[boost] tuple and virtual functions

I'm having a problem with Boost.Tuple virtual functions. Consider the code below, I would have expected the output to be "B::foo()" but instead get "A::foo()". Am I missing something here? #include <boost/tuple/tuple.hpp> #include <iostream> class A { public: virtual void foo() { std::cout << "A::foo()" << std::endl; } }; class B :public A { public: void foo() { std::cout << "B::foo()" << std::endl; } }; boost::tuple< A > make( const A& a ) { return boost::make_tuple( a ); } int main( int argc, char* argv[] ) { B b; make( b ).get< 0 >().foo(); return 0; }