SI-5845 Advances the example from a crasher to an inference failure.

The inference failure itself seems like an instance of of SI-3346.

But dependent method types (which triggered the crash), can be employed
to avoid inferring the type constructor CC.

class Num[T] {
  def mkOps = new Ops
  class Ops { def +++(rhs: T) = () }
}

class A {
  implicit def infixOps[T](lhs: T)(implicit num: Num[T]): num.Ops = num.mkOps
  implicit val n1: Num[Int] = new Num[Int] { }
  5 +++ 5
}

1 files changed, 16 insertions, 0 deletions

diff --git a/test/files/neg/t5845.scala b/test/files/neg/t5845.scala
new file mode 100644
index 0000000000..823c722c14
--- /dev/null
+++ b/test/files/neg/t5845.scala
@@ -0,0 +1,16 @@
+class Num[T] {
+  def mkOps = new Ops
+  class Ops { def +++(rhs: T) = () }
+}
+
+class A {
+  implicit def infixOps[T, CC[X] <: Num[X]](lhs: T)(implicit num: CC[T]) = num.mkOps
+  implicit val n1 = new Num[Int] { }
+  println(5 +++ 5)
+}
+
+class B {
+  implicit def infixOps[T, CC[X] <: Num[X]](lhs: T)(implicit num: CC[T]) : CC[T]#Ops = num.mkOps
+  implicit val n1 = new Num[Int] {}
+  println(5 +++ 5)
+}