by jacquesm | 2025-10-10 15:00:47+00:00
> Cost is a useful metric because it reflects a number of relevant things: Time to develop, effort to maintain - yes, but also people turnover, required expertise levels, satisfaction, and so on. Whether or not you like it, you have to care about cost if you want to make rational decisions. I'm not talking about assigning a Euro/Dollar/Yuan value to each hour spent on a project, but you need a rough idea about the size of the time and energy investment you are making when starting a project.

You are missing the cost to switch and that's a massive one and the one that I think most parties are using to decide whether or not to stick with what they know or to try something that is new to them. If you have a team of 50 embedded C++ developers and a deadline 'let's use rust' is a gamble very few managers will make.

> Things have changed for three important reasons: (1) C/C++ compilers have evolved, and UB is significantly more catastrophic than it was in the 90s and early 00s.

That depends on what industry you are looking at. For instance, in aviation the cost of undefined behavior, crashing software or wrong calculations was always that high. The difference is that in that industry (and a handful of others) there is enough budget to do it right resulting in far fewer in production issues than what we have come to accept in the 'always online, auto-update' world. That whole attitude is as much or more to blame for this than any particular language.

> (2) As societies digitize, the stakes are higher than even - leaking personal data has huge legal and moral consequences, and system outages can have business-killing financial consequences.

Show me the names of the businesses that have died because of data leaks or UB. See, the problem is that for those businesses it usually is just a speedbump. They don't care and no matter what the size of the breach the consequences are usually minor.

The employee sticking a USB drive found on the street into their laptop causing a cryptolocker incident is a much more concrete problem.

> (3) There are actual, viable alternatives - GC is no longer a requirement for memory safety.

GC is a convenience, and if you're going to switch languages you might as well pick one that is is more convenient. Java for instance is suitable now for 90% or so of the use cases where C or C++ would be your only option 15 years ago.

> Perhaps you didn't mean to say so, but Rust is not a managed language (that's a .NET term referring to C#, F#, etc.).

I know, but Java, Lisp and so on are managed languages, and they offer both safety and convenience. Rust only offers safety, other than that it is only marginally more convenient than C and some would argue less so.

> Me and other Rust users are obviously trying to convince even more people to use the language, and that's because we are having a great time over here.

Show, don't tell.

> It's a very pleasant language with a pleasant community and a high level of technical expertise, and it allows me to get significantly closer to living up to my own ideals.

Yes, but those are your ideals, which don't necessarily overlap with mine. I don't particularly care about one programming language or another, I've learned enough of them by now to know that all of them have their limitations, their warts, their good bits and their bad bits. I also know that the size of the eco-system is a large function in whether or not I'll be able to get through the day in a productive way.

> I'm not making a moral argument here, trying to say that you or anyone is a bad person for not using Rust, but I am making a moral argument saying that denying the huge cost and risk associated with developing software in C and C++ is bullshit.

See, your use of the word 'bullshit' triggers me in a way that you probably do not intend, but it is exactly that attitude that turns me off the language that you would like me to switch to. I don't particularly see that huge cost and risk as applied to myself because I'm not currently writing code that is going to be part of some network service. If I see an embedded shop doing their work in Rust then I'm happy because I can ignore at least one small aspect of the source of bugs in such software. But there are plenty remaining and Rust - no matter what you think - is not a silver bullet for all of the things that can go wrong with low level software. There are other, better alternatives for most of those applications, I'd be more inclined to use Java or Erlang if those are available, and Go if they are not. The speed at which I can develop software is a massive factor in that whole 'cost' evaluation for me.

> The point here is that, until Rust came along, you had the choice between wildly risky (but fast) C and C++ code, or completely safe (but slow) garbage collected languages with heavy runtimes and significant deployment challenges.

That just isn't true. There are more languages besides Rust that allow for low level and fast work. Go for instance is an excellent contender. And for long running processes Java is excellent, it is approaching C levels of throughput and excels at networked services.

> C is certainly not "the enemy" - I never said that, and I wouldn't. But that old world is gone.

Sorry, but this is not a realistic stance. That old world is not gone, and it is likely here to stay for many more decades. There is so much inertia here in terms of invested capital that you can't just make declarations like these and expect to be taken serious.

> The excuse of picking risky, problem-riddled languages that we know are associated with extreme costs for reasons of performance no longer has any technical merit. There can be other reasons, but this isn't it.

Do you realize that this is just your opinion and not a statement of fact?

> It's insane to me that anyone would limit themselves to a single language.

'Insane' is another very loaded word. Is this really the kind of language you want to be using while advocating for Rust? There are many programmers that learn one eco system well enough to carve out a career for themselves, and I'm not going to be the one to judge them for that. I'm not one of them, but I can see how it happens and I would definitely not label everybody that's not a polyglot as not entirely right in the head.

> Every competent programmer I know knows at least a handful.

I know some very competent programmers that only know one. But they know that one better than I know any of the ones that I'm familiar with. For instance, I know a guy that decided early on that if nobody wants to work on COBOL projects that that is exactly what he's going to do: become a world class expert in COBOL to help maintain all that old stuff. At a price. He's making very good money with that, far more than he'd have ever made by going with something more popular. I know plenty of Java only programmers and a couple that have decided that python is all they need. That's their right and it isn't up to me to look down on them or call them incompetent because they can do something that I apparently can't: focus, and get really good at one thing.

> Why are we worried about this? I'm a decent C programmer, and a very good C++ programmer - better at both because I'm also fairly good at Rust.

I would not label myself as 'very good' in any language, I always hope to get better and in spite of doing this for 4+ decades I have never felt that I was 'good enough'.

> "P[sic]obody's nerfect." I'm sorry, I really dislike this attitude.

Again, why the antagonism. We have many different classes of issues, and depending on the context some of them may not be a problem at all. I've built stuff in JavaScript because it was the most suitable for the job. But I stay the hell away from node and anything associated with it because I don't consider myself qualified to audit all of the code that could be pulled in through a dependency. And that's a good chunk of this: just know your limitations, and realize that not just 'nobody's perfect' but also that you yourself are not perfect and more than likely to mess up when you go into territory that is unfamiliar to you.

> We can't let the fact that security is hard, or that perfection is unattainable, be an excuse to deliver more crap.

Ok. So now you are labeling what other people produce as 'crap'. This isn't helping.

> Again, that's not my argument. My argument is that you should be honest about what the actual costs, or alternatively the actual quality.

So I'm not honest. If you are wondering what I meant when I wrote earlier that it is the attitude of some of the Rust advocates that turns me off then here in this thread you have a very nice example of that. All of this pontification and emotionally laden language serves nobody, least of all Rust.

If you want to win people over try the following:

- refrain from insulting your target audience

- respect the fact that your opinions are just that

- understand that there may be factors outside of your view that are part of the decision making process

- understand that you may not have a complete understanding of the problem domain or the restrictions involved (is a variation on the previous one)

- try to not use emotional language to make your point

- showing beats telling any day of the week