alt Hacker NewsI think the article's point is that you don't actually have to get weird at all to run into UB.
Lots of people mistakenly think that C and C++ are "really flexible" because they let you do "what you want". The truth of the matter is that almost every fancy, powerful thing you think you can do is an absolute minefield of UB.
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I've long said that the value a programming language offers is as much about what it doesn't allow as what it does allow. Efficiency aside, most useful programs could be written in most languages, but there are an infinite number of programs you could write that aren't particularly useful. Ruling out the programs you might accidentally write that resemble the one you intended is a pretty useful feature of a language, and it's a metric that C and C++ rate quite poorly on IMO.
I would agree that C is "really flexible", but I would say it's primarily flexible because it lets you cast say from a void pointer to a typed pointer without requiring much boilerplate. It's also flexible because it lets you control memory layout and resource management patterns quite closely.
If you want to be standards correct, yes you have to know the standard well. True. And you can always slip, and learn another gotcha. Also true. But it's still extremely flexible.
At which point it feels like some sort of high-level assembly-like language, which is simple enough to compile efficiently and stay crossplatform, with some primitives for calls, jumps, etc. could find a nice niche.
Maybe this already exists, even? A stripped down version of C? A more advanced LLVM IR? I feel like this is a problem that could use a resolution, just maybe not with enough of a scale for anyone to bother, vs. learning C, assembly of given architecture, or one of the new and fancy compiled languages.
My go-to example of "UB is everywhere" is this one:
Which is UB for certain values of x.