Make insert(pos, basic_json&&) move its argument instead of copying it

insert(const_iterator pos, basic_json&& val) delegated to
insert(pos, val), but val is a named rvalue reference, so inside the
function it is an lvalue: the call always resolved to
insert(const_iterator, const basic_json&) and deep-copied the value.
This has been the case since the overload was introduced, in every
release. push_back(basic_json&&), by contrast, already moves.

Give the rvalue overload its own body with the same two checks
(type_error.309, invalid_iterator.202), then move the argument into a
local before inserting it. Moving into a local first, rather than
inserting std::move(val) directly, keeps this safe even when val
aliases an element of the same array (e.g.
arr.insert(arr.begin(), std::move(arr[1]))), since
std::vector::insert(pos, T&&) is not guaranteed to handle an argument
that aliases one of its own elements.

This is a deliberate, small behavior change: the moved-from argument
now ends up null afterwards, the same as after push_back(&&), instead
of keeping its old value unchanged. No signature changes, so the
public API and ABI are unaffected. Add unit-modifiers coverage for
the moved-from state and for self-aliasing insertion, both with and
without reallocation of the underlying array.

Part of #5724

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

BUILD.bazel

@@ -51,6 +51,7 @@ cc_library(
         "include/nlohmann/detail/meta/detected.hpp",
         "include/nlohmann/detail/meta/identity_tag.hpp",
         "include/nlohmann/detail/meta/is_sax.hpp",
+        "include/nlohmann/detail/meta/logic.hpp",
         "include/nlohmann/detail/meta/std_fs.hpp",
         "include/nlohmann/detail/meta/type_traits.hpp",
         "include/nlohmann/detail/meta/void_t.hpp",

docs/mkdocs/docs/api/basic_json/meta.md

@@ -13,7 +13,7 @@ JSON object holding version information
 
 | key         | description                                                                                                                                                                                                                                                                    |
 |-------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| `compiler`  | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). On HP aCC compilers, `compiler` is instead the plain string `hp`. |
+| `compiler`  | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `hp`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). |
 | `copyright` | The copyright line for the library as string.                                                                                                                                                                                                                                  |
 | `name`      | The name of the library as string.                                                                                                                                                                                                                                             |
 | `platform`  | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`.                                                                                                                                                                             |

include/nlohmann/detail/conversions/from_json.hpp

@@ -27,6 +27,7 @@
 #include <nlohmann/detail/meta/identity_tag.hpp>
 #include <nlohmann/detail/meta/std_fs.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
+#include <nlohmann/detail/meta/logic.hpp>
 #include <nlohmann/detail/string_concat.hpp>
 #include <nlohmann/detail/value_t.hpp>
 
@@ -428,7 +429,9 @@ inline void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
 }
 
 // overload for arithmetic types, not chosen for basic_json template arguments
-// (BooleanType, etc.)
+// (BooleanType, etc.); note: Is it really necessary to provide explicit
+// overloads for boolean_t etc. in case of a custom BooleanType which is not
+// an arithmetic type?
 template < typename BasicJsonType, typename ArithmeticType,
            enable_if_t <
                std::is_arithmetic<ArithmeticType>::value&&
@@ -524,7 +527,7 @@ inline void from_json_tuple_impl(BasicJsonType&& j, std::pair<A1, A2>& p, priori
 template<typename BasicJsonType, typename... Args>
 std::tuple<Args...> from_json_tuple_impl(BasicJsonType&& j, identity_tag<std::tuple<Args...>> /*unused*/, priority_tag<2> /*unused*/)
 {
-    static_assert(conjunction<disjunction<negation<std::is_reference<Args>>, is_compatible_reference_type<BasicJsonType, Args>>...>::value,
+    static_assert(cxpr_and<cxpr_or<cxpr_not<std::is_reference<Args>>, is_compatible_reference_type<BasicJsonType, Args>>...>::value,
                   "Can not return a tuple containing references to types not contained in a Json, try Json::get_to()");
     return from_json_tuple_impl_base<1, Args...>(std::forward<BasicJsonType>(j), index_sequence_for<Args...> {});
 }
@@ -589,7 +592,7 @@ inline void from_json(const BasicJsonType& j, std::unordered_map<Key, Value, Has
 
 #if JSON_HAS_FILESYSTEM || JSON_HAS_EXPERIMENTAL_FILESYSTEM
 
-// Workaround for MSVC 19.51 (and possibly later): in large cpp files, the compiler may fail to resolve with generic has_from_json (issue #4996)
+// Workaround for MSVC 19.51 (and possibly later): in large in large cpp files, the compiler may fail to resolve with generic has_from_json (issue #4996)
 template<typename BasicJsonType>
 struct has_from_json<BasicJsonType, std_fs::path, void> : std::true_type {};
 

include/nlohmann/detail/iterators/iter_impl.hpp

@@ -60,11 +60,9 @@ class iter_impl // NOLINT(cppcoreguidelines-special-member-functions,hicpp-speci
     static_assert(is_basic_json<typename std::remove_const<BasicJsonType>::type>::value,
                   "iter_impl only accepts (const) basic_json");
     // superficial check for the LegacyBidirectionalIterator named requirement
-    // note: only array_t::iterator is checked here; object_t::iterator may be
-    // a forward-only iterator as long as reverse iteration and operator--
-    // are never used on it
-    static_assert(std::is_base_of<std::bidirectional_iterator_tag, typename std::iterator_traits<typename array_t::iterator>::iterator_category>::value,
-                  "basic_json iterator assumes array type iterators satisfy the LegacyBidirectionalIterator named requirement.");
+    static_assert(std::is_base_of<std::bidirectional_iterator_tag, std::bidirectional_iterator_tag>::value
+                  &&  std::is_base_of<std::bidirectional_iterator_tag, typename std::iterator_traits<typename array_t::iterator>::iterator_category>::value,
+                  "basic_json iterator assumes array and object type iterators satisfy the LegacyBidirectionalIterator named requirement.");
 
   public:
     /// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17.

include/nlohmann/detail/json_pointer.hpp

@@ -583,6 +583,63 @@ class json_pointer
         return *ptr;
     }
 
+    /*!
+    @throw parse_error.106   if an array index begins with '0'
+    @throw parse_error.109   if an array index was not a number
+    @throw out_of_range.402  if the array index '-' is used
+    @throw out_of_range.404  if the JSON pointer can not be resolved
+    */
+    template<typename BasicJsonType>
+    const BasicJsonType& get_checked(const BasicJsonType* ptr) const
+    {
+        for (const auto& reference_token : reference_tokens)
+        {
+            switch (ptr->type())
+            {
+                case detail::value_t::object:
+                {
+                    // note: at performs range check
+                    ptr = &ptr->at(reference_token);
+                    break;
+                }
+
+                case detail::value_t::array:
+                {
+                    if (JSON_HEDLEY_UNLIKELY(reference_token == "-"))
+                    {
+                        // "-" always fails the range check
+                        JSON_THROW(detail::out_of_range::create(402, detail::concat(
+                                "array index '-' (", std::to_string(ptr->m_data.m_value.array->size()),
+                                ") is out of range"), ptr));
+                    }
+
+                    const auto idx = array_index<BasicJsonType>(reference_token);
+                    // Bounds check before access to avoid exception with JSON_NOEXCEPTION
+                    if (JSON_HEDLEY_UNLIKELY(idx >= ptr->m_data.m_value.array->size()))
+                    {
+                        JSON_THROW(detail::out_of_range::create(401, detail::concat(
+                                "array index ", std::to_string(idx), " is out of range"), ptr));
+                    }
+                    ptr = &ptr->operator[](idx);
+                    break;
+                }
+
+                case detail::value_t::null:
+                case detail::value_t::string:
+                case detail::value_t::boolean:
+                case detail::value_t::number_integer:
+                case detail::value_t::number_unsigned:
+                case detail::value_t::number_float:
+                case detail::value_t::binary:
+                case detail::value_t::discarded:
+                default:
+                    JSON_THROW(detail::out_of_range::create(404, detail::concat("unresolved reference token '", reference_token, "'"), ptr));
+            }
+        }
+
+        return *ptr;
+    }
+
     /*!
     @brief return a pointer to the pointed to value, or `nullptr` if the
            pointer cannot be resolved because a key is missing, an array

include/nlohmann/detail/macro_scope.hpp

@@ -9,6 +9,7 @@
 #pragma once
 
 #include <utility> // declval, pair
+#include <nlohmann/detail/meta/detected.hpp>
 #include <nlohmann/thirdparty/hedley/hedley.hpp>
 
