title: Call c# from c++: how to pass nullptr to DateTime?
body: <p>In a c# assembly, I got a function taking a nullable DateTime as parameter:</p>
  
  <pre><code>public void DoSomething(DateTime? timestamp);
  </code></pre>
  
  <p>Now I want to call this method from c++/cli:</p>
  
  <pre><code>MyClass-&gt;DoSomething(nullptr);
  </code></pre>
  
  <p>This will not compile. Instead the c++ compiler will print an error message nullptr can not be converted to System::Nullable.</p>
  
  <p>So how do I pass nullptr from c++ to a nullable DateTime?</p>