title: Ruby 2.0.0 Array#bsearch behavior
body: <p>I noticed that as of Ruby 2.0.0 the array class has a <code>bsearch</code> method that I was testing and I'm not getting the behavior I'd expect.  Why does it return a value for 2 and 5 but <code>nil</code> for -1, 1, and 4?</p>
  
  <pre><code>arr_in = [-1, 1, 2, 4, 5]
  
  arr_in.bsearch { |x| x == 3 }   #=&gt; nil
  arr_in.bsearch { |x| x == -1 }  #=&gt; nil
  arr_in.bsearch { |x| x == 1 }   #=&gt; nil
  arr_in.bsearch { |x| x == 2 }   #=&gt; 2
  arr_in.bsearch { |x| x == 4 }   #=&gt; nil
  arr_in.bsearch { |x| x == 5 }   #=&gt; 5
  </code></pre>