diff options
Diffstat (limited to 'test/files/neg/t8104b')
-rw-r--r-- | test/files/neg/t8104b/Macros_1.scala | 23 | ||||
-rw-r--r-- | test/files/neg/t8104b/Test_2.scala | 24 |
2 files changed, 47 insertions, 0 deletions
diff --git a/test/files/neg/t8104b/Macros_1.scala b/test/files/neg/t8104b/Macros_1.scala new file mode 100644 index 0000000000..688d0694c0 --- /dev/null +++ b/test/files/neg/t8104b/Macros_1.scala @@ -0,0 +1,23 @@ +import scala.reflect.macros.Context + +object Macros { + def impl[T](c: Context)(implicit T: c.WeakTypeTag[T]) = { + import c.universe._ + import Flag._ + import definitions._ + val fields = T.tpe.declarations.toList.collect{ case x: TermSymbol if x.isVal && x.isCaseAccessor => x } + val Repr = appliedType(TupleClass(fields.length).asType.toType, fields.map(_.typeSignature)) + c.Expr(Block( + List(ClassDef( + Modifiers(FINAL), + newTypeName("$anon"), + List(), + Template( + List(AppliedTypeTree(Ident(newTypeName("Generic")), List(TypeTree(T.tpe)))), + emptyValDef, + List( + DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(), Block(List(Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List())), Literal(Constant(())))), + TypeDef(Modifiers(), newTypeName("Repr"), List(), TypeTree(Repr)))))), + Apply(Select(New(Ident(newTypeName("$anon"))), nme.CONSTRUCTOR), List()))) + } +}
\ No newline at end of file diff --git a/test/files/neg/t8104b/Test_2.scala b/test/files/neg/t8104b/Test_2.scala new file mode 100644 index 0000000000..a0d35942ba --- /dev/null +++ b/test/files/neg/t8104b/Test_2.scala @@ -0,0 +1,24 @@ +trait Generic[T] { type Repr } +object Generic { + type Aux[T, Repr0] = Generic[T] { type Repr = Repr0 } + import scala.language.experimental.macros + implicit def materializeGeneric[T, Repr]: Generic.Aux[T, Repr] = macro Macros.impl[T] +} + +object Test extends App { + case class C(x: Int, y: Int) + + // this doesn't work because of SI-7470 + // well, in fact SI-7470 has been fixed: https://github.com/scala/scala/pull/2499 + // it's just that the fix hasn't been backported to 2.10.x + // if you've made this compile, consider taking a look at the aforementioned pull request + def reprify[T, Repr](x: T)(implicit generic: Generic.Aux[T, Repr]) = ??? + reprify(C(40, 2)) + + // this is a compilation error at the moment as explained in SI-8104 + // because matchesPt in implicit search says that depoly(<type of materializeGeneric>) isn't a subtype of Generic.Aux[C, (Int, Int)] + // which is rightfully so, because depoly only replaces type parameters, not type members with wildcard types + // however in the future we might want to relax the matchesPt check, so this might start compiling + // therefore, if you've broken this test, then you should be happy, because most likely you've just enabled an interesting use case! + implicitly[Generic.Aux[C, (Int, Int)]] +} |