Google has been using Rust in Android more and more for its memory safety characteristics, and the results on that front were quite positive. It turns out, however, that not only does using Rust reduce the number memory safety issues, it’s also apparently a lot faster to code in Rust than C or C++.
We adopted Rust for its security and are seeing a 1000x reduction in memory safety vulnerability density compared to Android’s C and C++ code. But the biggest surprise was Rust’s impact on software delivery. With Rust changes having a 4x lower rollback rate and spending 25% less time in code review, the safer path is now also the faster one.
↫ Jeff Vander Stoep at the Google Security Blog
When you think about it, it actually makes sense. If you have fewer errors of a certain type, you’ll spend less time fixing those issues, time which you can then spend developing new code. Of course, it’s not that simple and there’s a ton more factors to consider, but on a base level, it definitely makes sense. Spellcheck in word processors means you have to spend less time detecting and fixing spelling errors, so you have more time to spend on actually writing.
I’m sure we’ll all be very civil about this, and nobody will be weird about Rust at all.
While I do think that some time is saved on fixing memory-related bugs, I do not think that is the primary driver of the increased productivity.
Rust is a modern language that feels familiar coming from other modern languages like Kotlin or Swift. It is much more expressive, allowing you to say more in fewer lines. I’m sure an argument can be made for the latest C++ on the basis of it bolting on some of these features onto an ever-increasing pile of features, but I would still take almost any language over C++ any day (and I used to write C++ for Microsoft).
C is respectable, of course, but it is very low level compared to Rust, so obviously it takes more time to write it.