Another test

Author: odersky

tests/pos/i5773a.scala

@@ -0,0 +1,17 @@
+trait Semigroup[T] {
+  def (x: T) combine (y: T): T
+}
+object Test {
+  implicit val IntSemigroup: Semigroup[Int] = new {
+    def (x: Int) combine (y: Int): Int = x + y
+  }
+  implicit def OptionSemigroup[T: Semigroup]: Semigroup[Option[T]] = new {
+    def (x: Option[T]) combine (y: Option[T]): Option[T] = for {
+      x0 <- x
+      y0 <- y
+    } yield x0.combine(y0)
+  }
+  1.combine(2)
+  Some(1).combine(Some(2))
+  Option(1) combine Option(2)
+}