title: Multiple constraint on type parameter
body: <p>I did this multiple constraint</p>
  
  <pre><code>public class BaseValidation&lt;S, R&gt; 
          where R : BaseRepository 
          where S : BaseService&lt;R&gt;, new()
      {
          public S service;
  
          public BaseValidation()
          {
              service = new S();
          }
      }
  </code></pre>
  
  <p>Here's the BaseService class</p>
  
  <pre><code>public class BaseService&lt;T&gt; where T : BaseRepository, new(){ }
  </code></pre>
  
  <p>And when I build, an error occurs like this...</p>
  
  <blockquote>
    <p>'R' must be a non-abstract type with a public parameterless
    constructor in order to use it as parameter 'T' in the generic type</p>
  </blockquote>
  
  <p>How to properly done this?
  Thank you.</p>