c++ - Calling one templated function isn't working -

c++ - Calling one templated function isn't working -

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isn't template argument (the signature) of std::function part of type? 4 answers

i don't know how phone call function call.

it's templated class, templated function call. how can utilize code?

#include <iostream> #include <conio.h> #include <functional> template <typename result> class imp { template <typename ...args> int call(std::function<result(args...)> func, args... args) { homecoming 0; } }; int f(double a, double b) { homecoming (int)a+b; } int main() { imp<int> a; a.call<double, double>(f, 1., 1.); //! } error c2784: 'int imp<int>::call(std::function<result(args...)>,args...)' : not deduce template argument 'overloaded function type' 'overloaded function type' [ result=int ] : see declaration of 'imp<int>::call'

you can't pass a function pointer std::function ( see question )

change :

template <typename result> class imp { public: template <class func,typename ...args> int call(func f, args... args) { homecoming 0; } }; int f(double a, double b) {return (int)a+b;} int main() { imp<int> a; a.call(f, 1., 1.); //! }

ideone

or :

#include <functional> template <typename result> class imp { public: template <typename ...args> int call(std::function<result(args...)> f, args... args) { homecoming 0; } }; int f(double a, double b) {return (int)a+b;} int main() { imp<int> a; a.call(std::function<int(double,double)>(f), 1., 1.); //! }

c++ templates c++11 variadic-templates std-function