Caching implicit resolution

Question

To reduce compile times of my project, I\'m caching certain type classes that are resolved by implicit lookups. This appears somewhat cumbersome though, because the straight for

Answer 1

Shapeless provides a cachedImplicit macro with an implementation that's very similar to yours (it uses shadowing to avoid the recursion, and the fact that it's a macro means the usage can be cleaner).

There are some limitations to be aware of, and you may not want to take on a new dependency for this single method, but the implementation is pretty concise, and it's at least a good starting point.

Answer 2

Just for the sake of completeness: the shapeless macro in the accepted answer shadows its own definition in a way I didn't come up with. My particular problem could therefore be solved this way:

implicit val x: String = {
    def x = ???
    implicitly[String]
}