I disagree with the downvotes here. C language "layers" are tricky to get right, source of footguns and a backdoor potential (especially the trigram that started this comment chain), and overall a bandaid invented when there were no better solutions (like modules, or Unicode). Trigrams are a weird archaic quirk of the C language (and no other modern language), and I'm glad to see them gone.

And since we're thinking about layers, character encoding hacks should be entirely outside of a programming language responsibility. Now that would be a proper layering.