These conditions already had assertions, but at runtime, an insufficiently tested and incorrect ASLayoutSpec could
generate values that cause UIKit to enter an infinite loop (e.g. inside of UICollectionView layout validation).
- ASRelativeSize and ASRelativeSizeRange are used only by ASStaticLayoutNode. They are declared in a standalone header.
- ASDimension contains a minimal set of new size types required to use the common layouts. Thus minimize the learning curve.
- The code is forked from LayoutComponents in ComponentKit.
- Public interfaces are modified to be strictly Objective-C. As a result, users are not forced to switch to Objective-C++, the linker can happily compile and Swift fans can continue using the mighty ASDK.