 // This file contains all internal macro definitions (except those affecting ABI)
@@ -139,12 +140,10 @@
         // libstdc++ < 11 has incomplete C++20 ranges (issue #4440)
     #elif defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE < 11
         #define JSON_HAS_RANGES 0
-        // clang < 16 with libstdc++ does not implement the ranges customization
-        // points libstdc++ declares, so its C++20 ranges support is incomplete (issue #5161)
+        // libc++ < 16 has incomplete C++20 ranges (issue #4440)
     #elif defined(__clang__) && !defined(__apple_build_version__) \
         && __clang_major__ < 16 && defined(__GLIBCXX__)
         #define JSON_HAS_RANGES 0
-        // libc++ < 16 has incomplete C++20 ranges (issue #4440)
     #elif defined(_LIBCPP_VERSION) && _LIBCPP_VERSION < 160000
         #define JSON_HAS_RANGES 0
         // nvcc CUDA 12.0/12.1 chokes on the enable_borrowed_range variable-template
@@ -306,7 +305,7 @@ void templated_json_throw(ExceptionType exception)
 @brief macro to briefly define a mapping between an enum and JSON with exception
        on invalid input
 @def NLOHMANN_JSON_SERIALIZE_ENUM_STRICT
-@since version 3.13.0
+@since version 3.12.0
 */
 #define NLOHMANN_JSON_SERIALIZE_ENUM_STRICT(ENUM_TYPE, ...)                                     \
     template<typename BasicJsonType>                                                            \
@@ -877,6 +876,30 @@ void templated_json_throw(ExceptionType exception)
     \
     template<typename... T>                                                       \
     using result_of_##std_name = decltype(std_name(std::declval<T>()...));        \
+    }                                                                             \
+    \
+    namespace detail2 {                                                           \
+    struct std_name##_tag                                                         \
+    {                                                                             \
+    };                                                                            \
+    \
+    template<typename... T>                                                       \
+    std_name##_tag std_name(T&&...);                                              \
+    \
+    template<typename... T>                                                       \
+    using result_of_##std_name = decltype(std_name(std::declval<T>()...));        \
+    \
+    template<typename... T>                                                       \
+    struct would_call_std_##std_name                                              \
+    {                                                                             \
+        static constexpr auto const value = ::nlohmann::detail::                  \
+                                            is_detected_exact<std_name##_tag, result_of_##std_name, T...>::value; \
+    };                                                                            \
+    } /* namespace detail2 */ \
+    \
+    template<typename... T>                                                       \
+    struct would_call_std_##std_name : detail2::would_call_std_##std_name<T...>   \
+    {                                                                             \
     }
 
 #ifndef JSON_USE_IMPLICIT_CONVERSIONS

include/nlohmann/detail/meta/call_std/begin.hpp

@@ -12,6 +12,6 @@
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 
-NLOHMANN_CAN_CALL_STD_FUNC_IMPL(begin)
+NLOHMANN_CAN_CALL_STD_FUNC_IMPL(begin);
 
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/meta/call_std/end.hpp

@@ -12,6 +12,6 @@
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 
-NLOHMANN_CAN_CALL_STD_FUNC_IMPL(end)
+NLOHMANN_CAN_CALL_STD_FUNC_IMPL(end);
 
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/meta/detected.hpp

@@ -62,5 +62,9 @@ using detected_or_t = typename detected_or<Default, Op, Args...>::type;
 template<class Expected, template<class...> class Op, class... Args>
 using is_detected_exact = std::is_same<Expected, detected_t<Op, Args...>>;
 
+template<class To, template<class...> class Op, class... Args>
+using is_detected_convertible =
+    std::is_convertible<detected_t<Op, Args...>, To>;
+
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/meta/is_sax.hpp

@@ -8,7 +8,7 @@
 
 #pragma once
 
-#include <cstddef> // size_t
+#include <cstdint> // size_t
 #include <utility> // declval
 #include <string> // string
 
@@ -70,6 +70,37 @@ using parse_error_function_t = decltype(std::declval<T&>().parse_error(
         std::declval<std::size_t>(), std::declval<const std::string&>(),
         std::declval<const Exception&>()));
 
+template<typename SAX, typename BasicJsonType>
+struct is_sax
+{
+  private:
+    static_assert(is_basic_json<BasicJsonType>::value,
+                  "BasicJsonType must be of type basic_json<...>");
+
+    using number_integer_t = typename BasicJsonType::number_integer_t;
+    using number_unsigned_t = typename BasicJsonType::number_unsigned_t;
+    using number_float_t = typename BasicJsonType::number_float_t;
+    using string_t = typename BasicJsonType::string_t;
+    using binary_t = typename BasicJsonType::binary_t;
+    using exception_t = typename BasicJsonType::exception;
+
+  public:
+    static constexpr bool value =
+        is_detected_exact<bool, null_function_t, SAX>::value &&
+        is_detected_exact<bool, boolean_function_t, SAX>::value &&
+        is_detected_exact<bool, number_integer_function_t, SAX, number_integer_t>::value &&
+        is_detected_exact<bool, number_unsigned_function_t, SAX, number_unsigned_t>::value &&
+        is_detected_exact<bool, number_float_function_t, SAX, number_float_t, string_t>::value &&
+        is_detected_exact<bool, string_function_t, SAX, string_t>::value &&
+        is_detected_exact<bool, binary_function_t, SAX, binary_t>::value &&
+        is_detected_exact<bool, start_object_function_t, SAX>::value &&
+        is_detected_exact<bool, key_function_t, SAX, string_t>::value &&
+        is_detected_exact<bool, end_object_function_t, SAX>::value &&
+        is_detected_exact<bool, start_array_function_t, SAX>::value &&
+        is_detected_exact<bool, end_array_function_t, SAX>::value &&
+        is_detected_exact<bool, parse_error_function_t, SAX, exception_t>::value;
+};
+
 template<typename SAX, typename BasicJsonType>
 struct is_sax_static_asserts
 {
@@ -89,6 +120,8 @@ struct is_sax_static_asserts
                   "Missing/invalid function: bool null()");
     static_assert(is_detected_exact<bool, boolean_function_t, SAX>::value,
                   "Missing/invalid function: bool boolean(bool)");
+    static_assert(is_detected_exact<bool, boolean_function_t, SAX>::value,
+                  "Missing/invalid function: bool boolean(bool)");
     static_assert(
         is_detected_exact<bool, number_integer_function_t, SAX,
         number_integer_t>::value,

include/nlohmann/detail/meta/logic.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <nlohmann/detail/macro_scope.hpp>
+
+NLOHMANN_JSON_NAMESPACE_BEGIN
+namespace detail
+{
+#ifdef JSON_HAS_CPP_17
+
+template<bool... Booleans>
+struct cxpr_or_impl : std::integral_constant < bool, (Booleans || ...) > {};
+
+template<bool... Booleans>
+struct cxpr_and_impl : std::integral_constant < bool, (Booleans &&...) > {};
+
+#else
+
+template<bool... Booleans>
+struct cxpr_or_impl : std::false_type {};
+
+template<bool... Booleans>
+struct cxpr_or_impl<true, Booleans...> : std::true_type {};
+
+template<bool... Booleans>
+struct cxpr_or_impl<false, Booleans...> : cxpr_or_impl<Booleans...> {};
+
+template<bool... Booleans>
+struct cxpr_and_impl : std::true_type {};
+
+template<bool... Booleans>
+struct cxpr_and_impl<true, Booleans...> : cxpr_and_impl<Booleans...> {};
+
+template<bool... Booleans>
+struct cxpr_and_impl<false, Booleans...> : std::false_type {};
+
+#endif
+
+template<class Boolean>
+struct cxpr_not : std::integral_constant < bool, !Boolean::value > {};
+
+template<class... Booleans>
+struct cxpr_or : cxpr_or_impl<Booleans::value...> {};
+
+template<bool... Booleans>
+struct cxpr_or_c : cxpr_or_impl<Booleans...> {};
+
+template<class... Booleans>
+struct cxpr_and : cxpr_and_impl<Booleans::value...> {};
+
+template<bool... Booleans>
+struct cxpr_and_c : cxpr_and_impl<Booleans...> {};
+
+}  // namespace detail
+NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/meta/type_traits.hpp

@@ -283,13 +283,6 @@ template<class B, class... Bn>
 struct conjunction<B, Bn...>
 : std::conditional<static_cast<bool>(B::value), conjunction<Bn...>, B>::type {};
 
-// https://en.cppreference.com/w/cpp/types/disjunction
-template<class...> struct disjunction : std::false_type { };
-template<class B> struct disjunction<B> : B { };
-template<class B, class... Bn>
-struct disjunction<B, Bn...>
-: std::conditional<static_cast<bool>(B::value), B, disjunction<Bn...>>::type {};
-
 // https://en.cppreference.com/w/cpp/types/negation
 template<class B> struct negation : std::integral_constant < bool, !B::value > { };
 
@@ -611,6 +604,7 @@ struct is_compatible_integer_type_impl <
     std::is_integral<CompatibleNumberIntegerType>::value&&
     !std::is_same<bool, CompatibleNumberIntegerType>::value >>
 {
+    // is there an assert somewhere on overflows?
     using RealLimits = std::numeric_limits<RealIntegerType>;
     using CompatibleLimits = std::numeric_limits<CompatibleNumberIntegerType>;
 
@@ -804,7 +798,20 @@ struct has_capacity : std::integral_constant<bool, is_detected<detect_capacity,
 // a naive helper to check if a type is an ordered_map (exploits the fact that
 // ordered_map inherits capacity() from std::vector)
 template <typename T>
-struct is_ordered_map : has_capacity<T> {};
+struct is_ordered_map
+{
+    using one = char;
+
+    struct two
+    {
+        char x[2]; // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+    };
+
+    template <typename C> static one test( decltype(&C::capacity) ) ;
+    template <typename C> static two test(...);
+
+    enum { value = sizeof(test<T>(nullptr)) == sizeof(char) }; // NOLINT(cppcoreguidelines-pro-type-vararg,hicpp-vararg,cppcoreguidelines-use-enum-class)
+};
 
