[outworlder]

> "is a huge advantage over Rust for mission critical and safety critical areas"

There's no C/C++. They are entirely different languages (even if C is supposed to be a subset).

Not exactly suitable for mission critical systems. The fact that they are used for that is more due to the fact that they can interface with hardware at a fairly low level and the amount of engineers with C (and nowadays, C++) knowledge.

The 'formal' standard doesn't help you much when there's so much undefined behavior.

Tool availability is a fair point.

[vowelless]

> There's no C/C++. They are entirely different languages (even if C is supposed to be a subset).

I think the OP is trying to say that both C and C++ have international standards.

> Not exactly suitable for mission critical systems. The fact that they are used for that is more due to the fact that they can interface with hardware at a fairly low level and the amount of engineers with C (and nowadays, C++) knowledge.

And highly deterministic behaviors, crucial in real time systems. But I think Rust is trying to provide those guarantees too.

[lambdaelite]

Ditto.

If Rust had a formal standard, and had the tool ecosystem, then I could see it being an interesting possibility for critical systems, certainly for the same places that Java + RTSJ would be appropriate. I won't be the first one to try and push a Rust-powered device through regulatory approval though.

[outworlder]

> And highly deterministic behaviors, crucial in real time systems. But I think Rust is trying to provide those guarantees too.

Forgot about that, a very good point.

[Alupis]

> There's no C/C++. They are entirely different languages (even if C is supposed to be a subset).

C++ is a subset of C, not the other way around.

> the fact that they can interface with hardware at a fairly low level

That's certainly one reason. Others include raw performance (think real-time safety-critical applications), no funny abstractions, tighter memory footprint, more flexibility, etc.

> and the amount of engineers with C (and nowadays, C++)

While I believe there are a number of C++ engineers out there, I'd wager that the number of competent C language engineers has dwindled over the years. Sure, everyone learns some C, but to know it well enough to write embedded real-time safety-critical systems is a whole different game. (not to mention the number of Java engineers has greatly outpaced even C++ engineers, thanks to University teaching Java, Android's dominance, and the lower barrier to entry).

> The 'formal' standard doesn't help you much when there's so much undefined behavior.

The formal standard defines what is undefined. Your safety-critical code shouldn't rely on some compiler-specific quirks or some magical code, but rather it should stay within the bounds of well-defined behavior.

[outworlder]

> C++ is a subset of C, not the other way around.

I can't see how this statement could possibly be true.

> no funny abstractions

Really? Maybe I suck at C++, but I can't meaningfully reason about template-heavy code. Not about the run-time performance, nor resource consumption. STL and Boost are beyond funny if you ask me.

> The formal standard defines what is undefined. Your safety-critical code shouldn't rely on some compiler-specific quirks or some magical code, but rather it should stay within the bounds of well-defined behavior.

Agreed. But take a look at the specification and you'll be amazed on just how much stuff is left for the actual implementation to figure out.

[lambdaelite]

> But take a look at the specification and you'll be amazed on just how much stuff is left for the actual implementation to figure out.

Which is why the coding standard for a critical project will disallow the use of things that can lead to undefined behavior.

[steveklabnik]

> C++ is a subset of C, not the other way around.

This is not true, the two languages have diverged: http://en.wikipedia.org/wiki/Compatibility_of_C_and_C%2B%2B

[Alupis]

You are right, they have diverged. However my initial statement was/is true, as C++ started as a subset of C (even though the two are totally incompatible for all non-trivial programs today).

[dorolow]

No it's not. You're confusing superset and subset.

[aikah]

Ok, i think it better to say that C and C++ share a subset of a language which is closer to C than C++.