🐛 fix BSON conformance issue

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

docs/mkdocs/docs/api/basic_json/swap.md

@@ -34,14 +34,10 @@ void swap(typename binary_t::container_type& other);
 ```
 
 1. Exchanges the contents of the JSON value with those of `other`. Does not invoke any move, copy, or swap operations on
-   individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. If macro
-   [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) is defined to `#!cpp 1`, the
-   [`start_pos()`](start_pos.md)/[`end_pos()`](end_pos.md) diagnostic positions are exchanged along with the value.
+   individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. 
 2. Exchanges the contents of the JSON value from `left` with those of `right`. Does not invoke any move, copy, or swap
    operations on individual elements. All iterators and references remain valid. The past-the-end iterator is
-   invalidated. Implemented as a friend function callable via ADL. If macro
-   [`JSON_DIAGNOSTIC_POSITIONS`](../macros/json_diagnostic_positions.md) is defined to `#!cpp 1`, the
-   [`start_pos()`](start_pos.md)/[`end_pos()`](end_pos.md) diagnostic positions are exchanged along with the value.
+   invalidated. Implemented as a friend function callable via ADL.
 3. Exchanges the contents of a JSON array with those of `other`. Does not invoke any move, copy, or swap operations on
    individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated. 
 4. Exchanges the contents of a JSON object with those of `other`. Does not invoke any move, copy, or swap operations on

include/nlohmann/detail/input/binary_reader.hpp

@@ -432,7 +432,21 @@ class binary_reader
                                     exception_message(input_format_t::bson, concat("string length must be at least 1, is ", std::to_string(len)), "string"), nullptr));
         }
 
-        return get_string(input_format_t::bson, len - static_cast<NumberType>(1), result) && get() != char_traits<char_type>::eof();
+        if (JSON_HEDLEY_UNLIKELY(!get_string(input_format_t::bson, len - static_cast<NumberType>(1), result)))
+        {
+            return false;
+        }
+
+        if (JSON_HEDLEY_UNLIKELY(get() != 0x00))
+        {
+            auto last_token = get_token_string();
+            return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read,
+                                    exception_message(input_format_t::bson,
+                                            "BSON string is not null-terminated",
+                                            "string"), nullptr));
+        }
+
+        return true;
     }
 
     /*!
@@ -550,8 +564,6 @@ class binary_reader
         }
     }
 
-
-
     //////////
     // CBOR //
     //////////
@@ -1434,7 +1446,7 @@ class binary_reader
                 // a copy, not a reference: it must stay valid across the
                 // pop_back() below, which destroys the container_stack element
                 // it would otherwise alias
-                const container_frame top = container_stack.back();
+                container_frame top = container_stack.back();
                 bool at_end = false;
 
                 if (top.remaining != npos)
@@ -2211,7 +2223,7 @@ class binary_reader
             // would otherwise alias.
             for (;;)
             {
-                const container_frame top = container_stack.back();
+                container_frame top = container_stack.back();
 
                 if (top.remaining != npos)
                 {

include/nlohmann/detail/input/json_sax.hpp

@@ -8,7 +8,6 @@
 
 #pragma once
 
-#include <algorithm> // min
 #include <cstddef>
 #include <string> // string
 #include <type_traits> // enable_if_t
@@ -18,7 +17,6 @@
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/input/lexer.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
-#include <nlohmann/detail/meta/cpp_future.hpp>
 #include <nlohmann/detail/string_concat.hpp>
 NLOHMANN_JSON_NAMESPACE_BEGIN
 
@@ -152,29 +150,6 @@ constexpr std::size_t unknown_size()
     return (std::numeric_limits<std::size_t>::max)();
 }
 
-/*!
-@brief reserve capacity for @a len elements in array @a arr
-
-Reserving upfront avoids repeated reallocations while the elements are added,
-but the reservation is capped so a bogus/hostile length (which is not bounded
-by max_size(), unlike e.g. std::vector) cannot trigger an oversized allocation
-for a small or truncated input.
-
-The overload below is selected for array types without reserve() (e.g.,
-std::deque), which are then left untouched.
-*/
-template<typename ArrayType>
-auto reserve_array(ArrayType& arr, std::size_t len, priority_tag<1> /*unused*/)
--> decltype(arr.reserve(len), void())
-{
-    constexpr std::size_t reserve_cap = 16384;
-    arr.reserve((std::min)(len, reserve_cap));
-}
-
-template<typename ArrayType>
-inline void reserve_array(ArrayType& /*arr*/, std::size_t /*len*/, priority_tag<0> /*unused*/)
-{}
-
 /*!
 @brief SAX implementation to create a JSON value from SAX events
 
@@ -330,11 +305,6 @@ class json_sax_dom_parser
             JSON_THROW(out_of_range::create(408, concat("excessive array size: ", std::to_string(len)), ref_stack.back()));
         }
 
-        if (len != detail::unknown_size())
-        {
-            reserve_array(*ref_stack.back()->m_data.m_value.array, len, priority_tag<1> {});
-        }
-
         return true;
     }
 
@@ -713,11 +683,6 @@ class json_sax_dom_callback_parser
             {
                 JSON_THROW(out_of_range::create(408, concat("excessive array size: ", std::to_string(len)), ref_stack.back()));
             }
-
-            if (len != detail::unknown_size())
-            {
-                reserve_array(*ref_stack.back()->m_data.m_value.array, len, priority_tag<1> {});
-            }
         }
 
         return true;

include/nlohmann/json.hpp

@@ -3576,11 +3576,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         std::swap(m_data.m_type, other.m_data.m_type);
         std::swap(m_data.m_value, other.m_data.m_value);
 
-#if JSON_DIAGNOSTIC_POSITIONS
-        std::swap(start_position, other.start_position);
-        std::swap(end_position, other.end_position);
-#endif
-
         set_parents();
         other.set_parents();
         assert_invariant();

single_include/nlohmann/json.hpp

@@ -7892,7 +7892,6 @@ NLOHMANN_JSON_NAMESPACE_END
 
 
 
-#include <algorithm> // min
 #include <cstddef>
 #include <string> // string
 #include <type_traits> // enable_if_t
@@ -10730,8 +10729,6 @@ NLOHMANN_JSON_NAMESPACE_END
 
 // #include <nlohmann/detail/macro_scope.hpp>
 
-// #include <nlohmann/detail/meta/cpp_future.hpp>
-
 // #include <nlohmann/detail/string_concat.hpp>
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
@@ -10866,29 +10863,6 @@ constexpr std::size_t unknown_size()
     return (std::numeric_limits<std::size_t>::max)();
 }
 
-/*!
