c++ - Using a class function in int main() -

i having problems calling functions main program.
these functions have in class.
how access them int main()?

#include <iostream> #include <stdio.h> #include <pthread.h> #include <stdlib.h> #include <math.h> #include <sys/types.h> #include <semaphore.h> #include <synch.h> using namespace std;      class mycountingsemaphoreusingbinarysemaphore {   public:       void waitsemaphore(pthread_mutex_t *thread)       {           pthread_mutex_lock(*thread);// makes value 1 (not available)       }       void signalsemaphore(pthread_mutex_t *thread)       {           pthread_mutex_unlock(*thread); // makes value 0 (available)       }       void deletesemaphore(pthread_mutex_t *thread)        {           pthread_mutex_destroy(*thread);// deletes       }   };   int readercount;    int database = (rand() / 100); // number less 1000   void reader_writer(void);    int main(int argc, char *argv[])   {          mycountingsemaphoreusingbinarysemaphore obj;       pthread_mutex_t mutex1;       pthread_mutex_t wrt;       pthread_create( &mutex1, null, reader_writer, void);       pthread_create( &wrt, null, reader_writer, void);       //----------------------reader------------------------//       do{           cout << "database before read = " << database << endl;           obj.waitsemaphore(mutex1);//lock           readercount++;           if (readercount == 1)           {           obj.waitsemaphore(wrt);//lock           obj.signalsemaphore(mutex1);//unlock           //reading preformed           obj.waitsemaphore(mutex1); // lock           readercount--;           }           if(readercount == 0)           {               obj.signalsemaphore(wrt);//unlock               obj.signalsemaphore(mutex1); // unlock           }           cout << "database after read = " << database << endl;       }while (true);       //-----------------------writer---------------------//       do{           cout << "database before write = " << database << endl;           obj.waitsemaphore(wrt);//lock           //writing preformed           database = database + 10;           obj.signalsemaphore(mutex1);//unlock           cout << "database after write = " << database << endl;       }while(true);       pthread_join( mutex1, null);       pthread_join( wrt, null);        obj.deletesemaphore(* mutex1);       obj.deletesemaphore(* wrt);       return 0;    }   void reader_writer () {}   

here error get:

what type need be? pthread_mutex_t_create? or pthread_t_create?
proper type?

functions inside class called methods. need instantiate object of class able use it's methods:

mycountingsemaphoreusingbinarysemaphore obj; // obj instance of class  obj.waitsemaphore(&mutex1);  obj.signalsemaphore(&mutex1); 

edit:

by way, pthread_create , pthread_join take pthread_t* , not mutex!

int pthread_create(pthread_t* thread,                     pthread_attr_t* attr,                     void* (*start_routine)(void*),                     void* arg);