diff options
Diffstat (limited to 'src/dotty/tools/dotc/core/TypeApplications.scala')
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeApplications.scala | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/core/TypeApplications.scala b/src/dotty/tools/dotc/core/TypeApplications.scala index 599e4b0f0..98249d8c9 100644 --- a/src/dotty/tools/dotc/core/TypeApplications.scala +++ b/src/dotty/tools/dotc/core/TypeApplications.scala @@ -127,11 +127,14 @@ class TypeApplications(val self: Type) extends AnyVal { /** Turn this type, which is used as an argument for * type parameter `tparam`, into a TypeBounds RHS */ - final def toBounds(tparam: Symbol)(implicit ctx: Context): TypeBounds = { - val v = tparam.variance - if (v > 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.upper(self) - else if (v < 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.lower(self) - else TypeAlias(self, v) + final def toBounds(tparam: Symbol)(implicit ctx: Context): TypeBounds = self match { + case self: TypeBounds => // this can happen for wildcard args + self + case _ => + val v = tparam.variance + if (v > 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.upper(self) + else if (v < 0 && !(tparam is Local) && !(tparam is ExpandedTypeParam)) TypeBounds.lower(self) + else TypeAlias(self, v) } /** The type arguments of the base type instance wrt `base` of this type */ |