-@brief reserve capacity for @a len elements in array @a arr
-
-Reserving upfront avoids repeated reallocations while the elements are added,
-but the reservation is capped so a bogus/hostile length (which is not bounded
-by max_size(), unlike e.g. std::vector) cannot trigger an oversized allocation
-for a small or truncated input.
-
-The overload below is selected for array types without reserve() (e.g.,
-std::deque), which are then left untouched.
-*/
-template<typename ArrayType>
-auto reserve_array(ArrayType& arr, std::size_t len, priority_tag<1> /*unused*/)
--> decltype(arr.reserve(len), void())
-{
-    constexpr std::size_t reserve_cap = 16384;
-    arr.reserve((std::min)(len, reserve_cap));
-}
-
-template<typename ArrayType>
-inline void reserve_array(ArrayType& /*arr*/, std::size_t /*len*/, priority_tag<0> /*unused*/)
-{}
-
 /*!
 @brief SAX implementation to create a JSON value from SAX events
 
@@ -11044,11 +11018,6 @@ class json_sax_dom_parser
             JSON_THROW(out_of_range::create(408, concat("excessive array size: ", std::to_string(len)), ref_stack.back()));
         }
 
-        if (len != detail::unknown_size())
-        {
-            reserve_array(*ref_stack.back()->m_data.m_value.array, len, priority_tag<1> {});
-        }
-
         return true;
     }
 
@@ -11427,11 +11396,6 @@ class json_sax_dom_callback_parser
             {
                 JSON_THROW(out_of_range::create(408, concat("excessive array size: ", std::to_string(len)), ref_stack.back()));
             }
-
-            if (len != detail::unknown_size())
-            {
-                reserve_array(*ref_stack.back()->m_data.m_value.array, len, priority_tag<1> {});
-            }
         }
 
         return true;
@@ -12417,7 +12381,21 @@ class binary_reader
                                     exception_message(input_format_t::bson, concat("string length must be at least 1, is ", std::to_string(len)), "string"), nullptr));
         }
 
-        return get_string(input_format_t::bson, len - static_cast<NumberType>(1), result) && get() != char_traits<char_type>::eof();
+        if (JSON_HEDLEY_UNLIKELY(!get_string(input_format_t::bson, len - static_cast<NumberType>(1), result)))
+        {
+            return false;
+        }
+
+        if (JSON_HEDLEY_UNLIKELY(get() != 0x00))
+        {
+            auto last_token = get_token_string();
+            return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read,
+                                    exception_message(input_format_t::bson,
+                                            "BSON string is not null-terminated",
+                                            "string"), nullptr));
+        }
+
+        return true;
     }
 
     /*!
@@ -12535,8 +12513,6 @@ class binary_reader
         }
     }
 
-
-
     //////////
     // CBOR //
     //////////
@@ -13419,7 +13395,7 @@ class binary_reader
                 // a copy, not a reference: it must stay valid across the
                 // pop_back() below, which destroys the container_stack element
                 // it would otherwise alias
-                const container_frame top = container_stack.back();
+                container_frame top = container_stack.back();
                 bool at_end = false;
 
                 if (top.remaining != npos)
@@ -14196,7 +14172,7 @@ class binary_reader
             // would otherwise alias.
             for (;;)
             {
-                const container_frame top = container_stack.back();
+                container_frame top = container_stack.back();
 
                 if (top.remaining != npos)
                 {
@@ -27345,11 +27321,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         std::swap(m_data.m_type, other.m_data.m_type);
         std::swap(m_data.m_value, other.m_data.m_value);
 
-#if JSON_DIAGNOSTIC_POSITIONS
-        std::swap(start_position, other.start_position);
-        std::swap(end_position, other.end_position);
-#endif
-
         set_parents();
         other.set_parents();
         assert_invariant();

tests/benchmarks/src/benchmarks.cpp

@@ -252,323 +252,4 @@ static void BinaryToCbor(benchmark::State& state)
 }
 BENCHMARK(BinaryToCbor)->RangeMultiplier(2)->Range(8, 8 << 12);
 
-//////////////////////////////////////////////////////////////////////////////
-// parse binary formats
-//////////////////////////////////////////////////////////////////////////////
-
-// Only MessagePack had a read benchmark (FromMsgpack above, left untouched so
-// its numbers stay comparable across releases). The benchmarks below cover the
-// other formats, and read from a contiguous buffer as well as from a FILE*:
-// most callers pass a container, and the two adapters compile to different
-// code. The test data repository ships JSON only, so the input for each is
-// derived at setup time by serializing a parsed test file.
