How to deal with base class and pointer variable in argument - c++

Question

I am trying to deal with abstract class argument, trying to figure out what to do, after running this code below getting the error : "In function 'int main()': 67:12: error: expected primary-expression before ')' token"
#include <iostream>
#include <string>
using namespace std;
class base1 {
protected:
int i;
public:
base1(int x) {
i=x;
cout << "Constructing base1\n";
}
virtual ~base1() {
cout << "Destructing base1\n";
}
};
class derived: public base1 {
int j;
public:
derived(int x, int y): base1(y){
j=x;
cout << "Constructing derived\n";
}
~derived() {
cout << "Destructing derived\n";
}
void show() {
cout << i << " " << j << " " << "\n";
}
};
class Isolver
{
public :
Isolver(){};
virtual ~ Isolver(){};
virtual void x(base1* pboard)=0;
};
class vr:public Isolver
{
void x(base1* pboard)
{
cout << "My virtual fun and base constructor are not working\n"<<endl;
};
};
int main()
{
vr obj;
obj. x(10, );
derived ob(3,4);
ob.show();
return 0;
}

Answer 1

Like Paul Rooney pointed out the comma inside obj.x(10,) should not be there because with the comma the compiler is expecting two arguments and since there is nothing after the comma it shows an error.
This is what you need to do inside main:
vr obj;
base1 b(1);
obj. x(&b);
or this:
vr obj;
derived ob(3,4);
obj. x(&ob);
ob.show();
and inside class vr
class vr:public Isolver
{
public:
void x(base1* pboard)
{
cout << "My virtual fun and base constructor are not working\n"<<endl;
}
};