import com.wacai.config.annotation._
import scala.concurrent.duration._
@conf trait kafka {
  val server = new {
    val host = "wacai.com"
    val port = 12306
  }
  val socket = new {
    val timeout = 3 seconds
    val buffer = 1024 * 64L
  }
  val client = "wacai"
}

class Consumer extends kafka {
  val client = new SimpleConsumer(
    server.host,
    server.port,
    socket.timeout,
    socket.buffer,
    client
  )
  ...
}

trait kafka {
  val server = new {
    val host = config.getString("kafka.server.host")
    val port = config.getInt("kafka.server.port")
  }
  val socket = new {
    val timeout = Duration(config.getDuration("kafka.socket.timeout", SECONDS))
    val buffer = config.getBytes("kafka.socket.buffer")
  }
  val client = config.getString("kafka.client")
  ...
}

addCompilerPlugin("org.scalamacros" % "paradise" % "2.0.1" cross CrossVersion.full)
libraryDependencies += "com.wacai" %% "config-annotation" % "0.3.5"

addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full)
libraryDependencies += "com.wacai" %% "config-annotation" % "0.3.6"

libraryDependencies += "com.wacai" %% "config-annotation" % "0.4.0"

import com.wacai.config.annotation._
@conf trait kafka extends Configurable { self: Actor =>
  def config = context.system.settings.config
  ...
}

scalacOptions += "-Xmacro-settings:conf.output.dir=/path/to/out"