title: Create a hashcode of two numbers
body: <p>I am trying to create a quick hashcode function for a complex number class <code>(a + b)</code> in C#.</p>
  
  <p>I have seen repeatedly the <code>a.GetHashcode()^b.GetHashCode()</code> method. 
  But this will give the same hashcode for <code>(a,b)</code> and <code>(b,a)</code>. </p>
  
  <p>Are there any standard algorithm to do this and are there any functions in the .Net framework to help?</p>