ошибка с C++ error expected primary-expression before ') ' token

Пишу калькулятор, и ошибка

error expected primary-expression before ') ' token

еще ошибка

error expected primary-expression before '/' token

#include <iostream>
#include <math.h>

using namespace std;
int main ()
{
    int a, b, y;
    cout << "y ";
    cin >> y;
    cout << "a ";
    cin >> a;
    cout << "b ";
    cin >> b;
    if (y == +) {
        int c = a + b;
    } else if (y == -) {
        int c = a - b;
    } else if (y == *)  {
        int c = a * b;
    } else if (y == /) {
        int c = a / b;
    } else {
        cout << "ERROR" << endl;
    }
    cout << c
    
return 0;
}