 // to avoid useless casts (see https://github.com/nlohmann/json/issues/2893#issuecomment-889152324)
 template < typename T, typename U, enable_if_t < !std::is_same<T, U>::value, int > = 0 >
@@ -828,8 +835,10 @@ using all_signed = conjunction<std::is_signed<Types>...>;
 template<typename... Types>
 using all_unsigned = conjunction<std::is_unsigned<Types>...>;
 
+// there's a disjunction trait in another PR; replace when merged
 template<typename... Types>
-using same_sign = disjunction<all_signed<Types...>, all_unsigned<Types...>>;
+using same_sign = std::integral_constant < bool,
+      all_signed<Types...>::value || all_unsigned<Types...>::value >;
 
 template<typename OfType, typename T>
 using never_out_of_range = std::integral_constant < bool,

include/nlohmann/detail/string_concat.hpp

@@ -39,7 +39,6 @@ inline std::size_t concat_length(const char /*c*/, const Args& ... rest)
 template<typename... Args>
 inline std::size_t concat_length(const char* cstr, const Args& ... rest)
 {
-    // cppcheck-suppress ignoredReturnValue
     return ::strlen(cstr) + concat_length(rest...);
 }
 

include/nlohmann/json.hpp

@@ -110,11 +110,12 @@ struct is_std_optional<std::optional<T>> : std::true_type {};
 @brief a class to store JSON values
 
 @internal
-@invariant The member variables @a m_value and @a m_type have the following
-relationship:
-- If `m_type == value_t::object`, then `m_value.object != nullptr`.
-- If `m_type == value_t::array`, then `m_value.array != nullptr`.
-- If `m_type == value_t::string`, then `m_value.string != nullptr`.
+@invariant The member variables @a m_data.m_value and @a m_data.m_type have
+the following relationship:
+- If `m_data.m_type == value_t::object`, then `m_data.m_value.object != nullptr`.
+- If `m_data.m_type == value_t::array`, then `m_data.m_value.array != nullptr`.
+- If `m_data.m_type == value_t::string`, then `m_data.m_value.string != nullptr`.
+- If `m_data.m_type == value_t::binary`, then `m_data.m_value.binary != nullptr`.
 The invariants are checked by member function assert_invariant().
 
 @note ObjectType trick from https://stackoverflow.com/a/9860911
@@ -174,18 +175,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     }
 
   private:
-    using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t;
-    template<typename BasicJsonType>
-    using internal_iterator = ::nlohmann::detail::internal_iterator<BasicJsonType>;
     template<typename BasicJsonType>
     using iter_impl = ::nlohmann::detail::iter_impl<BasicJsonType>;
     template<typename Iterator>
     using iteration_proxy = ::nlohmann::detail::iteration_proxy<Iterator>;
     template<typename Base> using json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator<Base>;
 
-    template<typename CharType>
-    using output_adapter_t = ::nlohmann::detail::output_adapter_t<CharType>;
-
     template<typename InputType>
     using binary_reader = ::nlohmann::detail::binary_reader<basic_json, InputType>;
     template<typename CharType> using binary_writer = ::nlohmann::detail::binary_writer<basic_json, CharType>;
@@ -326,8 +321,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                     std::to_string(__GNUC_PATCHLEVEL__))
             }
         };
-#elif defined(__HP_cc) || defined(__HP_aCC)
-        result["compiler"] = "hp"
+#elif defined(__HP_aCC)
+        result["compiler"] = {{"family", "hp"}, {"version", __HP_aCC}};
 #elif defined(__IBMCPP__)
         result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}};
 #elif defined(_MSC_VER)
@@ -469,9 +464,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     binary    | binary          | pointer to @ref binary_t
     null      | null            | *no value is stored*
 
-    @note Variable-length types (objects, arrays, and strings) are stored as
-    pointers. The size of the union should not exceed 64 bits if the default
-    value types are used.
+    @note Variable-length types (objects, arrays, strings, and binary
+    values) are stored as pointers. The size of the union should not exceed
+    64 bits if the default value types are used.
 
     @since version 1.0.0
     */
@@ -723,7 +718,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     end of every constructor to make sure that created objects respect the
     invariant. Furthermore, it has to be called each time the type of a JSON
     value is changed, because the invariant expresses a relationship between
-    @a m_type and @a m_value.
+    @a m_data.m_type and @a m_data.m_value.
 
