Add JSON_DELETE_DEPRECATED_FUNCTIONS to delete the deprecated functions

Defining JSON_DELETE_DEPRECATED_FUNCTIONS to 1 (or the CMake option JSON_DeleteDeprecatedFunctions) declares every deprecated function as deleted instead of deprecated, so that code that is not ready for 4.0.0 no longer compiles. A deleted function still takes part in overload resolution, so from_*(ptr, len) cannot silently bind len to the strict parameter of from_*(InputType&&, bool); the roadmap now plans to keep these overloads deleted in 4.0.0 instead of removing them. The legacy discarded-value comparison is left to its own macro. Also update the 4.0 roadmap: add JSON_DISABLE_TUPLE_REFERENCE_CONVERSION and JSON_DELETE_DEPRECATED_FUNCTIONS to the macro table, add the from_bjdata/from_bon8 (ptr, len) overloads to the deprecated functions, document the macro in the migration guide, and fix the docs style check findings (example titles, missing docset entry for JSON_STRICT_BINARY_UTF8). Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-04 13:40:33 +00:00 · 2026-10-04 12:54:07 +02:00
31 changed files with 833 additions and 18 deletions
@@ -107,7 +107,7 @@ jobs:
    container: ubuntu:24.04
    strategy:
      matrix:
-        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_disabletuplereferenceconversion, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_no_thread_local]
+        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_disabletuplereferenceconversion, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_delete_deprecated_functions, ci_test_no_thread_local]
    steps:
      - name: Install build-essential
        run: apt-get update ; apt-get install -y build-essential unzip wget git
@@ -62,6 +62,7 @@ option(JSON_MultipleHeaders                "Use non-amalgamated version of the l
 option(JSON_SystemInclude                  "Include as system headers (skip for clang-tidy)." OFF)
 option(JSON_StrictNulHandling              "Build with strict NUL-byte handling enabled." OFF)
 option(JSON_StrictBinaryUTF8               "Build with UTF-8 checks in the CBOR, UBJSON, BJData, and BSON writers enabled." OFF)
+option(JSON_DeleteDeprecatedFunctions      "Delete the deprecated functions instead of only deprecating them." OFF)

 if (JSON_CI)
    include(ci)
@@ -123,6 +124,10 @@ if (JSON_StrictBinaryUTF8)
    message(STATUS "Strict UTF-8 checks in binary writers enabled (JSON_STRICT_BINARY_UTF8=1)")
 endif()

+if (JSON_DeleteDeprecatedFunctions)
+    message(STATUS "Deprecated functions are deleted (JSON_DELETE_DEPRECATED_FUNCTIONS=1)")
+endif()
+
 if (JSON_Diagnostic_Positions)
    message(STATUS "Diagnostic positions enabled (JSON_DIAGNOSTIC_POSITIONS=1)")
 endif()
@@ -159,6 +164,7 @@ target_compile_definitions(
    $<$<BOOL:${JSON_LegacyDiscardedValueComparison}>:JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1>
    $<$<BOOL:${JSON_StrictNulHandling}>:JSON_STRICT_NUL_HANDLING=1>
    $<$<BOOL:${JSON_StrictBinaryUTF8}>:JSON_STRICT_BINARY_UTF8=1>
+    $<$<BOOL:${JSON_DeleteDeprecatedFunctions}>:JSON_DELETE_DEPRECATED_FUNCTIONS=1>
 )

 target_include_directories(
@@ -249,6 +249,20 @@ add_custom_target(ci_test_strict_nul_handling
    COMMENT "Compile and test with strict NUL-byte handling enabled"
 )

+###############################################################################
+# Delete the deprecated functions.
+###############################################################################
+
+add_custom_target(ci_test_delete_deprecated_functions
+    COMMAND ${CMAKE_COMMAND}
+    -DCMAKE_BUILD_TYPE=Debug -GNinja
+    -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_DeleteDeprecatedFunctions=ON
+    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_delete_deprecated_functions
+    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_delete_deprecated_functions
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_delete_deprecated_functions && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
+    COMMENT "Compile and test with the deprecated functions deleted"
+)
+
 ###############################################################################
 # Disable global UDLs.
 ###############################################################################
@@ -701,7 +715,7 @@ ci_get_cmake(4.0.0  CMAKE_4_0_0_BINARY)
 # the tests require CMake 3.13 or later, so they are excluded for CMake 3.5.0
 set(JSON_CMAKE_FLAGS_3_5_0 JSON_Diagnostics JSON_Diagnostic_Positions JSON_GlobalUDLs JSON_ImplicitConversions JSON_DisableEnumSerialization
    JSON_LegacyDiscardedValueComparison JSON_Install JSON_MultipleHeaders JSON_SystemInclude JSON_Valgrind
-    JSON_StrictNulHandling JSON_StrictBinaryUTF8)
+    JSON_StrictNulHandling JSON_StrictBinaryUTF8 JSON_DeleteDeprecatedFunctions)
 set(JSON_CMAKE_FLAGS_3_31_6 JSON_BuildTests ${JSON_CMAKE_FLAGS_3_5_0})
 set(JSON_CMAKE_FLAGS_4_0_0 JSON_BuildTests ${JSON_CMAKE_FLAGS_3_5_0})

@@ -219,6 +219,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('Supported Macros', 'Guide', '
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_ASSERT', 'Macro', 'api/macros/json_assert/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_BRACE_INIT_COPY_SEMANTICS', 'Macro', 'api/macros/json_brace_init_copy_semantics/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_CATCH_USER', 'Macro', 'api/macros/json_throw_user/index.html');
+INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DELETE_DEPRECATED_FUNCTIONS', 'Macro', 'api/macros/json_delete_deprecated_functions/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DIAGNOSTICS', 'Macro', 'api/macros/json_diagnostics/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DIAGNOSTIC_POSITIONS', 'Macro', 'api/macros/json_diagnostic_positions/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DISABLE_ENUM_SERIALIZATION', 'Macro', 'api/macros/json_disable_enum_serialization/index.html');
@@ -242,6 +243,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('JSON_NO_THREAD_LOCAL', 'Macro
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_PRECISE_STREAM_POSITION', 'Macro', 'api/macros/json_precise_stream_position/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_SKIP_LIBRARY_VERSION_CHECK', 'Macro', 'api/macros/json_skip_library_version_check/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_SKIP_UNSUPPORTED_COMPILER_CHECK', 'Macro', 'api/macros/json_skip_unsupported_compiler_check/index.html');
+INSERT INTO searchIndex(name, type, path) VALUES ('JSON_STRICT_BINARY_UTF8', 'Macro', 'api/macros/json_strict_binary_utf8/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_STRICT_NUL_HANDLING', 'Macro', 'api/macros/json_strict_nul_handling/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_THROW_USER', 'Macro', 'api/macros/json_throw_user/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_TRY_USER', 'Macro', 'api/macros/json_throw_user/index.html');
@@ -59,6 +59,11 @@ header. See also the [macro overview page](../../features/macros.md).
 - [**JSON_DISABLE_TUPLE_REFERENCE_CONVERSION**](json_disable_tuple_reference_conversion.md) - switch off conversion from a one-element tuple of a JSON reference
 - [**JSON_USE_IMPLICIT_CONVERSIONS**](json_use_implicit_conversions.md) - control implicit conversions

+## Deprecated functions
+
+- [**JSON_DELETE_DEPRECATED_FUNCTIONS**](json_delete_deprecated_functions.md) - opt in to deleting the deprecated
+  functions ahead of their removal in version 4.0.0
+
 ## Comparison behavior

