c++ - Invoking member of an object from another one by using `std::function` -

i'm trying create communication system between objects, in controller object keeps vector of member functions of other objects, , calls/invokes them when needed.
read several articles usage of std::function, couldn't find 1 covers use case.

my code is:

#include <functional> #include <windows.h>  class callable {  };  class classa : public callable {     public:         double callthis(double x, int y) const         {             messageboxw(null, l"callthis() called.", l"in classa", mb_iconinformation);             return x + y;         } };  class classb : public callable {     public:         double callme(double x, int y) const         {             messageboxw(null, l"callme() called.", l"in classb", mb_iconinformation);             return x + y;         } };  class caller {     public:         void addsubscriber( const callable & objecttocall,                             const std::function<double(const callable &, double, int)> & subscriber)         {             subscribers.push_back(subscriber);             objectstobecalled.push_back(objecttocall);         }         void callsubscribers()         {             (size_t i=0; i<subscribers.size(); i++)             {                 subscribers[i](objectstobecalled[i], 1.0, 2);             }         }     private:         std::vector<std::function<double(const callable &, double, int)>> subscribers;         std::vector<const callable &> objectstobecalled; };  int apientry wwinmain(  _in_        hinstance   hinstance,                         _in_opt_    hinstance   hprevinstance,                         _in_        lptstr      lpcmdline,                         _in_        int         ncmdshow) {     // ...      classa objecta;     classb objectb;     caller objectcaller;     objectcaller.addsubscriber(objecta, &classa::callthis);     objectcaller.addsubscriber(objecta, &classb::callme);     sleep(5000);     objectcaller.callsubscribers();      // ... } 

the strange that, when run code don't compiler errors in own code, errors stl files xmemory0 , vector. errors are:

error 1  xmemory0  527 error c2528: 'pointer' : pointer reference illegal error 2  xmemory0  528 error c2528: 'const_pointer' : pointer reference illegal error 3  xmemory0  561 error c2535: 'const callable &(*std::allocator<_ty>::address(const callable &) throw() const)' : member function defined or declared error 4  xmemory0  599 error c2528: '_ptr' : pointer reference illegal error 5  xmemory0  604 error c2528: '_ptr' : pointer reference illegal error 6  xmemory0  700 error c2528: 'pointer' : pointer reference illegal error 7  xmemory0  701 error c2528: 'const_pointer' : pointer reference illegal error 8  xmemory0  824 error c2535: 'const callable &(*std::_wrap_alloc<_alloc>::address(const callable &) const)' : member function defined or declared error 9  xmemory0  890 error c2528: '_ptr' : pointer reference illegal error 10 xmemory0  105 error c2528: 'abstract declarator' : pointer reference illegal error 11 xmemory0  107 error c2528: 'abstract declarator' : pointer reference illegal error 12 xmemory0  122 error c2528: 'pointer' : pointer reference illegal error 13 xmemory0  123 error c2528: 'const_pointer' : pointer reference illegal error 14 vector    773 error c2528: '_pval' : pointer reference illegal error 15 vector   1184 error c2535: 'void std::vector<_ty>::push_back(const callable &)' : member function defined or declared error 16 vector   1245 error c2535: 'std::_vector_iterator<_myvec> std::vector<_ty>::insert(std::_vector_const_iterator<_myvec>,_ty)' : member function defined or declared error 17 vector   1494 error c2528: '_ptr' : pointer reference illegal error 18 vector   1658 error c2528: '_pval' : pointer reference illegal 

what doing wrong? how make code run?

(my ide microsoft visual studio 2012.)

looking @ code, looks better off storing std::function<double(double, int)>, , use std::bind bind objects member functions.

template <typename f> void addsubscriber( const callable & obj,                     f subscriber) {     subscribers.push_back(std::bind(subscriber, obj, _1, _2)); } 

or de-couple callable caller completely, passing convertible std::function<double(double, int)> directly:

class caller  { public:   template <typename f>   void addsubscriber(f&& subscriber)   {      subscribers.emplace_back(std::forward<f>(subscriber));   }   void callsubscribers()   {       (const auto& subscriber : subscribers)       {           subscriber(1.0, 2);       }   }  private:   std::vector<std::function<double(double, int)> subscribers; }; 

and binding caller side.

caller c; classa a; using namespace std::placeholders; c.addsubscriber(std::bind(&classa::callthis, a, _1, _2));