Queue with capacity 1 is both empty and full

[jonas-schievink]

use heapless::spsc::Queue;

fn main() {
    let queue: Queue<[u8; 16], 1> = Queue::new();
    assert!(queue.is_empty());
    assert!(!queue.is_full());
}

thread 'main' panicked at 'assertion failed: !queue.is_full()', src/main.rs:6:5

[birkenfeld]

From the docs: "A statically allocated single producer single consumer queue with a capacity of N - 1 elements". This is, I think, because the needed const generic math to allocate N + 1 items is not stable yet.

Is it possible to statically assert N > 1?

[jonas-schievink]

Oh, I see, I missed that

[birkenfeld]

It's new in 0.7 (the first const generics based version).

[burrbull]

Is it possible to statically assert N > 1?

In nightly only.

[korken89]

Hi, it's possible to do asserts in const with some tricks.
nvzqz/static-assertions#40 (comment)

I'll look into adding them everywhere.

[korken89]

Yeah, the interface is a bit unfortunate.
I hope we get more const power soon so we can get the old interface back.