title: C# 7.0 Value Tuple compile error?
body: <p>When I am trying to compile the following code:</p>
  
  <pre><code>var post = iPostService.GetAll().Select(x =&gt; (x.Title, x.Author));
  </code></pre>
  
  <p>I get the compiler error: 'An expression tree may not contain a tuple literal.'</p>
  
  <p>So I also tried this: </p>
  
  <pre><code>var post = iPostService.GetAll().
                      Select(x =&gt; new ValueTuple&lt;string, string&gt;(x.Title, x.Author))
  </code></pre>
  
  <p>The result is runtime error:'Cannot resolve method Void .ctor(System.String, System.String) because the declaring type of the method handle System.ValueTuple`2[T1,T2] is generic. Explicitly provide the declaring type to GetMethodFromHandle.'</p>
  
  <p>I googled to find out the solution to this problem but nothing really helpful.</p>
  
  <p>Any help really appreciated.</p>
  
  <p>Thanks</p>