Function front

include/behaviortree_cpp/contrib/json.hpp:21696–21699

@brief access the first element @sa https://json.nlohmann.me/api/basic_json/front/

    /// @brief access the first element
    /// @sa https://json.nlohmann.me/api/basic_json/front/
    reference front()
    {
        return *begin();
    }

    /// @brief access the first element
    /// @sa https://json.nlohmann.me/api/basic_json/front/