http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52522
--- Comment #4 from Dave Steffen <dgsteffen at numerica dot us> 2012-03-07 19:06:56 UTC --- (In reply to comment #2) > The cause for this problem is the currently unconstrained constructor > > template<class InputIter> > vector(InputIter, InputIter); > > but I need to investigate whether this is a language or compiler problem. In > this case the problem should be fixed, once this constructor becomes > constrained (There is work on this in progress, but I have not the bug id > right > at my hands). Ahhh.... gotcha. Thanks. Either way (language or compiler problem) I know how to fix our code. Looks like an explicit qualification, e.g. vector<Matrix>{a,b} makes things happy. Thanks very much for the fast response time -- you guys are great.