title: format '%lld' expects type 'long long int', but argument 4 has type 'int64_t'
body: <p>I try to print a variable of type <code>int64_t</code> using <code>%lld</code> format specifier but get the following warning?</p>
  
  <blockquote>
    <p>Warning: format '%lld' expects type 'long long int', but argument 4
    has type 'int64_t'</p>
  </blockquote>
  
  <p>In my opinion, under linux, the <code>int64_t</code> is always <code>long long int</code>, then:</p>
  
  <ol>
  <li>Why does this warning occur?</li>
  <li>How can I fix this?</li>
  </ol>