No more than 10 types in boost::tuple?

I tried constructing a tuple with 12 types today without much luck. I've read through the headers to see if there was any obvious way of getting around the 10 limit but couldn't find one (I half expected to find something along the way of vectorxx<>, in MPL). Am I being stupid, or is there really no way of constructing a tuple with more than 10 elements? Also, are there any plans of integrating and/or making boost::tuple dependant on the MPL? I realize that tuple predates the MPL, but there's no use in duplicating efforts. boost::tuple has it's own compile time IF<> and also provides it's own typelist class which are both readily available in the MPL. Cheers, -- Tarjei