Have you seen someone juggle several items with one hand? That's the point of async. Blocking (non-async) it like writing - it requires constant work from each hand. If you want to write twice as fast you'll need two hands and write with both at the same time. That's multithreading. If you juggle, the moment the item leaves your hand and is in the air, you have it left with nothing to do. That's similar to network IO - you make a request and are just waiting for the server to respond. You could be doing something in the meantime, like catching another item and throwing it back up again. That's what "await" does - it says I threw and item into the air, so I want my current thread / hand to switch over to catch something else now.
don't worry: in 20 years we won't have Rust 2.0, but some upstart kid is gonna take all the lessons and mistakes we learned by then, make the Grime language, and slowly put us all out of work. Then we truly will be C++.
Finally, I feel it is necessary to debunk the “ fighting the borrow checker ” legend, a story depicting the Rust compiler as a boogeyman: in my experience, it happens mostly to beginners and the 1% trying to micro-optimize code or push the boundaries. Most experienced Rust developers know exactly how to model their code in a way that no time is wasted fighting the compiler on design issues, and can spot anti-patterns at a glance, just like most people know how to drive their car on the correct side of the road to avoid accidents, and notice those who don’t!
I remember reading something from a coder who grew up on C, learned Rust, and the next time he had to write something in C, got really frustrated with all the bugs the compiler let through, since he then knew that it was possible to catch them at compile time.
That stuck with me and changed how I think about my fights with the borrow checker a bit.
We describe a lot of things as “how systems work” when really it’s “how C works” and part of Rust’s integration pains are just that it’s the first thing to credibly come into spaces and not fit in a C-shaped hole.
It's a great example of the different attitudes of C/C++ and Rust: In C/C++ something is correct when someone can use it correctly, but in Rust something is correct when someone can't use it incorrectly.
I think Rust is in an interesting place wrt specs because it straddles two kinds of language communities -- C/C++/JS, with serious specs and multiple implementations, and Ruby/Python/Go, with reference manual, a test suite, and a single canonical implementation.
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Rust is a place where both of those traditions are being forced to reckon with the reasons why the other tradition exists.
I'm pretty sure that many modern cars with seat belts are lighter than old cars without.
The "seatbelts" of the Rust language do not necessarily require adding code to the binary. Mostly not.
Besides, car analogies are always terrible. And the number of instructions required to do anything are not a function of the source language per se.
I think the security of the internet is incredibly important obviously and I want it to be secure and I think bringing rust there is absolutely going to help it. Just by default it eliminates some of the most classic types of vulnerabilities.
But I don't think that's the most exciting part. I think the most exciting part is that the set of people for whom it is possible to implement these types of things, like who writes coreutils, who writes curl, who does those things. That used to be a really small pool of people. That had to be people who knew the dark arts, and only them and only their buddies or something.
And it's the goal of rust to empower that to be a larger group of people and ultimately I think that that is what is going to happen which means the sheer number of people will be larger, and also the diversity of that set of people is going to grow. And I that that that will probably actually do more for the security and usefulness of these tools than eliminating underfined behaviour.
"Clever" memory use is frowned upon in Rust. In C, anything goes. For example, in C I'd be tempted to reuse a buffer allocated for one purpose for another purpose later (a technique known as HEARTBLEED).
Whilst Rusts memory safety rules no doubt help greatly to prevent memory related security issues. I would not over sell the point.
It is still trivially easy to reuse a byte buffer for multiple purposes. For example to receive data into and then send that data elsewhere.
One of the first bugs I made in Rust was just doing a read into a buffer and then a write from the buffer. Forgetting the read might not filled the entire buffer and writing the entire buffer rather than the length that was read. Thus potentially sending sensitive data to the wrong place.
In C it's perfectly rational to overuse linear search and linked lists, because who's going to maintain yet another half-assed implementation of hash table? There are no built-in containers, dependencies are a pain, so I cut corners to get stuff done. ... OTOH in Rust it takes only 1 or 2 lines of code to get very high quality implementations all kinds of containers. This means that my Rust programs can afford to use proper, incredibly well-optimized data structures every time.
if a rustacean says something about an "invariant lifetime" in response to your question, it is too late, there is no escape, you are now one with the crab
Given Linus's well known position on C++ in the kernel (for those who are not familiar with it, imagine five minutes of swearing, followed by "Over my dead body"), this is practically a warm welcome.
