Hacker News: pkasting

New comment by pkasting in "Lore – Open source version control system designed for scalability"

pkasting — Wed, 17 Jun 2026 16:34:45 +0000

The idea sounds good, even if Epic's recent track record of tools is not inspiring. But the commit messages etc. are very clearly products of vibe-coding. And version control is not the situation where "works 97% of the time" is a good-enough bar.

Passing for now.

New comment by pkasting in "Forking the Web"

pkasting — Sun, 10 May 2026 00:12:35 +0000

XHTML was never all the rage. Your premise is false.

Hard errors up front are great when you control the full content pipeline. It's very rare that that's the case, and was rare even in 2004. As soon as including someone else's broken content in your page prevents users from seeing your content, and that someone else can break the content at any time and you can't control it... few people will want hard errors.

New comment by pkasting in "Forking the Web"

pkasting — Sun, 10 May 2026 00:10:18 +0000

On the contrary, image decoders all run complex processes that try and guess what to do in erroneous cases. I used to maintain Chrome's image decoders, and every single image format has "what the spec says" and then "what people actually do in practice"; you must handle the latter, and it is often very difficult to figure out how to do so. For BMPs, for example, determining whether the author intended 24-bit RGB or 32-bit RGBA sometimes requires decoding the full image and scanning to see whether any pixels' alpha bytes differ from the others, since "all 00" and "all FF" might both be "no alpha".

I also used to work on a production C compiler. Compilers can and do "guess what you meant" in various cases, notably for producing actual human-readable errors or proceeding past various warnings, but if I recall correctly even in more obscure non-error cases.

Hyrum's Law is a real jerk sometimes.

New comment by pkasting in "Laws of Software Engineering"

pkasting — Tue, 21 Apr 2026 19:50:14 +0000

(Tangent: What a pleasure to see your username again; will always think of your readability help fondly!)

New comment by pkasting in "Laws of Software Engineering"

pkasting — Tue, 21 Apr 2026 15:56:12 +0000

This list is missing my personal law, Kasting's Law:

Asking "who wrote this stupid code?" will retroactively travel back in time and cause it to have been you.

New comment by pkasting in "Gonon: Building a Clock with No Numerals"

pkasting — Mon, 30 Mar 2026 04:43:34 +0000

Crowing over omitting Arabic numerals in the name of avoiding any kind of cultural influence or bias seems silly when everything is still going to be expressed in decimal.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:38:39 +0000

C++ module implementation is a story with a lot of drama, if you ever want to read up on it.

The short summary, though, is that no toolchain yet has a bulletproof implementation, though everybody at least has enough to let people kick the tires a bit.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:37:15 +0000

Yeah, maintainers would certainly +1 a CL that added a note about the parts of //base to use instead. Trivial oversight.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:22:42 +0000

FWIW, I still think the Google Style Guide banning UDLs entirely is too harsh. I think they should be used sparingly, but there are cases where they make sense.

In Chromium's UI code, we have a lot of APIs that deal with coordinates, which may be in either px or dp. And we have a lot of code that needs to hardcode various constants, e.g. layout values for different dialogs. IMO, it's sane to have UDL support here, e.g. `20_px` (at least if we had separate types to represent these two things, which we don't... don't get me started).

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:18:50 +0000

A cursory Chromium code search does not find anything outside third_party/ forcing either signed or unsigned char.

I suspect if I dug into the archives, I'd find a discussion on cxx@ with some comments about how doing this would result in some esoteric risk. If I was still on the Chrome team I'd go looking and see if it made sense to reraise the issue now; I know we had at least one stable branch security bug this caused.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:15:15 +0000

Dunno! My last project there was to add support for one of the TI DSPs, but as I said, that's decades past now.

Anyway, I think there are two takeaways:

1. There probably do exist non-8-bit-byte architectures targeted by compilers that provide support for at-least-somewhat-recent C++ versions

2. Such cases are certainly rare

Where that leaves things, in terms of what the C++ standard should specify, I don't know. IIRC JF Bastien or one of the other Apple folks that's driven things like "twos complement is the only integer representation C++ supports" tried to push for "bytes are 8 bits" and got shot down?

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:11:21 +0000

Yes, reading the actual data would still be UB. Hopefully will be fixed in C++29: https://github.com/cplusplus/papers/issues/592

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:07:26 +0000

At least in Chromium that wouldn't help us, because we disable strict aliasing (and have to, as there are at least a few core places where we violate it and porting to an alternative looks challenging; some of our core string-handling APIs that presume that wchar_t* and char16_t* are actually interconvertible on Windows, for example, would have to begin memcpying, which rules out certain API shapes and adds a perf cost to the rest).

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 19:03:52 +0000

When I led C++ style/modernization for Chromium, I made this argument frequently: we should prefer the stdlib version of something unless we have reason not to, because incoming engineers will know it, you can find advice on the internet about it, clang-tidy passes will be written for it, and it will receive optimizations and maintenance your team doesn't have to pay for.

There are cases, however, when the migration costs are significant enough that even those benefits aren't really enough. Migrating our date/time stuff to seemed like one of those.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:55:37 +0000

It's weird to me, as the former lead maintainer of this page for ten years or so, that this got submitted to both r/c++ and HN on the same day. Like... what's so exciting about it? Was there something on the page that caught someone's eye?

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:53:33 +0000

The majority of things Chromium bans would still get banned in green-field use.

Some notable exceptions: we'd have allowed std::shared_ptr and . We might also have allowed and friends.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:49:59 +0000

This bit us in Chromium. We at least discussed forcing the compiler to use unsigned char on all platforms; I don't recall if that actually happened.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:48:19 +0000

Green Hills Software's compiler supports more recent versions of C++ (it uses the EDG frontend) and targets some DSPs.

Back when I worked in the embedded space, chips like ZSP were around that used 16-bit bytes. I am twenty years out of date on that space though.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:46:10 +0000

I don't think that's an accurate representation. There are a few features like that, but the majority of things banned in the Google style guide are banned for safety, clarity, or performance concerns. Usually in such cases Google and/or Chromium have in-house replacements that choose different tradeoffs.

That's different from an inability to refactor.

New comment by pkasting in "Banned C++ features in Chromium"

pkasting — Sat, 24 Jan 2026 15:40:06 +0000

Both parts of your sentence refer to the Google style guide. This doc isn't the Google style guide. It's the Chromium modern c++ features doc. We don't talk about exceptions or platform-specific stuff (save a note on [[no_unique_address]]) in this doc.