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-rw-r--r--tests/pos/gadts2.scala25
1 files changed, 25 insertions, 0 deletions
diff --git a/tests/pos/gadts2.scala b/tests/pos/gadts2.scala
new file mode 100644
index 000000000..71089c0f7
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+++ b/tests/pos/gadts2.scala
@@ -0,0 +1,25 @@
+object Test {
+
+ abstract class Number
+ case class MyInt(n: Int) extends Number
+ case class MyDouble(d: Double) extends Number
+
+ trait Term[a]
+ case class Cell[a](var x: a) extends Term[a]
+ final case class NumTerm(val n: Number) extends Term[Number]
+
+ def f[A](t: Term[A], c: Cell[A]): Unit = {
+ t match {
+ case NumTerm(n) => c.x = MyDouble(1.0) // problem is: this assignment is not type correct, since gadt variable is forgotten
+ }
+ }
+
+ val x: Term[Number] = NumTerm(MyInt(5))
+
+ def main(args: Array[String]): Unit = {
+ val cell = Cell[Number](MyInt(6))
+ Console.println(cell)
+ f[Number](new NumTerm(MyInt(5)), cell)
+ Console.println(cell)
+ }
+}