NLOHMANN_DEFINE_DERIVED_TYPE_*
-// macros below between a zero-member and a one-or-more-member implementation
-// (issue #4041, e.g. NLOHMANN_DEFINE_TYPE_INTRUSIVE(Type) with no further
-// arguments). NLOHMANN_JSON_TYPE_TAG(...) expands to the token EMPTY when
-// __VA_ARGS__ is a single token (Type alone) and to MEMBERS for two or more
-// (Type, member...), naming the body the public macro dispatches to. It
-// reuses the existing 64-slot NLOHMANN_JSON_GET_MACRO dispatch with one extra
-// trailing sentinel token appended so its own trailing "..." is never left
-// completely empty at the lowest supported argument count --
-// invoking a variadic macro so that "..." matches nothing is only granted
-// unconditionally by the standard since C++20, and pre-C++20 compilers may
-// reject it under -pedantic regardless of what the macro body does.
-//
-// NLOHMANN_JSON_DERIVED_TYPE_TAG(...) answers the same question for the
-// derived-type macros, whose fixed prefix is Type,BaseType. It drops the
-// leading Type and defers to NLOHMANN_JSON_TYPE_TAG rather than shifting the
-// slot table by one: NLOHMANN_JSON_GET_MACRO only resolves 64 positional
-// arguments, so tagging Type,BaseType,member... directly would run out one
-// slot early and cap the derived-type macros at 62 members instead of the 63
-// that NLOHMANN_JSON_PASTE supports.
-#define NLOHMANN_JSON_CAT_(x, y) x ## y
-#define NLOHMANN_JSON_CAT(x, y) NLOHMANN_JSON_CAT_(x, y)
-
-#define NLOHMANN_JSON_TYPE_TAG(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_GET_MACRO(__VA_ARGS__, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, MEMBERS, \
-        MEMBERS, MEMBERS, MEMBERS, EMPTY, \
-        NLOHMANN_JSON_TYPE_TAG_SENTINEL))
-
-#define NLOHMANN_JSON_DERIVED_TYPE_TAG_(Type, ...) NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__)
-#define NLOHMANN_JSON_DERIVED_TYPE_TAG(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DERIVED_TYPE_TAG_(__VA_ARGS__))
-
 /*!
 @brief macro
 @def NLOHMANN_DEFINE_TYPE_INTRUSIVE
 @since version 3.9.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type is used as a declarator type, not in an expression */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType&, Type&) noexcept { })
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -3025,15 +2982,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_EMPTY(Type) NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_EMPTY(Type)
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -3044,14 +2996,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.3
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); })
-
-#define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -3061,17 +3008,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.9.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type is used as a declarator type, not in an expression */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType&, Type&) noexcept { })
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -3082,15 +3022,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_EMPTY(Type) NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_EMPTY(Type)
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -3101,14 +3036,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.11.3
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/
 */
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, ...)  \
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type&) { nlohmann_json_j = BasicJsonType::object(); })
-
-#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -3118,17 +3048,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type/BaseType are used as declarator types, not in expressions */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -3139,15 +3062,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_EMPTY(Type, BaseType) NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_EMPTY(Type, BaseType)
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -3158,14 +3076,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(friend void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -3176,17 +3089,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); }) \
-    /* NOLINTNEXTLINE(bugprone-macro-parentheses) Type/BaseType are used as declarator types, not in expressions */ \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_NAME, __VA_ARGS__)) })
@@ -3197,15 +3103,10 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) })
 
-// identical to NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY: with no members there is nothing to default
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_EMPTY(Type, BaseType) NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_EMPTY(Type, BaseType)
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) }) \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void from_json(const BasicJsonType& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT_WITH_NAME, __VA_ARGS__)) })
@@ -3216,14 +3117,9 @@ void templated_json_throw(ExceptionType exception)
 @since version 3.12.0
 @sa https://json.nlohmann.me/api/macros/nlohmann_define_derived_type/
 */
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_MEMBERS(Type, BaseType, ...)  \
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) })
 
