Drop the version history note for a bug that was never released

The regression came from #5390, which is not in any release. Addresses review comment by @gregmarr.

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

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

@@ -111,12 +111,3 @@ Linear in the size of the input.
 - Added in version 3.11.0.
 - 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.
-
-!!! 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.

include/nlohmann/json.hpp

@@ -1307,15 +1307,65 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     */
     template<bool Ordered>
     static compare_result compare_leaves(const_reference lhs, const_reference rhs) noexcept
+    {
+        return compare_leaves(lhs, rhs, std::integral_constant<bool, Ordered> {});
+    }
+
+    /// @brief compare two leaves that are only being checked for equality
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::false_type /*ordered*/) noexcept
     {
         if (lhs == rhs)
         {
             return compare_result::equal;
         }
 
-        return order_leaves(lhs, rhs, std::integral_constant<bool, Ordered> {});
+        return order_leaves(lhs, rhs, std::false_type {});
     }
 
+#if JSON_HAS_THREE_WAY_COMPARISON
+    /*!
+    @brief compare two leaves that are being ordered, for operator<=>
+
+    Reached only from operator<=>, so the leaves must be classified exactly
+    as operator<=> classifies them - which is not the same as asking
+    == and then order_leaves(), the way the other overload does it. The two
+    disagree on a binary value: == also compares the subtype, but <=> compares
+    only the bytes, through std::vector<std::uint8_t>::operator<=>. Using <=>
+    itself here keeps a leaf pair classified the same way regardless of how
+    deep it is nested - == first would again call operator<=> a level down
+    through order_leaves(), but call it after a mismatching == already ended
+    the comparison for a pair that <=> alone would still call equivalent.
+    */
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::true_type /*ordered*/) noexcept
+    {
+        const std::partial_ordering order = lhs <=> rhs; // *NOPAD*
+        if (order == 0)
+        {
+            return compare_result::equal;
+        }
+        if (order < 0)
+        {
+            return compare_result::less;
+        }
+        if (order > 0)
+        {
+            return compare_result::greater;
+        }
+        return compare_result::unordered;
+    }
+#else
+    /// @brief compare two leaves that are being ordered, for operator<
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::true_type /*ordered*/) noexcept
+    {
+        if (lhs == rhs)
+        {
+            return compare_result::equal;
+        }
+
+        return order_leaves(lhs, rhs, std::true_type {});
+    }
+#endif
+
     /*!
     @brief compare two object keys
 
@@ -5547,16 +5597,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return result;
     }
 
-    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)
-    {
-        return from_bjdata(ptr, ptr + len, strict, allow_exceptions);
-    }
-
     /// @brief create a JSON value from an input in BON8 format
     /// @sa https://json.nlohmann.me/api/basic_json/from_bon8/
     template<typename InputType>
@@ -5594,16 +5634,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return result;
     }
 
-    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)
-    {
-        return from_bon8(ptr, ptr + len, strict, allow_exceptions);
-    }
-
     /// @brief create a JSON value from an input in BSON format
     /// @sa https://json.nlohmann.me/api/basic_json/from_bson/
     template<typename InputType>

single_include/nlohmann/json.hpp

@@ -27388,15 +27388,65 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     */
     template<bool Ordered>
     static compare_result compare_leaves(const_reference lhs, const_reference rhs) noexcept
+    {
+        return compare_leaves(lhs, rhs, std::integral_constant<bool, Ordered> {});
+    }
+
+    /// @brief compare two leaves that are only being checked for equality
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::false_type /*ordered*/) noexcept
     {
         if (lhs == rhs)
         {
             return compare_result::equal;
         }
 
-        return order_leaves(lhs, rhs, std::integral_constant<bool, Ordered> {});
+        return order_leaves(lhs, rhs, std::false_type {});
     }
 
