bitset::any

// bitset::any
#include <iostream>
#include <bitset>
using namespace std;
int main ()
{
  bitset<16> mybits;
  cout << "enter a binary number: ";
  cin >> mybits;
  if (mybits.any())
    cout << "mybits has " << (int)mybits.count() << " bits set.\n";
  else cout << "mybits has no bits set.\n";
  return 0;
}