-#define NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_EMPTY(Type, BaseType)  \
-    NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); })
-
-#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_CAT(NLOHMANN_JSON_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_, NLOHMANN_JSON_DERIVED_TYPE_TAG(__VA_ARGS__))(__VA_ARGS__))
-
 #define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(Type, BaseType, ...)  \
     NLOHMANN_JSON_BASIC_TYPE_TEMPLATE(void to_json(BasicJsonType& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_DOUBLE_PASTE(NLOHMANN_JSON_TO_WITH_NAME, __VA_ARGS__)) })
 
@@ -7311,20 +7207,29 @@ class iterator_input_adapter
     // whether IteratorType refers to a contiguous range and therefore supports
     // a std::memcpy fast path (pointers always do; in C++20 we can also detect
     // library iterators such as those of std::vector and std::string).
-    // The fast path also requires SentinelType == IteratorType so std::distance works.
+    // Computing the available element count needs either same-type iterators
+    // (plain std::distance) or, in C++20, a sized sentinel (std::ranges::distance),
+    // e.g. std::counted_iterator paired with std::default_sentinel_t.
     static constexpr bool iterator_is_contiguous =
-        std::is_same<IteratorType, SentinelType>::value && (
 #if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
-            std::contiguous_iterator<IteratorType> ||
+        (std::is_same<IteratorType, SentinelType>::value || std::sized_sentinel_for<SentinelType, IteratorType>)
+        && (std::contiguous_iterator<IteratorType> || std::is_pointer<IteratorType>::value);
+#else
+        std::is_same<IteratorType, SentinelType>::value && std::is_pointer<IteratorType>::value;
 #endif
-            std::is_pointer<IteratorType>::value);
 
     // contiguous fast path: bulk copy the remaining range with std::memcpy
     template<class T>
     std::size_t get_elements_impl(T* dest, std::size_t count, std::true_type /*contiguous*/)
     {
         const std::size_t wanted = count * sizeof(T);
+#if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
+        // std::ranges::distance also supports sized sentinels of a different
+        // type (e.g. std::counted_iterator + std::default_sentinel_t)
+        const std::size_t available = static_cast<std::size_t>(std::ranges::distance(current, end)) * sizeof(char_type);
+#else
         const std::size_t available = static_cast<std::size_t>(std::distance(current, end)) * sizeof(char_type);
+#endif
         const std::size_t copied = (std::min)(wanted, available);
         if (JSON_HEDLEY_LIKELY(copied != 0))
         {
@@ -7477,17 +7382,30 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             }
             else
             {
-                if (JSON_HEDLEY_UNLIKELY(!input.empty()))
+                // A supplementary code point is a high surrogate (0xD800..0xDBFF)
+                // followed by a low surrogate (0xDC00..0xDFFF). A lone low
+                // surrogate, a high surrogate at the end of the input, or a high
+                // surrogate followed by any other unit is malformed UTF-16. In
+                // that case the offending unit is passed through unchanged so the
+                // UTF-8 decoder rejects it, matching how \uXXXX surrogate escapes
+                // are handled in the lexer.
+                bool valid_pair = false;
+                if (wc <= 0xDBFF && JSON_HEDLEY_UNLIKELY(!input.empty()))
                 {
                     const auto wc2 = static_cast<unsigned int>(input.get_character());
-                    const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
+                    if (0xDC00 <= wc2 && wc2 <= 0xDFFF)
-                    utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
+                    {
-                    utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
+                        const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
-                    utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                        utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
-                    utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                        utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
-                    utf8_bytes_filled = 4;
+                        utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                        utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                        utf8_bytes_filled = 4;
+                        valid_pair = true;
+                    }
                 }
-                else
+
+                if (!valid_pair)
                 {
                     utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
                     utf8_bytes_filled = 1;
@@ -12477,6 +12395,47 @@ class binary_reader
         return get_ubjson_value(get_char ? get_ignore_noop() : current);
     }
 
