How to pass object whose constructor consist of one argument to a function in C++? [duplicate]

Answer 1

Here's the corrected code.

#include
using namespace std;
class A{
    int val;
public:
    A(int val){
        this->val=val;
    }
};
class B{
    A a;
    public:
    B(A& x):a(x) {
    }
};
int main(){
    A tempa(3);
    B tempb(tempa);
}

Corrections are:

1. Both Constructors of A and B should be public
2. Instead of assignment, let B constructor call A's copy constructor