Fix #10900: Avoid loop for F-bounds in checkCanEqual

liufengyun · liufengyun · commit 960164225ddc · 2021-06-08T15:49:58.000+02:00
diff --git a/compiler/src/dotty/tools/dotc/typer/Implicits.scala b/compiler/src/dotty/tools/dotc/typer/Implicits.scala
@@ -929,6 +929,8 @@ trait Implicits:
           apply(t.widen)
         case t: RefinedType =>
           apply(t.parent)
+        case t: LazyRef =>
+          t
         case _ =>
           if (variance > 0) mapOver(t) else t
       }
diff --git a/tests/pos/i10900.scala b/tests/pos/i10900.scala
@@ -0,0 +1,3 @@
+import scala.collection.IterableOps
+def foo[CC[A] <: IterableOps[A, CC, CC[A]], A](collection: CC[A]) =
+  collection == collection

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+import scala.collection.IterableOps`
	`2`	`+def foo[CC[A] <: IterableOps[A, CC, CC[A]], A](collection: CC[A]) =`
	`3`	`+ collection == collection`