title: Using non-copyable object as key for NSMutableDictionary?
body: <p>I tried to figure out this code referencing: <a href="https://stackoverflow.com/questions/1187112/cocoa-dictionary-with-enum-keys">Cocoa: Dictionary with enum keys?</a></p>
  
  <pre><code>+ (NSValue*)valueWithReference:(id)target
  {
      return [NSValue valueWithBytes:&amp;target objCType:@encode(id*)];
  }
  </code></pre>
  
  <p>And,</p>
  
  <pre><code>[table setObject:anObject forKey:[NSValue valueWithReference:keyObject]];
  </code></pre>
  
  <p>But it feels something not good. Any recommendations?</p>