c++: override template member function in parent class -

let's suppose have such structure of classes: base class object, parent class bool, int, float, bytes , unicode classes. before had functions bool cast_bool() const, int cast_int() const, etc. virtual functions in object class , in child classes i've implemented these functions separately.

it seems better solution implement template <typename type> type cast() const function instead. however, since c++ prohibits virtual template functions don't know how can complete task. need provide template <typename type> type cast() const object , childs. generic object::cast<type>() const throw casterror; every type bool, int, etc. i'll implement functions bool::cast<bool>() const, int::cast<bool>() const, etc. i'm planning add cast builtin objects, though overload operator bool() const, operator signed short() const, etc. if there no implementation, template must switch generic form object class, throwing error. there way (perhaps need use pattern)? or easier leave functions int cast_int() const? in advance!

add intermediate class in example below or use dynamic_cast without template methods.

#include <iostream> #include <string> using namespace std;  template <class> class objectimpl;  class object { public:     virtual ~object() {}      template <class t>     t cast() const     {         if (auto obj = dynamic_cast<const objectimpl<t>*>(this))         {             return obj->cast();         }         else         {             throw std::string("cast error");         }     } };  template <class t> class objectimpl : public object { public:     virtual t cast() const = 0; };  class bool : public objectimpl<bool> { public:     bool cast() const override { return true; } }; class float : public objectimpl<float> { public:     float cast() const  override { return 12.34f; } };  int main() {     object* obj = new float;      cout << obj->cast<float>() << endl;      try     {         cout << obj->cast<bool>() << endl;     }     catch (std::string e)     {         cout << e << endl;     }      return 0; }