diff options
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeComparer.scala | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala index 6532d51bf..1de2d7e98 100644 --- a/src/dotty/tools/dotc/core/TypeComparer.scala +++ b/src/dotty/tools/dotc/core/TypeComparer.scala @@ -50,6 +50,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi private var myNullClass: ClassSymbol = null private var myObjectClass: ClassSymbol = null private var myAnyType: TypeRef = null + private var myNothingType: TypeRef = null def AnyClass = { if (myAnyClass == null) myAnyClass = defn.AnyClass @@ -71,14 +72,16 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi if (myAnyType == null) myAnyType = AnyClass.typeRef myAnyType } + def NothingType = { + if (myNothingType == null) myNothingType = NothingClass.typeRef + myNothingType + } // Subtype testing `<:<` def topLevelSubType(tp1: Type, tp2: Type): Boolean = { if (tp2 eq NoType) return false - if ((tp2 eq tp1) || - (tp2 eq WildcardType) || - (tp2 eq AnyType) && tp1.isValueType) return true + if ((tp2 eq tp1) || (tp2 eq WildcardType)) return true try isSubType(tp1, tp2) finally if (Config.checkConstraintsSatisfiable) @@ -381,8 +384,8 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi case tp2 @ TypeBounds(lo2, hi2) => def compareTypeBounds = tp1 match { case tp1 @ TypeBounds(lo1, hi1) => - (tp2.variance > 0 && tp1.variance >= 0 || isSubType(lo2, lo1)) && - (tp2.variance < 0 && tp1.variance <= 0 || isSubType(hi1, hi2)) + (tp2.variance > 0 && tp1.variance >= 0 || (lo2 eq NothingType) || isSubType(lo2, lo1)) && + (tp2.variance < 0 && tp1.variance <= 0 || (hi2 eq AnyType) || isSubType(hi1, hi2)) case tp1: ClassInfo => val tt = tp1.typeRef isSubType(lo2, tt) && isSubType(tt, hi2) |