That's actually a very good example, but I'd argue that this is actually a violation of the standard: memset is defined as setting the value in memory. Most optimizations on undefined behavior don't really fall into this category.
I guess you could group this kind of thing into the category of "dead code elimination" which is useful, but results in parts of the code written not producing the specified executable. I have to think on this example more.
I guess you could group this kind of thing into the category of "dead code elimination" which is useful, but results in parts of the code written not producing the specified executable. I have to think on this example more.