-
-/// binary format to benchmark; the _optimized variants add UBJSON/BJData size
-/// and type annotations, which the readers handle in a separate code path
-enum class binary_format
-{
-    cbor,
-    msgpack,
-    ubjson,
-    ubjson_optimized,
-    bjdata,
-    bjdata_optimized,
-    bson
-};
-
-static std::vector<std::uint8_t> to_binary(const json& j, const binary_format format)
-{
-    switch (format)
-    {
-        case binary_format::cbor:
-            return json::to_cbor(j);
-        case binary_format::msgpack:
-            return json::to_msgpack(j);
-        case binary_format::ubjson:
-            return json::to_ubjson(j);
-        case binary_format::ubjson_optimized:
-            return json::to_ubjson(j, true, true);
-        case binary_format::bjdata:
-            return json::to_bjdata(j);
-        case binary_format::bjdata_optimized:
-            return json::to_bjdata(j, true, true);
-        case binary_format::bson:
-        default:
-            return json::to_bson(j);
-    }
-}
-
-static json from_binary(const std::vector<std::uint8_t>& bytes, const binary_format format)
-{
-    switch (format)
-    {
-        case binary_format::cbor:
-            return json::from_cbor(bytes);
-        case binary_format::msgpack:
-            return json::from_msgpack(bytes);
-        case binary_format::ubjson:
-        case binary_format::ubjson_optimized:
-            return json::from_ubjson(bytes);
-        case binary_format::bjdata:
-        case binary_format::bjdata_optimized:
-            return json::from_bjdata(bytes);
-        case binary_format::bson:
-        default:
-            return json::from_bson(bytes);
-    }
-}
-
-static json from_binary(std::FILE* file, const binary_format format)
-{
-    switch (format)
-    {
-        case binary_format::cbor:
-            return json::from_cbor(file);
-        case binary_format::msgpack:
-            return json::from_msgpack(file);
-        case binary_format::ubjson:
-        case binary_format::ubjson_optimized:
-            return json::from_ubjson(file);
-        case binary_format::bjdata:
-        case binary_format::bjdata_optimized:
-            return json::from_bjdata(file);
-        case binary_format::bson:
-        default:
-            return json::from_bson(file);
-    }
-}
-
-/*!
-@brief serialize a parsed test file to @a format
-
-Returns an empty vector and marks the benchmark as skipped if the file cannot
-be represented in the format, rather than letting the exception escape: BSON
-requires an object at the top level, and several test files are arrays.
-*/
-static std::vector<std::uint8_t> binary_input(benchmark::State& state, const char* filename, const binary_format format)
-{
-    std::ifstream f(filename);
-    std::string const str((std::istreambuf_iterator<char>(f)), std::istreambuf_iterator<char>());
-    const json j = json::parse(str);
-
-    if (format == binary_format::bson && !j.is_object())
-    {
-        state.SkipWithError("BSON requires an object at the top level");
-        return {};
-    }
-
-    return to_binary(j, format);
-}
-
-static void FromBinaryBuffer(benchmark::State& state, const char* filename, const binary_format format)
-{
-    const std::vector<std::uint8_t> bytes = binary_input(state, filename, format);
-    if (bytes.empty())
-    {
-        return;
-    }
-
-    for (auto _ : state)
-    {
-        // the value is destroyed outside the timed section, because destroying
-        // a large DOM is not what this benchmark measures
-        state.PauseTiming();
-        auto* j = new json();
-        state.ResumeTiming();
-
-        *j = from_binary(bytes, format);
-
-        state.PauseTiming();
-        delete j;
-        state.ResumeTiming();
-    }
-
-    state.SetBytesProcessed(state.iterations() * bytes.size());
-}
-
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / floats, TEST_DATA_DIRECTORY "/regression/floats.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, cbor / signed_ints, TEST_DATA_DIRECTORY "/regression/signed_ints.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryBuffer, msgpack / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / jeopardy, TEST_DATA_DIRECTORY "/jeopardy/jeopardy.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson_optimized / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson_optimized);
-BENCHMARK_CAPTURE(FromBinaryBuffer, ubjson_optimized / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson_optimized);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bjdata);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata_optimized / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bjdata_optimized);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bjdata_optimized / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata_optimized);
-// BSON requires an object at the top level, so the array-rooted test files
-// (jeopardy and the regression files) cannot be captured here
-BENCHMARK_CAPTURE(FromBinaryBuffer, bson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::bson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bson / citm_catalog, TEST_DATA_DIRECTORY "/nativejson-benchmark/citm_catalog.json", binary_format::bson);
-BENCHMARK_CAPTURE(FromBinaryBuffer, bson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bson);
-
-static void FromBinaryFile(benchmark::State& state, const char* filename, const binary_format format)
-{
-    const std::vector<std::uint8_t> bytes = binary_input(state, filename, format);
-    if (bytes.empty())
-    {
-        return;
-    }
-
-    const char* tmp = "benchmark_input.bin";
-    std::ofstream o(tmp, std::ios::binary);
-    o.write(reinterpret_cast<const char*>(bytes.data()), static_cast<std::streamsize>(bytes.size()));
-    o.flush();
-    o.close();
-
-    for (auto _ : state)
-    {
-        state.PauseTiming();
-        auto* j = new json();
-        auto* file = std::fopen(tmp, "rb");
-        state.ResumeTiming();
-
-        *j = from_binary(file, format);
-
-        state.PauseTiming();
-        std::fclose(file);
-        delete j;
-        state.ResumeTiming();
-    }
-
-    state.SetBytesProcessed(state.iterations() * bytes.size());
-}
-
-BENCHMARK_CAPTURE(FromBinaryFile, cbor / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryFile, cbor / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryFile, ubjson / canada, TEST_DATA_DIRECTORY "/nativejson-benchmark/canada.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryFile, ubjson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryFile, bjdata / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bjdata);
-BENCHMARK_CAPTURE(FromBinaryFile, bson / twitter, TEST_DATA_DIRECTORY "/nativejson-benchmark/twitter.json", binary_format::bson);
-
-//////////////////////////////////////////////////////////////////////////////
-// parse binary formats: value shapes
-//////////////////////////////////////////////////////////////////////////////
-
-// The test files above are wide and shallow, but the readers' cost is per
-// container, so these cover the shapes that stress the container handling
-// itself. Every shape is wrapped in an object so that BSON, which requires an
-// object at the top level, measures the same value as the other formats.
