title: What is the default equality comparer for a set type?
body: <p>In the MSDN API for the <a href="http://msdn.microsoft.com/en-us/library/bb359438.aspx" rel="noreferrer"><code>HashSet</code></a> constructor with no arguments it states</p>
  
  <blockquote>
    <p>Initializes a new instance of the HashSet class that is empty and
    uses the default equality comparer for the set type.</p>
  </blockquote>
  
  <p>What is the default equality comparer for the set type, e.g. for a custom class?</p>
  
  <p>BTW: Is it just me or is the MSDN API documentation really a bit thin on explanations? I stumble about such questions more than once when reading it.</p>