> But I have not needed to prove it because (as far as I know) only one programming language that uses async as its concurrency model claims to not have functio

> But I have not needed to prove it because (as far as I know) only one programming language that uses async as its concurrency model claims to not have function colors. The zig "colourless" innovation was informed by my work with cqueues in Lua[1]; which I gave as an example of good colourless-ness. [1] http://25thandclement.com/~william/projects/cqueues.html