title: warning: pointer targets in initialization differ in signedness
body: <p>My compiler(gcc) is showing the warning</p>
  
  <pre><code>#include&lt;stdio.h&gt;
  
  struct s{
       unsigned char *p;
  };
  
  int main() {
      struct s a = {"??/??/????"}; //warning
      printf("%s",a.p);
      return 0;
  }
  </code></pre>
  
  <p>warning: pointer targets in initialization differ in signedness</p>
  
  <p>please help me to why is this warning comes.</p>