t7509.scala:3: error: inferred type arguments [Int] do not conform to method crash's type parameter bounds [R <: AnyRef]
  crash(42)
  ^
t7509.scala:3: error: type mismatch;
 found   : Int(42)
 required: R
  crash(42)
        ^
t7509.scala:3: error: could not find implicit value for parameter ev: R
  crash(42)
       ^
three errors found