SI-2577, SI-6860: annotation type inference.

This is less than ideal:

  scala> class Bippy[T] extends annotation.StaticAnnotation
  defined class Bippy

  scala> def f: Int @Bippy = 5
  f: Int @Bippy[T]

Turns out we can infer such types. Now it says:

  scala> def f: Int @Bippy = 5
  f: Int @Bippy[Nothing]

This should put to rest many an issue with parameterized
annotations.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/files/run/t2577.scala b/test/files/run/t2577.scala
new file mode 100644
index 0000000000..6d836a3996
--- /dev/null
+++ b/test/files/run/t2577.scala
@@ -0,0 +1,17 @@
+case class annot[T]() extends scala.annotation.StaticAnnotation
+
+// type inference should infer @annot[Nothing] instead of @annot[T]
+// note the T is not in scope here!
+class Foo[@annot U]
+
+object Test {
+  import scala.reflect.runtime.universe._
+  val x = new Foo
+
+  def main(args: Array[String]): Unit = {
+    val targ = typeOf[x.type].widen match {
+      case TypeRef(_, _, arg :: _) => arg
+    }
+    println(targ)
+  }
+}