Document and test type_error.321 for discarded binary values

Add docs for the new exception (home/exceptions.md and the Exceptions
sections of to_cbor/to_msgpack/to_ubjson/to_bjdata/to_bson) and test
coverage for a discarded value nested in an array or object, nested
deeper, and (for UBJSON/BJData) inside an optimized same-type array,
for each of CBOR, MessagePack, UBJSON, BJData, and BSON. Adjust the
three pre-existing "discarded" tests that asserted the old silent
behavior (empty/short output) to expect type_error.321 instead.

Co-authored-by: ameliabarnabyhub <312084480+ameliabarnabyhub@users.noreply.github.com>
Signed-off-by: Niels Lohmann <mail@nlohmann.me>

.github/workflows/ubuntu.yml

@@ -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_delete_deprecated_functions, 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_no_thread_local]
     steps:
       - name: Install build-essential
         run: apt-get update ; apt-get install -y build-essential unzip wget git

CMakeLists.txt

@@ -62,7 +62,6 @@ 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)
@@ -124,10 +123,6 @@ 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()
@@ -164,7 +159,6 @@ 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(

cmake/ci.cmake

@@ -249,20 +249,6 @@ 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.
 ###############################################################################
@@ -719,7 +705,7 @@ 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_DeleteDeprecatedFunctions)
+    JSON_StrictNulHandling JSON_StrictBinaryUTF8)
 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})
 

docs/docset/docSet.sql

@@ -219,7 +219,6 @@ 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');

docs/mkdocs/docs/api/basic_json/diff.md

@@ -8,7 +8,7 @@ static basic_json diff(const basic_json& source,
 Creates a [JSON Patch](http://jsonpatch.com) so that value `source` can be changed into the value `target` by calling
 [`patch`](patch.md) function.
 
-For two JSON values `source` and `target`, the following code always yields `#!cpp true`:
+For two JSON values `source` and `target`, the following code yields always `#!cpp true`:
 ```cpp
 source.patch(diff(source, target)) == target;
 ```
@@ -27,7 +27,7 @@ a JSON patch to convert the `source` to `target`
 
 ## Exception safety
 
-Strong guarantee: `source` and `target` are never modified.
+Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
 
 ## Complexity
 

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

@@ -120,12 +120,3 @@ Linear in the size of the input.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
 - Added `error_handler` parameter in version 3.13.0.
-
-!!! warning "Deprecation"
-
-    - Overload (2) replaces calls to `from_bjdata` with a pointer and a length as first two parameters, which has been
-      deprecated in version 3.13.0. This overload will be removed in version 4.0.0. Please replace all calls like
-      `#!cpp from_bjdata(ptr, len, ...);` with `#!cpp from_bjdata(ptr, ptr+len, ...);`.
-
-    You should be warned by your compiler with a `-Wdeprecated-declarations` warning if you are using a deprecated
-    function.

docs/mkdocs/docs/api/basic_json/from_bon8.md

@@ -106,12 +106,3 @@ Linear in the size of the input.
 ## Version history
 
 - Added in version 3.13.0.
-
-!!! warning "Deprecation"
-
-    - Overload (2) replaces calls to `from_bon8` with a pointer and a length as first two parameters, which has been
-      deprecated in version 3.13.0. This overload will be removed in version 4.0.0. Please replace all calls like
-      `#!cpp from_bon8(ptr, len, ...);` with `#!cpp from_bon8(ptr, ptr+len, ...);`.
-
-    You should be warned by your compiler with a `-Wdeprecated-declarations` warning if you are using a deprecated
-    function.

docs/mkdocs/docs/api/basic_json/to_bjdata.md

@@ -68,6 +68,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
   not valid UTF-8 and `error_handler` is `strict` (the default only if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
+- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
+  discarded; example: `"cannot serialize discarded value to BJData"`
 
 ## Complexity
 
@@ -119,4 +121,6 @@ Linear in the size of the JSON value `j`.
 - BJData version parameter (for draft3 binary encoding) added in version 3.12.0.
 - Added `error_handler` parameter in version 3.13.0. Its default, `keep`, writes the bytes of a string or object key
   that is not valid UTF-8 unchanged, as before; `strict` (the default if
-  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
+  [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
+- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
+  array or object was silently skipped, producing invalid BJData.

docs/mkdocs/docs/api/basic_json/to_bson.md

@@ -58,6 +58,9 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key is
   not valid UTF-8 and `error_handler` is `strict` (the default only if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
+- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if a value nested in `j` is discarded
+  (the top-level value itself is covered by `type_error.317` above, since it must be an object); example:
+  `"cannot serialize discarded value to BSON"`
 
 ## Complexity
 
@@ -110,6 +113,8 @@ pass before anything is written.
 - Throws `out_of_range.412` and `out_of_range.415` since version 3.13.0.
 - Linear in the size of `j`, and no longer limited by the call stack for deeply nested values, since version 3.13.0.
 - `out_of_range.415` is now detected before anything is written, like the other exceptions above, since version 3.13.0.
+- Throws `type_error.321` for a discarded value nested in `j` since version 3.13.0; previously, it was silently
+  skipped, producing a document whose declared size did not match what was actually written.
 - Added `error_handler` parameter in version 3.13.0. Its default, `keep`, writes the bytes of a string or object key
   that is not valid UTF-8 unchanged, as before; `strict` (the default if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316` before anything

docs/mkdocs/docs/api/basic_json/to_cbor.md

@@ -49,6 +49,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
   not valid UTF-8 and `error_handler` is `strict` (the default only if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
+- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
+  discarded; example: `"cannot serialize discarded value to CBOR"`
 
