Scala macro to convert between a case class instance and a Map of constructor parameters. Developed by Jonathan Chow (see http://blog.echo.sh/post/65955606729/exploring-scala-macros-map-to-case-class-conversion for description and usage). This version simply updates Jonathan's code to Scala 2.11.2

gistfile1.scala

import scala.language.experimental.macros 
import scala.reflect.macros.blackbox.Context

trait Mappable[T] {
  def toMap(t: T): Map[String, Any]
  def fromMap(map: Map[String, Any]): T
}

object Mappable {
  
  implicit def materializeMappable[T]: Mappable[T] = macro materializeMappableImpl[T]

  def materializeMappableImpl[T: c.WeakTypeTag](c: Context): c.Expr[Mappable[T]] = {
    import c.universe._
    val tpe = weakTypeOf[T]
    val companion = tpe.typeSymbol.companion

    val fields = tpe.decls.collectFirst {
      case m: MethodSymbol if m.isPrimaryConstructor => m
    }.get.paramLists.head

    val (toMapParams, fromMapParams) = fields.map { field =>
      val name = field.asTerm.name
      val key = name.decodedName.toString
      val returnType = tpe.decl(name).typeSignature

      (q"$key -> t.$name", q"map($key).asInstanceOf[$returnType]")
    }.unzip
    

    c.Expr[Mappable[T]] { q"""
      new Mappable[$tpe] {
        def toMap(t: $tpe): Map[String, Any] = Map(..$toMapParams)
        def fromMap(map: Map[String, Any]): $tpe = $companion(..$fromMapParams)
      }
    """ }
  }
}