[$] Zig explores structured concurrency

Version 0.16.0 of the Zig programming language wasrecently announced, and withit an expanded version of the new Io interface that wecovered in December.The new interface is based on an idea called structured concurrency that makes writingcorrect concurrent applications easier. Zig's implementation ofthe idea is more explicit and verbose than other languages, however, which couldoffer an opportunity to explore the consequences of different designs.