Example code for http://stackoverflow.com/posts/14531884 answer

ViewController.mm

- (void)viewDidLoad
{
    [super viewDidLoad];    
    // Do any additional setup after loading the view, typically from a nib.
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.translatesAutoresizingMaskIntoConstraints = NO;
    [button setTitle:@"Press ME!" forState:UIControlStateNormal];
    UILabel *label = [[UILabel alloc] init];
    label.translatesAutoresizingMaskIntoConstraints = NO;
    label.text = @"Hi Mom!";
    
    [self.view addSubview:button];
    [self.view addSubview:label];
    
    
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[button]-[label]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(button, label)]];
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:button attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:4.0]];
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:button attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:label attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];

}