Operator overloading enum class

I'm trying to overload the & operator of an enum class, but I'm getting this compiler error: error: no match for 'operator&=' (operand types are 'int' and 'Numbers'). Any ideas about this?

#include <iostream>
using namespace std;

enum class Numbers : int
{
    zero                    = 0, 
    one                     = 0x01,
    two                     = 0x02
};

inline int operator &(int a, Numbers b)
{
    return ((a) & static_cast<int>(b));
}

int main() {
    int a=1;
    a&=Numbers::one;
    cout << a ;
    return 0;
}