title: Xcode 6 auto layout flexible width
body: <p>I have a UITextField which using Xcode 6s auto layout interface I have set to have a width of 400 points. This looks fine on larger screen devices but on the iPhone 5s these boxes disappear out of the containing view. What is the correct way to approach this?</p>
  
  <p>Is there a way to set a constraint that will make the UITextFields width 400 points if the screen is large than this or just fill the container view if not, instead of overflowing outside of the view or should I be using the size classes to set the UITextField to have equal widths to its parent view on compact views.</p>