title: Using Rhino Mocks to mock an out parameter, which is created within the method I am testing
body: <p>Trying to mock the following method:</p>
  
  <pre><code>bool IsLoginValid(LoginViewModel viewModel, out User user);
  </code></pre>
  
  <p>Tried this initially:</p>
  
  <pre><code>dependency&lt;ILoginService&gt;()
  .Stub(serv =&gt;
          serv.IsLoginValid(
              Arg&lt;LoginViewModel&gt;.Is.Equal(a_login_viewmodel),
              out Arg&lt;User&gt;.Is.Anything)
  .Return(false);
  </code></pre>
  
  <p>But, that fails, as it is an out parameter.  Did a bit of searching around and altered my code like such: </p>
  
  <pre><code>dependency&lt;ILoginService&gt;()
  .Stub(serv =&gt; 
          serv.IsLoginValid(
              Arg&lt;LoginViewModel&gt;.Is.Equal(a_login_viewmodel), 
              out Arg&lt;User&gt;.Out(new User()).Dummy))
  .Return(false);
  </code></pre>
  
  <p>That also fails.  I need 'new User()' to be sort of an 'Anything' argument.  As I think that is expecting a specific instance.</p>
  
  <p>Any idea how to get around this?  Thanks guys.</p>