init(unchecked:isKnownASCII:)

Creates a UTF8Span, bypassing safety and security checks. The caller must guarantee that codeUnits contains validly-encoded UTF-8, or else undefined behavior may result upon use. If isKnownASCII: true is passed, the contents must be ASCII, or else undefined behavior may result upon use.

init(unchecked codeUnits: Span<UInt8>, isKnownASCII: Bool = false)