c++ - Passing template arguments as target type -

in shortened example (not real world code), i'm attempting call callback int &, however, when going via callmethod method, template parameter interpreted int, meaning can't convert target parameter type.

is possible? know can cast parameter correct type when calling callmethod, i'd solution implicit if possible.

#include <functional> #include <iostream>  using namespace std;  void callback(int &value) {     value = 42; }  template <typename method, typename ...params> void callmethod(method method, params ...params) {     method(std::forward<params>(params)...); }  int main() {     int value = 0;     callmethod(&callback, value);      cout << "value: " << value << endl;      return 0; } 

you aren't correctly forwarding arguments. in order make use of perfect-forwarding std::forward should operate on forwarding references, when have rvalue reference in deduced context. callmethod function should this:

template <typename method, typename ...params> void callmethod(method method, params&& ...params) {     method(std::forward<params>(params)...); } 

demo