In my limited experience, unfortunately Rust isn't there yet for true "blazingly-fast" low-level code, not without using assembly[1] or linking to external code. For example, there is no (mature) support for SIMD yet. Neither C or C++ has it to be technicall, but at least the compilers do (in the form of intrinsics).

But I agree with the overal message, and I'm looking forward to Rust maturing. I think it is the better language although I am no expert at either.

[1]: but really, when you start using AVX instructions and the like beyond what the compiler will automate for you, you are just using wrappers around assembly instructions in languages like C today anyway (__mm256_shuffpd, __mm256_perm128f2d)

For us we support multiple platforms (win, osx, ios, android, ...) and need to interact with hardware io, codecs, and gpu apis. We could use C, I suppose, but we'd be giving up some of the niceties of C++11 such as smart pointers that make life much simpler.

That's not to say we don't have some platform-specific code in the "preferred" language (in some cases there is no choice in the matter), but most of the system is C++.

My main argument against Rust is the existence of D.

Over the years several languages have been the 'C++ killer'. For quite a long time it was D, and I know several people who converted. Then the standard library split in two, and the language got fairly unusable for a while. Now things have calmed down with D 2.0, but it's not clear it will still be around in 10-15 years time.

Similarly with Rust -- at the moment it seems to be a one company product (Mozilla). What if they get bored of it? Will my Rust code still work in 10 years time?

I asked about this and some Rust folks were kind enough to mention that Dropbox is one company that publicly has a large Rust deployment. Further, I think the main (huge?) advantage of Rust is it was designed to allow in situ replacements of pieces of a large c++ codebase. This really is a killer feature for lots of folks who simply can't afford to rewrite tens of millions of lines of tested c++.

previous discussion: https://news.ycombinator.com/item?id=10890310

> they can still probably find a better language today

Rust's ecosystem is still a bit anemic. I've played around with Rust, and I like the language, but C++ has a much wider array of battle-tested libraries at one's beck and call. Rust's development tools are also somewhat of a monoculture, at the moment.

> Rust's development tools are also somewhat of a monoculture, at the moment.

Care to elaborate? I'm curious

Did you just mention Go and performance? ROTFL!

Writing in other languages means you end up using ineffecient abstractions. C++ affords very efficient abstractions and really doesn't force a different code structure than other languages, so it is hard to see why there'd be an advantage with something else.