     Furthermore, the parent relation is checked for arrays and objects: If
     @a check_parents true and the value is an array or object, then the
@@ -744,7 +739,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #if JSON_DIAGNOSTICS
         JSON_TRY
         {
-            // cppcheck-suppress assertWithSideEffect
             JSON_ASSERT(!check_parents || !is_structured() || std::all_of(begin(), end(), [this](const basic_json & j)
             {
                 return j.m_parent == this;
@@ -1584,8 +1578,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     /// @brief create a null object
     /// @sa https://json.nlohmann.me/api/basic_json/basic_json/
-    basic_json(std::nullptr_t = nullptr) noexcept // NOLINT(bugprone-exception-escape)
-        : basic_json(value_t::null)
+    basic_json(std::nullptr_t = nullptr) noexcept
     {
         assert_invariant();
     }
@@ -1949,15 +1942,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @brief move constructor
     /// @sa https://json.nlohmann.me/api/basic_json/basic_json/
     basic_json(basic_json&& other) noexcept
-        : json_base_class_t(std::forward<json_base_class_t>(other)),
-          m_data(std::move(other.m_data)) // cppcheck-suppress[accessForwarded] TODO check
+        : json_base_class_t(std::move(static_cast<json_base_class_t&>(other))),
+          m_data(std::move(other.m_data))
 #if JSON_DIAGNOSTIC_POSITIONS
-        , start_position(other.start_position) // cppcheck-suppress[accessForwarded] TODO check
-        , end_position(other.end_position) // cppcheck-suppress[accessForwarded] TODO check
+        , start_position(other.start_position)
+        , end_position(other.end_position)
 #endif
     {
         // check that the passed value is valid
-        other.assert_invariant(false); // cppcheck-suppress[accessForwarded]
+        other.assert_invariant(false);
 
         // invalidate payload
         other.m_data.m_type = value_t::null;
@@ -2524,7 +2517,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 
     @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref
     object_t, @ref string_t, @ref boolean_t, @ref number_integer_t,
-    @ref number_unsigned_t, or @ref number_float_t.
+    @ref number_unsigned_t, @ref number_float_t, or @ref binary_t.
 
     @return pointer to the internally stored JSON value if the requested
     pointer type @a PointerType fits to the JSON value; `nullptr` otherwise
@@ -3050,7 +3043,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         JSON_THROW(type_error::create(306, detail::concat("cannot use value() with ", type_name()), this));
     }
 
-    /// @brief access specified object element via JSON Pointer with default value
+    /// @brief access specified object element with default value
     /// @sa https://json.nlohmann.me/api/basic_json/value/
     template < class ValueType, class KeyType, class ReturnType = typename value_return_type<ValueType>::type,
                detail::enable_if_t <
@@ -3208,21 +3201,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                     JSON_THROW(invalid_iterator::create(205, "iterator out of range", this));
                 }
 
-                if (is_string())
-                {
-                    AllocatorType<string_t> alloc;
-                    std::allocator_traits<decltype(alloc)>::destroy(alloc, m_data.m_value.string);
-                    std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_data.m_value.string, 1);
-                    m_data.m_value.string = nullptr;
-                }
-                else if (is_binary())
-                {
-                    AllocatorType<binary_t> alloc;
-                    std::allocator_traits<decltype(alloc)>::destroy(alloc, m_data.m_value.binary);
-                    std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_data.m_value.binary, 1);
-                    m_data.m_value.binary = nullptr;
-                }
-
+                m_data.m_value.destroy(m_data.m_type);
+                m_data.m_value = {};
                 m_data.m_type = value_t::null;
                 assert_invariant();
                 break;
@@ -3274,27 +3254,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
             case value_t::string:
             case value_t::binary:
             {
-                if (JSON_HEDLEY_LIKELY(!first.m_it.primitive_iterator.is_begin()
-                                       || !last.m_it.primitive_iterator.is_end()))
+                if (JSON_HEDLEY_UNLIKELY(!first.m_it.primitive_iterator.is_begin()
+                                         || !last.m_it.primitive_iterator.is_end()))
                 {
                     JSON_THROW(invalid_iterator::create(204, "iterators out of range", this));
                 }
 
-                if (is_string())
-                {
-                    AllocatorType<string_t> alloc;
-                    std::allocator_traits<decltype(alloc)>::destroy(alloc, m_data.m_value.string);
-                    std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_data.m_value.string, 1);
-                    m_data.m_value.string = nullptr;
-                }
-                else if (is_binary())
-                {
-                    AllocatorType<binary_t> alloc;
-                    std::allocator_traits<decltype(alloc)>::destroy(alloc, m_data.m_value.binary);
-                    std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_data.m_value.binary, 1);
-                    m_data.m_value.binary = nullptr;
-                }
-
+                m_data.m_value.destroy(m_data.m_type);
+                m_data.m_value = {};
                 m_data.m_type = value_t::null;
                 assert_invariant();
                 break;
@@ -4076,7 +4043,22 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/insert/
     iterator insert(const_iterator pos, basic_json&& val) // NOLINT(performance-unnecessary-value-param)
     {
-        return insert(std::move(pos), val);
+        // insert only works for arrays
+        if (JSON_HEDLEY_LIKELY(is_array()))
+        {
+            // check if iterator pos fits to this JSON value
+            if (JSON_HEDLEY_UNLIKELY(pos.m_object != this))
+            {
+                JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value", this));
+            }
+
+            // moving into a local first keeps this safe even if val aliases
+            // an element of this array
+            basic_json tmp(std::move(val));
+            return insert_iterator(pos, std::move(tmp));
+        }
+
+        JSON_THROW(type_error::create(309, detail::concat("cannot use insert() with ", type_name()), this));
     }
 