 ## Complexity
 
@@ -86,3 +88,5 @@ Linear in the size of the JSON value `j`.
 - Added `error_handler` parameter in version 3.13.0. Its default, `keep`, writes the bytes of a string or object key
   that is not valid UTF-8 unchanged, as before; `strict` (the default if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
+- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
+  array or object was silently skipped, producing invalid CBOR.

docs/mkdocs/docs/api/basic_json/to_msgpack.md

@@ -54,6 +54,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   `"subtype 70000 is too large for the MessagePack ext type (max 255)"`
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
   not valid UTF-8 and `error_handler` is `strict`
+- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
+  discarded; example: `"cannot serialize discarded value to MessagePack"`
 
 ## Complexity
 
@@ -108,3 +110,5 @@ Linear in the size of the JSON value `j`.
 - Fixed in version 3.13.0 to serialize `number_integer_t`/`number_unsigned_t` pairs of different width correctly;
   before, integers could be serialized with the wrong value if `number_integer_t` was narrower than
   `number_unsigned_t`.
+- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
+  array or object was silently skipped, producing invalid MessagePack.

docs/mkdocs/docs/api/basic_json/to_ubjson.md

@@ -61,6 +61,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
   not valid UTF-8 and `error_handler` is `strict` (the default only if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled)
+- Throws [type_error.321](../../home/exceptions.md#jsonexceptiontype_error321) if `j` or a value nested in it is
+  discarded; example: `"cannot serialize discarded value to UBJSON"`
 
 ## Complexity
 
@@ -112,3 +114,5 @@ Linear in the size of the JSON value `j`.
 - Added `error_handler` parameter in version 3.13.0. Its default, `keep`, writes the bytes of a string or object key
   that is not valid UTF-8 unchanged, as before; `strict` (the default if
   [`JSON_STRICT_BINARY_UTF8`](../macros/json_strict_binary_utf8.md) is enabled) throws `type_error.316`.
+- Throws `type_error.321` for a discarded value since version 3.13.0; previously, a discarded value nested in an
+  array or object was silently skipped, producing invalid UBJSON.

docs/mkdocs/docs/api/macros/index.md

@@ -61,11 +61,6 @@ header. See also the [macro overview page](../../features/macros.md).
 - [**JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS**](json_use_objects_for_enum_keyed_maps.md) - opt in to storing maps with enum
   keys as objects
 
-## 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) -

docs/mkdocs/docs/api/macros/json_delete_deprecated_functions.md

@@ -1,96 +0,0 @@
-# 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.

docs/mkdocs/docs/api/macros/json_disable_tuple_reference_conversion.md

@@ -112,4 +112,3 @@ 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.

docs/mkdocs/docs/api/macros/json_use_implicit_conversions.md

@@ -44,7 +44,7 @@ By default, implicit conversions are enabled.
 
 ## Examples
 
-??? example "Example: implicit and explicit conversions"
+??? example "Example: implicit conversion"
 
     This is an example for an implicit conversion:
 

docs/mkdocs/docs/community/roadmap.md

@@ -64,8 +64,6 @@ 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:
 
