Merge pull request #1242 from joroKr21/witness-refinement-backport

Remove refinement from Witness.value

Author: joroKr21

core/jvm/src/test/scala/shapeless/witness.scala

@@ -0,0 +1,18 @@
+package shapeless
+
+import org.junit.Assert._
+import org.junit.Test
+
+import scala.reflect.runtime.universe.WeakTypeTag
+
+class WitnessJvmTests {
+
+  @Test
+  def testRuntimeReflection: Unit = {
+    val w1: Witness.Lt[Int] = Witness(1)
+    val v1 = w1.value
+    def infer[T](v: T)(implicit ev: WeakTypeTag[T]): WeakTypeTag[T] = ev
+    val tag = infer(v1)
+    assertEquals(tag.tpe.toString, "w1.T")
+  }
+}

core/src/main/scala/shapeless/singletons.scala

@@ -31,7 +31,7 @@ import scala.util.Try
  */
 trait Witness extends Serializable {
   type T
-  val value: T {}
+  val value: T
 }
 
 object Witness extends Dynamic {

core/src/test/scala/shapeless/singletons.scala

@@ -589,6 +589,15 @@ class SingletonTypesTests {
     assertTypedEquals[ObjectThis.type](ObjectThis.w1.value, ObjectThis.w2.value)
   }
 
+  @Test
+  def testTypeInference: Unit = {
+    val singletonW = Witness(3)
+    def s3[T](v: T)(implicit ev: Witness.Aux[T]) = v
+    val v = singletonW.value
+    val s = s3(v)
+    assertEquals(s, v)
+  }
+
   class NestingBug {
     val o: AnyRef = new Object {}