 - [**JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON**](json_use_legacy_discarded_value_comparison.md) -
@@ -0,0 +1,96 @@
+# JSON_DELETE_DEPRECATED_FUNCTIONS
+
+```cpp
+#define JSON_DELETE_DEPRECATED_FUNCTIONS /* value */
+```
+
+When defined to `1`, all [deprecated functions](../../community/roadmap.md#removal-of-deprecated-functions) of the
+library are declared as deleted (`= delete`) instead of only being marked as deprecated. Code that still calls one of
+them no longer compiles. This way, you can find all calls that need to be replaced before version 4.0.0 removes these
+functions; the [migration guide](../../integration/migration_guide.md#replace-deprecated-functions) describes how.
+
+A deleted function, unlike a removed one, still takes part in overload resolution. A call that would select it
+therefore fails to compile instead of silently selecting another overload. This matters for the deprecated
+`from_*(ptr, len)` overloads of [`from_cbor`](../basic_json/from_cbor.md), [`from_msgpack`](../basic_json/from_msgpack.md),
+[`from_ubjson`](../basic_json/from_ubjson.md), [`from_bjdata`](../basic_json/from_bjdata.md),
+[`from_bon8`](../basic_json/from_bon8.md), and [`from_bson`](../basic_json/from_bson.md): without them, a call like
+`from_cbor(ptr, len)` would compile, read `ptr` as a NUL-terminated string, and convert `len` to the `strict` parameter.
+
+The macro does not affect the deprecated legacy comparison of discarded values, which is controlled by
+[`JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON`](json_use_legacy_discarded_value_comparison.md).
+
+## Default definition
+
+The default value is `0` (disabled, the deprecated functions can still be called, and the compiler warns about it).
+
+```cpp
+#define JSON_DELETE_DEPRECATED_FUNCTIONS 0
+```
+
+## Notes
+
+!!! info "CMake option"
+
+    The macro can also be set with the CMake option
+    [`JSON_DeleteDeprecatedFunctions`](../../integration/cmake.md#json_deletedeprecatedfunctions) (`OFF` by default).
+
+!!! warning "Opt-in only"
+
+    This macro must be defined **before** including `<nlohmann/json.hpp>`. Defining it after the include has no
+    effect. Define it for the whole project to avoid different declarations of the same class in different
+    translation units.
+
+!!! note "ABI compatibility"
+
+    The macro only turns calls that compile into calls that do not; it does not change the layout or the behavior of
+    any type. Its value is therefore not encoded in the [namespace](../../features/namespace.md).
+
+## Examples
+
+??? example "Example: default behavior (macro not defined)"
+
+    Without the macro, the deprecated overload is called, and the compiler warns about it:
+
+    ```cpp
+    #include <nlohmann/json.hpp>
+
+    using json = nlohmann::json;
+
+    int main()
+    {
+        const std::vector<std::uint8_t> v = {0x82, 0x01, 0x02};
+        auto j = json::from_cbor(v.data(), v.size());
+        // warning: 'from_cbor' is deprecated: Since 3.8.0; use from_cbor(ptr, ptr + len)
+    }
+    ```
+
+??? example "Example: deleted deprecated functions (macro defined to 1)"
+
+    With the macro, the call does not compile:
+
+    ```cpp
+    #define JSON_DELETE_DEPRECATED_FUNCTIONS 1
+    #include <nlohmann/json.hpp>
+
+    using json = nlohmann::json;
+
+    int main()
+    {
+        const std::vector<std::uint8_t> v = {0x82, 0x01, 0x02};
+        auto j = json::from_cbor(v.data(), v.size());
+        // error: call to deleted function 'from_cbor'
+    }
+    ```
+
+## See also
+
+- [Roadmap: removal of deprecated functions](../../community/roadmap.md#removal-of-deprecated-functions) - the
+  deprecated functions and the version they were deprecated in
+- [Migration guide: replace deprecated functions](../../integration/migration_guide.md#replace-deprecated-functions) -
+  how to replace each deprecated function
+
+## Version history
+
+- Added in version 3.13.0.
+- Planned to be removed in version 4.0.0, which removes the deprecated functions. The deprecated `from_*(ptr, len)`
+  overloads stay deleted in version 4.0.0.
@@ -112,3 +112,4 @@ The default value is `0` (disabled — existing behavior is preserved).
 ## Version history

 - Added in version 3.13.0.
+- Planned to become the default (with the macro removed) in version 4.0.0.
@@ -54,7 +54,7 @@ The default value is `0` (disabled, the behavior of version 3.12.0 and earlier i

 ## Examples

-??? example "Default behavior (macro not defined)"
+??? example "Example: default behavior (macro not defined)"

    Without the macro, the bytes are written unchanged:

@@ -70,7 +70,7 @@ The default value is `0` (disabled, the behavior of version 3.12.0 and earlier i
    }
    ```

-??? example "Opt-in check (macro defined to 1)"
+??? example "Example: opt-in check (macro defined to 1)"

    With the macro, ill-formed UTF-8 is rejected:

@@ -44,7 +44,7 @@ By default, implicit conversions are enabled.

 ## Examples

-??? example
+??? example "Example: implicit and explicit conversions"

    This is an example for an implicit conversion:

@@ -61,7 +61,7 @@ By default, implicit conversions are enabled.
    auto s = j.get<std::string>();
    ```

-??? example "Conversion between `basic_json` specializations"
+??? example "Example: conversion between `basic_json` specializations"

    A `basic_json` specialization with a different string type is also no longer converted implicitly when
    `JSON_USE_IMPLICIT_CONVERSIONS` is defined to `0`:
@@ -64,6 +64,8 @@ The following macros guard changes that are planned to become the default in ver
 | [`JSON_PRECISE_STREAM_POSITION`](../api/macros/json_precise_stream_position.md)                                  | `0`         | `1`: reading from a stream does not consume the character after a number                                                      | –                                                                                                                  | 3.13.0 |
 | [`JSON_STRICT_NUL_HANDLING`](../api/macros/json_strict_nul_handling.md)                                          | `0`         | `1`: a NUL byte in the input is a parse error instead of the end of input                                                     | [`JSON_StrictNulHandling`](../integration/cmake.md#json_strictnulhandling)                                         | 3.13.0 |
 | [`JSON_STRICT_BINARY_UTF8`](../api/macros/json_strict_binary_utf8.md)                                            | `0`         | `1`: `to_cbor`, `to_ubjson`, `to_bjdata`, and `to_bson` throw for strings that are not valid UTF-8 by default                 | [`JSON_StrictBinaryUTF8`](../integration/cmake.md#json_strictbinaryutf8)                                           | 3.13.0 |
+| [`JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../api/macros/json_disable_tuple_reference_conversion.md)            | `0`         | `1`: a `basic_json` value can no longer be created from a one-element tuple of a reference to it, such as `std::forward_as_tuple(j)`| [`JSON_DisableTupleReferenceConversion`](../integration/cmake.md#json_disabletuplereferenceconversion)             | 3.13.0 |
+| [`JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md)                          | `0`         | removed: the deprecated functions are removed (see below); the `from_*(ptr, len)` overloads stay deleted                      | [`JSON_DeleteDeprecatedFunctions`](../integration/cmake.md#json_deletedeprecatedfunctions)                         | 3.13.0 |

 For example, the following makes a 3.x release behave like version 4.0 with respect to these changes:

