title: compiler can't find "aligned_alloc" function
body: <p>Trying to get a portable function to allocate on heap with aligned feature.</p>
  
  <p>Found "aligned_alloc", which I think is in stdlib.h but gcc seems to not think so</p>
  
  <blockquote>
    <p>error: 'aligned_alloc' was not declared in this scope</p>
  </blockquote>
  
  <p>using gcc with flags -std=c++11 -m64</p>
  
  <p>tried importing</p>
  
  <pre><code>#include &lt;stdlib.h&gt;
  #include &lt;cstdlib&gt;
  </code></pre>