+    /*!
+    @brief reject a negative UBJSON/BJData string length
+
+    String and key lengths are written with signed integer markers (i, I, l,
+    L). A negative value is malformed; without this check get_string() would
+    silently treat it as an empty string and leave the following bytes to be
+    misread as the next value. This mirrors the non-negative check the
+    optimized-container count path already performs in get_ubjson_size_value.
+
+    @param[in] len  the string length read from the input
+    @return whether the length is valid (non-negative)
+    */
+    template<typename NumberType>
+    bool check_ubjson_string_length(const NumberType len)
+    {
+        if (JSON_HEDLEY_UNLIKELY(len < 0))
+        {
+            return sax->parse_error(chars_read, get_token_string(), parse_error::create(113, chars_read,
+                                    exception_message(input_format, "string length must not be negative", "string"), nullptr));
+        }
+        return true;
+    }
+
+    /*!
+    @brief create the error message for a missing/invalid length-type marker
+
+    Used both when reading a UBJSON/BJData string and when reading an optimized
+    container size. The accepted markers depend on the input format, and the
+    size variant appends " after '#'" via @a infix.
+
+    @param[in] last_token  the offending byte as returned by get_token_string()
+    @param[in] infix       extra context inserted after the marker list
+    @return the formatted error message
+    */
+    std::string unexpected_length_type_message(const std::string& last_token, const char* infix) const
+    {
+        return concat("expected length type specification (",
+                      input_format == input_format_t::bjdata ? "U, i, u, I, m, l, M, L" : "U, i, I, l, L",
+                      ")", infix, "; last byte: 0x", last_token);
+    }
+
     /*!
     @brief reads a UBJSON string
 
@@ -12514,25 +12473,25 @@ class binary_reader
             case 'i':
             {
                 std::int8_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'I':
             {
                 std::int16_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'l':
             {
                 std::int32_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'L':
             {
                 std::int64_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'u':
@@ -12569,17 +12528,8 @@ class binary_reader
                 break;
         }
         auto last_token = get_token_string();
-        std::string message;
+        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read,
-
+                                exception_message(input_format, unexpected_length_type_message(last_token, ""), "string"), nullptr));
-        if (input_format != input_format_t::bjdata)
-        {
-            message = "expected length type specification (U, i, I, l, L); last byte: 0x" + last_token;
-        }
-        else
-        {
-            message = "expected length type specification (U, i, u, I, m, l, M, L); last byte: 0x" + last_token;
-        }
-        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format, message, "string"), nullptr));
     }
 
     /*!
@@ -12858,17 +12808,8 @@ class binary_reader
                 break;
         }
         auto last_token = get_token_string();
-        std::string message;
+        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read,
-
+                                exception_message(input_format, unexpected_length_type_message(last_token, " after '#'"), "size"), nullptr));
-        if (input_format != input_format_t::bjdata)
-        {
-            message = "expected length type specification (U, i, I, l, L) after '#'; last byte: 0x" + last_token;
-        }
-        else
-        {
-            message = "expected length type specification (U, i, u, I, m, l, M, L) after '#'; last byte: 0x" + last_token;
-        }
-        return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, exception_message(input_format, message, "size"), nullptr));
     }
 
     /*!

tests/src/unit-bjdata.cpp

@@ -2721,6 +2721,19 @@ TEST_CASE("BJData")
                 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

tests/src/unit-conversions.cpp

@@ -1782,6 +1782,21 @@ TEST_CASE("std::optional")
                              "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
         CHECK_THROWS_WITH_AS(std::optional<int>(j_null),
                              "[json.exception.type_error.302] type must be number, but is null", json::type_error&);
+
+        // Assignment goes through the same overload resolution as direct
+        // construction, so it throws for the same reason. This relies on
+        // basic_json's implicit conversion operator, so it only applies
+        // when JSON_USE_IMPLICIT_CONVERSIONS is enabled (the default).
+#if JSON_USE_IMPLICIT_CONVERSIONS
+        std::optional<std::string> opt_assign;
+        CHECK_THROWS_WITH_AS(opt_assign = j_null,
+                             "[json.exception.type_error.302] type must be string, but is null", json::type_error&);
+#endif
+
+        // get_to() is the correct way to obtain std::nullopt from a JSON null.
+        std::optional<std::string> opt_get_to = "placeholder";
+        j_null.get_to(opt_get_to);
+        CHECK(opt_get_to == std::nullopt);
     }
 
