[Boost-users] accumulator extended quantil value

Hello, I have got created an extended_p_square_quantile into an accumulator, with 3 quantils (0.25, 0.5, 0.75) as a boost::array. How can I get access to the quantil values of the accumulator? For the variance I use accumulator::variance(myacc), but a call with quantil(myacc, 0.5) does not work. Thanks Phil