@@ -75,6 +77,8 @@ For example, the following makes a 3.x release behave like version 4.0 with resp
 #define JSON_PRECISE_STREAM_POSITION 1
 #define JSON_STRICT_NUL_HANDLING 1
 #define JSON_STRICT_BINARY_UTF8 1
+#define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 1
+#define JSON_DELETE_DEPRECATED_FUNCTIONS 1
 #include <nlohmann/json.hpp>
 ```

@@ -84,8 +88,13 @@ way to achieve this.
 ### Removal of deprecated functions

 Version 4.0 will remove all deprecated functions. Compiling with deprecation warnings enabled shows which of them your
-code still uses. The [migration guide](../integration/migration_guide.md#replace-deprecated-functions) shows how to
-replace each of them.
+code still uses. Defining [`JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md) to
+`1` turns these warnings into errors, as the deprecated functions are then deleted. The
+[migration guide](../integration/migration_guide.md#replace-deprecated-functions) shows how to replace each of them.
+
+The `from_*` overloads taking a pointer and a length are not removed in version 4.0, but stay deleted. Without them, a
+call like `from_cbor(ptr, len)` would still compile: it would read `ptr` as a NUL-terminated string and convert `len`
+to the `strict` parameter.

 | Deprecated                                                                                                                                                                                                                                         | Since  | Migration                                                                        |
 |----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------------------------------------------------------------|
@@ -97,6 +106,7 @@ replace each of them.
 | [`json_pointer::operator string_t`](../api/json_pointer/operator_string_t.md)                                                                                                                                                                      | 3.11.0 | [JSON Pointers](../integration/migration_guide.md#json-pointers)                 |
 | [`json_pointer`](../api/json_pointer/index.md) with a `basic_json` type as template argument, and the overloads of `value`, `contains`, `operator[]`, and `at` accepting such a pointer                                                           | 3.11.0 | [JSON Pointers](../integration/migration_guide.md#json-pointers)                 |
 | Comparing a [`json_pointer`](../api/json_pointer/index.md) with a string via [`operator==`](../api/json_pointer/operator_eq.md) or [`operator!=`](../api/json_pointer/operator_ne.md)                                                              | 3.11.2 | [JSON Pointers](../integration/migration_guide.md#json-pointers)                 |
+| [`from_bjdata`](../api/basic_json/from_bjdata.md) and [`from_bon8`](../api/basic_json/from_bon8.md) with `(ptr, len)`                                                                                                                              | 3.13.0 | [Parsing](../integration/migration_guide.md#parsing)                             |

 The deprecated legacy comparison of discarded values is controlled by a macro and therefore listed in the table above.

@@ -23,6 +23,17 @@ This macro overrides [`#!cpp catch`](https://en.cppreference.com/w/cpp/language/

 See [full documentation of `JSON_CATCH_USER(exception)`](../api/macros/json_throw_user.md).

+## `JSON_DELETE_DEPRECATED_FUNCTIONS`
+
+When defined to `1`, all deprecated functions are declared as deleted instead of only being marked as deprecated, so
+code that still calls them no longer compiles. This way, you can find all calls that need to be replaced before version
+4.0.0 removes these functions.
+
+The macro can also be set with the CMake option
+[`JSON_DeleteDeprecatedFunctions`](../integration/cmake.md#json_deletedeprecatedfunctions) (`OFF` by default).
+
+See [full documentation of `JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md).
+
 ## `JSON_DIAGNOSTICS`

 This macro enables extended diagnostics for exception messages. Possible values are `1` to enable or `0` to disable
@@ -86,7 +97,8 @@ See [full documentation of `JSON_DISABLE_ENUM_SERIALIZATION`](../api/macros/json
 ## `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`

 When defined to `1`, a JSON value can no longer be created from a one-element `std::tuple` holding a reference to a JSON
-value, such as the result of `std::forward_as_tuple(j)`. This lets `std::tuple` convert such tuples element-wise.
+value, such as the result of `std::forward_as_tuple(j)`. This lets `std::tuple` convert such tuples element-wise. This
+is planned to become the default in version 4.0.0.

 See [full documentation of `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../api/macros/json_disable_tuple_reference_conversion.md).

@@ -132,6 +132,12 @@ Build the unit tests when [`BUILD_TESTING`](https://cmake.org/cmake/help/latest/

 Enable CI build targets. The exact targets are used during the several CI steps and are subject to change without notice. This option is `OFF` by default.

+### `JSON_DeleteDeprecatedFunctions`
+
+Delete the deprecated functions instead of only deprecating them by defining the macro
+[`JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md). This option is `OFF` by
+default.
+
 ### `JSON_Diagnostics`

 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.
@@ -14,6 +14,13 @@ deprecations are annotated with
 [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which
 function to use instead.

+!!! tip "Find all calls of deprecated functions"
+
+    Define [`JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md) to `1` (or set the
+    CMake option [`JSON_DeleteDeprecatedFunctions`](cmake.md#json_deletedeprecatedfunctions)) to delete all deprecated
+    functions. Every remaining call then fails to compile, even if deprecation warnings are disabled, so your code is
+    ready for version 4.0.0 once it compiles with the macro.
+
 ### Parsing

 - Function `friend std::istream& operator<<(basic_json&, std::istream&)` is deprecated since 3.0.0. Please use
@@ -41,8 +48,10 @@ function to use instead.
  [`from_ubjson`](../api/basic_json/from_ubjson.md), and [`from_bson`](../api/basic_json/from_bson.md)) via initializer
  lists is deprecated since 3.8.0. Instead, pass two iterators; for instance, call `from_cbor(ptr, ptr+len)` instead of
  `from_cbor({ptr, len})`. Likewise, passing a pointer and a length as two separate arguments to `from_cbor`,
-  `from_msgpack`, `from_ubjson`, and `from_bson` is deprecated since 3.8.0; call `from_cbor(ptr, ptr+len)` instead of
-  `from_cbor(ptr, len)`.
+  `from_msgpack`, `from_ubjson`, and `from_bson` is deprecated since 3.8.0, and to
+  [`from_bjdata`](../api/basic_json/from_bjdata.md) and [`from_bon8`](../api/basic_json/from_bon8.md) since 3.13.0; call
+  `from_cbor(ptr, ptr+len)` instead of `from_cbor(ptr, len)`. These overloads will not be removed in version 4.0.0, but
+  deleted, so a call like `from_cbor(ptr, len)` cannot compile and convert `len` to the `strict` parameter.

    === "Deprecated"
  
@@ -292,6 +292,7 @@ nav:
          - 'JSON_BRACE_INIT_COPY_SEMANTICS': api/macros/json_brace_init_copy_semantics.md
          - 'JSON_CATCH_USER, JSON_THROW_USER, JSON_TRY_USER': api/macros/json_throw_user.md
          - 'JSON_DIAGNOSTICS': api/macros/json_diagnostics.md
+          - 'JSON_DELETE_DEPRECATED_FUNCTIONS': api/macros/json_delete_deprecated_functions.md
          - 'JSON_DIAGNOSTIC_POSITIONS': api/macros/json_diagnostic_positions.md
          - 'JSON_DISABLE_ENUM_SERIALIZATION': api/macros/json_disable_enum_serialization.md
          - 'JSON_DISABLE_TUPLE_REFERENCE_CONVERSION': api/macros/json_disable_tuple_reference_conversion.md
@@ -79,11 +79,15 @@ class json_pointer

    /// @brief return a string representation of the JSON pointer
    /// @sa https://json.nlohmann.me/api/json_pointer/operator_string_t/
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    operator string_t() const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, to_string())
    operator string_t() const
    {
        return to_string();
    }
+#endif

 #ifndef JSON_NO_IO
    /// @brief write string representation of the JSON pointer to stream
@@ -1016,11 +1020,15 @@ class json_pointer

    /// @brief compares JSON pointer and string for equality
    /// @sa https://json.nlohmann.me/api/json_pointer/operator_eq/
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    bool operator==(const string_t& rhs) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer))
    bool operator==(const string_t& rhs) const
    {
        return *this == json_pointer(rhs);
    }
+#endif

    /// @brief 3-way compares two JSON pointers
    template<typename RefStringTypeRhs>
@@ -1095,21 +1103,31 @@ inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,

 template<typename RefStringTypeLhs,
         typename StringType = typename json_pointer<RefStringTypeLhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
+                       const StringType& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
                       const StringType& rhs)
 {
    return lhs == json_pointer<RefStringTypeLhs>(rhs);
 }
+#endif

 template<typename RefStringTypeRhs,
         typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator==(const StringType& lhs,
+                       const json_pointer<RefStringTypeRhs>& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const StringType& lhs,
                       const json_pointer<RefStringTypeRhs>& rhs)
 {
    return json_pointer<RefStringTypeRhs>(lhs) == rhs;
 }
+#endif

 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
@@ -1120,21 +1138,31 @@ inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,

 template<typename RefStringTypeLhs,
         typename StringType = typename json_pointer<RefStringTypeLhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
+                       const StringType& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
                       const StringType& rhs)
 {
    return !(lhs == rhs);
 }
+#endif

 template<typename RefStringTypeRhs,
         typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator!=(const StringType& lhs,
+                       const json_pointer<RefStringTypeRhs>& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const StringType& lhs,
                       const json_pointer<RefStringTypeRhs>& rhs)
 {
    return !(lhs == rhs);
 }
+#endif

 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator<(const json_pointer<RefStringTypeLhs>& lhs,
