Consider supporting the Stable channel too

[Lokathor]

If possible, you should support the Stable channel by default and then have an opt-in for const generics.

[notgull]

Hello! Thank you for your comment, I'm a big fan of tinyvec, thank you for making it.

The following is the current declaration of TinyMap:

pub struct TinyMap<K: PartialOrd, V, const N: usize> {
    arena: ArrayVec<[Option<Node<K, V>>; N]>,
    root: Option<usize>,
}

The key portion of this is that the arena property does not directly store K's or V's. It stores the Option<Node<K, V>> variant, which cannot be specified normally in an array. In addition, the software that I created this crate for was pinned to Nightly anyways.

However, an alternative API could be as follows:

use tinyvec::Array;

pub trait TwoTuple {
    type Item1;
    type Item2;
    
    // other convenience functions
}

impl<T1, T2> TwoTuple for (T1, T2) {
    type Item1 = T1;
    type Item2 = T2;
  
    // other convenience functions
}

pub struct TinyMap<A: Array> where A::Item: TwoTuple {
    arena: ArrayVec<[Option<Node<<A::Item as TwoTuple>::Item1>, <A::Item as TwoTuple>::Item2>; A::CAPACITY]>,
    root: Option<usize>,
}

The other issue is that this crate also uses the feature const_in_array_repeat_expressions. This is because [None; N] doesn't work because Option<T> does not implement Copy. Performing this array initialization is possible on Stable, but not without unsafe code, as far as I know.

[Lokathor]

Ah, yes I see.

Well, I think the aim was to have min_const_generics be stable by the end of the year, so we won't have to wait too long I suppose.

[Swoorup]

any updates?

[notgull]

I forgot that I wrote this crate. I think it's probably worth a rewrite using more modern Rust.