[Boost-users] tuple<...involves template par...>

Hi, I have the following: template<typename T> class A: public std::unary_function&, void>{ public: typedef typename std::unary_function&, void> parent_type; typedef typename parent_type::argument_type argument_type; void operator()(argument_type t)const{ t.get<0>(); //error: expected primary-expression before ')' token t.get<1>(); //error: expected primary-expression before ')' token }; }; Similar code without the template (i.e. fix say T = double) works fine. Anybody, pls help. Thanks.