There is no implicit conversion (except to bool, but that tells you whether the optional contains a value), and operator* / operator-> throw std::bad_optional_access if it’s empty. See https://en.cppreference.com/w/cpp/utility/optional
No problem, if I caused you to fix a bug before it happened that's great. Yes, I find that reading sources I'm about to cite is often eye-opening. Our memories are not as good as we think they are, and our condensed understanding of a complex situation may have ignored something which is now crucial.
Once in a while I go down a rabbit hole, but hey, it's not as though HN isn't a rabbit hole anyway.
They were really in a pickle here. It’s easy to be snarky, but both options (no pun intended) have downsides. In short, do you choose consistency by default, or safety by default?
This feels like an easy choice in isolation, but at the time this was being developed (and arguably even now), there’s no definitive plan to holistically move C++ code to being safe by default. So whenever that happens, a ton of things will need to be dealt with, and there’s always the possibility that being an odd API here makes that overall move harder not easier. And C++ is regularly criticized for being inconsistent. Do you deepen those criticisms just so that one tiny corner of an API is better?
If I’m honest with myself, I probably would have made the same choices they did in this situation.
> If I’m honest with myself, I probably would have made the same choices they did in this situation.
Some of the more modern proposals (std::optional is quite old) actually make an explicit appeal to WG21 not to choose consistency at the price of safety because it just needlessly makes the language worse. "But we made the language worse before" is more like a plea for help than an excuse.
Barry Revzin did this in his "do expressions" which are an attempt to kludge compound expressions into C++ which really wants them to be compound statements instead. For consistency, all the obvious mistakes you'll make in do expressions could introduce UB like they would in equivalent C++ core features, but Barry argues they should be Ill-Formed instead - resulting in your mistakes not compiling rather than having undefined behaviour.
This is not the norm, as the employment modalities in that thread are super strange. If you’re employed by a German entity and your salary is 91.1k€, your take-home income would be around 53.8k€. Put another way - the $100k / 91.1k€ are the Arbeitgeberbrutto, they correspond to 75.5k€ Arbeitnehmerbrutto (the number you’d normally see on your contract). The difference exists because there are employer deductions and employee deductions, but the employer deductions don’t show up on the pay slip. Only in this constellation the employee has to pay both. It’s very much the exception, not the norm.
> If you’re employed by a German entity and your salary is 91.1k€, your take-home income would be around 53.8k€.
> Put another way - the $100k / 91.1k€ are the Arbeitgeberbrutto, they correspond to 75.5k€ Arbeitnehmerbrutto
I fully disagree. I'm talking about the Arbeitgeberbrutto as it does not make any difference for the employer if he sends the money to you or to the state/health insurance/.... He is already paying it so he would be willing to also pay it to you if he would not have to pay it to the state/health insurance/... So in my opinion it is part of the salary and I think the split into employer deductions and employee deductions just exists to make the contributions appear to be smaller than they actually are.
The post I linked just made it clear to me that salaries aren't that bad in germany compared to other states it is just that we have to pay most of it to the state/health insurance/...
As an employee, the Arbeitgeberbrutto is a number you never see. You’re not saying that employing people isn’t worth it, you’re saying that working in Germany isn’t worth it. Then you have to take the employee’s perspective, not the employer’s. Nobody advertises the true cost to the employer in other countries either. How much do all those benefits to US employees cost? Do you include that when you list US salaries, or do those get magically excluded because health insurance isn’t mandatory?
> you’re saying that working in Germany isn’t worth it.
Yes, that's my first sentence in my first comment.
My comment was not about reasoning if it is worth to employ people in germany but to state why people may prefer to work less.
> How much do all those benefits to US employees cost? Do you include that when you list US salaries, or do those get magically excluded because health insurance isn’t mandatory?
Yes, if the employer pays it it is part of the loan and should be considered if you compare the loans between different countries.
> Your premise just seems fundamentally flawed.
Okay, to be honest I just don't see how it is flawed. Also I don't have anything left to say. I just don't see why I shouldn't consider it as part of the salary as it would not make a difference to the employer to pay it to the employee instead if the employee deductions wouldn't exist.
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Edit:
I can't answer anymore. So I'm editing this post.