@@ -77,8 +75,6 @@ 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>
 ```
 
@@ -88,13 +84,8 @@ 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. Defining [`JSON_DELETE_DEPRECATED_FUNCTIONS`](../api/macros/json_delete_deprecated_functions.md) to
+code still uses. The [migration guide](../integration/migration_guide.md#replace-deprecated-functions) shows how to
-`1` turns these warnings into errors, as the deprecated functions are then deleted. The
+replace each of them.
-[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                                                                        |
 |----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------------------------------------------------------------|
@@ -106,7 +97,6 @@ to the `strict` parameter.
 | [`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.
 

docs/mkdocs/docs/features/macros.md

@@ -23,17 +23,6 @@ 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
@@ -97,8 +86,7 @@ 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. This
+value, such as the result of `std::forward_as_tuple(j)`. This lets `std::tuple` convert such tuples element-wise.
-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).
 

docs/mkdocs/docs/home/exceptions.md

@@ -804,6 +804,20 @@ does not list an enumerator and it is therefore converted like the first listed
     [json.exception.type_error.318] duplicate object key 'red'
     ```
 
+### json.exception.type_error.321
+
+A discarded value (one created by [`parse()`](../api/basic_json/parse.md) with a callback that returns `false` for the
+value, or by default-constructing a [`basic_json`](../api/basic_json/index.md) with
+[`value_t::discarded`](../api/basic_json/value_t.md)) was passed to a binary serialization function, either directly or
+nested in an array or object. There is no way to represent a discarded value in CBOR, MessagePack, UBJSON, BJData, or BSON.
+
+!!! failure "Example message"
+
+    Serializing `#!json [1, 2]` to CBOR, where the second element was discarded by a parser callback:
+    ```
+    [json.exception.type_error.321] cannot serialize discarded value to CBOR
+    ```
+
 ## Out of range
 
 This exception is thrown in case a library function is called on an input parameter that exceeds the expected range, for instance, in the case of array indices or nonexisting object keys.

docs/mkdocs/docs/integration/cmake.md

@@ -132,12 +132,6 @@ 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.

docs/mkdocs/docs/integration/migration_guide.md

@@ -14,13 +14,6 @@ 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
@@ -48,10 +41,8 @@ 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, and to
+  `from_msgpack`, `from_ubjson`, and `from_bson` is deprecated since 3.8.0; call `from_cbor(ptr, ptr+len)` instead of
-  [`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, len)`.
-  `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"
   

docs/mkdocs/mkdocs.yml

@@ -292,7 +292,6 @@ 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

include/nlohmann/detail/json_pointer.hpp

@@ -81,13 +81,9 @@ class json_pointer
     /// @sa https://json.nlohmann.me/api/json_pointer/operator_string_t/
     JSON_HEDLEY_DEPRECATED_FOR(3.11.0, to_string())
     operator string_t() const
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return to_string();
     }
-#endif
 
 #ifndef JSON_NO_IO
     /// @brief write string representation of the JSON pointer to stream
@@ -1026,13 +1022,9 @@ class json_pointer
     /// @sa https://json.nlohmann.me/api/json_pointer/operator_eq/
     JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer))
     bool operator==(const string_t& rhs) const
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return *this == json_pointer(rhs);
     }
-#endif
 
     /// @brief 3-way compares two JSON pointers
     template<typename RefStringTypeRhs>
@@ -1110,26 +1102,18 @@ template<typename RefStringTypeLhs,
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
                        const StringType& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return lhs == json_pointer<RefStringTypeLhs>(rhs);
 }
-#endif
 
 template<typename RefStringTypeRhs,
          typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const StringType& lhs,
                        const json_pointer<RefStringTypeRhs>& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return json_pointer<RefStringTypeRhs>(lhs) == rhs;
 }
-#endif
 
 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
@@ -1143,26 +1127,18 @@ template<typename RefStringTypeLhs,
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
                        const StringType& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return !(lhs == rhs);
 }
-#endif
 
 template<typename RefStringTypeRhs,
          typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const StringType& lhs,
                        const json_pointer<RefStringTypeRhs>& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return !(lhs == rhs);
 }
-#endif
 
 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator<(const json_pointer<RefStringTypeLhs>& lhs,

include/nlohmann/detail/macro_scope.hpp

@@ -888,10 +888,6 @@
     #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

include/nlohmann/detail/macro_unscope.hpp

@@ -43,7 +43,6 @@
     #undef JSON_PRECISE_STREAM_POSITION
     #undef JSON_STRICT_NUL_HANDLING
     #undef JSON_STRICT_BINARY_UTF8
-    #undef JSON_DELETE_DEPRECATED_FUNCTIONS
     #undef JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS
 #endif
 

include/nlohmann/detail/output/binary_writer.hpp

@@ -127,6 +127,7 @@ class binary_writer
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
     @throw type_error.317 if @a j is not an object
+    @throw type_error.321 if a value nested in @a j is discarded
     */
     void write_bson(const BasicJsonType& j)
     {
@@ -158,6 +159,7 @@ class binary_writer
     @param[in] j  JSON value to serialize
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_cbor(const BasicJsonType& j)
     {
@@ -322,7 +324,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, "CBOR");
         }
     }
 
@@ -382,6 +384,7 @@ class binary_writer
 
     /*!
     @param[in] j  JSON value to serialize
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_msgpack(const BasicJsonType& j)
     {
@@ -655,7 +658,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, "MessagePack");
         }
     }
 
@@ -668,6 +671,7 @@ class binary_writer
     @param[in] bjdata_version  which BJData version to use, default is draft2
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_ubjson(const BasicJsonType& j, const bool use_count,
                       const bool use_type, const bool add_prefix = true,
@@ -901,7 +905,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, use_bjdata ? "BJData" : "UBJSON");
         }
     }
 
@@ -921,6 +925,15 @@ class binary_writer
     }
 
   private:
+    /*!
+    @brief throws because @a j is discarded and cannot be serialized
+    @throw type_error.321 always
+    */
+    JSON_HEDLEY_NO_RETURN static void throw_on_discarded(const BasicJsonType& j, const char* format_name)
+    {
+        JSON_THROW(type_error::create(321, concat("cannot serialize discarded value to ", format_name), &j));
+    }
+
     //////////
     // BSON //
     //////////
@@ -1172,6 +1185,7 @@ class binary_writer
            into a byte, before anything is written
     @throw type_error.316 if @a j is a string that is not valid UTF-8, before
            anything is written
+    @throw type_error.321 if @a j is discarded
     */
     std::size_t calc_bson_value_size(const BasicJsonType& j)
     {
@@ -1198,10 +1212,12 @@ class binary_writer
             case value_t::null:
                 return 0ul;
 
+            case value_t::discarded:
+                throw_on_discarded(j, "BSON");
+
             // LCOV_EXCL_START
             case value_t::object:
             case value_t::array:
-            case value_t::discarded:
             default:
                 JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert)
                 return 0ul;
@@ -1238,10 +1254,12 @@ class binary_writer
             case value_t::null:
                 return write_bson_null(name);
 
+            case value_t::discarded:
+                throw_on_discarded(j, "BSON");
+
             // LCOV_EXCL_START
             case value_t::object:
             case value_t::array:
-            case value_t::discarded:
             default:
                 JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert)
                 return;
@@ -1308,6 +1326,8 @@ class binary_writer
            byte, before anything is written
     @throw type_error.316 if a string value or a key is not valid UTF-8,
            before anything is written
+    @throw type_error.321 if a value nested in @a document is discarded,
+           before anything is written
     */
     std::size_t calc_bson_sizes(const BasicJsonType& document, std::vector<std::size_t>& nested_sizes)
     {

include/nlohmann/json.hpp

@@ -3492,13 +3492,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                    && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return value(ptr.convert(), default_value);
     }
-#endif
 
     template < class ValueType, class BasicJsonType, class ReturnType = typename value_return_type<ValueType>::type,
                detail::enable_if_t <
@@ -3507,13 +3503,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                    && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return value(ptr.convert(), std::forward<ValueType>(default_value));
     }
-#endif
 
     /// @brief access the first element
     /// @sa https://json.nlohmann.me/api/basic_json/front/
@@ -3871,13 +3863,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.contains(this);
     }
-#endif
 
     /// @}
 
@@ -3988,13 +3976,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             that is, replace `json::iterator_wrapper(j)` with `j.items()`.
     JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
     static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return ref.items();
     }
-#endif
 
     /// @brief wrapper to access iterator member functions in range-based for
     /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -4003,13 +3987,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///         that is, replace `json::iterator_wrapper(j)` with `j.items()`.
     JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
     static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return ref.items();
     }
-#endif
 
     /// @brief helper to access iterator member functions in range-based for
     /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -5327,13 +5307,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j >> o;` with `o << j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
     friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return o << j;
     }
-#endif
 #endif  // JSON_NO_IO
     /// @}
 
@@ -5385,16 +5361,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                             const bool allow_exceptions = true,
                             const bool ignore_comments = false,
                             const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         basic_json result;
         auto p = parser(i.get(), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
         p.parse(true, result);
         return result;
     }
-#endif
 
     /// @brief check if the input is valid JSON
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
@@ -5424,13 +5396,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static bool accept(detail::span_input_adapter&& i,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -5491,9 +5459,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                           const bool strict = true,
                           const bool ignore_comments = false,
                           const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         auto ia = i.get();
         return format == input_format_t::json
@@ -5502,7 +5467,6 @@ 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
@@ -5515,13 +5479,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j << i;` with `i >> j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
     friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return operator>>(i, j);
     }
-#endif
 
     /// @brief deserialize from stream
     /// @sa https://json.nlohmann.me/api/operator_gtgt/
@@ -5869,13 +5829,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_cbor(ptr, ptr + len, strict, allow_exceptions, tag_handler);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
@@ -5883,13 +5839,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -5922,26 +5874,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_msgpack(const T* ptr, std::size_t len,
                                    const bool strict = true,
                                    const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_msgpack(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                    const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -5974,26 +5918,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_ubjson(const T* ptr, std::size_t len,
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_ubjson(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                   const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -6020,20 +5956,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bjdata, strict, allow_exceptions, error_handler);
     }
 
-    template<typename T>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
-    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,
-                                  const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
-    {
-        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/
     template<typename InputType>
@@ -6057,20 +5979,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bon8, strict, allow_exceptions);
     }
 
-    template<typename T>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
-    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,
-                                const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
-    {
-        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/
     template<typename InputType>
@@ -6102,26 +6010,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_bson(const T* ptr, std::size_t len,
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_bson(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                 const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return from_binary_impl(i.get(), input_format_t::bson, strict, allow_exceptions);
     }
-#endif
     /// @}
 
     //////////////////////////
@@ -6141,13 +6041,9 @@ 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_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)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_unchecked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
@@ -6159,13 +6055,9 @@ 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_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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_unchecked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -6177,13 +6069,9 @@ 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_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)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_checked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -6195,13 +6083,9 @@ 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_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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_checked(this);
     }
-#endif
 
     /// @brief return flattened JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/flatten/

single_include/nlohmann/json.hpp

@@ -3225,10 +3225,6 @@ 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