-
-/// deeply nested arrays: one container per level, no other work
-static json make_nested()
-{
-    json nested = json::array();
-    json* p = &nested;
-    for (std::size_t i = 1; i < 1000; ++i)
-    {
-        p->push_back(json::array());
-        p = &p->operator[](0);
-    }
-
-    json j = json::object();
-    j["data"] = std::move(nested);
-    return j;
-}
-
-/// many sibling containers: maximum container churn, minimum nesting
-static json make_containers()
-{
-    json data = json::array();
-    for (std::size_t i = 0; i < 100000; ++i)
-    {
-        data.push_back(json::array({1, 2}));
-    }
-
-    json j = json::object();
-    j["data"] = std::move(data);
-    return j;
-}
-
-/// one flat array of numbers: the scalar decoding path, which must not move
-static json make_scalars()
-{
-    json data = json::array();
-    for (std::size_t i = 0; i < 1000000; ++i)
-    {
-        data.push_back(i);
-    }
-
-    json j = json::object();
-    j["data"] = std::move(data);
-    return j;
-}
-
-static void FromBinaryShape(benchmark::State& state, json (*build)(), const binary_format format)
-{
-    const std::vector<std::uint8_t> bytes = to_binary(build(), format);
-
-    for (auto _ : state)
-    {
-        state.PauseTiming();
-        auto* j = new json();
-        state.ResumeTiming();
-
-        *j = from_binary(bytes, format);
-
-        state.PauseTiming();
-        delete j;
-        state.ResumeTiming();
-    }
-
-    state.SetBytesProcessed(state.iterations() * bytes.size());
-}
-
-BENCHMARK_CAPTURE(FromBinaryShape, nested / cbor, make_nested, binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryShape, nested / msgpack, make_nested, binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryShape, nested / ubjson, make_nested, binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryShape, nested / bjdata, make_nested, binary_format::bjdata);
-BENCHMARK_CAPTURE(FromBinaryShape, nested / bson, make_nested, binary_format::bson);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / cbor, make_containers, binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / msgpack, make_containers, binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / ubjson, make_containers, binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / ubjson_optimized, make_containers, binary_format::ubjson_optimized);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / bjdata, make_containers, binary_format::bjdata);
-BENCHMARK_CAPTURE(FromBinaryShape, containers / bson, make_containers, binary_format::bson);
-// BSON names every array element, so a large array measures key generation
-// rather than scalar decoding and is left out here
-BENCHMARK_CAPTURE(FromBinaryShape, scalars / cbor, make_scalars, binary_format::cbor);
-BENCHMARK_CAPTURE(FromBinaryShape, scalars / msgpack, make_scalars, binary_format::msgpack);
-BENCHMARK_CAPTURE(FromBinaryShape, scalars / ubjson, make_scalars, binary_format::ubjson);
-BENCHMARK_CAPTURE(FromBinaryShape, scalars / bjdata, make_scalars, binary_format::bjdata);
-
-/*!
-@brief parse an indefinite-length CBOR string
-
-The writer never emits this form, so the input is assembled by hand: 0x7F
-opens the string, each chunk is a one-character string, and 0xFF closes it.
-*/
-static void FromCborChunkedString(benchmark::State& state, const std::size_t chunks)
-{
-    std::vector<std::uint8_t> bytes;
-    bytes.reserve(2 * chunks + 2);
-    bytes.push_back(0x7F);
-    for (std::size_t i = 0; i < chunks; ++i)
-    {
-        bytes.push_back(0x61); // string of length 1
-        bytes.push_back(0x61); // 'a'
-    }
-    bytes.push_back(0xFF);
-
-    for (auto _ : state)
-    {
-        json j = json::from_cbor(bytes);
-        benchmark::DoNotOptimize(j);
-    }
-
-    state.SetBytesProcessed(state.iterations() * bytes.size());
-}
-
-BENCHMARK_CAPTURE(FromCborChunkedString, 10000 chunks, 10000);
-
 BENCHMARK_MAIN();

tests/src/unit-bjdata.cpp

@@ -3551,111 +3551,6 @@ TEST_CASE("BJData")
     }
 }
 
-TEST_CASE("issue #5405 - array reserve for definite-length BJData arrays")
-{
-#if !defined(JSON_NOEXCEPTION)
-    // this SECTION relies on catching a thrown exception to distinguish
-    // which of two acceptable, bounded rejections a hostile header took;
-    // under JSON_NOEXCEPTION, JSON_THROW never produces a catchable C++
-    // exception (it aborts instead), so this cannot be tested that way here
-    SECTION("a huge claimed length with no element data must not over-allocate")
-    {
-        // optimized form [$type#count: type 'i' (int8), count as a four-byte
-        // little-endian 'l' (int32) of 0x7FFFFFFF (2147483647), but no
-        // element data at all. max_size() for a std::vector is far larger
-        // than this count, so it does not reject the header outright; the
-        // (capped) reservation must not attempt to allocate space for
-        // billions of elements before the missing data is detected.
-        json _;
-        const std::vector<uint8_t> input = {'[', '$', 'i', '#', 'l', 0xFF, 0xFF, 0xFF, 0x7F};
-        // On a platform where std::vector<json>::max_size() is smaller than
-        // the claimed count (e.g. 32-bit, where max_size() is bounded by a
-        // 32-bit SIZE_MAX divided by sizeof(json)), the SAX consumer's own
-        // check rejects the header outright (out_of_range.408, with the
-        // claimed count in the message) instead of accepting it and only
-        // finding it short of data once the (capped) reservation looks for
-        // element bytes that were never provided (parse_error.110). Either
-        // is an acceptable, bounded rejection of the hostile header -- the
-        // property under test is that no path attempts to allocate space
-        // for billions of elements.
-        bool threw = false;
-        try
-        {
-            _ = json::from_bjdata(input);
-        }
-        catch (const json::parse_error& e)
-        {
-            threw = true;
-            CHECK(e.id == 110);
-            CHECK(std::string(e.what()) == "[json.exception.parse_error.110] parse error at byte 10: syntax error while parsing BJData number: unexpected end of input");
-        }
-        catch (const json::out_of_range& e)
-        {
-            threw = true;
-            CHECK(e.id == 408);
-            CHECK(std::string(e.what()).find("excessive array size") != std::string::npos);
-        }
-        CHECK(threw);
-
-        // json_sax_dom_parser::start_array()'s max_size() check (unlike the
-        // scanner's own parse_error path) throws unconditionally via
-        // JSON_THROW rather than going through sax->parse_error(), so it is
-        // not gated by allow_exceptions=false on a platform where this
-        // header hits that check (e.g. 32-bit, see above) -- allow either
-        // a discarded result or the same out_of_range it throws with
-        // exceptions enabled.