> Making an argument about how people may want to work less based on a number most have never seen [...] is a flawed argument no matter how you approach it.
Yes, that makes sense. Most employees likely won't think about how much of the Arbeitgeberbrutto is taken away.
Still I think if you know it then it reduces ones motivation and
it also has the indirect effect of reducing the Arbeitnehmerbrutto an employer is willing to pay and therefore employees may be less motivated due to a low salary.
Making an argument about how people may want to work less based on a number most have never seen or care about is a flawed argument no matter how you approach it.
Your information is quite a few years out of date. The solar learning curve has continued in the meantime, reducing the cost every year. Especially in sunny places like California, unsubsidised solar pays for itself surprisingly quickly (I don’t have the numbers for CA, but I wouldn’t be surprised if the number was 10 years).
If you enjoyed XOR filters, you might also like ribbon filters, something that I had the pleasure of working on last year. They share the basic idea of using a system of linear equations, but instead of considering 3 random positions per key, the positions to probe are narrowly concentrated along a ribbon with a typical width of 64. This makes them far more cache-efficient to construct and query.
By purposefully overloading the data structure by a few per cent and bumping those items that cannot be inserted as a result of this overloading to the next layer (making this a recursive data structure), we can achieve almost arbitrarily small space overheads: <1% is no problem for the fast configurations, and <0.1% overhead with around 50% extra runtime cost. This compares to around 10% for XOR filters and ≥ 44% for Bloom filters.
This made my day, thank you so much. :) Your explanation makes sense and it sounds brilliant/clever yet obvious. (like many good ideas are)
I'm reading the paper and looking at your github now, and look forward to "github/academia" stalking you in the future. Skimming your list of repositories and seeing a lot of stuff I understand and could possibly use. ;-)
(I find it to be a useful strategy to, when I find a clever concept in a paper, or in code on github, then look at all the other things done by the same person, or the works of people they co-author with. "collaborative filtering" for ideas.)
Indeed! Funny enough, I rewrote that article a few years ago, it previously contained an approximation of something like Algorithm L that some person with a blog came up with, having no idea that an even simpler and provably correct algorithm was published as early as 1994 :) Though others have improved the article a lot since then, adding explanations for how/why it works. Couldn't be happier to see it cited in this list!
The App Store page says "Simply take photos of an object from all angles and upload them to our service, and we will create and send you a 3D model ready for 3D printing, Augmented Reality and our web app r3Dent." so not it appears to use some kind of server-side processing. So it's not even on-device.
https://signal.org/android/apk/ and it appears to work without Google Play Services (though push notifications drain more battery iirc because they can't use the google push notification service)
Cosmic background radiation is a thing and water is really good at blocking it, so it's not complete bullshit. Of course, without knowing what dose the GP received, it's impossible to say whether it's a comparable dose to what they would have received on the surface - but it's plausible.
There is some good information about the relative exposure levels to cosmic radiation that one can expect to encounter on this site. They have been doing balloon launches and measuring in-flight levels for quite a while now.
Indeed. But isn't it really only "a thing" for airline pilots, cabin crew and a few unfortunate people at ground level who happen to live/work high-altitude on mountains or somewhere lower down with the wrong kind of rocks ?
Depends how you look at it. Cosmic radiation might not be extremely high level on the sea level, but it is a thing. So the total radiation dosis in a nuclear submarine might equal or even be less than on the surface.
Fun story: as part of my physics education we did an experiment on the cosmic radiation with a "radiation" telescope. That were 2 Geiger counters with a logic that only registered events which basically occured in both counters at the same time. That made the observation reasonably detectable and you could "see" the sun with this. This experiment was conducted indoors, just on the top floor of the building. We had about 1 event/second, our bodies would be getting a similar dosis all the time.
No, it is a gradient, with more exposure happening higher up. Radiation damage is considered “additive” over your lifetime. So if you are somewhere with less background radiation, you can receive more radiation from other sources and still be considered within “safe” limits. This is the basis for the policy mentioned.
I think they just poorly explained that his exposure in the sub was lower than background radiation levels on the sea surface. You get more rads living in Colorado for a year than anyone would get working in a nuclear power plant for a year at sea level.
