Adding helper function to instanciate caches within Cats Resource

[GrafBlutwurst]

I couldn't figure out where and what sort of meaningful tests to add. so I'd be happy for any pointers.

[cb372]

I'm a bit confused. Why do you need to split this into 2 objects? This would be a breaking change for anyone who is using cats-effect Async but not IO.

[GrafBlutwurst]

oh yeah you're right. I was intending to make this a proper lowPrio trait but screwed it up. I had ambigous implicit issues for Async[IO] due to both the explicit instance io and the def async matching. Why are those both in there and not just the async one since that should cover cats IO as well?

[GrafBlutwurst]

ah well now I have an odd diverging implicit expansion for type cats.effect.Async[F] I'll takle this tomorrow.

[cb372]

Explanation of why both IO and Async are there: #173 (comment)

But the IO one could probably be removed without anyone noticing, if it's causing you problems.

[GrafBlutwurst]

So even though all the tests are passing now I have a weird situation provoking "diverging implicits"

import scalacache._
import scalacache.caffeine._
import scalacache.CatsEffect.modes._
import cats.effect.IO

object Main {

  def main(args:Array[String]) = {
    val cacheResource = CatsEffect.resourceCache(IO {CaffeineCache[String]})

    implicitly[Mode[IO]] //works
    implicitly[Flags] //works

    val prog = cacheResource.use(
      cache => for {
        //diverging implicits
        _ <- cache.put("1")("a")//(CatsEffect.modes.async[IO], Flags())
        a <- cache.get("1")//(CatsEffect.modes.async[IO], Flags())

      } yield a
    )


    println(prog.unsafeRunSync)

  }

}

[GrafBlutwurst]

I fiddled around with the implicit resolution error but without success. So any help is welcome. I'll try to find a second pair of eyes to have a look at this.

[lewisjkl]

Thinking that this will be done a different way now that #345 will remove modes and instead rely on cats-effect typeclasses. I am going to close this for now and we can look into more alternatives once #345 is merged in.