Eric, The recent changes to the new std_min/std_max caused some unexpected problems in uBLAS. I have narrowed them down to support for boost::numeric::interval in uBLAS. This is picked up by ublas/libs/test7. This test is however not at present part of the regression run. The new std_max (or std_min) is implemented by returning a constant reference to the return value of std::max. This should be OK as std::max similarly returns a const reference to one of its const reference parameters. For gcc this causes some problems when the type is a boost::numeric::interval. The test case is very simple. #include <boost/numeric/interval.hpp> #include <boost/minmax.hpp> int main() { boost::numeric::interval<float> a,b,c; c = boost::std_max(a, a); } gcc (2.95.3 and 3.3.1) is only warning "returning reference to temporary". I am surprised this doesn't show up in more cases. Why gcc thinks it needs a temporary here is beyond me Michael -- ___________________________________ Michael Stevens Systems Engineering ___________________________________