title: what is the meaning of restrict in pthread_create
body: <p>I am looking at pthread_create manual page.</p>
  
  <pre><code>int pthread_create(pthread_t *restrict thread,
            const pthread_attr_t *restrict attr,
            void *(*start_routine)(void*), void *restrict arg);
  </code></pre>
  
  <p>What is the meaning of 'restrict' in this function signature ?. what is the purpose of it?</p>