@@ -19934,13 +19930,9 @@ class json_pointer
     /// @sa https://json.nlohmann.me/api/json_pointer/operator_string_t/
     JSON_HEDLEY_DEPRECATED_FOR(3.11.0, to_string())
     operator string_t() const
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return to_string();
     }
-#endif
 
 #ifndef JSON_NO_IO
     /// @brief write string representation of the JSON pointer to stream
@@ -20879,13 +20871,9 @@ class json_pointer
     /// @sa https://json.nlohmann.me/api/json_pointer/operator_eq/
     JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer))
     bool operator==(const string_t& rhs) const
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return *this == json_pointer(rhs);
     }
-#endif
 
     /// @brief 3-way compares two JSON pointers
     template<typename RefStringTypeRhs>
@@ -20963,26 +20951,18 @@ template<typename RefStringTypeLhs,
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const json_pointer<RefStringTypeLhs>& lhs,
                        const StringType& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return lhs == json_pointer<RefStringTypeLhs>(rhs);
 }
-#endif
 
 template<typename RefStringTypeRhs,
          typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator==(json_pointer, json_pointer))
 inline bool operator==(const StringType& lhs,
                        const json_pointer<RefStringTypeRhs>& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return json_pointer<RefStringTypeRhs>(lhs) == rhs;
 }
-#endif
 
 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
@@ -20996,26 +20976,18 @@ template<typename RefStringTypeLhs,
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const json_pointer<RefStringTypeLhs>& lhs,
                        const StringType& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return !(lhs == rhs);
 }
-#endif
 
 template<typename RefStringTypeRhs,
          typename StringType = typename json_pointer<RefStringTypeRhs>::string_t>
 JSON_HEDLEY_DEPRECATED_FOR(3.11.2, operator!=(json_pointer, json_pointer))
 inline bool operator!=(const StringType& lhs,
                        const json_pointer<RefStringTypeRhs>& rhs)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
 {
     return !(lhs == rhs);
 }
-#endif
 
 template<typename RefStringTypeLhs, typename RefStringTypeRhs>
 inline bool operator<(const json_pointer<RefStringTypeLhs>& lhs,
@@ -21557,6 +21529,7 @@ class binary_writer
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
     @throw type_error.317 if @a j is not an object
+    @throw type_error.321 if a value nested in @a j is discarded
     */
     void write_bson(const BasicJsonType& j)
     {
@@ -21588,6 +21561,7 @@ class binary_writer
     @param[in] j  JSON value to serialize
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_cbor(const BasicJsonType& j)
     {
@@ -21752,7 +21726,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, "CBOR");
         }
     }
 
@@ -21812,6 +21786,7 @@ class binary_writer
 
     /*!
     @param[in] j  JSON value to serialize
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_msgpack(const BasicJsonType& j)
     {
@@ -22085,7 +22060,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, "MessagePack");
         }
     }
 
@@ -22098,6 +22073,7 @@ class binary_writer
     @param[in] bjdata_version  which BJData version to use, default is draft2
     @throw type_error.316 if a string value or an object key is not valid
            UTF-8
+    @throw type_error.321 if @a j or a value nested in it is discarded
     */
     void write_ubjson(const BasicJsonType& j, const bool use_count,
                       const bool use_type, const bool add_prefix = true,
@@ -22331,7 +22307,7 @@ class binary_writer
 
             case value_t::discarded:
             default:
-                break;
+                throw_on_discarded(j, use_bjdata ? "BJData" : "UBJSON");
         }
     }
 
@@ -22351,6 +22327,15 @@ class binary_writer
     }
 
   private:
+    /*!
+    @brief throws because @a j is discarded and cannot be serialized
+    @throw type_error.321 always
+    */
+    JSON_HEDLEY_NO_RETURN static void throw_on_discarded(const BasicJsonType& j, const char* format_name)
+    {
+        JSON_THROW(type_error::create(321, concat("cannot serialize discarded value to ", format_name), &j));
+    }
+
     //////////
     // BSON //
     //////////
@@ -22602,6 +22587,7 @@ class binary_writer
            into a byte, before anything is written
     @throw type_error.316 if @a j is a string that is not valid UTF-8, before
            anything is written
+    @throw type_error.321 if @a j is discarded
     */
     std::size_t calc_bson_value_size(const BasicJsonType& j)
     {
@@ -22628,10 +22614,12 @@ class binary_writer
             case value_t::null:
                 return 0ul;
 
+            case value_t::discarded:
+                throw_on_discarded(j, "BSON");
+
             // LCOV_EXCL_START
             case value_t::object:
             case value_t::array:
-            case value_t::discarded:
             default:
                 JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert)
                 return 0ul;
@@ -22668,10 +22656,12 @@ class binary_writer
             case value_t::null:
                 return write_bson_null(name);
 
+            case value_t::discarded:
+                throw_on_discarded(j, "BSON");
+
             // LCOV_EXCL_START
             case value_t::object:
             case value_t::array:
-            case value_t::discarded:
             default:
                 JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert)
                 return;
@@ -22738,6 +22728,8 @@ class binary_writer
            byte, before anything is written
     @throw type_error.316 if a string value or a key is not valid UTF-8,
            before anything is written
+    @throw type_error.321 if a value nested in @a document is discarded,
+           before anything is written
     */
     std::size_t calc_bson_sizes(const BasicJsonType& document, std::vector<std::size_t>& nested_sizes)
     {
@@ -30642,13 +30634,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                    && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return value(ptr.convert(), default_value);
     }
-#endif
 
     template < class ValueType, class BasicJsonType, class ReturnType = typename value_return_type<ValueType>::type,
                detail::enable_if_t <
@@ -30657,13 +30645,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                    && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value, int > = 0 >
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return value(ptr.convert(), std::forward<ValueType>(default_value));
     }
-#endif
 
     /// @brief access the first element
     /// @sa https://json.nlohmann.me/api/basic_json/front/
@@ -31021,13 +31005,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.contains(this);
     }
-#endif
 
     /// @}
 
@@ -31138,13 +31118,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             that is, replace `json::iterator_wrapper(j)` with `j.items()`.
     JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
     static iteration_proxy<iterator> iterator_wrapper(reference ref) noexcept
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return ref.items();
     }
-#endif
 
     /// @brief wrapper to access iterator member functions in range-based for
     /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -31153,13 +31129,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///         that is, replace `json::iterator_wrapper(j)` with `j.items()`.
     JSON_HEDLEY_DEPRECATED_FOR(3.1.0, items())
     static iteration_proxy<const_iterator> iterator_wrapper(const_reference ref) noexcept
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return ref.items();
     }
-#endif
 
     /// @brief helper to access iterator member functions in range-based for
     /// @sa https://json.nlohmann.me/api/basic_json/items/
