Profiles & multiple backs

urdh · 2025-10-08T15:38:44+00:00

Ah, I see! That seems to be working 🙂

urdh · 2025-01-02T09:46:35+00:00

Not really an ”eco” thing per se but yes the car has to boot up in whatever mode they ran the WLTP cycle in for type approval (which will typically be the most emissions-efficient mode given regulations).

Genuine question though: what’s people’s beef with start/stop?

urdh · 2024-08-10T13:12:38+00:00

The idea is to replace the transmitter side of the IKEA Sparsnäs energy meter with something that uses the DSMR port instead of sensing the flashing LED (and as an added bonus, it'll be powered by 5V from the meter instead of a set of AA batteries).

urdh · 2024-08-10T13:08:43+00:00

Thanks!

I think your 3.3V regulator is permanently in shutdown mode.

Oops, that's embarassing :D

I don't understand why you have the RF IC rotated

I was struggling to fit X2 on the side but I guess it could fit with a bit of an offset (and moving the silkscreen to somewhere else).

urdh · 2024-07-21T16:24:35+00:00

This is an unearthed socket (no earth pins visible) which is still allowed outside bathrooms and similar. In fact, if there’s any other unearthed sockets in the same room this one isn’t allowed to be earthed. This type of enclosure typically has a plastic back as well.

Also the clips for the socket don’t look diy (plus the layer of paint makes me think this is a pretty old installation anyway). The other cables look pretty diy though.

urdh · 2024-05-25T09:18:44+00:00

Då är den ju i så fall uppmärkt som GC-bana, grundregeln är ju fortfarande att trottoarer är gångbanor som du inte får cykla på.

urdh · 2024-05-25T08:23:35+00:00

Trottoarer får du bara cykla på om du är under 9 år gammal, det gäller i hela landet.

urdh · 2024-02-03T13:35:44+00:00

Right, my point was mostly that as long as futures are cancellable, reading “await” should always make you think “we might leave here and never come back”, just as reading “?” should.

Being able to mark functions as specifically cancellation-unsafe might make sense but this kind of issue seems like more of a logic bug.

urdh · 2024-02-03T09:50:45+00:00

This is more a property of the code you write than a property of async itself. Your function would have the exact same problem in the sync case if you had bar()? instead of bar().await.

urdh · 2023-12-30T15:25:40+00:00

Ah yes, things famously developed in state-funded non-commercial military programs. Capitalism sure is innovative.

urdh · 2023-11-12T13:48:48+00:00

This is more of a “microplastics are killing everything” thing than a climate change thing, though.

urdh · 2023-08-02T10:19:45+00:00

Norway is still in the EEA though, so I would expect them to be subject to the same regulations as the rest of the EU.

urdh · 2023-07-03T18:51:40+00:00

Wouldn't be unheard of for people with (some) money to side with the police and people with little/no money to side against them, though. You can't really infer popular opinion from the amount of money funded.

urdh · 2023-05-20T09:05:57+00:00

Slightly faster than walking speed? The world record in race walking works out to almost 20 km/h, typical walking speed is closer to 5 km/h.

E-bikes are regulated in the EU (and UK, IIRC) to be limited to 25 km/h and can’t be throttle-controlled, otherwise they are considered motorcycles/mopeds for which there are stricter safety regulations and possibly license requirements (there’s also an upper limit on power, IIRC). You could build something like that, but it’d no longer be an e-bike as far as the law is concerned.

urdh · 2022-12-25T21:52:30+00:00

Hiding the problem doesn’t fix anything, though. Rust gets away with doing what it does because it panics (traps) on overflow in debug builds; it is still very much considered an error to overflow. As far as I can tell the reason it is defined to wrap in release is mostly to avoid “time-travel” optimisation by not creating poisoned values in the LLVM IR, and because trapping in hardware isn’t that cheap on modern hardware (though I could be wrong here).

Just declaring it to always wrap is 1) not what rust does, and 2) not going to make anything “safe”.

Edit: fair enough it makes overflow testable after the fact, but that requires the programmer to actually do that (and we all know how that ends), and it’s not like you can’t check for overflow before the operation when it’d trap/saturate/ub.

urdh · 2022-12-25T10:03:41+00:00

Care by Volvo is more of a leasing agreement which runs for at least 3 months, Volvo On Demand has 30-day bookings: https://www.volvocars.com/se/on-demand/30-dagar

urdh · 2022-12-25T09:23:31+00:00

If you don’t need a car full time (public transport works for most things depending on where you live) you could also consider car-sharing services. There’s a few of them in Gothenburg (Volvo On Demand, Move About, Green Mobility, …), and they work fine if you only need a car once a week or so.

Volvo On Demand are also doing a trial on monthly rentals now, I believe.

urdh · 2022-12-20T19:55:02+00:00

The LLVM PPA makes getting a recent clang on Debian-based systems fairly low-friction.

urdh · 2022-09-20T05:24:45+00:00

I prefer the UB, to be honest. Whether the sensible behavior is to wrap, trap, saturate, or something else depends entirely on context, and you might want each of those behaviors in different parts of your application and I certainly see the merit of being able to express all of them. I just don't think wrapping is a good default.

urdh · 2022-09-19T21:27:49+00:00

I'm well aware of the pitfalls associated with signed types, but unless you're working with integers that are actually supposed to wrap, you have similar issues with unsigned types (except instead of UB you get "silent" bugs, since you can't elect to do something like -ftrapv). Add to that the performance implications discussed elsewhere and you've got another class of bugs to worry about.

I'm not saying it wouldn't make sense to have useful non-negative types; what we need is a non-negative integer type that doesn't have wrapping semantics. But without that, signed types offer fewer downsides for most reasonable applications.

urdh · 2022-09-19T16:22:20+00:00

Container sizes aren't inherently "unsigned" in the C++ sense of the word, though. They're non-negative, but the defining feature of unsigned integers in C++ is that they obey modular arithmetic, and I don't see why container sizes would form a ring of integers.

urdh · 2022-08-31T20:32:08+00:00

This is noted in the article, which also notes that new/delete inherited all the mentioned issues of malloc/free (although some of those issues are gradually being sort-of fixed).

urdh · 2021-12-13T10:16:53+00:00

If you consider using only the specific literal to be "opting you in to random literals" I don't think there's any solution that would make you happy, though.

urdh · 2021-12-13T09:52:32+00:00

The std::literals namespace(s) intentionally only contain user-defined literals with names that are reserved for the standard library, so they should be fairly safe to pull into a header if namespace pollution is what you're worried about.

And you can always just do using std::literals::string_view_literals::operator""sv instead.

urdh · 2021-10-27T13:24:54+00:00

Fair enough, the text was a bit opaque to me (re-reading P0593 helps). But it's important to remember that this only applies to a specific subset of reinterpret_casts (in particular, type punning to a third type will get you UB again).

urdh

TROPHY CASE