Tamschi

5 ms·

1.
by Tamschi 4y ago
Hmm… I'd say for IO-bound tasks/loading in a DBMS yes, async/await coroutines are the correct abstraction, since you're waiting to reschedule on external notice and normally don't want to spin-wait (or you could blo
2.
by Tamschi 4y ago
It's "Tokio". Coroutines in Rust are a native language feature and their API is part of `std`, but the executors indeed come from community libraries. Tokio is one option, but as long as you don't contextually fork (for
3.
by Tamschi 4y ago
Ah, you're right, I missed it because it's callee-controlled in C++. (See Heap Allocation and Promise on https://en.cppreference.com/w/cpp/language/coroutines , for those curious.) Rust coroutines e
4.
by Tamschi 4y ago
They aren't strictly comparable. While the heap allocation may be optimised out, there is no way to use native C++ coroutines as guaranteed zero-cost construct due to the automatic heap allocation in the API. Rust's coroutines cur
5.
by Tamschi 5y ago
I should. I'm not too familiar with the process so far, but I'll find some time for it. These functions are indeed generally sound (also for `Rc`), as any value that cares would be `!Unpin`, which would still bar access to `&m
6.
by Tamschi 5y ago
There's actually a direct mention of that in my post already, but it's all the way near the bottom in the "Weakening non-moveability" section. It probably goes a bit too far to link in the intro, so I inlined a quick def
7.
by Tamschi 5y ago
That's understandable, I originally come from about the same position too, with a bit less functional programming background. I updated the intro to also cover that angle: https://github.com/Tamschi/Abstraction-Hav
8.
by Tamschi 5y ago
Something else that I didn't mention in the post is that `Pin<Box<T>>` is `From<Box<T>>` (so it can be cast directly, and here without reallocation or such), and this could also be implemented for (other) exclus
9.
by Tamschi 5y ago
There's a hole or oversight in `Arc`'s API in this regard, annoyingly. The function you're looking for would be something like pub fn get_mut_pinned(this: &mut Pin<Arc<T>>) -> Option<Pin<&mut T&gt
10.
by Tamschi 5y ago
This is why I insist on never calling it "pinned pointer" in the post, even if not explicitly. I'm aware the term is used in the standard library docs (for context: `Pin`'s tagline is "A pinned pointer."), but
11.
by Tamschi 5y ago
"Trivially movable" means anyone can take an instance (that they own) and copy its data (just the plain memory cells) to a new location with a new address, then continue to use that instance at that new location without breaking a