docs/examples/nlohmann_json_version.cpp

#include <iostream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main()
{
    std::cout << "JSON for Modern C++ version "
              << NLOHMANN_JSON_VERSION_MAJOR << "."
              << NLOHMANN_JSON_VERSION_MINOR << "."
              << NLOHMANN_JSON_VERSION_PATCH << std::endl;
}