4 files changed, 61 insertions, 4 deletions
diff --git a/src/library/scala/annotation/bridge.scala b/src/library/scala/annotation/bridge.scala
index 9f25e2beb3..c0c6dba424 100644
--- a/src/library/scala/annotation/bridge.scala
+++ b/src/library/scala/annotation/bridge.scala
@@ -10,5 +10,5 @@ package scala.annotation
 
 /** If this annotation is present on a method, it will be treated as a bridge method.
  */
-@deprecated("Reconsider whether using this annotation will accomplish anything", "2.10.0")
+@deprecated("reconsider whether using this annotation will accomplish anything", "2.10.0")
 private[scala] class bridge extends scala.annotation.StaticAnnotation
diff --git a/src/library/scala/annotation/elidable.scala b/src/library/scala/annotation/elidable.scala
index f9c5e8a744..dd0d9b511c 100644
--- a/src/library/scala/annotation/elidable.scala
+++ b/src/library/scala/annotation/elidable.scala
@@ -8,8 +8,6 @@
 
 package scala.annotation
 
-import java.util.logging.Level
-
 /** An annotation for methods whose bodies may be excluded
  *  from compiler-generated bytecode.
  *
@@ -62,7 +60,7 @@ import java.util.logging.Level
  *  @author   Paul Phillips
  *  @since    2.8
  */
-final class elidable(final val level: Int) extends scala.annotation.StaticAnnotation {}
+final class elidable(final val level: Int) extends scala.annotation.StaticAnnotation
 
 /** This useless appearing code was necessary to allow people to use
  *  named constants for the elidable annotation.  This is what it takes
diff --git a/src/library/scala/annotation/implicitAmbiguous.scala b/src/library/scala/annotation/implicitAmbiguous.scala
new file mode 100644
index 0000000000..44e8d23085
--- /dev/null
+++ b/src/library/scala/annotation/implicitAmbiguous.scala
@@ -0,0 +1,32 @@
+package scala.annotation
+
+/**
+  * To customize the error message that's emitted when an implicit search finds
+  * multiple ambiguous values, annotate at least one of the implicit values
+  * `@implicitAmbiguous`. Assuming the implicit value is a method with type
+  * parameters `X1,..., XN`, the error message will be the result of replacing
+  * all occurrences of `${Xi}` in the string `msg` with the string representation
+  * of the corresponding type argument `Ti`.
+  *
+  * If more than one `@implicitAmbiguous` annotation is collected, the compiler is
+  * free to pick any of them to display.
+  *
+  * Nice errors can direct users to fix imports or even tell them why code
+  * intentionally doesn't compile.
+  *
+  * {{{
+  * trait =!=[C, D]
+  *
+  * implicit def neq[E, F] : E =!= F = null
+  *
+  * @annotation.implicitAmbiguous("Could not prove ${J} =!= ${J}")
+  * implicit def neqAmbig1[G, H, J] : J =!= J = null
+  * implicit def neqAmbig2[I] : I =!= I = null
+  *
+  * implicitly[Int =!= Int]
+  * }}}
+  *
+  * @author Brian McKenna
+  * @since 2.12.0
+  */
+final class implicitAmbiguous(msg: String) extends scala.annotation.StaticAnnotation
diff --git a/src/library/scala/annotation/showAsInfix.scala b/src/library/scala/annotation/showAsInfix.scala
new file mode 100644
index 0000000000..6c25e08efa
--- /dev/null
+++ b/src/library/scala/annotation/showAsInfix.scala
@@ -0,0 +1,27 @@
+package scala.annotation
+
+/**
+ * This annotation configures how Scala prints two-parameter generic types.
+  *
+  * By default, types with symbolic names are printed infix; while types without
+  * them are printed using the regular generic type syntax.
+  *
+  * Example of usage:
+  {{{
+    scala> class Map[T, U]
+    defined class Map
+
+    scala> def foo: Int Map Int = ???
+    foo: Map[Int,Int]
+
+    scala> @showAsInfix class Map[T, U]
+    defined class Map
+
+    scala> def foo: Int Map Int = ???
+    foo: Int Map Int
+  }}}
+  *
+  * @param enabled whether to show this type as an infix type operator.
+  * @since 2.12.2
+  */
+class showAsInfix(enabled: Boolean = true) extends annotation.StaticAnnotation
+\ No newline at end of file