@@ -888,6 +888,10 @@
    #define JSON_DISABLE_ENUM_SERIALIZATION 0
 #endif

+#ifndef JSON_DELETE_DEPRECATED_FUNCTIONS
+    #define JSON_DELETE_DEPRECATED_FUNCTIONS 0
+#endif
+
 #ifndef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
    #define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 0
 #endif
@@ -43,6 +43,7 @@
    #undef JSON_PRECISE_STREAM_POSITION
    #undef JSON_STRICT_NUL_HANDLING
    #undef JSON_STRICT_BINARY_UTF8
+    #undef JSON_DELETE_DEPRECATED_FUNCTIONS
 #endif

 #include <nlohmann/thirdparty/hedley/hedley_undef.hpp>
@@ -3470,22 +3470,30 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                   detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    ValueType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, const ValueType& default_value) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    ValueType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, const ValueType& default_value) const
    {
        return value(ptr.convert(), default_value);
    }
+#endif

    template < class ValueType, class BasicJsonType, class ReturnType = typename value_return_type<ValueType>::type,
               detail::enable_if_t <
                   detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    ReturnType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, ValueType && default_value) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    ReturnType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, ValueType && default_value) const
    {
        return value(ptr.convert(), std::forward<ValueType>(default_value));
    }
+#endif

    /// @brief access the first element
    /// @sa https://json.nlohmann.me/api/basic_json/front/
@@ -3841,11 +3849,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.contains(this);
    }
+#endif

    /// @}

@@ -3954,22 +3966,30 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @deprecated This function is deprecated since 3.1.0 and will be removed in
    ///             version 4.0.0 of the library. Please use @ref items() instead;
    ///             that is, replace `json::iterator_wrapper(j)` with `j.items()`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
    static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept
    {
        return ref.items();
    }
+#endif

    /// @brief wrapper to access iterator member functions in range-based for
    /// @sa https://json.nlohmann.me/api/basic_json/items/
    /// @deprecated This function is deprecated since 3.1.0 and will be removed in
    ///         version 4.0.0 of the library. Please use @ref items() instead;
    ///         that is, replace `json::iterator_wrapper(j)` with `j.items()`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
    static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept
    {
        return ref.items();
    }
+#endif

    /// @brief helper to access iterator member functions in range-based for
    /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -5285,11 +5305,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             version 4.0.0 of the library. Please use
    ///             operator<<(std::ostream&, const basic_json&) instead; that is,
    ///             replace calls like `j >> o;` with `o << j;`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    friend std::ostream& operator>>(const basic_json& j, std::ostream& o) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
    friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
    {
        return o << j;
    }
+#endif
 #endif  // JSON_NO_IO
    /// @}

@@ -5335,6 +5359,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json parse(detail::span_input_adapter&& i,
+                            parser_callback_t cb = nullptr,
+                            const bool allow_exceptions = true,
+                            const bool ignore_comments = false,
+                            const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, parse(ptr, ptr + len))
    static basic_json parse(detail::span_input_adapter&& i,
                            parser_callback_t cb = nullptr,
@@ -5347,6 +5378,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        p.parse(true, result);
        return result;
    }
+#endif

    /// @brief check if the input is valid JSON
    /// @sa https://json.nlohmann.me/api/basic_json/accept/
@@ -5372,6 +5404,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static bool accept(detail::span_input_adapter&& i,
+                       const bool ignore_comments = false,
+                       const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, accept(ptr, ptr + len))
    static bool accept(detail::span_input_adapter&& i,
                       const bool ignore_comments = false,
@@ -5379,6 +5416,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
    }
+#endif

    /// @brief generate SAX events
    /// @sa https://json.nlohmann.me/api/basic_json/sax_parse/
@@ -5432,6 +5470,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic ignored "-Wdocumentation-deprecated-sync"
 #endif
    template <typename SAX>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    JSON_HEDLEY_NON_NULL(2)
+    static bool sax_parse(detail::span_input_adapter&& i, SAX* sax,
+                          input_format_t format = input_format_t::json,
+                          const bool strict = true,
+                          const bool ignore_comments = false,
+                          const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, sax_parse(ptr, ptr + len, ...))
    JSON_HEDLEY_NON_NULL(2)
    static bool sax_parse(detail::span_input_adapter&& i, SAX* sax,
@@ -5447,6 +5493,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
               // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
               : detail::binary_reader<basic_json, decltype(ia), SAX>(std::move(ia), format).sax_parse(sax, strict);
    }
+#endif
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
@@ -5457,11 +5504,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             version 4.0.0 of the library. Please use
    ///             operator>>(std::istream&, basic_json&) instead; that is,
    ///             replace calls like `j << i;` with `i >> j;`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    friend std::istream& operator<<(basic_json& j, std::istream& i) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
    friend std::istream& operator<<(basic_json& j, std::istream& i)
    {
        return operator>>(i, j);
    }
+#endif

    /// @brief deserialize from stream
    /// @sa https://json.nlohmann.me/api/operator_gtgt/
@@ -5804,6 +5855,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_cbor(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
    static basic_json from_cbor(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -5812,8 +5869,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_cbor(ptr, ptr + len, strict, allow_exceptions, tag_handler);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_cbor(detail::span_input_adapter&& i,
+                                const bool strict = true,
+                                const bool allow_exceptions = true,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
    static basic_json from_cbor(detail::span_input_adapter&& i,
                                const bool strict = true,
@@ -5822,6 +5886,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::cbor, strict, allow_exceptions, error_handler_t::keep, tag_handler);
    }
+#endif

    /// @brief create a JSON value from an input in MessagePack format
    /// @sa https://json.nlohmann.me/api/basic_json/from_msgpack/
@@ -5850,6 +5915,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_msgpack(const T* ptr, std::size_t len,
+                                   const bool strict = true,
+                                   const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_msgpack(ptr, ptr + len))
    static basic_json from_msgpack(const T* ptr, std::size_t len,
                                   const bool strict = true,
@@ -5857,8 +5927,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_msgpack(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_msgpack(detail::span_input_adapter&& i,
+                                   const bool strict = true,
+                                   const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_msgpack(ptr, ptr + len))
    static basic_json from_msgpack(detail::span_input_adapter&& i,
                                   const bool strict = true,
@@ -5866,6 +5942,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::msgpack, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in UBJSON format
    /// @sa https://json.nlohmann.me/api/basic_json/from_ubjson/
@@ -5894,6 +5971,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_ubjson(const T* ptr, std::size_t len,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_ubjson(ptr, ptr + len))
    static basic_json from_ubjson(const T* ptr, std::size_t len,
                                  const bool strict = true,
@@ -5901,8 +5983,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_ubjson(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_ubjson(detail::span_input_adapter&& i,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_ubjson(ptr, ptr + len))
    static basic_json from_ubjson(detail::span_input_adapter&& i,
                                  const bool strict = true,
@@ -5910,6 +5998,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::ubjson, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BJData format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bjdata/
@@ -5938,6 +6027,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bjdata(const T* ptr, std::size_t len,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.13.0, from_bjdata(ptr, ptr + len))
    static basic_json from_bjdata(const T* ptr, std::size_t len,
                                  const bool strict = true,
@@ -5945,6 +6039,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bjdata(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BON8 format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bon8/
@@ -5971,6 +6066,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bon8(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.13.0, from_bon8(ptr, ptr + len))
    static basic_json from_bon8(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -5978,6 +6078,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bon8(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BSON format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bson/