-        try
-        {
-            CHECK(json::from_bjdata(input, true, false).is_discarded());
-        }
-        catch (const json::out_of_range& e)
-        {
-            CHECK(e.id == 408);
-        }
-    }
-#endif
-
-    SECTION("arrays of various sizes decode to the same value as before the reserve optimization")
-    {
-        for (const auto size :
-                {
-                    std::size_t{0}, std::size_t{1}, std::size_t{5}, // small
-                    std::size_t{16384},                             // exactly at the reserve cap
-                    std::size_t{20000}                              // above the reserve cap
-                })
-        {
-            CAPTURE(size)
-            json j = json::array();
-            for (std::size_t i = 0; i < size; ++i)
-            {
-                j.push_back(static_cast<int>(i % 1000));
-            }
-
-            // exercise both the plain and the optimized [$type#count encoding
-            const auto packed_plain = json::to_bjdata(j);
-            CHECK(json::from_bjdata(packed_plain) == j);
-
-            const auto packed_optimized = json::to_bjdata(j, true, true);
-            CHECK(json::from_bjdata(packed_optimized) == j);
-        }
-    }
-
-    SECTION("a user-defined SAX consumer is unaffected by the internal DOM reserve optimization")
-    {
-        // the reserve() call is local to json_sax_dom_parser / json_sax_dom_callback_parser;
-        // a custom SAX consumer that does not touch a DOM array sees identical events
-        json j = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            j.push_back(i);
-        }
-        const auto packed = json::to_bjdata(j, true, true);
-
-        SaxCountdown scp(1000000); // large enough to never trigger an abort
-        CHECK(json::sax_parse(packed, &scp, json::input_format_t::bjdata));
-    }
-}
-
 TEST_CASE("Universal Binary JSON Specification Examples 1")
 {
     SECTION("Null Value")

tests/src/unit-bson.cpp

@@ -1688,3 +1688,76 @@ TEST_CASE("BSON roundtrips" * doctest::skip())
         }
     }
 }
+
+TEST_CASE("Invalid document size handling")
+{
+    SECTION("document size must be at least 5")
+    {
+        std::vector<std::uint8_t> const v = {0x04, 0x00, 0x00, 0x00, 0x00};
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 5: syntax error while parsing BSON document: document size 4 does not match the number of bytes read (5)", json::parse_error&);
+        CHECK(json::from_bson(v, true, false).is_discarded());
+    }
+
+    SECTION("declared document size must match consumed bytes (extra trailing element)")
+    {
+        // Declares 5-byte empty document but appends an int32 element after the declared end.
+        std::vector<std::uint8_t> const v =
+        {
+            0x05, 0x00, 0x00, 0x00,
+            0x10, 'a', 'd', 'm', 'i', 'n', 0x00,
+            0x01, 0x00, 0x00, 0x00,
+            0x00
+        };
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 16: syntax error while parsing BSON document: document size 5 does not match the number of bytes read (16)", json::parse_error&);
+        CHECK(json::from_bson(v, true, false).is_discarded());
+    }
+
+    SECTION("declared document size must match consumed bytes (premature terminator)")
+    {
+        // Declares 32-byte document but only contains the size field followed by an immediate terminator.
+        std::vector<std::uint8_t> const v =
+        {
+            0x20, 0x00, 0x00, 0x00,
+            0x00
+        };
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 5: syntax error while parsing BSON document: document size 32 does not match the number of bytes read (5)", json::parse_error&);
+        CHECK(json::from_bson(v, true, false).is_discarded());
+    }
+
+    SECTION("array declared size must match consumed bytes")
+    {
+        // Outer object contains an array "a" that declares 5 bytes (empty) but
+        // actually contains an int32 element before its terminator.
+        std::vector<std::uint8_t> const v =
+        {
+            0x14, 0x00, 0x00, 0x00,                         // object size = 20
+            0x04, 'a', 0x00,                                // key "a", array type
+            0x05, 0x00, 0x00, 0x00,                         // array declared size = 5 (empty)
+            0x10, '0', 0x00, 0x01, 0x00, 0x00, 0x00,        // extra int32 element "0" = 1
+            0x00,                                           // array terminator
+            0x00                                            // object terminator
+        };
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 19: syntax error while parsing BSON document: document size 5 does not match the number of bytes read (12)", json::parse_error&);
+        CHECK(json::from_bson(v, true, false).is_discarded());
+    }
+
+    SECTION("BSON string must end with 0x00")
+    {
+        // Length-prefixed string whose terminator byte is 'X' (0x58), not 0x00.
+        std::vector<std::uint8_t> const v =
+        {
+            0x0F, 0x00, 0x00, 0x00,
+            0x02, 's', 0x00,
+            0x02, 0x00, 0x00, 0x00,
+            'A', 'X',
+            0x00
+        };
+        json _;
+        CHECK_THROWS_WITH_AS(_ = json::from_bson(v), "[json.exception.parse_error.112] parse error at byte 13: syntax error while parsing BSON string: BSON string is not null-terminated", json::parse_error&);
+        CHECK(json::from_bson(v, true, false).is_discarded());
+    }
+}

tests/src/unit-cbor.cpp

@@ -2174,92 +2174,6 @@ TEST_CASE("CBOR indefinite-length strings do not recurse per chunk")
     }
 }
 
-TEST_CASE("issue #5405 - array reserve for definite-length CBOR arrays")
-{
-#if !defined(JSON_NOEXCEPTION)
-    // this SECTION relies on catching a thrown exception to distinguish
-    // which of two acceptable, bounded rejections a hostile header took;
-    // under JSON_NOEXCEPTION, JSON_THROW never produces a catchable C++
-    // exception (it aborts instead), so this cannot be tested that way here
-    SECTION("a huge claimed length with no element data must not over-allocate")
-    {
-        // 0x9A: array with a four-byte length; claims 0xFFFFFFFF (4294967295)
-        // elements but provides none. max_size() for a std::vector is far
-        // larger than this count, so it does not reject the header outright;
-        // the (capped) reservation must not attempt to allocate space for
-        // billions of elements before the missing data is detected.
