[captainmuon]

I think it is a good blog post, because it highlights an issue that I was not aware of and that I think many programmers are not. I do think I am a decent C programmer, and I spotted the strict aliasing issue immediately, but I didn't know that unaligned pointer access is UB. Because let's face it, the majority of programmers didn't read the standard, and those who did don't remember all facets.

I first learned many years ago that you should pick apart binary data by casting structs, using pointers to the middle of fields and so on. It was ubiquitous for both speed and convenience. I don't know if it was legal even in the 90s, but it was general practice - MS Office file formats from that time were just dumped structs. Then at some point I learned about pointer alignment - but it was always framed due to performance, and due to the capabilities of exotic platforms, never as a correctness issue. But it's not just important to learn what to do, but also why to do it, which is why we need more articles highlighting these issues.

(And I have to admit, I am one of these misguided people who would love a flag to turn C into "portable assembler" again. Even if it is 10x slower, and even if I had to add annotations to every damn for loop to tell the compiler that I'm not overflowing. There are just cases where understanding what you are actually doing to the hardware trumps performance.)