title: Terminology of Optionals in Swift or other languages
body: <p>In Swift the elements we manipulates all have types.</p>
  
  <p>When we use theses types, we can add a '<em>!</em>', '<em>?</em>' or <em>nothing</em> to express their nullability.</p>
  
  <ol>
  <li>What shall I call the '<em>?</em>' or '<em>!</em>' used to express this trait ? </li>
  </ol>
  
  <p>A type decorator ? A decorator ? Operator ? Something else ? </p>
  
  <ol start="2">
  <li>What shall I call the type created when using this character ?</li>
  </ol>
  
  <p>Is it a new type ? Is it a decorated type ? A type variation ?</p>
  
  <p>The swift compiler, seems to consider them as new types, However my question is not implementation or language dependent and therefor I tagged it as language agnostic.</p>
  
  <p>Edit: <strong>I'm looking for a language agnostic name.</strong> I understand with pranjalsatija's comment optionals are defined as <code>compound type</code>.
  However, this is a language implementation detail.
  I could rephrase my questions as:</p>
  
  <p><strong>What do you call a character with a special meaning when used it a type definition, and how to call the derived type</strong>.</p>
  
  <p>This term should probably apply to capital casing constants in ruby as the concept is similar.</p>