-        json _;
-        const std::vector<uint8_t> input = {0x9A, 0xFF, 0xFF, 0xFF, 0xFF};
-        // On a platform where std::size_t is narrower than 64 bits (e.g.
-        // 32-bit), the claimed count 0xFFFFFFFF coincides with that
-        // platform's detail::unknown_size() sentinel (SIZE_MAX), so the
-        // format-level size check rejects it outright (out_of_range.408,
-        // "excessive ... size") before the SAX consumer's own max_size()
-        // check would even run; on a 64-bit platform it passes both of
-        // those checks and is only found short of data once the (capped)
-        // reservation looks for element bytes that were never provided
-        // (parse_error.110). Either is an acceptable, bounded rejection of
-        // the hostile header -- the property under test is that no path
-        // attempts to allocate space for billions of elements.
-        bool threw = false;
-        try
-        {
-            _ = json::from_cbor(input);
-        }
-        catch (const json::parse_error& e)
-        {
-            threw = true;
-            CHECK(e.id == 110);
-            CHECK(std::string(e.what()) == "[json.exception.parse_error.110] parse error at byte 6: syntax error while parsing CBOR value: unexpected end of input");
-        }
-        catch (const json::out_of_range& e)
-        {
-            threw = true;
-            CHECK(e.id == 408);
-            CHECK(std::string(e.what()).find("excessive") != std::string::npos);
-        }
-        CHECK(threw);
-        CHECK(json::from_cbor(input, true, false).is_discarded());
-    }
-#endif
-
-    SECTION("arrays of various sizes decode to the same value as before the reserve optimization")
-    {
-        for (const auto size :
-                {
-                    std::size_t{0}, std::size_t{1}, std::size_t{5}, // small
-                    std::size_t{16384},                             // exactly at the reserve cap
-                    std::size_t{20000}                              // above the reserve cap
-                })
-        {
-            CAPTURE(size)
-            json j = json::array();
-            for (std::size_t i = 0; i < size; ++i)
-            {
-                j.push_back(static_cast<int>(i % 1000));
-            }
-
-            const auto packed = json::to_cbor(j);
-            CHECK(json::from_cbor(packed) == j);
-        }
-    }
-
-    SECTION("a user-defined SAX consumer is unaffected by the internal DOM reserve optimization")
-    {
-        // the reserve() call is local to json_sax_dom_parser / json_sax_dom_callback_parser;
-        // a custom SAX consumer that does not touch a DOM array sees identical events
-        json j = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            j.push_back(i);
-        }
-        const auto packed = json::to_cbor(j);
-
-        SaxCountdown scp(1000000); // large enough to never trigger an abort
-        CHECK(json::sax_parse(packed, &scp, json::input_format_t::cbor));
-    }
-}
-
 TEST_CASE("CBOR roundtrips" * doctest::skip())
 {
     SECTION("input from flynn")

tests/src/unit-class_parser.cpp

@@ -2259,86 +2259,6 @@ TEST_CASE("parser class")
 #endif
 }
 
-#if JSON_DIAGNOSTIC_POSITIONS
-
-TEST_CASE("diagnostic positions: value lifetime")
-{
-    SECTION("copy constructor copies positions, recursively")
-    {
-        const std::string s = R"({"a":1,"b":[1,2,3]})";
-        const json a = json::parse(s);
-        const json b = a; // NOLINT(performance-unnecessary-copy-initialization)
-
-        CHECK(b.start_pos() == a.start_pos());
-        CHECK(b.end_pos() == a.end_pos());
-        CHECK(b["b"].start_pos() == a["b"].start_pos());
-        CHECK(b["b"].end_pos() == a["b"].end_pos());
-    }
-
-    SECTION("move constructor resets the moved-from value to npos")
-    {
-        const std::string s = R"({"a":1,"b":[1,2,3]})";
-        json a = json::parse(s);
-        const auto a_start = a.start_pos();
-        const auto a_end = a.end_pos();
-
-        const json b(std::move(a));
-
-        CHECK(b.start_pos() == a_start);
-        CHECK(b.end_pos() == a_end);
-
-        CHECK(a.start_pos() == std::string::npos); // NOLINT(bugprone-use-after-move,clang-analyzer-cplusplus.Move)
-        CHECK(a.end_pos() == std::string::npos); // NOLINT(bugprone-use-after-move,clang-analyzer-cplusplus.Move)
-    }
-
-    SECTION("swap() exchanges positions along with the values")
-    {
-        // basic_json::swap() (and the friend swap() that forwards to it) used
-        // to swap only m_data.m_type/m_data.m_value, leaving
-        // start_position/end_position untouched -- unlike copy-assignment's
-        // operator=(basic_json), which swaps positions as part of its
-        // copy-and-swap implementation. After swap(a, b), each value ended up
-        // with the *other* value's content but its *own* original position.
-        // This is now fixed so that swap() is consistent with copy-assignment.
