title: Autolayout in UITextField: Auto Layout still required after executing -layoutSubviews
body: <p>I'm subclassing UITextField to add a label on the left side. I'm using autolayout to layout the label. However, I keep getting this crash:</p>
  
  <p>Here's how I am doing my layout code:</p>
  
  <pre><code>- (void)updateConstraints {
  
  self.segmentLabel.translatesAutoresizingMaskIntoConstraints = NO;
  
  NSLayoutConstraint *constraint;
  constraint = [NSLayoutConstraint constraintWithItem:self.segmentLabel attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeHeight multiplier:1.0 constant:0.0f];
  [self addConstraint:constraint];
  constraint = [NSLayoutConstraint constraintWithItem:self.segmentLabel attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeLeading multiplier:1.0 constant:0.0f];
  [self addConstraint:constraint];
  constraint = [NSLayoutConstraint constraintWithItem:self.segmentLabel attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeTop multiplier:1.0 constant:0.0f];
  [self addConstraint:constraint];
  constraint = [NSLayoutConstraint constraintWithItem:self.segmentLabel attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:self.segmentWidth];
  [self addConstraint:constraint];
  
  [super updateConstraints];
  </code></pre>
  
  <p>}</p>
  
  <p>When I don't make any adjustments to the textfield, this works fine.</p>
  
  <p>However, if I try to set the placeholder text, I get this exception:</p>
  
  <blockquote>
    <p>Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Auto Layout still required after executing -layoutSubviews. DDSegmentedTextField's implementation of -layoutSubviews needs to call super.'</p>
  </blockquote>
  
  <p>However, I'm not overriding -layoutSubviews.</p>
  
  <p>Has anyone encountered this? What am I doing wrong?</p>
  
  <p>Thanks!</p>