@@ -6006,6 +6107,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bson(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_bson(ptr, ptr + len))
    static basic_json from_bson(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -6013,8 +6119,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bson(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bson(detail::span_input_adapter&& i,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_bson(ptr, ptr + len))
    static basic_json from_bson(detail::span_input_adapter&& i,
                                const bool strict = true,
@@ -6022,6 +6134,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::bson, strict, allow_exceptions);
    }
+#endif
    /// @}

    //////////////////////////
@@ -6039,11 +6152,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr)
    {
        return ptr.get_unchecked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
@@ -6053,11 +6170,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    const_reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    const_reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.get_unchecked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -6067,11 +6188,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr)
    {
        return ptr.get_checked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -6081,11 +6206,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    const_reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    const_reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.get_checked(this);
    }
+#endif

    /// @brief return flattened JSON value
    /// @sa https://json.nlohmann.me/api/basic_json/flatten/
@@ -3214,6 +3214,10 @@ JSON_HEDLEY_DIAGNOSTIC_POP
    #define JSON_DISABLE_ENUM_SERIALIZATION 0
 #endif

+#ifndef JSON_DELETE_DEPRECATED_FUNCTIONS
+    #define JSON_DELETE_DEPRECATED_FUNCTIONS 0
+#endif
+
 #ifndef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
    #define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 0
 #endif
@@ -19755,11 +19759,15 @@ class json_pointer

    /// @brief return a string representation of the JSON pointer
    /// @sa https://json.nlohmann.me/api/json_pointer/operator_string_t/
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    operator string_t() const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, to_string())
    operator string_t() const
    {
        return to_string();
    }
+#endif

 #ifndef JSON_NO_IO
    /// @brief write string representation of the JSON pointer to stream
@@ -20692,11 +20700,15 @@ class json_pointer

    /// @brief compares JSON pointer and string for equality
    /// @sa https://json.nlohmann.me/api/json_pointer/operator_eq/
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    bool operator==(const string_t& rhs) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer))
    bool operator==(const string_t& rhs) const
    {
        return *this == json_pointer(rhs);
    }
+#endif

    /// @brief 3-way compares two JSON pointers
    template<typename RefStringTypeRhs>
@@ -20771,21 +20783,31 @@ inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,

 template<typename RefStringTypeLhs,
         typename StringType = typename json_pointer<RefStringTypeLhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
+                       const StringType& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
                       const StringType& rhs)
 {
    return lhs == json_pointer<RefStringTypeLhs>(rhs);
 }
+#endif

 template<typename RefStringTypeRhs,
         typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator==(const StringType& lhs,
+                       const json_pointer<RefStringTypeRhs>& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const StringType& lhs,
                       const json_pointer<RefStringTypeRhs>& rhs)
 {
    return json_pointer<RefStringTypeRhs>(lhs) == rhs;
 }
+#endif

 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
@@ -20796,21 +20818,31 @@ inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,

 template<typename RefStringTypeLhs,
         typename StringType = typename json_pointer<RefStringTypeLhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
+                       const StringType& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
                       const StringType& rhs)
 {
    return !(lhs == rhs);
 }
+#endif

 template<typename RefStringTypeRhs,
         typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+inline bool operator!=(const StringType& lhs,
+                       const json_pointer<RefStringTypeRhs>& rhs) = delete;
+#else
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const StringType& lhs,
                       const json_pointer<RefStringTypeRhs>& rhs)
 {
    return !(lhs == rhs);
 }
+#endif

 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator<(const json_pointer<RefStringTypeLhs>& lhs,
@@ -30407,22 +30439,30 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                   detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    ValueType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, const ValueType& default_value) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    ValueType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, const ValueType& default_value) const
    {
        return value(ptr.convert(), default_value);
    }
+#endif

    template < class ValueType, class BasicJsonType, class ReturnType = typename value_return_type<ValueType>::type,
               detail::enable_if_t <
                   detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    ReturnType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, ValueType && default_value) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    ReturnType value(const ::nlohmann::json_pointer<BasicJsonType>& ptr, ValueType && default_value) const
    {
        return value(ptr.convert(), std::forward<ValueType>(default_value));
    }
+#endif

    /// @brief access the first element
    /// @sa https://json.nlohmann.me/api/basic_json/front/
@@ -30778,11 +30818,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    bool contains(const typename ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.contains(this);
    }
+#endif

    /// @}

@@ -30891,22 +30935,30 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @deprecated This function is deprecated since 3.1.0 and will be removed in
    ///             version 4.0.0 of the library. Please use @ref items() instead;
    ///             that is, replace `json::iterator_wrapper(j)` with `j.items()`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
    static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept
    {
        return ref.items();
    }
+#endif

    /// @brief wrapper to access iterator member functions in range-based for
    /// @sa https://json.nlohmann.me/api/basic_json/items/
    /// @deprecated This function is deprecated since 3.1.0 and will be removed in
    ///         version 4.0.0 of the library. Please use @ref items() instead;
    ///         that is, replace `json::iterator_wrapper(j)` with `j.items()`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
    static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept
    {
        return ref.items();
    }
+#endif

    /// @brief helper to access iterator member functions in range-based for
    /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -32222,11 +32274,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             version 4.0.0 of the library. Please use
    ///             operator<<(std::ostream&, const basic_json&) instead; that is,
    ///             replace calls like `j >> o;` with `o << j;`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    friend std::ostream& operator>>(const basic_json& j, std::ostream& o) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
    friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
    {
        return o << j;
    }
+#endif
 #endif  // JSON_NO_IO
    /// @}

@@ -32272,6 +32328,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json parse(detail::span_input_adapter&& i,
+                            parser_callback_t cb = nullptr,
+                            const bool allow_exceptions = true,
+                            const bool ignore_comments = false,
+                            const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, parse(ptr, ptr + len))
    static basic_json parse(detail::span_input_adapter&& i,
                            parser_callback_t cb = nullptr,
@@ -32284,6 +32347,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        p.parse(true, result);
        return result;
    }
+#endif

    /// @brief check if the input is valid JSON
    /// @sa https://json.nlohmann.me/api/basic_json/accept/
@@ -32309,6 +32373,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static bool accept(detail::span_input_adapter&& i,
+                       const bool ignore_comments = false,
+                       const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, accept(ptr, ptr + len))
    static bool accept(detail::span_input_adapter&& i,
                       const bool ignore_comments = false,
@@ -32316,6 +32385,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return parser(i.get(), nullptr, false, ignore_comments, ignore_trailing_commas, true).accept(true);
    }
+#endif

    /// @brief generate SAX events
    /// @sa https://json.nlohmann.me/api/basic_json/sax_parse/
@@ -32369,6 +32439,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic ignored "-Wdocumentation-deprecated-sync"
 #endif
    template <typename SAX>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    JSON_HEDLEY_NON_NULL(2)
+    static bool sax_parse(detail::span_input_adapter&& i, SAX* sax,
+                          input_format_t format = input_format_t::json,
+                          const bool strict = true,
+                          const bool ignore_comments = false,
+                          const bool ignore_trailing_commas = false) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, sax_parse(ptr, ptr + len, ...))
    JSON_HEDLEY_NON_NULL(2)
    static bool sax_parse(detail::span_input_adapter&& i, SAX* sax,
@@ -32384,6 +32462,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
               // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
               : detail::binary_reader<basic_json, decltype(ia), SAX>(std::move(ia), format).sax_parse(sax, strict);
    }
+#endif
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
