If I instantiate a Boost.Variant templated on a bool and a std::string , then I get the following behaviour ... not sure why #include <string> #include typedef boost::variant< bool,std::string> BoostVariant; int main () { BoostVariant v("A String"); bool &Bref ( boost::get(v)) ; // this is ok std::string &Sref ( boost::getstd::string &(v) ) ; // but this throws return 0; } Is this what is supposed to happen ? Ninds