title: F# Optional Record Field
body: <p>I have a F# record type and want one of the fields to be optional:</p>
  
  <pre><code>type legComponents = {
      shares : int&lt;share&gt; ;
      price : float&lt;dollar / share&gt; ;
      totalInvestment : float&lt;dollar&gt; ;
  }
  
  type tradeLeg = {
      id : int ;
      tradeId : int ;
      legActivity : LegActivityType ;
      actedOn : DateTime ;
      estimates : legComponents ;
      ?actuals : legComponents ; 
  }
  </code></pre>
  
  <p>in the tradeLeg type I would like the the actuals field to be optional.  I can't seem to figure it out nor can I seem to find a reliable example on the web. It seem like this should be easy like </p>
  
  <pre><code>let ?t : int = None
  </code></pre>
  
  <p>but I realy can't seem to get this to work. Ugh - thank you</p>
  
  <p>T</p>