An alternative higher level API over NSLayoutConstraint, NOT inspired by ASCII art.

NSLayoutConstraintBuilder.mm

NSLayoutConstraintBuilder *builder = [NSLayoutConstraintBuilder builder];

UIView *mySubview = [[UIView alloc] initWithFrame:CGRectZero];

// API deliberately mirrors the terminology of IB:

[builder pin:mySubview toWidth:200];
[builder pin:mySubview toHeight:200];
[builder pin:mySubview toSize:CGSizeMake(200, 200)];

// Relationship with parent view:

// this could be offset, constant or padding, not sure which is best
[builder pin:mySubview leadingSpaceToSuperview:self.parentView offset:10];
[builder pin:mySubview trailingSpaceToSuperview:self.parentView offset:10];

// etc.., or perhaps:

// will this always be the parent view? If so, no need to pass it in, we can just ask for the superview
[builder pin:mySubview toParentView:NSLayoutAttributeTop offset:10];
[builder pin:mySubview toParentView:NSLayoutAttributeBottom offset:0];

// a few higher level ideas:

// equivalent to pinning top, bottom, leading and trailing, no dimension constraints
[builder stretchWithSuperView:mySubview];

// assuming mySubview has explicit dimensions, pins it's centerY and centerX to superview
[builder centerViewInParentView:mySubview];