I'm trying to make sure my code compiles under gcc-4.3 before that compiler comes out. I'm currently stuck on an error it reports in boost, version 1.34.1 (which I downloaded seconds ago; error was also present in 1.34.0): In file included from ../boost/function/detail/prologue.hpp:16, from ../boost/function.hpp:22, from ../boost/iterator/transform_iterator.hpp:10, from [my code]: ../boost/function/function_base.hpp: In member function 'const std::type_info& boost::function_base::target_type() const': ../boost/function/function_base.hpp:485: error: dereferencing type-punned pointer will break strict-aliasing rules I don't understand how there's any type-punning going on at line 485, although to my untrained eye it looks a lot like it's returning a ref to a temporary. A couple lines later looks only very slightly fishier, but still shouldn't be breaking any aliasing rules. So I leave it to the experts to figure out what's going on here. -- Benoît