A set of NSArray category methods (for arrays of UIViews) to automatically layout auto-hugging rows or columns. Requires PureLayout.

UIVIew+Layout Example.m

// Example — say you had some content for a scrollView. 
// Create a contentView and add each row as a subview.
// Then simply call the category method on the subviews array to layout
// the subviews as rows.
//
// This requires that the contentView be setup via autolayout to
// properly pin to the scrollView.

[contentView addSubviews:@[
     viewA,
     viewB,
     viewC
 ]];

// Pin each subview as a full-width, flexible-height row.
[contentView.subviews pinAutoHuggingRows];

UIView+Layout.h

@interface NSArray (EDLayout)

- (NSArray*)pinAutoHuggingRows;
- (NSArray*)pinAutoHuggingRowsWithSeparation:(CGFloat)separation;

- (NSArray*)pinAutoHuggingColumns;
- (NSArray*)pinAutoHuggingColumnsWithSeparation:(CGFloat)separation;

@end

UIView+Layout.m

typedef NS_ENUM (NSInteger, EDLayoutViewPosition) {
    EDLayoutViewPositionLonely,
    EDLayoutViewPositionFirst,
    EDLayoutViewPositionMiddle,
    EDLayoutViewPositionLast
};

@implementation NSArray (EDLayout)

- (NSArray*)pinAutoHuggingRows
{
    return [self pinAutoHuggingRowsWithSeparation:0.0];
}

- (NSArray*)pinAutoHuggingRowsWithSeparation:(CGFloat)separation
{
    [self iterateViewsWithBlock:^(EDLayoutViewPosition position, UIView* previousView, UIView* view, UIView* nextView) {
        [view pinFullWidth];

        switch (position) {
        case EDLayoutViewPositionLonely:
            [view pinFullHeight];
            break;

        case EDLayoutViewPositionFirst:
            [view pinTop];
            break;

        case EDLayoutViewPositionMiddle:
            [view autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:previousView withOffset:separation];
            break;

        case EDLayoutViewPositionLast:
            [view pinBottom];
            [view autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:previousView withOffset:separation];
            break;
        }

        [view autoHugContent];
    }];
    return self;
}

- (NSArray*)pinAutoHuggingColumns
{
    return [self pinAutoHuggingColumnsWithSeparation:0.0];
}

- (NSArray*)pinAutoHuggingColumnsWithSeparation:(CGFloat)separation
{
    [self iterateViewsWithBlock:^(EDLayoutViewPosition position, UIView* previousView, UIView* view, UIView* nextView) {
        [view pinFullHeight];

        switch (position) {
        case EDLayoutViewPositionLonely:
            [view pinFullWidth];
            break;

        case EDLayoutViewPositionFirst:
            [view pinLeft];
            break;

        case EDLayoutViewPositionMiddle:
            [view autoPinEdge:ALEdgeLeft toEdge:ALEdgeRight ofView:previousView withOffset:separation];
            break;

        case EDLayoutViewPositionLast:
            [view pinRight];
            [view autoPinEdge:ALEdgeLeft toEdge:ALEdgeRight ofView:previousView withOffset:separation];
            break;
        }

        [view autoHugContent];
    }];
    return self;
}