     /// @brief inserts copies of element into array
@@ -4417,7 +4399,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/swap/
     void swap(binary_t& other) // NOLINT(bugprone-exception-escape,cppcoreguidelines-noexcept-swap,performance-noexcept-swap)
     {
-        // swap only works for strings
+        // swap only works for binary values
         if (JSON_HEDLEY_LIKELY(is_binary()))
         {
             using std::swap;
@@ -4433,7 +4415,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/swap/
     void swap(typename binary_t::container_type& other) // NOLINT(bugprone-exception-escape)
     {
-        // swap only works for strings
+        // swap only works for binary values
         if (JSON_HEDLEY_LIKELY(is_binary()))
         {
             using std::swap;
@@ -4913,7 +4895,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                             const bool ignore_trailing_commas = false)
     {
         basic_json result;
-        parser(detail::input_adapter(std::forward<InputType>(i)), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas).parse(true, result); // cppcheck-suppress[accessMoved,accessForwarded]
+        auto p = parser(detail::input_adapter(std::forward<InputType>(i)), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
+        p.parse(true, result);
         return result;
     }
 
@@ -4930,7 +4913,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                             const bool ignore_trailing_commas = false)
     {
         basic_json result;
-        parser(detail::input_adapter(std::move(first), std::move(last)), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas).parse(true, result); // cppcheck-suppress[accessMoved]
+        auto p = parser(detail::input_adapter(std::move(first), std::move(last)), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
+        p.parse(true, result);
         return result;
     }
 
@@ -4943,7 +4927,8 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                             const bool ignore_trailing_commas = false)
     {
         basic_json result;
-        parser(i.get(), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas).parse(true, result); // cppcheck-suppress[accessMoved]
+        auto p = parser(i.get(), std::move(cb), allow_exceptions, ignore_comments, ignore_trailing_commas);
+        p.parse(true, result);
         return result;
     }
 
@@ -5151,6 +5136,31 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     }
 #endif
 
+  private:
+    /*!
+    @brief shared implementation of the binary from_cbor/from_msgpack/
+           from_ubjson/from_bjdata/from_bon8/from_bson overloads
+
+    Building the @ref binary_reader as a named local, rather than as a
+    temporary that @ref detail::json_sax_dom_parser::parse is called on in
+    the same expression, avoids a false-positive cppcheck accessMoved
+    warning in each of the 16 callers.
+    */
+    template<typename InputAdapterType>
+    static basic_json from_binary_impl(InputAdapterType ia, const input_format_t format,
+                                       const bool strict, const bool allow_exceptions,
+                                       const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
+    {
+        basic_json result;
+        detail::json_sax_dom_parser<basic_json, InputAdapterType> sdp(result, allow_exceptions);
+        binary_reader<InputAdapterType> reader(std::move(ia), format);
+        if (!reader.sax_parse(format, &sdp, strict, tag_handler))
+        {
+            result = value_t::discarded;
+        }
+        return result;
+    }
+
     //////////////////////////////////////////
     // binary serialization/deserialization //
     //////////////////////////////////////////
@@ -5323,14 +5333,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor).sax_parse(input_format_t::cbor, &sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::cbor, strict, allow_exceptions, tag_handler);
     }
 
     /// @brief create a JSON value from an input in CBOR format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5343,14 +5346,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor).sax_parse(input_format_t::cbor, &sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::cbor, strict, allow_exceptions, tag_handler);
     }
 
     template<typename T>
@@ -5371,15 +5367,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool allow_exceptions = true,
                                 const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
     {
-        basic_json result;
-        auto ia = i.get();
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor).sax_parse(input_format_t::cbor, &sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(i.get(), input_format_t::cbor, strict, allow_exceptions, tag_handler);
     }
 
