Invalid parsed value for big integer

[ammarfaizi2]

What is the issue you have?

I have a JSON string like this

{
    "message": {
        "chat": {
            "id": -1001128970273,
            "title": "Private Cloud",
            "type": "supergroup"
        }
    }
}

Then, I want to get the ["message"]["chat"]["id"], but cannot get the correct value.

Please describe the steps to reproduce the issue. Can you provide a small but working code example?

Example code

#include <cstdio>
#include "include/json.hpp"

using json = nlohmann::json;

int main() {
	json me = json::parse("{\"message\":{\"chat\":{\"id\":-1001128970273,\"title\":\"Private Cloud\",\"type\":\"supergroup\"}}}");

	int me_int = me["message"]["chat"].value("id", 0);
	long me_long = me["message"]["chat"].value("id", 0);
	long long me_long_long = me["message"]["chat"].value("id", 0);

	printf("Int: %d\n", me_int);
	printf("Long: %ld\n", me_long);
	printf("Long long: %lld\n", me_long_long);
}

What is the actual behavior?

Program output:

ammarfaizi2@CraynerCenter:~/project/now/bot-s6$ g++ test.cpp -o test
ammarfaizi2@CraynerCenter:~/project/now/bot-s6$ ./test
Int: -401590305
Long: -401590305
Long long: -401590305

What is the expected behavior?

Expected result

How can I get the -1001128970273 value?

Which compiler and operating system are you using? Is it a supported compiler?

Compiler Detail:

ammarfaizi2@CraynerCenter:~/project/now/bot-s6/build$ g++ --version
g++ (Ubuntu 7.3.0-27ubuntu1~18.04) 7.3.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

OS Detail:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Linux Lite 4.0"
NAME="Ubuntu"
VERSION="18.04.2 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.2 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

Did you use a released version of the library or the version from the develop branch?

I used the released version (downloaded from: https://github.com/nlohmann/json/releases/download/v3.6.1/json.hpp)

• If you experience a compilation error: can you compile and run the unit tests?
  I will check it up soon.

[nlohmann]

The problem seems to be that the literal 0 is used to derive the return type of value. This is the overload:

template<class ValueType, typename std::enable_if<
             std::is_convertible<basic_json_t, ValueType>::value, int>::type = 0>
ValueType value(const typename object_t::key_type& key, const ValueType& default_value)

In case for 0, the return type is int all the time. If you change the calls to 0L or 0LL the result is -1001128970273.

[ammarfaizi2]

@nlohmann Thank you for your assistance