diff options
Diffstat (limited to 'test/files/pos/t8237.scala')
-rw-r--r-- | test/files/pos/t8237.scala | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/test/files/pos/t8237.scala b/test/files/pos/t8237.scala new file mode 100644 index 0000000000..005089079e --- /dev/null +++ b/test/files/pos/t8237.scala @@ -0,0 +1,29 @@ +import scala.language.higherKinds + +object TestExplicit { + trait TC[A] + def fTt[A,E[X] <: List[X]](a: A)(implicit tt: TC[E[A]]) = a + implicit def tc[T]: TC[T] = ??? + + // Typechecking results in SOE in TypeVar.isGround + fTt(1)(tc) + // fun = TestExplicit.this.fTt[Int, E](1) + // args = TestExplicit.this.tc[E[Int]] + // argTpes.head.instantiateTypeParams = TC[?E#1[Int]] + // formals.head.instantiateTypeParams = TC[?E#2[Int]] + // (where ?E#1 and ?E#2 as distinct AppliedTypeVars that resulted + // from separate applications of type args to the same HKTypeVar, ?E) + // + // As we check if the argument conforms to the formal, we would have + // AppliedTypeVars sharing the same TypeConstraints on the LHS and RHS, + // which leads to a cyclic constraint. +} + +object TestImplicit { + trait TC[A] + def fTt[A,E[X] <: List[X]](a: A)(implicit tt: TC[E[A]]) = a + implicit def tc[T]: TC[T] = ??? + + // Oddly enough, this one works. + fTt(1) +} |