title: Undefined reference to methods of a templated class
body: <p>I'm trying to make a generic 2D array matrix class, but I am getting "error: undefined reference to `Zero::StaticMatrix::StaticMatrix(unsigned int, unsigned int)'" for my [] overloads and constructors of these two classes.</p>
  
  <p>Here is a pastebin of the class definitions.  <a href="http://pastebin.com/Yq8fMAdy" rel="nofollow">http://pastebin.com/Yq8fMAdy</a></p>
  
  <p>p.s. I am using a friend helper class so I can access the _internal vector using something like <code>matrix[i][j]</code>, since there is no <code>[][]</code> overload.</p>