title: Something very similar to predicate, but not a predicate
body: <p>I want to have a "predicate" (it's in quotes, since I don't know the right word), that returns different fields of an object, based on conditions. I hope a short example will illustrate.</p>
  
  <pre><code> Predicate&lt;MyClass&gt; predicate
   if (condition1)
      predicate = x =&gt; x.Field1;
   else if (condition2)
       predicate = x =&gt; x.Field2;
  foreach(vat item in ListOfItems)
  {
      predicate(item) = someValue;//Here I am changing the value of that field.
  }
  </code></pre>