@@ -32394,11 +32473,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    ///             version 4.0.0 of the library. Please use
    ///             operator>>(std::istream&, basic_json&) instead; that is,
    ///             replace calls like `j << i;` with `i >> j;`.
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    friend std::istream& operator<<(basic_json& j, std::istream& i) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
    friend std::istream& operator<<(basic_json& j, std::istream& i)
    {
        return operator>>(i, j);
    }
+#endif

    /// @brief deserialize from stream
    /// @sa https://json.nlohmann.me/api/operator_gtgt/
@@ -32741,6 +32824,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_cbor(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
    static basic_json from_cbor(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -32749,8 +32838,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_cbor(ptr, ptr + len, strict, allow_exceptions, tag_handler);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_cbor(detail::span_input_adapter&& i,
+                                const bool strict = true,
+                                const bool allow_exceptions = true,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
    static basic_json from_cbor(detail::span_input_adapter&& i,
                                const bool strict = true,
@@ -32759,6 +32855,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::cbor, strict, allow_exceptions, error_handler_t::keep, tag_handler);
    }
+#endif

    /// @brief create a JSON value from an input in MessagePack format
    /// @sa https://json.nlohmann.me/api/basic_json/from_msgpack/
@@ -32787,6 +32884,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_msgpack(const T* ptr, std::size_t len,
+                                   const bool strict = true,
+                                   const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_msgpack(ptr, ptr + len))
    static basic_json from_msgpack(const T* ptr, std::size_t len,
                                   const bool strict = true,
@@ -32794,8 +32896,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_msgpack(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_msgpack(detail::span_input_adapter&& i,
+                                   const bool strict = true,
+                                   const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_msgpack(ptr, ptr + len))
    static basic_json from_msgpack(detail::span_input_adapter&& i,
                                   const bool strict = true,
@@ -32803,6 +32911,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::msgpack, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in UBJSON format
    /// @sa https://json.nlohmann.me/api/basic_json/from_ubjson/
@@ -32831,6 +32940,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_ubjson(const T* ptr, std::size_t len,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_ubjson(ptr, ptr + len))
    static basic_json from_ubjson(const T* ptr, std::size_t len,
                                  const bool strict = true,
@@ -32838,8 +32952,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_ubjson(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_ubjson(detail::span_input_adapter&& i,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_ubjson(ptr, ptr + len))
    static basic_json from_ubjson(detail::span_input_adapter&& i,
                                  const bool strict = true,
@@ -32847,6 +32967,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::ubjson, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BJData format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bjdata/
@@ -32875,6 +32996,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bjdata(const T* ptr, std::size_t len,
+                                  const bool strict = true,
+                                  const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.13.0, from_bjdata(ptr, ptr + len))
    static basic_json from_bjdata(const T* ptr, std::size_t len,
                                  const bool strict = true,
@@ -32882,6 +33008,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bjdata(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BON8 format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bon8/
@@ -32908,6 +33035,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bon8(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.13.0, from_bon8(ptr, ptr + len))
    static basic_json from_bon8(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -32915,6 +33047,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bon8(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    /// @brief create a JSON value from an input in BSON format
    /// @sa https://json.nlohmann.me/api/basic_json/from_bson/
@@ -32943,6 +33076,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    template<typename T>
    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bson(const T* ptr, std::size_t len,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_bson(ptr, ptr + len))
    static basic_json from_bson(const T* ptr, std::size_t len,
                                const bool strict = true,
@@ -32950,8 +33088,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_bson(ptr, ptr + len, strict, allow_exceptions);
    }
+#endif

    JSON_HEDLEY_WARN_UNUSED_RESULT
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    static basic_json from_bson(detail::span_input_adapter&& i,
+                                const bool strict = true,
+                                const bool allow_exceptions = true) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_bson(ptr, ptr + len))
    static basic_json from_bson(detail::span_input_adapter&& i,
                                const bool strict = true,
@@ -32959,6 +33103,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    {
        return from_binary_impl(i.get(), input_format_t::bson, strict, allow_exceptions);
    }
+#endif
    /// @}

    //////////////////////////
@@ -32976,11 +33121,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr)
    {
        return ptr.get_unchecked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
@@ -32990,11 +33139,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    const_reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    const_reference operator[](const ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.get_unchecked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -33004,11 +33157,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr)
    {
        return ptr.get_checked(this);
    }
+#endif

    /// @brief access specified element via JSON Pointer
    /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -33018,11 +33175,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    }

    template<typename BasicJsonType, detail::enable_if_t<detail::is_basic_json<BasicJsonType>::value, int> = 0>
+#if JSON_DELETE_DEPRECATED_FUNCTIONS
+    const_reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) const = delete;
+#else
    JSON_HEDLEY_DEPRECATED_FOR(3.11.0, basic_json::json_pointer or nlohmann::json_pointer<basic_json::string_t>) // NOLINT(readability/alt_tokens)
    const_reference at(const ::nlohmann::json_pointer<BasicJsonType>& ptr) const
    {
        return ptr.get_checked(this);
    }
+#endif

    /// @brief return flattened JSON value
    /// @sa https://json.nlohmann.me/api/basic_json/flatten/
@@ -34182,6 +34343,7 @@ struct formatter<nlohmann::NLOHMANN_BASIC_JSON_TPL, char> // NOLINT(cert-dcl58-c
    #undef JSON_PRECISE_STREAM_POSITION
    #undef JSON_STRICT_NUL_HANDLING
    #undef JSON_STRICT_BINARY_UTF8
+    #undef JSON_DELETE_DEPRECATED_FUNCTIONS
 #endif

 // #include <nlohmann/thirdparty/hedley/hedley_undef.hpp>
@@ -9,6 +9,14 @@
 #include "doctest_compatibility.h"

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

@@ -4505,6 +4513,7 @@ TEST_CASE("issue #5648 - from_bjdata(ptr, len) must read len bytes, not treat pt
    }
    REQUIRE(contains_nul);

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    // before the fix, from_bjdata had no (ptr, len) overload, so this call
    // bound to from_bjdata(InputType&&, bool strict) instead: ptr was read
    // as a NUL-terminated C string (stopping at the embedded 0x00 byte), and
@@ -4517,4 +4526,5 @@ TEST_CASE("issue #5648 - from_bjdata(ptr, len) must read len bytes, not treat pt

    // len must not collapse into the strict flag either
    CHECK(json::from_bjdata(packed.data(), packed.size(), false) == j);
+#endif
 }
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

+// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
+// line *before* including json.hpp, since the library #undefs it once the header
+// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
+// tests of deprecated functions are skipped if these functions are deleted
+#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
+    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
+#endif
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 #ifdef JSON_TEST_NO_GLOBAL_UDLS
@@ -1026,6 +1034,7 @@ TEST_CASE("issue #5648 - from_bon8(ptr, len) must read len bytes, not treat ptr
    }
    REQUIRE(contains_nul);

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    // before the fix, from_bon8 had no (ptr, len) overload, so this call
    // bound to from_bon8(InputType&&, bool strict) instead: ptr was read as
    // a NUL-terminated C string (stopping at the embedded 0x00 byte), and
@@ -1038,6 +1047,7 @@ TEST_CASE("issue #5648 - from_bon8(ptr, len) must read len bytes, not treat ptr

    // len must not collapse into the strict flag either
    CHECK(json::from_bon8(packed.data(), packed.size(), false) == j);
+#endif
 }

 #ifdef JSON_HAS_CPP_17
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

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

@@ -1259,8 +1267,10 @@ TEST_CASE("BSON input that cannot be read is discarded by every overload")
    CHECK_THROWS_AS(_ = json::from_bson(input.begin(), input.end()), json::parse_error&);
    CHECK(json::from_bson(input, true, false).is_discarded());
    CHECK(json::from_bson(input.begin(), input.end(), true, false).is_discarded());
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    CHECK(json::from_bson(input.data(), input.size(), true, false).is_discarded());
    CHECK(json::from_bson({input.data(), input.size()}, true, false).is_discarded());
+#endif
 }

 TEST_CASE("BSON SAX parsing stops at every event")
@@ -1738,6 +1748,7 @@ TEST_CASE("BSON roundtrips" * doctest::skip())
                CHECK(j1 == j2);
