title: How to Create hash from a class and selector? (objective c)
body: <p>I have a dictionary that stores an object using a combination of the class name and selector as the key. I'm using the following function in order to calculate the hash:</p>
  
  <pre><code>+(NSString*) getKeyForClass:(Class) clazz andSelector:(SEL) selector {
      return [NSString stringWithFormat:@"%@_%@",NSStringFromClass(clazz), NSStringFromSelector(selector)];
  }
  </code></pre>
  
  <p>While running a profiler i've discovered that this function is the bottleneck of the computation. Is there a better (= more efficient) way to create a key from a class and a selector? </p>