[swift-evolution] Int indexing into UTF16View

[Charles Srstka]

> On Jun 8, 2017, at 2:35 PM, Tony Allevato via swift-evolution <swift-evolution at swift.org> wrote:
> 
> It is an extremely rare case for a developer to know a priori what literal numeric indices should be used when indexing into a string, because it only applies when strings fall into a very specific format and encoding.

Knowing this is required for accessibility support on macOS, since it’s needed to implement NSAccessibility methods such as accessibilityAttributedString(for:), accessibilityRTF(for:), accessibilityFrame(for:), etc.

Charles