            }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
            {
                INFO_WITH_TEMP(filename + ": uint8_t* and size");
                // parse JSON file
@@ -1752,6 +1763,7 @@ TEST_CASE("BSON roundtrips" * doctest::skip())
                // compare parsed JSON values
                CHECK(j1 == j2);
            }
+#endif

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

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

@@ -2215,8 +2223,10 @@ TEST_CASE("CBOR input that cannot be read is discarded by every overload")
    CHECK_THROWS_AS(_ = json::from_cbor(input.begin(), input.end()), json::parse_error&);
    CHECK(json::from_cbor(input, true, false).is_discarded());
    CHECK(json::from_cbor(input.begin(), input.end(), true, false).is_discarded());
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    CHECK(json::from_cbor(input.data(), input.size(), true, false).is_discarded());
    CHECK(json::from_cbor({input.data(), input.size()}, true, false).is_discarded());
+#endif

    // a string that ends early, read through iterators that are not
    // contiguous and have to be copied from one element at a time
@@ -2611,12 +2621,14 @@ TEST_CASE("CBOR roundtrips" * doctest::skip())
                CHECK(j1 == j2);
            }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
            {
                INFO_WITH_TEMP(filename + ": uint8_t* and size");
                json j2;
                CHECK_NOTHROW(j2 = json::from_cbor({packed.data(), packed.size()}));
                CHECK(j1 == j2);
            }
+#endif

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");
@@ -0,0 +1,214 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+#include "doctest_compatibility.h"
+
+// This file tests the opt-in JSON_DELETE_DEPRECATED_FUNCTIONS, so it defines the
+// macro itself instead of relying on the build configuration.
+#ifdef JSON_DELETE_DEPRECATED_FUNCTIONS
+    #undef JSON_DELETE_DEPRECATED_FUNCTIONS
+#endif
+#define JSON_DELETE_DEPRECATED_FUNCTIONS 1
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+#include <cstddef>
+#include <cstdint>
+#include <istream>
+#include <ostream>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+namespace
+{
+template<typename...>
+struct make_void
+{
+    using type = void;
+};
+
+template<typename... Ts>
+using void_t = typename make_void<Ts...>::type;
+
+// A deleted function is still found by overload resolution, but naming it in an
+// unevaluated operand is ill-formed, so each of the following traits is false
+// exactly if the expression selects a deleted (or no) function.
+#define JSON_TEST_DETECT(name, expr)                                 \
+    template<typename J, typename = void>                            \
+    struct name : std::false_type {};                                \
+    template<typename J>                                             \
+    struct name<J, void_t<decltype(expr)>> : std::true_type {}
+
+using ptr_t = const std::uint8_t*;
+
+JSON_TEST_DETECT(from_cbor_ptr_len, J::from_cbor(std::declval<ptr_t>(), std::declval<std::size_t>()));
+JSON_TEST_DETECT(from_msgpack_ptr_len, J::from_msgpack(std::declval<ptr_t>(), std::declval<std::size_t>()));
+JSON_TEST_DETECT(from_ubjson_ptr_len, J::from_ubjson(std::declval<ptr_t>(), std::declval<std::size_t>()));
+JSON_TEST_DETECT(from_bjdata_ptr_len, J::from_bjdata(std::declval<ptr_t>(), std::declval<std::size_t>()));
+JSON_TEST_DETECT(from_bon8_ptr_len, J::from_bon8(std::declval<ptr_t>(), std::declval<std::size_t>()));
+JSON_TEST_DETECT(from_bson_ptr_len, J::from_bson(std::declval<ptr_t>(), std::declval<std::size_t>()));
+
+JSON_TEST_DETECT(from_cbor_ptr_ptr, J::from_cbor(std::declval<ptr_t>(), std::declval<ptr_t>()));
+JSON_TEST_DETECT(from_msgpack_ptr_ptr, J::from_msgpack(std::declval<ptr_t>(), std::declval<ptr_t>()));
+JSON_TEST_DETECT(from_ubjson_ptr_ptr, J::from_ubjson(std::declval<ptr_t>(), std::declval<ptr_t>()));
+JSON_TEST_DETECT(from_bjdata_ptr_ptr, J::from_bjdata(std::declval<ptr_t>(), std::declval<ptr_t>()));
+JSON_TEST_DETECT(from_bon8_ptr_ptr, J::from_bon8(std::declval<ptr_t>(), std::declval<ptr_t>()));
+JSON_TEST_DETECT(from_bson_ptr_ptr, J::from_bson(std::declval<ptr_t>(), std::declval<ptr_t>()));
+
+JSON_TEST_DETECT(from_cbor_init_list, J::from_cbor({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+JSON_TEST_DETECT(from_msgpack_init_list, J::from_msgpack({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+JSON_TEST_DETECT(from_ubjson_init_list, J::from_ubjson({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+JSON_TEST_DETECT(from_bson_init_list, J::from_bson({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+
+JSON_TEST_DETECT(parse_init_list, J::parse({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+JSON_TEST_DETECT(accept_init_list, J::accept({std::declval<ptr_t>(), std::declval<std::size_t>()}));
+JSON_TEST_DETECT(sax_parse_init_list, J::sax_parse({std::declval<ptr_t>(), std::declval<std::size_t>()}, std::declval<nlohmann::json_sax<J>*>()));
+JSON_TEST_DETECT(parse_ptr_ptr, J::parse(std::declval<ptr_t>(), std::declval<ptr_t>()));
+
+JSON_TEST_DETECT(iterator_wrapper, J::iterator_wrapper(std::declval<J&>()));
+JSON_TEST_DETECT(iterator_wrapper_const, J::iterator_wrapper(std::declval<const J&>()));
+JSON_TEST_DETECT(items, std::declval<J&>().items());
+
+JSON_TEST_DETECT(json_ltlt_istream, std::declval<J&>() << std::declval<std::istream&>());
+JSON_TEST_DETECT(istream_gtgt_json, std::declval<std::istream&>() >> std::declval<J&>());
+JSON_TEST_DETECT(json_gtgt_ostream, std::declval<const J&>() >> std::declval<std::ostream&>());
+JSON_TEST_DETECT(ostream_ltlt_json, std::declval<std::ostream&>() << std::declval<const J&>());
+
+JSON_TEST_DETECT(ptr_eq_ptr, std::declval<const typename J::json_pointer&>() == std::declval<const typename J::json_pointer&>());
+JSON_TEST_DETECT(ptr_ne_ptr, std::declval<const typename J::json_pointer&>() != std::declval<const typename J::json_pointer&>());
+JSON_TEST_DETECT(ptr_eq_string, std::declval<const typename J::json_pointer&>() == std::declval<const std::string&>());
+JSON_TEST_DETECT(string_eq_ptr, std::declval<const std::string&>() == std::declval<const typename J::json_pointer&>());
+JSON_TEST_DETECT(ptr_eq_c_string, std::declval<const typename J::json_pointer&>() == std::declval<const char*>());
+JSON_TEST_DETECT(c_string_eq_ptr, std::declval<const char*>() == std::declval<const typename J::json_pointer&>());
+JSON_TEST_DETECT(ptr_ne_string, std::declval<const typename J::json_pointer&>() != std::declval<const std::string&>());
+JSON_TEST_DETECT(string_ne_ptr, std::declval<const std::string&>() != std::declval<const typename J::json_pointer&>());
+JSON_TEST_DETECT(ptr_to_string, std::declval<const typename J::json_pointer&>().to_string());
+
+// json_pointer with a basic_json type as template argument
+template<typename J>
+using legacy_ptr_t = const nlohmann::json_pointer<J>& ;
+JSON_TEST_DETECT(legacy_ptr_value, std::declval<const J&>().value(std::declval<legacy_ptr_t<J>>(), 0));
+JSON_TEST_DETECT(legacy_ptr_value_rvalue, std::declval<const J&>().value(std::declval<legacy_ptr_t<J>>(), std::string()));
+JSON_TEST_DETECT(legacy_ptr_contains, std::declval<const J&>().contains(std::declval<legacy_ptr_t<J>>()));
+JSON_TEST_DETECT(legacy_ptr_subscript, std::declval<J&>()[std::declval<legacy_ptr_t<J>>()]);
+JSON_TEST_DETECT(legacy_ptr_subscript_const, std::declval<const J&>()[std::declval<legacy_ptr_t<J>>()]);
+JSON_TEST_DETECT(legacy_ptr_at, std::declval<J&>().at(std::declval<legacy_ptr_t<J>>()));
+JSON_TEST_DETECT(legacy_ptr_at_const, std::declval<const J&>().at(std::declval<legacy_ptr_t<J>>()));
+JSON_TEST_DETECT(ptr_value, std::declval<const J&>().value(std::declval<const typename J::json_pointer&>(), 0));
+JSON_TEST_DETECT(ptr_at, std::declval<J&>().at(std::declval<const typename J::json_pointer&>()));
+
+#undef JSON_TEST_DETECT
+} // namespace
+
+TEST_CASE("JSON_DELETE_DEPRECATED_FUNCTIONS")
+{
+    SECTION("from_* with a pointer and a length")
+    {
+        // the overloads are deleted rather than removed, so the length cannot
+        // silently bind to the strict parameter of from_*(InputType&&, bool)
+        CHECK_FALSE(from_cbor_ptr_len<json>::value);
+        CHECK_FALSE(from_msgpack_ptr_len<json>::value);
+        CHECK_FALSE(from_ubjson_ptr_len<json>::value);
+        CHECK_FALSE(from_bjdata_ptr_len<json>::value);
+        CHECK_FALSE(from_bon8_ptr_len<json>::value);
+        CHECK_FALSE(from_bson_ptr_len<json>::value);
+
+        // the replacement
+        CHECK(from_cbor_ptr_ptr<json>::value);
+        CHECK(from_msgpack_ptr_ptr<json>::value);
+        CHECK(from_ubjson_ptr_ptr<json>::value);
+        CHECK(from_bjdata_ptr_ptr<json>::value);
+        CHECK(from_bon8_ptr_ptr<json>::value);
+        CHECK(from_bson_ptr_ptr<json>::value);
+    }
+
+    SECTION("initializer lists of a pointer and a length")
+    {
+        CHECK_FALSE(from_cbor_init_list<json>::value);
+        CHECK_FALSE(from_msgpack_init_list<json>::value);
+        CHECK_FALSE(from_ubjson_init_list<json>::value);
+        CHECK_FALSE(from_bson_init_list<json>::value);
+        CHECK_FALSE(parse_init_list<json>::value);
+        CHECK_FALSE(accept_init_list<json>::value);
+        CHECK_FALSE(sax_parse_init_list<json>::value);
+
+        // the replacement
+        CHECK(parse_ptr_ptr<json>::value);
+    }
+
+    SECTION("iterator_wrapper")
+    {
+        CHECK_FALSE(iterator_wrapper<json>::value);
+        CHECK_FALSE(iterator_wrapper_const<json>::value);
+
+        // the replacement
+        CHECK(items<json>::value);
+    }
+
+    SECTION("stream operators with reversed operands")
+    {
+        CHECK_FALSE(json_ltlt_istream<json>::value);
+        CHECK_FALSE(json_gtgt_ostream<json>::value);
+
+        // the replacement
+        CHECK(istream_gtgt_json<json>::value);
+        CHECK(ostream_ltlt_json<json>::value);
+    }
+
+    SECTION("json_pointer")
+    {
+        // conversion to a string
+        CHECK_FALSE(std::is_constructible<std::string, json::json_pointer>::value);
+        CHECK_FALSE(std::is_convertible<json::json_pointer, std::string>::value);
+
+        // comparison with a string
+        CHECK_FALSE(ptr_eq_string<json>::value);
+        CHECK_FALSE(string_eq_ptr<json>::value);
+        CHECK_FALSE(ptr_eq_c_string<json>::value);
+        CHECK_FALSE(c_string_eq_ptr<json>::value);
+        CHECK_FALSE(ptr_ne_string<json>::value);
+        CHECK_FALSE(string_ne_ptr<json>::value);
+
+        // the replacement
+        CHECK(ptr_to_string<json>::value);
+        CHECK(ptr_eq_ptr<json>::value);