@@ -32477,13 +32449,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j >> o;` with `o << j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
     friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return o << j;
     }
-#endif
 #endif  // JSON_NO_IO
     /// @}
 
@@ -32535,16 +32503,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                             const bool allow_exceptions = true,
                             const bool ignore_comments = false,
                             const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         basic_json result;
         auto p = parser(i.get(), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
         p.parse(true, result);
         return result;
     }
-#endif
 
     /// @brief check if the input is valid JSON
     /// @sa https://json.nlohmann.me/api/basic_json/accept/
@@ -32574,13 +32538,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static bool accept(detail::span_input_adapter&& i,
                        const bool ignore_comments = false,
                        const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -32641,9 +32601,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                           const bool strict = true,
                           const bool ignore_comments = false,
                           const bool ignore_trailing_commas = false)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         auto ia = i.get();
         return format == input_format_t::json
@@ -32652,7 +32609,6 @@ 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
@@ -32665,13 +32621,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j << i;` with `i >> j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
     friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return operator>>(i, j);
     }
-#endif
 
     /// @brief deserialize from stream
     /// @sa https://json.nlohmann.me/api/operator_gtgt/
@@ -33019,13 +32971,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_cbor(ptr, ptr + len, strict, allow_exceptions, tag_handler);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_DEPRECATED_FOR(3.8.0, from_cbor(ptr, ptr + len))
@@ -33033,13 +32981,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -33072,26 +33016,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_msgpack(const T* ptr, std::size_t len,
                                    const bool strict = true,
                                    const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_msgpack(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                    const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -33124,26 +33060,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_ubjson(const T* ptr, std::size_t len,
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_ubjson(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                   const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         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/
@@ -33170,20 +33098,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bjdata, strict, allow_exceptions, error_handler);
     }
 
-    template<typename T>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
-    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,
-                                  const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
-    {
-        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/
     template<typename InputType>
@@ -33207,20 +33121,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bon8, strict, allow_exceptions);
     }
 
-    template<typename T>
-    JSON_HEDLEY_WARN_UNUSED_RESULT
-    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,
-                                const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
-    {
-        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/
     template<typename InputType>
@@ -33252,26 +33152,18 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_bson(const T* ptr, std::size_t len,
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return from_bson(ptr, ptr + len, strict, allow_exceptions);
     }
-#endif
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     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,
                                 const bool allow_exceptions = true)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return from_binary_impl(i.get(), input_format_t::bson, strict, allow_exceptions);
     }
-#endif
     /// @}
 
     //////////////////////////
@@ -33291,13 +33183,9 @@ 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_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)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_unchecked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
@@ -33309,13 +33197,9 @@ 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_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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_unchecked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -33327,13 +33211,9 @@ 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_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)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_checked(this);
     }
-#endif
 
     /// @brief access specified element via JSON Pointer
     /// @sa https://json.nlohmann.me/api/basic_json/at/
@@ -33345,13 +33225,9 @@ 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_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
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-    = delete;
-#else
     {
         return ptr.get_checked(this);
     }
-#endif
 
     /// @brief return flattened JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/flatten/
@@ -34511,7 +34387,6 @@ 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
     #undef JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS
 #endif
 

tests/src/unit-bjdata.cpp

@@ -9,14 +9,6 @@
 #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;
 
@@ -114,10 +106,59 @@ TEST_CASE("BJData")
     {
         SECTION("discarded")
         {
-            // discarded values are not serialized
+            // a discarded value cannot be serialized to BJData
             json const j = json::value_t::discarded;
-            const auto result = json::to_bjdata(j);
+            CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
-            CHECK(result.empty());
+        }
+
+        SECTION("discarded values nested in a container")
+        {
+            json const discarded = json::value_t::discarded;
+
+            SECTION("in an array")
+            {
+                json const j = {1, discarded, 2};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/1) cannot serialize discarded value to BJData", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
+#endif
+            }
+
+            SECTION("as an object value")
+            {
+                json j;
+                j["a"] = 1;
+                j["b"] = discarded;
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to BJData", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
+#endif
+            }
+
+            SECTION("nested deeper (array in object in array)")
+            {
+                json inner_array = {1, discarded};
+                json middle_object;
+                middle_object["x"] = inner_array;
+                json const j = {middle_object};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] (/0/x/1) cannot serialize discarded value to BJData", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
+#endif
+            }
+
+            SECTION("optimized array of all-discarded elements")
+            {
+                json const j = {discarded, discarded};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j, true, true), "[json.exception.type_error.321] (/0) cannot serialize discarded value to BJData", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_bjdata(j, true, true), "[json.exception.type_error.321] cannot serialize discarded value to BJData", json::type_error&);