-        json a = json::parse(R"({"a":1})");
-        json b = json::parse(R"([1,2,3,4,5])");
-        const auto a_start = a.start_pos();
-        const auto a_end = a.end_pos();
-        const auto b_start = b.start_pos();
-        const auto b_end = b.end_pos();
-        // lengths (and thus end positions) differ, which is enough to tell
-        // after the swap whether positions actually moved with the values
-        CHECK(a_end != b_end);
-
-        using std::swap;
-        swap(a, b);
-
-        CHECK(a == json::parse(R"([1,2,3,4,5])"));
-        CHECK(b == json::parse(R"({"a":1})"));
-
-        CHECK(a.start_pos() == b_start);
-        CHECK(a.end_pos() == b_end);
-        CHECK(b.start_pos() == a_start);
-        CHECK(b.end_pos() == a_end);
-
-        // member swap() behaves the same as the free function
-        json c = json::parse(R"({"a":1})");
-        json d = json::parse(R"([1,2,3,4,5])");
-        const auto c_start = c.start_pos();
-        const auto c_end = c.end_pos();
-        const auto d_start = d.start_pos();
-        const auto d_end = d.end_pos();
-
-        c.swap(d);
-
-        CHECK(c.start_pos() == d_start);
-        CHECK(c.end_pos() == d_end);
-        CHECK(d.start_pos() == c_start);
-        CHECK(d.end_pos() == c_end);
-    }
-}
-#endif
-
 // this test relies on parse errors being thrown, so it is skipped when
 // exceptions are disabled (json::parse aborts instead of throwing there)
 #if !defined(JSON_NOEXCEPTION)

tests/src/unit-msgpack.cpp

@@ -1597,91 +1597,6 @@ TEST_CASE("MessagePack")
     }
 }
 
-TEST_CASE("issue #5405 - array reserve for definite-length MessagePack arrays")
-{
-#if !defined(JSON_NOEXCEPTION)
-    // this SECTION relies on catching a thrown exception to distinguish
-    // which of two acceptable, bounded rejections a hostile header took;
-    // under JSON_NOEXCEPTION, JSON_THROW never produces a catchable C++
-    // exception (it aborts instead), so this cannot be tested that way here
-    SECTION("a huge claimed length with no element data must not over-allocate")
-    {
-        // 0xdd: array 32 (four-byte length); claims 0xFFFFFFFF (4294967295)
-        // elements but provides none. max_size() for a std::vector is far
-        // larger than this count, so it does not reject the header outright;
-        // the (capped) reservation must not attempt to allocate space for
-        // billions of elements before the missing data is detected.
-        json _;
-        const std::vector<uint8_t> input = {0xdd, 0xFF, 0xFF, 0xFF, 0xFF};
-        // On a platform where std::size_t is narrower than 64 bits (e.g.
-        // 32-bit), the claimed count 0xFFFFFFFF coincides with that
-        // platform's SIZE_MAX, which some size-narrowing checks treat the
-        // same as detail::unknown_size(); it may then be rejected before
-        // the SAX consumer's own max_size() check (out_of_range.408) rather
-        // than being accepted and only found short of data once the
-        // (capped) reservation looks for element bytes that were never
-        // provided (parse_error.110). Either is an acceptable, bounded
-        // rejection of the hostile header -- the property under test is
-        // that no path attempts to allocate space for billions of elements.
-        bool threw = false;
-        try
-        {
-            _ = json::from_msgpack(input);
-        }
-        catch (const json::parse_error& e)
-        {
-            threw = true;
-            CHECK(e.id == 110);
-            CHECK(std::string(e.what()) == "[json.exception.parse_error.110] parse error at byte 6: syntax error while parsing MessagePack value: unexpected end of input");
-        }
-        catch (const json::out_of_range& e)
-        {
-            threw = true;
-            CHECK(e.id == 408);
-            CHECK(std::string(e.what()).find("excessive") != std::string::npos);
-        }
-        CHECK(threw);
-        CHECK(json::from_msgpack(input, true, false).is_discarded());
-    }
-#endif
-
-    SECTION("arrays of various sizes decode to the same value as before the reserve optimization")
-    {
-        for (const auto size :
-                {
-                    std::size_t{0}, std::size_t{1}, std::size_t{5}, // small
-                    std::size_t{16384},                             // exactly at the reserve cap
-                    std::size_t{20000}                              // above the reserve cap
-                })
-        {
-            CAPTURE(size)
-            json j = json::array();
-            for (std::size_t i = 0; i < size; ++i)
-            {
-                j.push_back(static_cast<int>(i % 1000));
-            }
-
-            const auto packed = json::to_msgpack(j);
-            CHECK(json::from_msgpack(packed) == j);
-        }
-    }
-
-    SECTION("a user-defined SAX consumer is unaffected by the internal DOM reserve optimization")
-    {
-        // the reserve() call is local to json_sax_dom_parser / json_sax_dom_callback_parser;
-        // a custom SAX consumer that does not touch a DOM array sees identical events
-        json j = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            j.push_back(i);
-        }
-        const auto packed = json::to_msgpack(j);
-
-        SaxCountdown scp(1000000); // large enough to never trigger an abort
-        CHECK(json::sax_parse(packed, &scp, json::input_format_t::msgpack));
-    }
-}
-
 // use this testcase outside [hide] to run it with Valgrind
 TEST_CASE("MessagePack nesting does not consume the call stack")
 {

tests/src/unit-regression3.cpp

@@ -27,7 +27,6 @@ using ordered_json = nlohmann::ordered_json;
 #endif
 
 #include <cstdio>
-#include <deque>
 #include <list>
 #include <type_traits>
 #include <utility>
@@ -897,49 +896,4 @@ TEST_CASE("issue #5402 - update(merge_objects=true) overwrites a primitive with
 }
 
 
-TEST_CASE("regression test #5476 - array type without reserve()")
-{
-    // the capacity reserved for definite-length arrays must not require the
-    // array type to have a reserve() member function
-    using deque_json = nlohmann::basic_json<std::map, std::deque>;
-
-    SECTION("std::deque")
-    {
-        const auto j = deque_json::parse(R"({"a":[1,[2,3]],"b":[]})");
-        CHECK(j.dump() == R"({"a":[1,[2,3]],"b":[]})");
-
-        // the binary formats pass a definite length to start_array()
-        CHECK(deque_json::from_cbor(deque_json::to_cbor(j)) == j);
-        CHECK(deque_json::from_msgpack(deque_json::to_msgpack(j)) == j);
-
-        // parse() instantiates the callback parser as well, which reserves too
-        const auto with_callback = deque_json::parse(R"([1,2,3])", [](int /*depth*/, deque_json::parse_event_t /*event*/, deque_json& /*parsed*/) noexcept