+#if JSON_HAS_THREE_WAY_COMPARISON
+    /*!
+    @brief compare two leaves that are being ordered, for operator<=>
+
+    Reached only from operator<=>, so the leaves must be classified exactly
+    as operator<=> classifies them - which is not the same as asking
+    == and then order_leaves(), the way the other overload does it. The two
+    disagree on a binary value: == also compares the subtype, but <=> compares
+    only the bytes, through std::vector<std::uint8_t>::operator<=>. Using <=>
+    itself here keeps a leaf pair classified the same way regardless of how
+    deep it is nested - == first would again call operator<=> a level down
+    through order_leaves(), but call it after a mismatching == already ended
+    the comparison for a pair that <=> alone would still call equivalent.
+    */
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::true_type /*ordered*/) noexcept
+    {
+        const std::partial_ordering order = lhs <=> rhs; // *NOPAD*
+        if (order == 0)
+        {
+            return compare_result::equal;
+        }
+        if (order < 0)
+        {
+            return compare_result::less;
+        }
+        if (order > 0)
+        {
+            return compare_result::greater;
+        }
+        return compare_result::unordered;
+    }
+#else
+    /// @brief compare two leaves that are being ordered, for operator<
+    static compare_result compare_leaves(const_reference lhs, const_reference rhs, std::true_type /*ordered*/) noexcept
+    {
+        if (lhs == rhs)
+        {
+            return compare_result::equal;
+        }
+
+        return order_leaves(lhs, rhs, std::true_type {});
+    }
+#endif
+
     /*!
     @brief compare two object keys
 
@@ -31628,16 +31678,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return result;
     }
 
-    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)
-    {
-        return from_bjdata(ptr, ptr + len, strict, allow_exceptions);
-    }
-
     /// @brief create a JSON value from an input in BON8 format
     /// @sa https://json.nlohmann.me/api/basic_json/from_bon8/
     template<typename InputType>
@@ -31675,16 +31715,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return result;
     }
 
-    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)
-    {
-        return from_bon8(ptr, ptr + len, strict, allow_exceptions);
-    }
-
     /// @brief create a JSON value from an input in BSON format
     /// @sa https://json.nlohmann.me/api/basic_json/from_bson/
     template<typename InputType>

tests/src/unit-bjdata.cpp

@@ -4572,31 +4572,3 @@ 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);
-
-    // 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);
-}

tests/src/unit-bon8.cpp

@@ -1010,34 +1010,6 @@ 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);
-
-    // 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);
-}
-
 #ifdef JSON_HAS_CPP_17
 TEST_CASE("BON8 with std::byte")
 {

tests/src/unit-comparison.cpp

@@ -952,3 +952,51 @@ TEST_CASE("containers are compared element by element")
         }
     }
 }
+
+#if JSON_HAS_THREE_WAY_COMPARISON
+// JSON_HAS_CPP_20 (do not remove; see note at top of file)
+TEST_CASE("operator<=> of binary values with a different subtype does not depend on nesting depth")
+{
+    // #5654: std::vector<std::uint8_t>::operator<=>, which the binary type's
+    // own operator<=> uses, ignores the subtype that operator== checks. So a
+    // pair of binary values with the same bytes but a different subtype is
+    // unequal, yet <=>-equivalent - the same inconsistency between == and <=>
+    // that a NaN has. Within the nesting bound, an array compares itself
+    // with std::vector's own operator<=>, which treats an equivalent pair as
+    // undecided and lets the next element decide, same as
+    // std::lexicographical_compare_three_way does. Past the bound,
+    // compare_iteratively<true>() takes over and must classify the pair the
+    // same way, or the result of operator<=> - and of <, which C++20 derives
+    // from it - depends on how deeply the values are nested.
+    const json a = json::array({json::binary({1}, 1), 1});
+    const json b = json::array({json::binary({1}, 2), 2});
+
+    // the root inconsistency: unequal, yet <=>-equivalent
+    CHECK_FALSE(a[0] == b[0]);
+    CHECK((a[0] <=> b[0]) == std::partial_ordering::equivalent); // *NOPAD*
+
+    const auto deep = [](const json & j, const std::size_t depth)
+    {
+        json result = j;
+        for (std::size_t i = 0; i < depth; ++i)
+        {
+            result = json::array({std::move(result)});
+        }
+        return result;
+    };
+
+    // 127 levels stay within nesting_depth_limit() (128); 128 and 200 do not,
+    // and must still agree with the levels that do
+    for (const std::size_t depth : std::vector<std::size_t> {0, 127, 128, 200})
+    {
+        CAPTURE(depth);
+        const json x = deep(a, depth);
+        const json y = deep(b, depth);
+        CHECK((x <=> y) == std::partial_ordering::less); // *NOPAD*
+        CHECK((y <=> x) == std::partial_ordering::greater); // *NOPAD*
+        CHECK(x < y);
+        CHECK(y > x);
+        CHECK_FALSE(y < x);
+    }
+}
+#endif