title: How do I add a CGPoint to NSMutableArray?
body: <p>I want to store my CGPoint to the NSMutable Array, so , I have method like this:</p>
  
  <pre><code>[self.points addObject:CGPointMake(x, y)];
  </code></pre>
  
  <p>But I got the error, it said that :</p>
  
  <blockquote>
    <p>Incompatible type for argument 1 of
    "addObject".</p>
  </blockquote>
  
  <p>So, I check out the API, </p>
  
  <pre><code>- (void)addObject:(id)anObject
  </code></pre>
  
  <blockquote>
    <p>anObject The object to add to the end
    of the receiver's content. This value
    must not be nil.</p>
  </blockquote>
  
  <p>So, I think the "<strong>CGPointMake</strong>" can make a Object, but it can't be assigned. What happens?</p>