-        {
-            return true;
-        });
-        CHECK(with_callback == deque_json({1, 2, 3}));
-    }
-
-    SECTION("std::vector still reserves")
-    {
-        json array = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            array.push_back(i);
-        }
-
-        const auto j = json::from_cbor(json::to_cbor(array));
-        CHECK(j == array);
-        CHECK(j.get_ref<const json::array_t&>().capacity() >= 100);
-    }
-
-    SECTION("the reservation stays capped")
-    {
-        // CBOR array announcing 2^32-1 elements, but truncated right after the
-        // header: the input must be rejected without reserving that capacity
-        const std::vector<std::uint8_t> truncated = {0x9A, 0xFF, 0xFF, 0xFF, 0xFF};
-        CHECK(json::from_cbor(truncated, true, false).is_discarded());
-    }
-}
-
 DOCTEST_CLANG_SUPPRESS_WARNING_POP

tests/src/unit-serialization.cpp

@@ -469,7 +469,7 @@ TEST_CASE("serialization of strings (bulk fast path)")
     SECTION("invalid UTF-8 handling is unaffected by the fast path")
     {
         const json j = std::string("valid\xff" "more");
-        CHECK_THROWS_WITH_AS(utils::ignore_return_value(j.dump()), "[json.exception.type_error.316] invalid UTF-8 byte at index 5: 0xFF", json::type_error&);
+        CHECK_THROWS_WITH_AS(j.dump(), "[json.exception.type_error.316] invalid UTF-8 byte at index 5: 0xFF", json::type_error&);
         CHECK(j.dump(-1, ' ', false, json::error_handler_t::replace) == "\"valid\xef\xbf\xbd" "more\"");
         CHECK(j.dump(-1, ' ', true, json::error_handler_t::replace) == "\"valid\\ufffdmore\"");
         CHECK(j.dump(-1, ' ', false, json::error_handler_t::ignore) == "\"validmore\"");

tests/src/unit-ubjson.cpp

@@ -2315,112 +2315,6 @@ TEST_CASE("UBJSON optimized arrays of a valueless type are bounded")
     }
 }
 
-TEST_CASE("issue #5405 - array reserve for definite-length UBJSON arrays")
-{
-#if !defined(JSON_NOEXCEPTION)
-    // this SECTION relies on catching a thrown exception to distinguish
-    // which of two acceptable, bounded rejections a hostile header took;
-    // under JSON_NOEXCEPTION, JSON_THROW never produces a catchable C++
-    // exception (it aborts instead), so this cannot be tested that way here
-    SECTION("a huge claimed length with no element data must not over-allocate")
-    {
-        // optimized form [$type#count: type 'i' (int8), count as a four-byte
-        // 'l' (int32) of 0x7FFFFFFF (2147483647), but no element data at all.
-        // max_size() for a std::vector is far larger than this count, so it
-        // does not reject the header outright; the (capped) reservation must
-        // not attempt to allocate space for billions of elements before the
-        // missing data is detected.
-        json _;
-        const std::vector<uint8_t> input = {'[', '$', 'i', '#', 'l', 0x7F, 0xFF, 0xFF, 0xFF};
-        // On a platform where std::vector<json>::max_size() is smaller than
-        // the claimed count (e.g. 32-bit, where max_size() is bounded by a
-        // 32-bit SIZE_MAX divided by sizeof(json)), the SAX consumer's own
-        // check rejects the header outright (out_of_range.408, with the
-        // claimed count in the message) instead of accepting it and only
-        // finding it short of data once the (capped) reservation looks for
-        // element bytes that were never provided (parse_error.110). Either
-        // is an acceptable, bounded rejection of the hostile header -- the
-        // property under test is that no path attempts to allocate space
-        // for billions of elements.
-        bool threw = false;
-        try
-        {
-            _ = json::from_ubjson(input);
-        }
-        catch (const json::parse_error& e)
-        {
-            threw = true;
-            CHECK(e.id == 110);
-            CHECK(std::string(e.what()) == "[json.exception.parse_error.110] parse error at byte 10: syntax error while parsing UBJSON number: unexpected end of input");
-        }
-        catch (const json::out_of_range& e)
-        {
-            threw = true;
-            CHECK(e.id == 408);
-            CHECK(std::string(e.what()).find("excessive array size") != std::string::npos);
-        }
-        CHECK(threw);
-
-        // json_sax_dom_parser::start_array()'s max_size() check (unlike the
-        // scanner's own parse_error path) throws unconditionally via
-        // JSON_THROW rather than going through sax->parse_error(), so it is
-        // not gated by allow_exceptions=false on a platform where this
-        // header hits that check (e.g. 32-bit, see above) -- allow either
-        // a discarded result or the same out_of_range it throws with
-        // exceptions enabled.
-        try
-        {
-            CHECK(json::from_ubjson(input, true, false).is_discarded());
-        }
-        catch (const json::out_of_range& e)
-        {
-            CHECK(e.id == 408);
-        }
-    }
-#endif
-
-    SECTION("arrays of various sizes decode to the same value as before the reserve optimization")
-    {
-        for (const auto size :
-                {
-                    std::size_t{0}, std::size_t{1}, std::size_t{5}, // small
-                    std::size_t{16384},                             // exactly at the reserve cap
-                    std::size_t{20000}                              // above the reserve cap
-                })
-        {
-            CAPTURE(size)
-            json j = json::array();
-            for (std::size_t i = 0; i < size; ++i)
-            {
-                j.push_back(static_cast<int>(i % 1000));
-            }
-
-            // exercise both the plain and the optimized [$type#count encoding
-            const auto packed_plain = json::to_ubjson(j);
-            CHECK(json::from_ubjson(packed_plain) == j);
-
-            const auto packed_optimized = json::to_ubjson(j, true, true);
-            CHECK(json::from_ubjson(packed_optimized) == j);
-        }
-    }
-
-    SECTION("a user-defined SAX consumer is unaffected by the internal DOM reserve optimization")
-    {
-        // the reserve() call is local to json_sax_dom_parser / json_sax_dom_callback_parser;
-        // a custom SAX consumer that does not touch a DOM array sees identical events
-        json j = json::array();
-        for (int i = 0; i < 100; ++i)
-        {
-            j.push_back(i);
-        }
-        const auto packed = json::to_ubjson(j, true, true);
-
-        SaxCountdown scp(1000000); // large enough to never trigger an abort
-        CHECK(json::sax_parse(packed, &scp, json::input_format_t::ubjson));
-    }
-}
-
-
 TEST_CASE("Universal Binary JSON Specification Examples 1")
 {
     SECTION("Null Value")