How to access and pass as a function parameter nested json objects in for loop?

[dreambeyondorange]

I send a sequence of several messages in a json object like this:

 {
    "msg1" : {
        "time_since_epoch_ms" : 1612969709407,
        "timestamp" : "Wed Feb 10 10:08:29 2021\n",
        "type" : 1305,
        "value" : -999.0
    }
    "msg2" : {
        "time_since_epoch_ms" : 1612969709407,
        "timestamp" : "Wed Feb 10 10:08:29 2021\n",
        "type" : 1305,
        "value" : -999.0
    }
} 

And I'd like to iterate over these messages and pass the nested json to a function.

I keep running into this error during linking undefined reference to `(nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits, std::allocator >, bool, long, unsigned long, double, std::allocator, nlohmann::adl_serializer, std::vector<unsigned char, std::allocator > >)

I have a function
return_t func(nlohmann::json msg);

And I've tried using range based loops like this
for (const auto &msg : incomingJSON->front().items())
with msg.value() as my nested object but when i try to call the function it gives me the above error no matter how i try to call it
func(msg.value());
func(json::parse(msg.value()));

I also tried range based loops like below, which works fine for access within the loop to the objects, but I cannot pass the iterator object as json to another function.

for (auto &msg : json_object) {
                switch ((int)msg["type"]) {
...
                      func(msg);

What is the right way to do this?

[nlohmann]

The return value of items() is not nlohmann::json. You would need to use declytype to derive the type for the definition of func.

[nlohmann]

@dreambeyondorange Do you need further assistance?

[dreambeyondorange]

No, I have found a solution ty!

…

Sent from my iPhone

On Mar 23, 2021, at 1:24 PM, Niels Lohmann ***@***.***> wrote:  @dreambeyondorange Do you need further assistance? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.