title: Initializer list in user-defined literal parameter
body: <p>I don't know if it's possible but I want to do stuff like </p>
  
  <pre><code>int someval = 1;
  if({1,2,3,4}_v.contains(someval ))
  </code></pre>
  
  <p>but when I try to define literal as:</p>
  
  <pre><code>std::vector&lt;int&gt; operator"" _v ( std::initializer_list&lt;int&gt; t )
  {
      return std::vector&lt;int&gt; (t);
  }
  </code></pre>
  
  <p>to accept initializer list of ints I get </p>
  
  <pre><code> error: 'std::vector&lt;int&gt; operator"" _v(std::initializer_list&lt;int&gt; t)' has invalid argument list
  </code></pre>
  
  <p>Is there a way to do this? What I really want is to finally be rid of stuff like</p>
  
  <pre><code>if(value == 1 || value ==2 || value == 3 ...
  </code></pre>
  
  <p>Having to write stuff like this is really annoying, because you'd expect syntax to be</p>
  
  <pre><code>if value in (value1, value2 ...) 
  </code></pre>
  
  <p>or something similar.</p>