Replace generic array with vec

[rishflab]

This speeds up the painfully slow compilation of the swap crate in
xmr-btc-swap.

Attempt to fix comit-network/xmr-btc-swap#31

[bonomat]

🎊

[thomaseizinger]

I assume @luckysori wanted to get the typesystem to verify certain properties by using GenericArray instead of Vec? Have you thought about how this is affected once GenericArray is no longer used?

I assume the refactoring towards Vec will require quite a bit more changes then just replacing GenericArray with Vec, starting with Vec taking only a single type parameter :D

Edit: I see @luckysori is actually part of the commit, should be fine then :)

[luckysori]

Edit: I see @luckysori is actually part of the commit, should be fine then :)

Hehe, I just rebased onto master now that I added CI and force pushed so that this cannot be merged by mistake.

But yeah, type safety was the main reason behind using GenericArray. We were trying to verify if giving up the type safety would resolve our slow compilation in xmr-btc-swap, but we have to make it compile first 😛. In any case, I recommend replacing this library with secp256kfun/sigma_fun as soon as LLFourn/secp256kfun#29 is merged.

[bonomat]

Edit: I see @luckysori is actually part of the commit, should be fine then :)

Hehe, I just rebased onto master now that I added CI and force pushed so that this cannot be merged by mistake.

But yeah, type safety was the main reason behind using GenericArray. We were trying to verify if giving up the type safety would resolve our slow compilation in xmr-btc-swap, but we have to make it compile first 😛. In any case, I recommend replacing this library with secp256kfun/sigma_fun as soon as LLFourn/secp256kfun#29 is merged.

This PR makes use of GenericArrays as well unfortunately.

CC @LLFourn