     SECTION("string")

tests/src/unit-ubjson.cpp

@@ -1862,6 +1862,31 @@ TEST_CASE("UBJSON")
                 json _;
                 CHECK_THROWS_WITH_AS(_ = json::from_ubjson(v), "[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: 0x31", json::parse_error&);
             }
+
+            SECTION("negative length")
+            {
+                json _;
+
+                std::vector<uint8_t> const vi = {'S', 'i', 0xFF};
+                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vi), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
+                CHECK(json::from_ubjson(vi, true, false).is_discarded());
+
+                std::vector<uint8_t> const vI = {'S', 'I', 0xFF, 0xFF};
+                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vI), "[json.exception.parse_error.113] parse error at byte 4: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
+                CHECK(json::from_ubjson(vI, true, false).is_discarded());
+
+                std::vector<uint8_t> const vl = {'S', 'l', 0xFF, 0xFF, 0xFF, 0xFF};
+                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vl), "[json.exception.parse_error.113] parse error at byte 6: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
+                CHECK(json::from_ubjson(vl, true, false).is_discarded());
+
+                std::vector<uint8_t> const vL = {'S', 'L', 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+                CHECK_THROWS_WITH_AS(_ = json::from_ubjson(vL), "[json.exception.parse_error.113] parse error at byte 10: syntax error while parsing UBJSON string: string length must not be negative", json::parse_error&);
+                CHECK(json::from_ubjson(vL, true, false).is_discarded());
+
+                // a length of zero remains valid and yields an empty string
+                std::vector<uint8_t> const v0 = {'S', 'i', 0};
+                CHECK(json::from_ubjson(v0) == json(""));
+            }
         }
 
         SECTION("array")

tests/src/unit-udt_macro.cpp

@@ -778,154 +778,6 @@ class derived_person_only_serialize_private_3 : person_without_default_construct
     NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE_WITH_NAMES(derived_person_only_serialize_private_3, person_without_default_constructor_3, "json_hair_color", hair_color)
 };
 
