What happens when you attempt to compile and run the following code?

What happens when you attempt to compile and run the following code?

#include

#include

#include

using namespace std;

class A {

int a;

public:

A(int a) : a(a) {}

int getA() const { return a; } void setA(int a) { this?>a = a; }

bool operator < (const A & b) const { return a

};

struct Compare {

bool operator ()(A & a) {

if (a.getA() < 5) return true;

return false;

}

};

int main () {

int t[] = {1,2,3,2,3,5,1,2,7,3,2,1,10, 4,4,5};

set d (t,t+15);

int number = count_if(d.begin(), d.end(), Compare());

cout<< number<

return 0;

}

Program outputs: