title: Can a lambda capturing nothing access global variables?
body: <pre><code>int n;    
  int main()
  {
      [](){ n = 0; }(); // clang says "ok"
  
      int m;
      [](){ m = 0; }(); // clang says "not ok"
  }
  </code></pre>
  
  <p>I just wonder:</p>
  
  <p>If the lambda captures nothing, is it allowed to access global variables as per the C++ standard?</p>