Assigning different json types (different binary_t type)

[renatossevero]

I have 2 different json types that I would like to convert to each other:

using buffer_t = std::vector<uint64_t>;

using my_json = nlohmann::basic_json <
    std::map,
    std::vector,
    std::string,
    bool,
    std::int64_t,
    std::uint64_t,
    double,
    std::allocator,
    nlohmann::adl_serializer,
    buffer_t
>;

using json = nlohmann::json;

Then I defined the following to_json and from_json functions.

template<typename BinaryType>
void to_json(BinaryType& j, const buffer_t& value) {
    // some code here
}

template<typename BinaryType>
void from_json(const BinaryType& j, buffer_t& value) {
    // some code here
}

But when I try to run the following code I have an assertion:

int main()
{
    my_json mj;
    buffer_t buffer{};

    mj.push_back(static_cast<my_json::binary_t>(buffer));

    nlohmann::json j;
    j = mj;
    return 0;
}

/usr/include/nlohmann/json.hpp:895: nlohmann::json_abi_v3_11_3::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType, CustomBaseClass>::basic_json(const BasicJsonType&) [with BasicJsonType = nlohmann::json_abi_v3_11_3::basic_json<std::map, std::vector, std::__cxx11::basic_string<char>, bool, long int, long unsigned int, double, std::allocator, nlohmann::json_abi_v3_11_3::adl_serializer, std::vector<long unsigned int> >; typename std::enable_if<(nlohmann::json_abi_v3_11_3::detail::is_basic_json<BasicJsonType>::value && (! std::is_same<nlohmann::json_abi_v3_11_3::basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType, CustomBaseClass>, BasicJsonType>::value)), int>::type <anonymous> = 0; ObjectType = std::map; ArrayType = std::vector; StringType = std::__cxx11::basic_string<char>; BooleanType = bool; NumberIntegerType = long int; NumberUnsignedType = long unsigned int; NumberFloatType = double; AllocatorType = std::allocator; JSONSerializer = nlohmann::json_abi_v3_11_3::adl_serializer; BinaryType = std::vector<unsigned char>; CustomBaseClass = void]: Assertion `m_data.m_type == val.type()' failed.
Aborted (core dumped)

Any ideas what could be wrong?
I thought it could be related to issue 977, but no luck so far.

[gregmarr]

You are using static_cast to try to convert std::vector<uint64_t> to nlohmann::byte_container_with_subtype<std::vector<uint64_t>>. That is not valid, and is going to result in reading outside the bounds of the buffer object when the library tries to access the m_subtype and m_has_subtype members of the binary_t.