Function is_array

include/behaviortree_cpp/contrib/json.hpp:20666–20669

@brief return whether value is an array @sa https://json.nlohmann.me/api/basic_json/is_array/

    /// @brief return whether value is an array
    /// @sa https://json.nlohmann.me/api/basic_json/is_array/
    constexpr bool is_array() const noexcept
    {
        return m_data.m_type == value_t::array;
    }

    /// @brief return whether value is a string
    /// @sa https://json.nlohmann.me/api/basic_json/is_string/