     /// @brief create a JSON value from an input in MessagePack format
@@ -5390,14 +5378,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                    const bool strict = true,
                                    const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack).sax_parse(input_format_t::msgpack, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::msgpack, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in MessagePack format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5409,14 +5390,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                    const bool strict = true,
                                    const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack).sax_parse(input_format_t::msgpack, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::msgpack, strict, allow_exceptions);
     }
 
     template<typename T>
@@ -5435,15 +5409,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                    const bool strict = true,
                                    const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = i.get();
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack).sax_parse(input_format_t::msgpack, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(i.get(), input_format_t::msgpack, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in UBJSON format
@@ -5454,14 +5420,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson).sax_parse(input_format_t::ubjson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::ubjson, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in UBJSON format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5473,14 +5432,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson).sax_parse(input_format_t::ubjson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::ubjson, strict, allow_exceptions);
     }
 
     template<typename T>
@@ -5499,15 +5451,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = i.get();
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson).sax_parse(input_format_t::ubjson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(i.get(), input_format_t::ubjson, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BJData format
@@ -5518,14 +5462,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata).sax_parse(input_format_t::bjdata, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::bjdata, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BJData format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5537,14 +5474,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                   const bool strict = true,
                                   const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata).sax_parse(input_format_t::bjdata, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bjdata, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BON8 format
@@ -5555,14 +5485,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bon8).sax_parse(input_format_t::bon8, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::bon8, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BON8 format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5574,14 +5497,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bon8).sax_parse(input_format_t::bon8, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bon8, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BSON format
@@ -5592,14 +5508,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::forward<InputType>(i));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson).sax_parse(input_format_t::bson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::forward<InputType>(i)), input_format_t::bson, strict, allow_exceptions);
     }
 
     /// @brief create a JSON value from an input in BSON format (iterator pair, or iterator+sentinel pair for C++20 ranges support)
@@ -5611,14 +5520,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = detail::input_adapter(std::move(first), std::move(last));
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson).sax_parse(input_format_t::bson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(detail::input_adapter(std::move(first), std::move(last)), input_format_t::bson, strict, allow_exceptions);
     }
 
     template<typename T>
@@ -5637,15 +5539,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                                 const bool strict = true,
                                 const bool allow_exceptions = true)
     {
-        basic_json result;
-        auto ia = i.get();
-        detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson).sax_parse(input_format_t::bson, &sdp, strict)) // cppcheck-suppress[accessMoved]
-        {
-            result = value_t::discarded;
-        }
-        return result;
+        return from_binary_impl(i.get(), input_format_t::bson, strict, allow_exceptions);
     }
     /// @}
 

tests/src/unit-modifiers.cpp

@@ -618,6 +618,49 @@ TEST_CASE("modifiers")
             }
         }
 
+        SECTION("rvalue at position moves rather than copies")
+        {
+            // regression test: insert(pos, basic_json&&) used to forward to
+            // insert(pos, const basic_json&) because the named rvalue
+            // reference parameter is itself an lvalue, so it always
+            // deep-copied its argument instead of moving it
+            json j_big = std::string(1000, 'x');
+            const auto* const original_buffer = j_big.get_ref<const std::string&>().data();
+
+            auto it = j_array.insert(j_array.begin(), std::move(j_big));
+            CHECK(j_array.size() == 5);
+            CHECK(*it == json(std::string(1000, 'x')));
+            CHECK((*it).get_ref<const std::string&>().data() == original_buffer);
+
+            // the moved-from value is null, the same as after push_back(&&)
+            CHECK(j_big.is_null()); // NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)
+        }
+
+        SECTION("self-aliasing insertion")
+        {
+            SECTION("without reallocation")
+            {
+                json j_self = {1, 2, 3, 4};
+                j_self.get_ref<json::array_t&>().reserve(j_self.size() + 1);
+
+                auto it = j_self.insert(j_self.begin(), std::move(j_self[1]));
+                CHECK(j_self.size() == 5);
+                CHECK(*it == json(2));
+                CHECK(j_self == json({2, 1, nullptr, 3, 4}));
+            }
+
+            SECTION("with reallocation")
+            {
+                json j_self = {1, 2, 3, 4};
+                j_self.get_ref<json::array_t&>().shrink_to_fit();
+
+                auto it = j_self.insert(j_self.begin(), std::move(j_self[1]));
+                CHECK(j_self.size() == 5);
+                CHECK(*it == json(2));
+                CHECK(j_self == json({2, 1, nullptr, 3, 4}));
+            }
+        }
+
         SECTION("copies at position")
         {
             SECTION("insert before begin()")

tests/src/unit-type_traits.cpp

@@ -10,14 +10,10 @@
 
 #if JSON_TEST_USING_MULTIPLE_HEADERS
     #include <nlohmann/detail/meta/type_traits.hpp>
-    #include <nlohmann/ordered_map.hpp>
 #else
     #include <nlohmann/json.hpp>
 #endif
 
-#include <map>
-#include <string>
-
 TEST_CASE("type traits")
 {
     SECTION("is_c_string")
@@ -87,12 +83,4 @@ TEST_CASE("type traits")
             }
         }
     }
-
-    SECTION("is_ordered_map")
-    {
-        using nlohmann::detail::is_ordered_map;
-
-        CHECK(is_ordered_map<nlohmann::ordered_map<std::string, int>>::value);
-        CHECK_FALSE(is_ordered_map<std::map<std::string, int>>::value);
-    }
 }