Replace array impls with const generics

[austinabell]

Closes #752

Not sure if you would like it under a feature to not be a breaking change (if msrv is important), but happy to make that change if so :D

[Robbepop]

Thank you for the PR @austinabell !

Not sure if you would like it under a feature to not be a breaking change (if msrv is important), but happy to make that change if so :D

We won't need to feature flag this since we are on Rust nightly which includes (by definition) the latest Rust 1.51 where this feature has already been stabilized.

[Robbepop]

The CI is currently unhappy due to examples needing to be updated with the updated SCALE codec crate. However, I'd instead love to see support for this in SCALE codec crate prior to merging this PR. Would be cool if you want to spearhead this!

[austinabell]

The CI is currently unhappy due to examples needing to be updated with the updated SCALE codec crate. However, I'd instead love to see support for this in SCALE codec crate prior to merging this PR. Would be cool if you want to spearhead this!

Ah my bad, I thought this was assumed, I should have put that comment in the description. Yeah I'm leaving this PR in draft state until paritytech/parity-scale-codec#261 comes in, then I'll update the reference here and open up the PR.

I was just too lazy to patch all examples since it was a temporary check to make sure everything compiles.

Edit: Also have no rush to release the scale codec, happy to leave this sitting until it does. I don't need this change for anything, just did it for fun

[Robbepop]

LGTM

Requires update to cargo-contract template.

[austinabell]

LGTM

Requires update to cargo-contract template.

That change is merged :) Anything else needed?

[Robbepop]

LGTM
Requires update to cargo-contract template.

That change is merged :) Anything else needed?

Does not look like it to me tbh /~https://github.com/paritytech/cargo-contract/blob/master/templates/new/_Cargo.toml#L14

[austinabell]

LGTM
Requires update to cargo-contract template.

That change is merged :) Anything else needed?

Does not look like it to me tbh /~https://github.com/paritytech/cargo-contract/blob/master/templates/new/_Cargo.toml#L14

oh ooops lol, the different naming threw me off there. That's a dumb mistake, I'll update that now

edit: PR link - use-ink/cargo-contract#252

[Robbepop]

Thanks a lot for your PR @austinabell ! :)