C++ toString member-function and ostream operator << integration via templates -

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i'm beginner c++ developer , have question tostring , ostream operator integration via templates. have such code:

    struct methodcheckertypes{         typedef unsigned char truetype;         typedef long falsetype;     };     template<typename t>struct hastostring{         template<typename k>static typename methodcheckertypes::truetype test(decltype(&k::tostring));         template<typename> static typename methodcheckertypes::falsetype test(...);         static const bool value = sizeof(test<t>(0)) == sizeof(typename methodcheckertypes::truetype);         typedef decltype(test<t>(0)) valuetype;     };      template<typename t, typename k> struct ifdef{};     template<> struct ifdef<typename methodcheckertypes::truetype, ostream&>{         typedef ostream& type;     };      class withtostring{     public:         string tostring() const{             return "hello";         }     };      template<typename f, typename chart, typename traits> typename ifdef<typename hastostring<f>::valuetype, basic_ostream<chart, traits>&>::type operator<<(basic_ostream<chart, traits>& out, const f &ref){         out<<ref.tostring().c_str();         return out;     } int main(int argc, char **argv){     withtostring hastostring;     cout<<hastostring<<endl;     return 0; }

the code has been compilled without errors, , application executed successfuly. use such approach? wanted implement without boost.

the approach implementing operator<< normal. using parts of language not understand bad practice (i not believe beginner can write such code). have 2 alternatives: implement tostring member function or overload operator<<(std::ostream&, t). latter approach enables use boost::lexical_cast convert object string. me, latter approach more c++ish, if can without member function better so.


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