title: CSS: Fixed width + Dynamic width children, filling 100% parent width?
body: <p>I have a parent div (- in diagram) who's width I don't know in advance.</p>
  
  <p>I have two child divs (a and b):</p>
  
  <p><strong>b</strong> - is always a <strong>known fixed width</strong>, and should always be <strong>positioned on the right</strong>.</p>
  
  <p><strong>a</strong> - should <strong>fill the remaining space</strong></p>
  
  <pre><code>-----------------------------------
  - aaaaaaaaaaaaaaaaaaaaaaaaaa bbbb -
  - a                        a b  b -
  - aaaaaaaaaaaaaaaaaaaaaaaaaa bbbb -
  -----------------------------------
  </code></pre>
  
  <p>Both a and b are of equal fixed height.</p>
  
  <p>I imagine there is a simple solution to this,  but I haven't found it yet.  I've tried floating both, but one or the other gets pushed below.</p>
  
  <p>Any ideas?</p>