title: what does operator"" overloading mean in C++?
body: <p>In codeproject, i found a interesting program which implements a meaning of unit ,like</p>
  
  <pre><code>unsigned long long operator"" s(unsigned long long n)
  {
      return n + 1;
  }
  int main()
  {
      int x = 16s;
  }
  </code></pre>
  
  <p>x will be 17, so interesting. can someone tell me what magic this is?</p>