start p thread with static wrapper around non static function

pthread.cpp

#include <unistd.h>
#include <iostream>
#include <map>
#include <set>
#include <vector>
#include <pthread.h>

class Base{
public:
    int x;
    Base(int x_): x(x_){}
    virtual ~Base(){}
    
    void myFunc( )
    {   
        int N = 10000000;
        for ( int i = 0; i < N; ++i )
        {
            ++x;
        }
    }   
    static void *wrapper( void *VoidBaseInstance )
    {   
        Base* BaseInstance = static_cast<Base *>( VoidBaseInstance );
        BaseInstance->myFunc();
    }   
};

int main(int argc, char** argv){
    Base b(0);
    pthread_t t;
    pthread_create( &t, NULL, &Base::wrapper, &b );
    pthread_detach( t );
    b.myFunc();
    sleep(2);
    std::cout << b.x << std::endl;

}