const std::string json_text;
boost::json::value json_value = boost::json::parse(json_text);
boost::json::object root = json_value.get_object();

std::string string_key = boost::json::value_to<std::string>(root.at("string_key"));
int int_key = boost::json::value_to<int>(root.at("int_key"));
double double_key = boost::json::value_to<double>(root.at("double_key"));
bool bool_key = boost::json::value_to<bool>(root.at("bool_key"));

const std::string json_text;
std::vector<std::string> units = json::parsing::parse_array(json_text.c_str());
   
// Iterate over root
for (const std::string &unit_text : units) {
        json::jobject unit = json::jobject::parse(unit_text);
        std::map<std::string, std::string> unit_attributes;

        for (const std::string &key : keys) {
            // For some reason, parser adds quotes
            if(unit.has_key(key)) {
                const std::string attribute = unit.get(key);
                const std::string stripped_attribute = attribute.substr(1, attribute.size() - 2);
                unit_attributes[key] = stripped_attribute;
                ...