Hi, I've got a Karma generator that should emit a vector of records, writing out the index of every entry at the start. My code looks like this (note that GEOPOINT is a fusion-adapted struct of two doubles): typedef std::vector<GEOPOINT> Contour; typedef std::vector<Contour> Poly; rule<Iterator, GEOPOINT()> point; rule<Iterator, Contour(int)> contour; rule<Iterator, locals<int>, Poly()> polygon; rule<Iterator, Poly()> start; point = L';' << double_ << L';' << double_; contour = L";SUBPOLYGON " << lit(_r1 - 1) << L" POINTS " << lit(phoenix::size(_val)) << L" MASK XOR" << *point; polygon = L"POLYGON COUNT " << lit(phoenix::size(_val)) << *(contour(_a)[++_a]); start = polygon; This doesn't work. If I take away the modification of _a, it works, except that of course the index is 0 in every iteration. But the moment I modify _a in any way (including assigning to it anywhere in the polygon rule), suddenly contour seems to get an incorrect attribute: it never fails, but never emits points either, i.e. I get an endless string of ";SUBPOLYGON 1 POINTS 0 MASK XOR;SUBPOLYGON 2 POINTS 0 MASK XOR;SUBPOLYGON 3 POINTS 0 MASK XOR...". Any idea why that is? Sebastian