diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 9 | ||||
| -rw-r--r-- | test/files/neg/t6336.check | 5 | ||||
| -rw-r--r-- | test/files/neg/t6336.scala | 1 |
3 files changed, 12 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 089245e124..6ecd7911fd 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -1977,6 +1977,8 @@ trait Typers extends Modes with Adaptations with Tags { * - the self-type of the refinement * - a type member of the refinement * - an abstract type declared outside of the refinement. + * - an instance of a value class + * Furthermore, the result type may not be a value class either */ def checkMethodStructuralCompatible(meth: Symbol): Unit = { def fail(msg: String) = unit.error(meth.pos, msg) @@ -1986,8 +1988,8 @@ trait Typers extends Modes with Adaptations with Tags { case PolyType(_, restpe) => restpe case _ => NoType } - def failStruct(what: String) = - fail(s"Parameter type in structural refinement may not refer to $what") + def failStruct(what: String, where: String = "Parameter") = + fail(s"$where type in structural refinement may not refer to $what") for (paramType <- tp.paramTypes) { val sym = paramType.typeSymbol @@ -2002,7 +2004,10 @@ trait Typers extends Modes with Adaptations with Tags { if (paramType.isInstanceOf[ThisType] && sym == meth.owner) failStruct("the type of that refinement (self type)") } + if (tp.resultType.typeSymbol.isDerivedValueClass) + failStruct("a user-defined value class", where = "Result") } + def typedUseCase(useCase: UseCase) { def stringParser(str: String): syntaxAnalyzer.Parser = { val file = new BatchSourceFile(context.unit.source.file, str) { diff --git a/test/files/neg/t6336.check b/test/files/neg/t6336.check index f6b35ad232..c3ddf81f21 100644 --- a/test/files/neg/t6336.check +++ b/test/files/neg/t6336.check @@ -1,4 +1,7 @@ t6336.scala:3: error: Parameter type in structural refinement may not refer to a user-defined value class val a = new { def y[T](x: X[T]) = x.i } ^ -one error found +t6336.scala:4: error: Result type in structural refinement may not refer to a user-defined value class + val b = new { def y[T](x: T): X[T] = new X(2) } + ^ +two errors found diff --git a/test/files/neg/t6336.scala b/test/files/neg/t6336.scala index a9844ff94f..b1d61f4dd2 100644 --- a/test/files/neg/t6336.scala +++ b/test/files/neg/t6336.scala @@ -1,6 +1,7 @@ object D { def main(args: Array[String]) { val a = new { def y[T](x: X[T]) = x.i } + val b = new { def y[T](x: T): X[T] = new X(2) } val x = new X(3) val t = a.y(x) println(t) |