+#endif
+            }
         }
 
         SECTION("null")
@@ -4498,33 +4539,3 @@ TEST_CASE("BJData roundtrips" * doctest::skip())
         }
     }
 }
-
-TEST_CASE("issue #5648 - from_bjdata(ptr, len) must read len bytes, not treat ptr as a C string")
-{
-    // to_bjdata() encodes the integer 0 as the two bytes 'i' 0x00 (a BJData
-    // type marker followed by the value byte 0x00), so the packed data
-    // below contains a 0x00 byte before its end.
-    const json j = {{"a", 0}};
-    const std::vector<std::uint8_t> packed = json::to_bjdata(j);
-    bool contains_nul = false;
-    for (const auto byte : packed)
-    {
-        contains_nul |= (byte == 0x00);
-    }
-    REQUIRE(contains_nul);
-
-#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
-    // before the fix, from_bjdata had no (ptr, len) overload, so this call
-    // bound to from_bjdata(InputType&&, bool strict) instead: ptr was read
-    // as a NUL-terminated C string (stopping at the embedded 0x00 byte), and
-    // len was silently converted to the strict flag. The deprecated
-    // overload added for this issue forwards to from_bjdata(ptr, ptr + len,
-    // ...) instead, like from_ubjson's deprecated (ptr, len) overload does.
-    json result;
-    CHECK_NOTHROW(result = json::from_bjdata(packed.data(), packed.size()));
-    CHECK(result == j);
-
-    // len must not collapse into the strict flag either
-    CHECK(json::from_bjdata(packed.data(), packed.size(), false) == j);
-#endif
-}

tests/src/unit-bon8.cpp

@@ -8,14 +8,6 @@
 
 #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
@@ -1022,36 +1014,6 @@ TEST_CASE("BON8 roundtrips" * doctest::skip())
     }
 }
 
-TEST_CASE("issue #5648 - from_bon8(ptr, len) must read len bytes, not treat ptr as a C string")
-{
-    // to_bon8() encodes the integer 40 as the two bytes 0xC2 0x00 (a BON8
-    // lead byte followed by a continuation byte of 0x00), so the packed data
-    // below contains a 0x00 byte before its end.
-    const json j = {{"a", 40}, {"b", "x"}};
-    const std::vector<std::uint8_t> packed = json::to_bon8(j);
-    bool contains_nul = false;
-    for (const auto byte : packed)
-    {
-        contains_nul |= (byte == 0x00);
-    }
-    REQUIRE(contains_nul);
-
-#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
-    // before the fix, from_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
-    // len was silently converted to the strict flag. The deprecated
-    // overload added for this issue forwards to from_bon8(ptr, ptr + len,
-    // ...) instead, like from_cbor's deprecated (ptr, len) overload does.
-    json result;
-    CHECK_NOTHROW(result = json::from_bon8(packed.data(), packed.size()));
-    CHECK(result == j);
-
-    // 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
 TEST_CASE("BON8 with std::byte")
 {

tests/src/unit-bson.cpp

@@ -8,14 +8,6 @@
 
 #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;
 
@@ -149,6 +141,54 @@ TEST_CASE("BSON")
             json const j = std::vector<int> {1, 2, 3, 4, 5, 6, 7};
             CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is array", json::type_error&);
         }
+
+        SECTION("discarded")
+        {
+            json const j = json::value_t::discarded;
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.317] to serialize to BSON, top-level type must be object, but is discarded", json::type_error&);
+        }
+    }
+
+    SECTION("discarded values nested in a container cannot be serialized to BSON")
+    {
+        json const discarded = json::value_t::discarded;
+
+        SECTION("as an object value")
+        {
+            json j;
+            j["a"] = 1;
+            j["b"] = discarded;
+#if JSON_DIAGNOSTICS
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to BSON", json::type_error&);
+#else
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] cannot serialize discarded value to BSON", json::type_error&);
+#endif
+        }
+
+        SECTION("in an array that is an object value")
+        {
+            json j;
+            j["a"] = json::array({1, discarded, 2});
+#if JSON_DIAGNOSTICS
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] (/a/1) cannot serialize discarded value to BSON", json::type_error&);
+#else
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] cannot serialize discarded value to BSON", json::type_error&);
+#endif
+        }
+
+        SECTION("nested deeper (array in object in object)")
+        {
+            json inner_array = {1, discarded};
+            json middle_object;
+            middle_object["x"] = inner_array;
+            json j;
+            j["outer"] = middle_object;
+#if JSON_DIAGNOSTICS
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] (/outer/x/1) cannot serialize discarded value to BSON", json::type_error&);
+#else
+            CHECK_THROWS_WITH_AS(json::to_bson(j), "[json.exception.type_error.321] cannot serialize discarded value to BSON", json::type_error&);
+#endif
+        }
     }
 
     SECTION("keys containing code-point U+0000 cannot be serialized to BSON")
@@ -1269,10 +1309,8 @@ 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")
@@ -1750,7 +1788,6 @@ 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
@@ -1765,7 +1802,6 @@ TEST_CASE("BSON roundtrips" * doctest::skip())
                 // compare parsed JSON values
                 CHECK(j1 == j2);
             }
-#endif
 
             {
                 INFO_WITH_TEMP(filename + ": output to output adapters");

tests/src/unit-cbor.cpp

@@ -8,14 +8,6 @@
 
 #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;
 
@@ -38,10 +30,49 @@ TEST_CASE("CBOR")
     {
         SECTION("discarded")
         {
-            // discarded values are not serialized
+            // a discarded value cannot be serialized to CBOR
             json const j = json::value_t::discarded;
-            const auto result = json::to_cbor(j);
+            CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] cannot serialize discarded value to CBOR", json::type_error&);
-            CHECK(result.empty());
+        }
+
+        SECTION("discarded values nested in a container")
+        {
+            json const discarded = json::value_t::discarded;
+
+            SECTION("in an array")
+            {
+                json const j = {1, discarded, 2};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] (/1) cannot serialize discarded value to CBOR", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] cannot serialize discarded value to CBOR", json::type_error&);
+#endif
+            }
+
+            SECTION("as an object value")
+            {
+                json j;
+                j["a"] = 1;
+                j["b"] = discarded;
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to CBOR", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] cannot serialize discarded value to CBOR", json::type_error&);
+#endif
+            }
+
+            SECTION("nested deeper (array in object in array)")
+            {
+                json inner_array = {1, discarded};
+                json middle_object;
+                middle_object["x"] = inner_array;
+                json const j = {middle_object};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] (/0/x/1) cannot serialize discarded value to CBOR", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_cbor(j), "[json.exception.type_error.321] cannot serialize discarded value to CBOR", json::type_error&);
+#endif
+            }
         }
 
         SECTION("NaN")
@@ -2223,10 +2254,8 @@ 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
@@ -2623,14 +2652,12 @@ 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");

tests/src/unit-delete_deprecated_functions.cpp

@@ -1,214 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  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));
-    }
-}

tests/src/unit-deserialization.cpp

@@ -16,14 +16,6 @@
     #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
@@ -299,7 +291,6 @@ TEST_CASE("deserialization")
