CHG: explicit size checks and more expressive exceptions for converstion of fixed size containers from json

MNT: updated amalgamation header

include/nlohmann/detail/conversions/from_json.hpp

@@ -164,6 +164,14 @@ template<typename BasicJsonType, typename T, std::size_t N>
 auto from_json(const BasicJsonType& j, T (&arr)[N])
 -> decltype(j.template get<T>(), void())
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != N))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(N) + ", but is " + std::to_string(j.size())));
+    }
     for (std::size_t i = 0; i < N; ++i)
     {
         arr[i] = j.at(i).template get<T>();
@@ -181,6 +189,14 @@ auto from_json_array_impl(const BasicJsonType& j, std::array<T, N>& arr,
                           priority_tag<2> /*unused*/)
 -> decltype(j.template get<T>(), void())
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != N))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(N) + ", but is " + std::to_string(j.size())));
+    }
     for (std::size_t i = 0; i < N; ++i)
     {
         arr[i] = j.at(i).template get<T>();
@@ -326,12 +342,28 @@ void from_json(const BasicJsonType& j, ArithmeticType& val)
 template<typename BasicJsonType, typename A1, typename A2>
 void from_json(const BasicJsonType& j, std::pair<A1, A2>& p)
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != 2))
+    {
+        JSON_THROW(type_error::create(302, "array size must be 2, but is " + std::to_string(j.size())));
+    }
     p = {j.at(0).template get<A1>(), j.at(1).template get<A2>()};
 }
 
 template<typename BasicJsonType, typename Tuple, std::size_t... Idx>
 void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence<Idx...> /*unused*/)
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != sizeof...(Idx)))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(sizeof...(Idx)) + ", but is " + std::to_string(j.size())));
+    }
     t = std::make_tuple(j.at(Idx).template get<typename std::tuple_element<Idx, Tuple>::type>()...);
 }
 

single_include/nlohmann/json.hpp

@@ -3564,6 +3564,14 @@ template<typename BasicJsonType, typename T, std::size_t N>
 auto from_json(const BasicJsonType& j, T (&arr)[N])
 -> decltype(j.template get<T>(), void())
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != N))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(N) + ", but is " + std::to_string(j.size())));
+    }
     for (std::size_t i = 0; i < N; ++i)
     {
         arr[i] = j.at(i).template get<T>();
@@ -3581,6 +3589,14 @@ auto from_json_array_impl(const BasicJsonType& j, std::array<T, N>& arr,
                           priority_tag<2> /*unused*/)
 -> decltype(j.template get<T>(), void())
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != N))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(N) + ", but is " + std::to_string(j.size())));
+    }
     for (std::size_t i = 0; i < N; ++i)
     {
         arr[i] = j.at(i).template get<T>();
@@ -3726,12 +3742,28 @@ void from_json(const BasicJsonType& j, ArithmeticType& val)
 template<typename BasicJsonType, typename A1, typename A2>
 void from_json(const BasicJsonType& j, std::pair<A1, A2>& p)
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != 2))
+    {
+        JSON_THROW(type_error::create(302, "array size must be 2, but is " + std::to_string(j.size())));
+    }
     p = {j.at(0).template get<A1>(), j.at(1).template get<A2>()};
 }
 
 template<typename BasicJsonType, typename Tuple, std::size_t... Idx>
 void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence<Idx...> /*unused*/)
 {
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
+    {
+        JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
+    }
+    if (JSON_HEDLEY_UNLIKELY(j.size() != sizeof...(Idx)))
+    {
+        JSON_THROW(type_error::create(302, "array size must be " + std::to_string(sizeof...(Idx)) + ", but is " + std::to_string(j.size())));
+    }
     t = std::make_tuple(j.at(Idx).template get<typename std::tuple_element<Idx, Tuple>::type>()...);
 }
 
@@ -16686,7 +16718,7 @@ class basic_json
         detail::parser_callback_t<basic_json>cb = nullptr,
         const bool allow_exceptions = true,
         const bool ignore_comments = false
-                                 )
+    )
     {
         return ::nlohmann::detail::parser<basic_json, InputAdapterType>(std::move(adapter),
                 std::move(cb), allow_exceptions, ignore_comments);
@@ -25227,7 +25259,7 @@ template<>
 inline void swap<nlohmann::json>(nlohmann::json& j1, nlohmann::json& j2) noexcept(
     is_nothrow_move_constructible<nlohmann::json>::value&&
     is_nothrow_move_assignable<nlohmann::json>::value
-                              )
+)
 {
     j1.swap(j2);
 }