I am using Dev-C++ with boost 1.34.1,the program is the following: ....................... typedef std::map<int, int> IIPrimemap; IIPrimemap primemapvec; # define BetaKGre2 1 # define EqualToOne 2 #define ProductOfKPrime 3 ......................... (switch_statement(_1, case_statement<BetaKGre2> (var(result)=0), case_statement<EqualToOne> (var(result)=1), case_statement<ProductOfKPrime> (var(result)=bind(static_cast<long double (*)(long double,int)>(std::pow), constant(-1.0),bind(&IIPrimemap::size,var(primemapvec)))), default_statement ( var(result)=234) ))(switchvalue); the complier told me no errors.But the linker told me that: nstantiated from `Arg::sig<boost::tuples::tuple<A&, B&, C&, Env&, boost::tuples::null_type, boost::tuples::null_type, boost......... instantiated from `RET boost::lambda::lambda_functor_base<boost::lambda::s................ nstantiated from `T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, bo........... instantiated from here..........// indicating the line: ))(switchvalue); And after the second compling and linking , the program passed and ran. I do not know why. And this was caused after I added the line: (var(result)=bind(static_cast<long double (*)(long double,int)>(std::pow), constant(-1.0),bind(&IIPrimemap::size,var(primemapvec)))), otherwise the program do not have such problems. How can I solve it? Can anyone with kindness help me?