             }));
         }
 
-#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
         SECTION("operator<<")
         {
             std::stringstream ss;
@@ -308,7 +299,6 @@ TEST_CASE("deserialization")
             j << ss;
             CHECK(j == json({"foo", 1, 2, 3, false, {{"one", 1}}}));
         }
-#endif
 
         SECTION("operator>>")
         {
@@ -433,7 +423,6 @@ 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;
@@ -441,7 +430,6 @@ 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>>")
         {
@@ -1160,9 +1148,9 @@ TEST_CASE("deserialization")
         {
             std::istringstream s(bom + "123 456");
             json j;
-            s >> j;
+            j << s;
             CHECK(j == 123);
-            s >> j;
+            j << s;
             CHECK(j == 456);
         }
     }

tests/src/unit-items.cpp

@@ -8,14 +8,6 @@
 
 #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;
 
@@ -27,7 +19,6 @@ 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")
@@ -724,7 +715,6 @@ TEST_CASE("iterator_wrapper")
         }
     }
 }
-#endif
 
 TEST_CASE("items()")
 {

tests/src/unit-json_pointer.cpp

@@ -9,14 +9,6 @@
 #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
@@ -572,9 +564,7 @@ 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);
         }
     }
@@ -754,6 +744,8 @@ 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);
@@ -763,12 +755,6 @@ 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);
@@ -779,6 +765,8 @@ 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);
@@ -800,7 +788,6 @@ 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")
@@ -852,7 +839,6 @@ 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));
@@ -865,7 +851,6 @@ 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);

tests/src/unit-msgpack.cpp

@@ -8,14 +8,6 @@
 
 #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
@@ -41,10 +33,49 @@ TEST_CASE("MessagePack")
     {
         SECTION("discarded")
         {
-            // discarded values are not serialized
+            // a discarded value cannot be serialized to MessagePack
             json const j = json::value_t::discarded;
-            const auto result = json::to_msgpack(j);
+            CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] cannot serialize discarded value to MessagePack", json::type_error&);
-            CHECK(result.empty());
+        }
+
+        SECTION("discarded values nested in a container")
+        {
+            json const discarded = json::value_t::discarded;
+
+            SECTION("in an array")
+            {
+                json const j = {1, discarded, 2};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] (/1) cannot serialize discarded value to MessagePack", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] cannot serialize discarded value to MessagePack", json::type_error&);
+#endif
+            }
+
+            SECTION("as an object value")
+            {
+                json j;
+                j["a"] = 1;
+                j["b"] = discarded;
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to MessagePack", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] cannot serialize discarded value to MessagePack", json::type_error&);
+#endif
+            }
+
+            SECTION("nested deeper (array in object in array)")
+            {
+                json inner_array = {1, discarded};
+                json middle_object;
+                middle_object["x"] = inner_array;
+                json const j = {middle_object};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] (/0/x/1) cannot serialize discarded value to MessagePack", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_msgpack(j), "[json.exception.type_error.321] cannot serialize discarded value to MessagePack", json::type_error&);
+#endif
+            }
         }
 
         SECTION("null")
@@ -1803,10 +1834,8 @@ 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")
@@ -2109,14 +2138,12 @@ 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");

tests/src/unit-regression2.cpp

@@ -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.begin(), data.end());
+        const json j = json::from_msgpack(data.data(), data.size());
         // dump() is nodiscard; this only checks that dumping does not throw
         CHECK_NOTHROW(
             utils::ignore_return_value(

tests/src/unit-serialization.cpp

@@ -8,14 +8,6 @@
 
 #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;
 
@@ -56,7 +48,6 @@ TEST_CASE("serialization")
         }
     }
 
-#ifndef JSON_TEST_DEPRECATED_FUNCTIONS_DELETED
     SECTION("operator>>")
     {
         SECTION("no given width")
@@ -88,7 +79,6 @@ 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")
     {

tests/src/unit-ubjson.cpp

@@ -8,14 +8,6 @@
 
 #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;
 
@@ -35,10 +27,59 @@ TEST_CASE("UBJSON")
     {
         SECTION("discarded")
         {
-            // discarded values are not serialized
+            // a discarded value cannot be serialized to UBJSON
             json const j = json::value_t::discarded;
-            const auto result = json::to_ubjson(j);
+            CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
-            CHECK(result.empty());
+        }
+
+        SECTION("discarded values nested in a container")
+        {
+            json const discarded = json::value_t::discarded;
+
+            SECTION("in an array")
+            {
+                json const j = {1, discarded, 2};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] (/1) cannot serialize discarded value to UBJSON", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
+#endif
+            }
+
+            SECTION("as an object value")
+            {
+                json j;
+                j["a"] = 1;
+                j["b"] = discarded;
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] (/b) cannot serialize discarded value to UBJSON", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
+#endif
+            }
+
+            SECTION("nested deeper (array in object in array)")
+            {
+                json inner_array = {1, discarded};
+                json middle_object;
+                middle_object["x"] = inner_array;
+                json const j = {middle_object};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] (/0/x/1) cannot serialize discarded value to UBJSON", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
+#endif
+            }
+
+            SECTION("optimized array of all-discarded elements")
+            {
+                json const j = {discarded, discarded};
+#if JSON_DIAGNOSTICS
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j, true, true), "[json.exception.type_error.321] (/0) cannot serialize discarded value to UBJSON", json::type_error&);
+#else
+                CHECK_THROWS_WITH_AS(json::to_ubjson(j, true, true), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
+#endif
+            }
         }
 
         SECTION("null")
@@ -2099,9 +2140,14 @@ TEST_CASE("UBJSON")
 
         SECTION("discarded")
         {
+            // a discarded value cannot be serialized to UBJSON, even as part
+            // of an optimized array of a single (here: valueless) type
             json const j = {json::value_t::discarded, json::value_t::discarded};
-            std::vector<uint8_t> expected = {'[', '$', 'N', '#', 'i', 2};
+#if JSON_DIAGNOSTICS
-            CHECK(json::to_ubjson(j, true, true) == expected);
+            CHECK_THROWS_WITH_AS(json::to_ubjson(j, true, true), "[json.exception.type_error.321] (/0) cannot serialize discarded value to UBJSON", json::type_error&);
+#else
+            CHECK_THROWS_WITH_AS(json::to_ubjson(j, true, true), "[json.exception.type_error.321] cannot serialize discarded value to UBJSON", json::type_error&);
+#endif
         }
     }
 }
@@ -2220,10 +2266,8 @@ 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")
@@ -2971,14 +3015,12 @@ 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");