[Boost-users] Looking for arithmetic metafunctions for ratios.

Hi, I'm looking for a metafunction like this: template < class N1, class D1, class N2, class D2 > struct times { typedef ... numer; typedef ... denom; }; N1, D1, N2, and D2 are all MPL integral constant wrappers. The numer member of the times metafunction is the numerator N of the ratio (preferably in reduced form) produced by (N1/D1) * (N2/D2) = (N/D). Likewise, the denom member is the denominator D of the ratio produced from this equation. Any help greatly appreciated. Thanks, Eric.