title: Strange function declaration
body: <p>I am was reading a source code and I found this:</p>
  
  <pre><code>extern size_t (*MEM_allocN_len)(const void *vmemh) ATTR_WARN_UNUSED_RESULT;
  </code></pre>
  
  <p>and this:</p>
  
  <pre><code>extern void (*MEM_freeN)(void *vmemh);
  </code></pre>
  
  <p>I cannot figure out what is the function name and what is/are parameter/s.
  How should I interpret these function declarations?</p>