+        CHECK(ptr_ne_ptr<json>::value);
+    }
+
+    SECTION("json_pointer with a basic_json type as template argument")
+    {
+        CHECK_FALSE(legacy_ptr_value<json>::value);
+        CHECK_FALSE(legacy_ptr_value_rvalue<json>::value);
+        CHECK_FALSE(legacy_ptr_contains<json>::value);
+        CHECK_FALSE(legacy_ptr_subscript<json>::value);
+        CHECK_FALSE(legacy_ptr_subscript_const<json>::value);
+        CHECK_FALSE(legacy_ptr_at<json>::value);
+        CHECK_FALSE(legacy_ptr_at_const<json>::value);
+
+        // the replacement
+        CHECK(ptr_value<json>::value);
+        CHECK(ptr_at<json>::value);
+    }
+
+    SECTION("the non-deprecated functions still work")
+    {
+        const json j = {{"a", {1, 2}}};
+        const auto cbor = json::to_cbor(j);
+        CHECK(json::from_cbor(cbor.data(), cbor.data() + cbor.size()) == j);
+
+        const json::json_pointer ptr("/a/1");
+        CHECK(ptr == json::json_pointer("/a/1"));
+        CHECK(ptr.to_string() == "/a/1");
+        CHECK(j[ptr] == 2);
+        CHECK(j.at(ptr) == 2);
+        CHECK(j.value(ptr, 0) == 2);
+        CHECK(j.contains(ptr));
+    }
+}
@@ -16,6 +16,14 @@
    #define JSON_TEST_STRICT_NUL_HANDLING_ENABLED 1
 #endif

+// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
+// line *before* including json.hpp, since the library #undefs it once the header
+// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
+// tests of deprecated functions are skipped if these functions are deleted
+#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
+    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
+#endif
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 #ifdef JSON_TEST_NO_GLOBAL_UDLS
@@ -291,6 +299,7 @@ TEST_CASE("deserialization")
            }));
        }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
        SECTION("operator<<")
        {
            std::stringstream ss;
@@ -299,6 +308,7 @@ TEST_CASE("deserialization")
            j << ss;
            CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
        }
+#endif

        SECTION("operator>>")
        {
@@ -423,6 +433,7 @@ TEST_CASE("deserialization")
            CHECK_THROWS_WITH_AS(_ = json::parse(nullptr), "[json.exception.parse_error.101] parse error: attempting to parse an empty input; check that your input string or stream contains the expected JSON", json::parse_error&);
        }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
        SECTION("operator<<")
        {
            std::stringstream ss;
@@ -430,6 +441,7 @@ TEST_CASE("deserialization")
            json j;
            CHECK_THROWS_WITH_AS(j << ss, "[json.exception.parse_error.101] parse error at line 1, column 29: syntax error while parsing array - unexpected end of input; expected ']'", json::parse_error&);
        }
+#endif

        SECTION("operator>>")
        {
@@ -1148,9 +1160,9 @@ TEST_CASE("deserialization")
        {
            std::istringstream s(bom + "123 456");
            json j;
-            j << s;
+            s >> j;
            CHECK(j == 123);
-            j << s;
+            s >> j;
            CHECK(j == 456);
        }
    }
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

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

@@ -19,6 +27,7 @@ DOCTEST_GCC_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING("-Wrange-loop-construct")

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
 TEST_CASE("iterator_wrapper")
 {
    SECTION("object")
@@ -715,6 +724,7 @@ TEST_CASE("iterator_wrapper")
        }
    }
 }
+#endif

 TEST_CASE("items()")
 {
@@ -9,6 +9,14 @@
 #include "doctest_compatibility.h"

 #define JSON_TESTS_PRIVATE
+// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
+// line *before* including json.hpp, since the library #undefs it once the header
+// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
+// tests of deprecated functions are skipped if these functions are deleted
+#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
+    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
+#endif
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 #ifdef JSON_TEST_NO_GLOBAL_UDLS
@@ -564,7 +572,9 @@ TEST_CASE("JSON pointers")
            std::stringstream ss;
            ss << ptr;
            CHECK(ptr.to_string() == ptr_str);
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
            CHECK(std::string(ptr) == ptr_str);
+#endif
            CHECK(ss.str() == ptr_str);
        }
    }
@@ -744,8 +754,6 @@ TEST_CASE("JSON pointers")

    SECTION("equality comparison")
    {
-        const char* ptr_cpstring = "/foo/bar";
-        const char ptr_castring[] = "/foo/bar"; // NOLINT(misc-const-correctness,hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
        std::string ptr_string{"/foo/bar"};
        auto ptr1 = json::json_pointer(ptr_string);
        auto ptr2 = json::json_pointer(ptr_string);
@@ -755,6 +763,12 @@ TEST_CASE("JSON pointers")

        CHECK(ptr1 == ptr2);

+        CHECK_FALSE(ptr1 != ptr2);
+
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
+        const char* ptr_cpstring = "/foo/bar";
+        const char ptr_castring[] = "/foo/bar"; // NOLINT(misc-const-correctness,hicpp-avoid-c-arrays,modernize-avoid-c-arrays,cppcoreguidelines-avoid-c-arrays)
+
        CHECK(ptr1 == "/foo/bar");
        CHECK(ptr1 == ptr_cpstring);
        CHECK(ptr1 == ptr_castring);
@@ -765,8 +779,6 @@ TEST_CASE("JSON pointers")
        CHECK(ptr_castring == ptr1);
        CHECK(ptr_string == ptr1);

-        CHECK_FALSE(ptr1 != ptr2);
-
        CHECK_FALSE(ptr1 != "/foo/bar");
        CHECK_FALSE(ptr1 != ptr_cpstring);
        CHECK_FALSE(ptr1 != ptr_castring);
@@ -788,6 +800,7 @@ TEST_CASE("JSON pointers")
            CHECK_THROWS_WITH_AS("/~~" == ptr1,
                                 "[json.exception.parse_error.108] parse error: escape character '~' must be followed with '0' or '1'", json::parse_error&);
        }
+#endif
    }

    SECTION("less-than comparison")
@@ -839,6 +852,7 @@ TEST_CASE("JSON pointers")
        json_ptr_j ptr_j{ptr_string};
        json_ptr_oj ptr_oj{ptr_string};

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
        CHECK(j.contains(ptr));
        CHECK(j.contains(ptr_j));
        CHECK(j.contains(ptr_oj));
@@ -851,6 +865,7 @@ TEST_CASE("JSON pointers")

        CHECK(j.value(ptr, "x") == j.value(ptr_j, "x"));
        CHECK(j.value(ptr, "x") == j.value(ptr_oj, "x"));
+#endif

        CHECK(ptr == ptr_j);
        CHECK(ptr == ptr_oj);
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

+// capture whether JSON_DELETE_DEPRECATED_FUNCTIONS was enabled on the command
+// line *before* including json.hpp, since the library #undefs it once the header
+// has been fully processed (see include/nlohmann/detail/macro_unscope.hpp); the
+// tests of deprecated functions are skipped if these functions are deleted
+#if defined(JSON_DELETE_DEPRECATED_FUNCTIONS) && (JSON_DELETE_DEPRECATED_FUNCTIONS == 1)
+    #define JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
+#endif
+
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 #ifdef JSON_TEST_NO_GLOBAL_UDLS
@@ -1795,8 +1803,10 @@ TEST_CASE("MessagePack input that cannot be read is discarded by every overload"
    CHECK_THROWS_AS(_ = json::from_msgpack(input.begin(), input.end()), json::parse_error&);
    CHECK(json::from_msgpack(input, true, false).is_discarded());
    CHECK(json::from_msgpack(input.begin(), input.end(), true, false).is_discarded());
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    CHECK(json::from_msgpack(input.data(), input.size(), true, false).is_discarded());
    CHECK(json::from_msgpack({input.data(), input.size()}, true, false).is_discarded());
+#endif
 }

 TEST_CASE("MessagePack SAX parsing stops at every event")
@@ -2099,12 +2109,14 @@ TEST_CASE("MessagePack roundtrips" * doctest::skip())
                CHECK(j1 == j2);
            }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
            {
                INFO_WITH_TEMP(filename + ": uint8_t* and size");
                json j2;
                CHECK_NOTHROW(j2 = json::from_msgpack({packed.data(), packed.size()}));
                CHECK(j1 == j2);
            }
+#endif

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");
@@ -569,7 +569,7 @@ TEST_CASE("regression tests 2")
    SECTION("issue #2067 - cannot serialize binary data to text JSON")
    {
        const std::array<unsigned char, 23> data = {{0x81, 0xA4, 0x64, 0x61, 0x74, 0x61, 0xC4, 0x0F, 0x33, 0x30, 0x30, 0x32, 0x33, 0x34, 0x30, 0x31, 0x30, 0x37, 0x30, 0x35, 0x30, 0x31, 0x30}};
-        const json j = json::from_msgpack(data.data(), data.size());
+        const json j = json::from_msgpack(data.begin(), data.end());
        // dump() is nodiscard; this only checks that dumping does not throw
        CHECK_NOTHROW(
            utils::ignore_return_value(
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

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

@@ -48,6 +56,7 @@ TEST_CASE("serialization")
        }
    }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    SECTION("operator>>")
    {
        SECTION("no given width")
@@ -79,6 +88,7 @@ TEST_CASE("serialization")
                  "[\n\t\"foo\",\n\t1,\n\t2,\n\t3,\n\tfalse,\n\t{\n\t\t\"one\": 1\n\t}\n]");
        }
    }
+#endif

    SECTION("dump")
    {
@@ -8,6 +8,14 @@

 #include "doctest_compatibility.h"

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

@@ -2212,8 +2220,10 @@ TEST_CASE("UBJSON input that cannot be read is discarded by every overload")
    CHECK_THROWS_AS(_ = json::from_ubjson(input.begin(), input.end()), json::parse_error&);
    CHECK(json::from_ubjson(input, true, false).is_discarded());
    CHECK(json::from_ubjson(input.begin(), input.end(), true, false).is_discarded());
+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
    CHECK(json::from_ubjson(input.data(), input.size(), true, false).is_discarded());
    CHECK(json::from_ubjson({input.data(), input.size()}, true, false).is_discarded());
+#endif
 }

 TEST_CASE("UBJSON SAX parsing stops at every event")
@@ -2961,12 +2971,14 @@ TEST_CASE("UBJSON roundtrips" * doctest::skip())
                CHECK(j1 == j2);
            }

+#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
            {
                INFO_WITH_TEMP(filename + ": uint8_t* and size");
                json j2;
                CHECK_NOTHROW(j2 = json::from_ubjson({packed.data(), packed.size()}));
                CHECK(j1 == j2);
            }
+#endif

            {
                INFO_WITH_TEMP(filename + ": output to output adapters");