Mark result types of anonymous functions as InferredTypeTrees

Author: odersky

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -458,7 +458,11 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
   def AppliedTypeTree(tpt: Tree, arg: Tree)(implicit src: SourceFile): AppliedTypeTree =
     AppliedTypeTree(tpt, arg :: Nil)
 
-  def TypeTree(tpe: Type)(using Context): TypedSplice = TypedSplice(TypeTree().withTypeUnchecked(tpe))
+  def TypeTree(tpe: Type)(using Context): TypedSplice =
+    TypedSplice(TypeTree().withTypeUnchecked(tpe))
+
+  def InferredTypeTree(tpe: Type)(using Context): TypedSplice =
+    TypedSplice(new InferredTypeTree().withTypeUnchecked(tpe))
 
   def unitLiteral(implicit src: SourceFile): Literal = Literal(Constant(()))
 

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1134,8 +1134,8 @@ class Typer extends Namer
    */
   private def decomposeProtoFunction(pt: Type, defaultArity: Int, pos: SrcPos)(using Context): (List[Type], untpd.Tree) = {
     def typeTree(tp: Type) = tp match {
-      case _: WildcardType => untpd.TypeTree()
-      case _ => untpd.TypeTree(tp)
+      case _: WildcardType => new untpd.InferredTypeTree()
+      case _ => untpd.InferredTypeTree(tp)
     }
     def interpolateWildcards = new TypeMap {
       def apply(t: Type): Type = t match