-// Zero-member types for issue #4041: NLOHMANN_DEFINE_TYPE_* and
-// NLOHMANN_DEFINE_DERIVED_TYPE_* must compile and produce a valid (empty)
-// JSON object when no member arguments are given.
-class empty_intrusive
-{
-  public:
-    bool operator==(const empty_intrusive& /*rhs*/) const
-    {
-        return true;
-    }
-    NLOHMANN_DEFINE_TYPE_INTRUSIVE(empty_intrusive)
-};
-
-class empty_intrusive_with_default
-{
-  public:
-    bool operator==(const empty_intrusive_with_default& /*rhs*/) const
-    {
-        return true;
-    }
-    NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(empty_intrusive_with_default)
-};
-
-class empty_intrusive_only_serialize
-{
-  public:
-    NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE(empty_intrusive_only_serialize)
-};
-
-class empty_non_intrusive
-{
-  public:
-    bool operator==(const empty_non_intrusive& /*rhs*/) const
-    {
-        return true;
-    }
-};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(empty_non_intrusive)
-
-class empty_non_intrusive_with_default
-{
-  public:
-    bool operator==(const empty_non_intrusive_with_default& /*rhs*/) const
-    {
-        return true;
-    }
-};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(empty_non_intrusive_with_default)
-
-class empty_non_intrusive_only_serialize {};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(empty_non_intrusive_only_serialize)
-
-class empty_derived_intrusive : public person_with_private_data
-{
-  public:
-    empty_derived_intrusive() = default;
-    empty_derived_intrusive(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(empty_derived_intrusive, person_with_private_data)
-};
-
-class empty_derived_intrusive_with_default : public person_with_private_data
-{
-  public:
-    empty_derived_intrusive_with_default() = default;
-    empty_derived_intrusive_with_default(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(empty_derived_intrusive_with_default, person_with_private_data)
-};
-
-class empty_derived_intrusive_only_serialize : public person_with_private_data
-{
-  public:
-    empty_derived_intrusive_only_serialize() = default;
-    empty_derived_intrusive_only_serialize(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE(empty_derived_intrusive_only_serialize, person_with_private_data)
-};
-
-class empty_derived_non_intrusive : public person_with_private_data
-{
-  public:
-    empty_derived_non_intrusive() = default;
-    empty_derived_non_intrusive(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(empty_derived_non_intrusive, person_with_private_data)
-
-class empty_derived_non_intrusive_with_default : public person_with_private_data
-{
-  public:
-    empty_derived_non_intrusive_with_default() = default;
-    empty_derived_non_intrusive_with_default(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(empty_derived_non_intrusive_with_default, person_with_private_data)
-
-class empty_derived_non_intrusive_only_serialize : public person_with_private_data
-{
-  public:
-    empty_derived_non_intrusive_only_serialize() = default;
-    empty_derived_non_intrusive_only_serialize(std::string name_, int age_, json metadata_)
-        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
-    {}
-};
-// NOLINTNEXTLINE(misc-use-internal-linkage)
-NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(empty_derived_non_intrusive_only_serialize, person_with_private_data)
-
-// Types at the documented maximum member count (63) for issue #4041's
-// argument-count dispatch. The derived-type macros carry a two-token
-// Type,BaseType prefix, so they reach two slots further into
-// NLOHMANN_JSON_GET_MACRO than the non-derived ones and are the first to break
-// if the tag dispatch runs out of positional slots.
-class max_members
-{
-  public:
-    int m1{}, m2{}, m3{}, m4{}, m5{}, m6{}, m7{}, m8{}, m9{}, m10{}, m11{}, m12{}, m13{}, m14{}, m15{}, m16{}, m17{}, m18{}, m19{}, m20{}, m21{}, m22{}, m23{}, m24{}, m25{}, m26{}, m27{}, m28{}, m29{}, m30{}, m31{}, m32{}, m33{}, m34{}, m35{}, m36{}, m37{}, m38{}, m39{}, m40{}, m41{}, m42{}, m43{}, m44{}, m45{}, m46{}, m47{}, m48{}, m49{}, m50{}, m51{}, m52{}, m53{}, m54{}, m55{}, m56{}, m57{}, m58{}, m59{}, m60{}, m61{}, m62{}, m63{};
-
-    NLOHMANN_DEFINE_TYPE_INTRUSIVE(max_members, m1, m2, m3, m4, m5, m6, m7, m8, m9, m10, m11, m12, m13, m14, m15, m16, m17, m18, m19, m20, m21, m22, m23, m24, m25, m26, m27, m28, m29, m30, m31, m32, m33, m34, m35, m36, m37, m38, m39, m40, m41, m42, m43, m44, m45, m46, m47, m48, m49, m50, m51, m52, m53, m54, m55, m56, m57, m58, m59, m60, m61, m62, m63)
-};
-
-class max_members_base
-{
-  public:
-    int base_value = 0;
-
-    NLOHMANN_DEFINE_TYPE_INTRUSIVE(max_members_base, base_value)
-};
-
-class max_members_derived : public max_members_base
-{
-  public:
-    int m1{}, m2{}, m3{}, m4{}, m5{}, m6{}, m7{}, m8{}, m9{}, m10{}, m11{}, m12{}, m13{}, m14{}, m15{}, m16{}, m17{}, m18{}, m19{}, m20{}, m21{}, m22{}, m23{}, m24{}, m25{}, m26{}, m27{}, m28{}, m29{}, m30{}, m31{}, m32{}, m33{}, m34{}, m35{}, m36{}, m37{}, m38{}, m39{}, m40{}, m41{}, m42{}, m43{}, m44{}, m45{}, m46{}, m47{}, m48{}, m49{}, m50{}, m51{}, m52{}, m53{}, m54{}, m55{}, m56{}, m57{}, m58{}, m59{}, m60{}, m61{}, m62{}, m63{};
-
-    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(max_members_derived, max_members_base, m1, m2, m3, m4, m5, m6, m7, m8, m9, m10, m11, m12, m13, m14, m15, m16, m17, m18, m19, m20, m21, m22, m23, m24, m25, m26, m27, m28, m29, m30, m31, m32, m33, m34, m35, m36, m37, m38, m39, m40, m41, m42, m43, m44, m45, m46, m47, m48, m49, m50, m51, m52, m53, m54, m55, m56, m57, m58, m59, m60, m61, m62, m63)
-};
-
-
 } // namespace persons
 
 TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", Pair, // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
@@ -1339,141 +1191,3 @@ TEST_CASE_TEMPLATE("Serialization of non-default-constructible classes via NLOHM
         }
     }
 }
-
-// Regression tests for issue #4041: NLOHMANN_DEFINE_TYPE_* and
-// NLOHMANN_DEFINE_DERIVED_TYPE_* macros must compile and produce valid
-// (empty, or base-only for the derived case) JSON objects when no member
-// arguments are given, on every supported C++ standard.
-TEST_CASE_TEMPLATE("Serialization/deserialization of zero-member types via NLOHMANN_DEFINE_TYPE_* (issue #4041)", Json, // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
-                   nlohmann::json, nlohmann::ordered_json)
-{
-    constexpr bool is_ordered = std::is_same<Json, nlohmann::ordered_json>::value;
-    const char* const derived_dump = is_ordered
-                                     ? R"({"age":1,"name":"Erik","metadata":null})"
-                                     : R"({"age":1,"metadata":null,"name":"Erik"})";
-
-    SECTION("NLOHMANN_DEFINE_TYPE_INTRUSIVE with zero members")
-    {
-        persons::empty_intrusive obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-        CHECK(j.template get<persons::empty_intrusive>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT with zero members")
-    {
-        persons::empty_intrusive_with_default obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-        CHECK(j.template get<persons::empty_intrusive_with_default>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE with zero members")
-    {
-        const persons::empty_intrusive_only_serialize obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-    }
-
-    SECTION("NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE with zero members")
-    {
-        persons::empty_non_intrusive obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-        CHECK(j.template get<persons::empty_non_intrusive>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT with zero members")
-    {
-        persons::empty_non_intrusive_with_default obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-        CHECK(j.template get<persons::empty_non_intrusive_with_default>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE with zero members")
-    {
-        const persons::empty_non_intrusive_only_serialize obj{};
-        Json j = obj;
-        CHECK(j.dump() == "{}");
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE with zero own members")
-    {
-        persons::empty_derived_intrusive obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-        CHECK(j.template get<persons::empty_derived_intrusive>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT with zero own members")
-    {
-        persons::empty_derived_intrusive_with_default obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-        CHECK(j.template get<persons::empty_derived_intrusive_with_default>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_ONLY_SERIALIZE with zero own members")
-    {
-        const persons::empty_derived_intrusive_only_serialize obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE with zero own members")
-    {
-        persons::empty_derived_non_intrusive obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-        CHECK(j.template get<persons::empty_derived_non_intrusive>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT with zero own members")
-    {
-        persons::empty_derived_non_intrusive_with_default obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-        CHECK(j.template get<persons::empty_derived_non_intrusive_with_default>() == obj);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE with zero own members")
-    {
-        const persons::empty_derived_non_intrusive_only_serialize obj{"Erik", 1, nullptr};
-        Json j = obj;
-        CHECK(j.dump() == derived_dump);
-    }
-}
-
-// Regression test for the argument-count dispatch added for issue #4041: the
-// documented maximum of 63 members must keep working, including for the
-// derived-type macros whose Type,BaseType prefix consumes two dispatch slots.
-TEST_CASE_TEMPLATE("Serialization/deserialization of maximum-member-count types via NLOHMANN_DEFINE_TYPE_*", Json, // NOLINT(readability-math-missing-parentheses, bugprone-throwing-static-initialization)
-                   nlohmann::json, nlohmann::ordered_json)
-{
-    SECTION("NLOHMANN_DEFINE_TYPE_INTRUSIVE with 63 members")
-    {
-        persons::max_members obj{};
-        obj.m1 = 1;
-        obj.m63 = 63;
-        Json j = obj;
-        CHECK(j.size() == 63);
-        const auto obj2 = j.template get<persons::max_members>();
-        CHECK(obj2.m1 == 1);
-        CHECK(obj2.m63 == 63);
-    }
-
-    SECTION("NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE with 63 own members")
-    {
-        persons::max_members_derived obj{};
-        obj.base_value = 7;
-        obj.m1 = 1;
-        obj.m63 = 63;
-        Json j = obj;
-        CHECK(j.size() == 64);
-        const auto obj2 = j.template get<persons::max_members_derived>();
-        CHECK(obj2.base_value == 7);
-        CHECK(obj2.m1 == 1);
-        CHECK(obj2.m63 == 63);
-    }
-}

tests/src/unit-user_defined_input.cpp

@@ -6,6 +6,13 @@
 // SPDX-FileCopyrightText: 2013-2026 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 <nlohmann/json.hpp>
@@ -13,6 +20,10 @@ using nlohmann::json;
 
