Merge pull request #9616 from dotty-staging/harden-constraints

Harden constraints so bounds can only be value types or lambdas
scala · Aug 21, 2020 · 387c562 · 387c562
2 parents 1fb07cb + d26f1f4
commit 387c562
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala b/compiler/src/dotty/tools/dotc/core/ConstraintHandling.scala
@@ -484,6 +484,7 @@ trait ConstraintHandling {
    *  way isSubType is organized.
    */
   protected def addConstraint(param: TypeParamRef, bound: Type, fromBelow: Boolean)(using Context): Boolean =
+    if !bound.isValueTypeOrLambda then return false
 
     /** When comparing lambdas we might get constraints such as
      *  `A <: X0` or `A = List[X0]` where `A` is a constrained parameter