title: Can one define NSFound macro?
body: <p>This may sound like a silly question but Apple provides us with NSNotFound but why didn't they provide one called NSFound? Is there a way one can define a NSFound macro on their own? </p>
  
  <p>The reason I am asking all this is that in order for me to check if a string "contains" a certain character I have to do double negative i.e.</p>
  
  <pre><code>if ([XML rangeOfString:@"error" options:NSCaseInsensitiveSearch].location != NSNotFound)
  {
       //server is down
  }
  else
  {
       //server is up
  }
  </code></pre>
  
  <p>At least for me this would have been so much easier to read if I could simply do this instead</p>
  
  <pre><code>if ([XML rangeOfString:@"error" options:NSCaseInsensitiveSearch].location == NSFound)
  {
   //server is down
  }
  else
  {
   //server is up
  }
  </code></pre>
  
  <p>If I want to define NSFound or SAMFound, how would I go about doing that?</p>