 #include <list>
 
+#if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
+    #include <iterator>
+#endif
+
 namespace
 {
 TEST_CASE("Use arbitrary stdlib container")
@@ -201,4 +212,22 @@ TEST_CASE("Parse with heterogeneous iterator and sentinel types")
     CHECK(j2.at(0) == 1);
 }
 
+#if defined(__cpp_lib_concepts) && defined(JSON_HAS_CPP_20)
+// JSON_HAS_CPP_20 (do not remove; see note at top of file)
+TEST_CASE("Parse with std::counted_iterator and std::default_sentinel_t")
+{
+    using iterator_type = std::string::const_iterator;
+    const std::string json_str = R"({"key":"value","array":[1,2,3]})";
+    const auto len = static_cast<std::iter_difference_t<iterator_type>>(json_str.size());
+
+    const std::counted_iterator<iterator_type> first(json_str.begin(), len);
+    const json j = json::parse(first, std::default_sentinel);
+    CHECK(j["key"] == "value");
+    CHECK(j["array"].size() == 3);
+
+    const std::counted_iterator<iterator_type> first2(json_str.begin(), len);
+    CHECK(json::accept(first2, std::default_sentinel));
+}
+#endif
+
 } // namespace

tests/src/unit-wstring.cpp

@@ -53,6 +53,27 @@ TEST_CASE("wide strings")
             std::wstring const w = L"\"\xDBFF";
             json _;
             CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
+
+            // the exact message depends on the width of wchar_t: a 16-bit
+            // wchar_t passes the lone surrogate to the UTF-8 decoder unchanged
+            // (rejected as a single ill-formed byte at column 2), while a
+            // 32-bit wchar_t first encodes it as an ill-formed three-byte
+            // sequence (rejected one byte later, at column 3)
+            const char* const error_low_surrogate = sizeof(wchar_t) == 2
+                                                    ? "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'"
+                                                    : "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"\xED\xB0'";
+            const char* const error_high_surrogate = sizeof(wchar_t) == 2
+                ? "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'"
+                : "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"\xED\xA0'";
+
+            // a lone low surrogate cannot start a pair
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xDC00), L'"'}), error_low_surrogate, json::parse_error&);
+            // a high surrogate followed by a non-low-surrogate unit is invalid
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xD800), L'a', L'"'}), error_high_surrogate, json::parse_error&);
+            // a lone low surrogate must not swallow the following unit: pairing
+            // it with any second unit would produce valid UTF-8, so the error
+            // has to report an ill-formed byte at the surrogate's own position
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::wstring{L'"', static_cast<wchar_t>(0xDC00), L'a', L'"'}), error_low_surrogate, json::parse_error&);
         }
     }
 
@@ -68,11 +89,22 @@ TEST_CASE("wide strings")
 
     SECTION("invalid std::u16string")
     {
-        if (wstring_is_utf16())
+        if (u16string_is_utf16())
         {
             std::u16string const w = u"\"\xDBFF";
             json _;
             CHECK_THROWS_AS(_ = json::parse(w), json::parse_error&);
+
+            // a lone low surrogate cannot start a pair
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xDC00, u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
+            // a high surrogate followed by a non-low-surrogate unit is invalid
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xD800, u'a', u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
+            // a lone low surrogate must not swallow the following unit: pairing
+            // it with any second unit would produce valid UTF-8, so the error
+            // has to report an ill-formed byte at the surrogate's own position
+            CHECK_THROWS_WITH_AS(_ = json::parse(std::u16string{u'"', 0xDC00, u'a', u'"'}), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"<U+0000>'", json::parse_error&);
+            // a valid surrogate pair is still decoded (U+1F600)
+            CHECK(json::parse(std::u16string{u'"', 0xD83D, 0xDE00, u'"'}).get<std::string>() == "\xF0\x9F\x98\x80");
         }
     }