• jeffhykin@lemm.ee
    21·
    1 year ago

    If you think that’s good, then you’re gonna love this “simplified” real code posted as a real issue on one of my Github repos.

    Edit: updated link to address the stack-trace comment

    • parlaptie@feddit.de
      2·
      1 year ago

      That’s not actual code though, it looks like some kind of trace. Notice the filenames at the end of each line.

      The actual solution the issue opener there might be looking for is to disable C++ parsing, since it’s not actually C++ code, it’s just some text they pasted into VSCode and they’re wondering why their editor can’t handle it.

  • Murdo Maclachlan@lemmy.world
    16·
    1 year ago

    Image Transcription: Code

    [Transcriber’s note: the first line in the following transcription is incorrect. After the equals, there should be eight instances of the word “Option”, each succeeded by a less-than symbol, then two brackets, like (), before the first greater-tha symbol. However, if you type a less-than symbol on Lemmy, it seems to strip that symbol and whatever word comes next out of the source when you save the comment.]

    type Wtf = Option>>>>>>>;
let two = Some(Some(Some(Some(Some(Some(None))))));
let three = Some(Some(Some(Some(Some(None)))));
let six = Some(Some(None));
unsafe {
    assert_eq!(
        std::mem::transmute::(two) * std::mem::transmute::(three)
        std::mem::transmute::(six)
    );
}

    I am a human who transcribes posts to improve accessibility on Lemmy. Transcriptions help people who use screen readers or other assistive technology to use the site. For more information, see here.

      • Murdo Maclachlan@lemmy.world
        5·
        1 year ago

        Still needs to be checked over to make sure it didn’t get anything wrong. In my experience the mistakes AI make with monospace fonts tend to be very awkward to notice (like 1 and l and I and | being interchanged), so I’d have to go over with a fine tooth comb which, for me, since I type quickly, isn’t noticeably faster and is a lot more boring.

  • gsfraley@lemmy.world
    2·
    1 year ago

    For those interested, this is because of how Rust uses value gaps to represent its nullable/enum structures. E.g., like how None for Option NonZeroU8 [sic, can’t get formatting to work] is represented internally by a 0 instead of a wrapping structure.

    When you have that many layers around a unit, it will start at 0 and bump the internal representation for each Some you turn into a None.

  • GissaMittJobb@lemmy.ml
    0·
    1 year ago

    Since all of the expressions just wrap a None, I wouldn’t be surprised if the transmutes basically get compiled to 0, making the assertion at the end assert_eq!(0 * 0, 0).

    • tatterdemalion@programming.devOP
      1·
      1 year ago

      Nah these are the actual integer representations. Otherwise you would have Some(None) == Some(Some(None)) which is way too Javascripty for Rust folks.

    • Knusper@feddit.de
      1·
      1 year ago

      No, not at all. It’s a joke post, abusing the in-memory representation of the Option type to construct numbers. When nesting the Option type, it turns into a densely packed bit vector…

      And if I understand the purpose of Fin correctly, you’re picking on the one ‘peasant language’ that actually has something like that built-in.
      In Rust, you can specify the type of an array as e.g [u8; 3]. Which is an array containing values of type u8 (unsigned 8-bit integer) with a fixed, compile-time-guaranteed length of 3. So, [u8; 3] could be used to represent an RGB color, for example.
      It is an array, not a set, but well, close enough.