This code gives me compilation error:

#include <bits/stdc++.h> 

#define debug(x) cerr << #x << ": " << x << endl

using namespace std;

typedef long long ll;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << 2 ^ 3;
  return 0;
}

But when instead of 2 ^ 3 I write (2 ^ 3) it becomes OK. Does anybody know why?