1 files changed, 34 insertions, 0 deletions
diff --git a/src/library/scala/reflect/TagInterop.scala b/src/library/scala/reflect/TagInterop.scala
new file mode 100644
index 0000000000..6c6bfcc2f2
--- /dev/null
+++ b/src/library/scala/reflect/TagInterop.scala
@@ -0,0 +1,34 @@
+package scala.reflect
+
+import scala.runtime.ScalaRunTime._
+import mirror._
+import definitions._
+
+object TagInterop {
+  def arrayTagToClassManifest[T](tag: ArrayTag[T]): ClassManifest[T] = {
+    val erasure = arrayElementClass(tag)
+    if (erasure.isArray) {
+      val elementClass = arrayElementClass(erasure)
+      val elementManifest = arrayTagToClassManifest(ClassTag(elementClass))
+      ClassManifest.arrayType(elementManifest).asInstanceOf[ClassManifest[T]]
+    } else {
+      ClassManifest.fromClass(erasure.asInstanceOf[Class[T]])
+    }
+  }
+
+  def concreteTypeTagToManifest[T](tag: ConcreteTypeTag[T]): Manifest[T] = {
+    // todo. reproduce manifest generation code here. toolboxes are too slow.
+    val implicitly = PredefModule.typeSignature.member(newTermName("implicitly"))
+    val taggedTpe = appliedType(staticClass("scala.reflect.Manifest").asTypeConstructor, List(tag.tpe))
+    val materializer = TypeApply(Ident(implicitly), List(TypeTree(taggedTpe)))
+    try mkToolBox().runExpr(materializer).asInstanceOf[Manifest[T]]
+    catch { case ex: Throwable => Manifest.classType(tag.erasure).asInstanceOf[Manifest[T]] }
+  }
+
+  def manifestToConcreteTypeTag[T](tag: Manifest[T]): ConcreteTypeTag[T] = {
+    val tpe =
+      if (tag.typeArguments.isEmpty) classToType(tag.erasure)
+      else appliedType(classToType(tag.erasure).typeConstructor, tag.typeArguments map (manifestToConcreteTypeTag(_)) map (_.tpe))
+    ConcreteTypeTag(tpe, tag.erasure)
+  }
+}
+\ No newline at end of file