abstract class NoAbstract abstract class TwoAbstract { def ap(a: Int): Int; def pa(a: Int): Int } abstract class Base // check that the super class constructor isn't considered. abstract class NoEmptyConstructor(a: Int) extends Base { def this(a: String) = this(0); def ap(a: Int): Int } abstract class OneEmptyConstructor() { def this(a: Int) = this(); def ap(a: Int): Int } abstract class OneEmptySecondaryConstructor(a: Int) { def this() = this(0); def ap(a: Int): Int } abstract class MultipleConstructorLists()() { def ap(a: Int): Int } abstract class MultipleMethodLists()() { def ap(a: Int)(): Int } abstract class ImplicitConstructorParam()(implicit a: String) { def ap(a: Int): Int } abstract class ImplicitMethodParam() { def ap(a: Int)(implicit b: String): Int } abstract class PolyClass[T] { def ap(a: T): T } abstract class PolyMethod { def ap[T](a: T): T } abstract class OneAbstract { def ap(a: Int): Any } abstract class DerivedOneAbstract extends OneAbstract object Test { implicit val s: String = "" type NonClassType = DerivedOneAbstract with OneAbstract (() => 0) : NoAbstract ((x: Int) => 0): TwoAbstract ((x: Int) => 0): DerivedOneAbstract // okay ((x: Int) => 0): NonClassType // "class type required". I think we should avoid SAM translation here. ((x: Int) => 0): NoEmptyConstructor ((x: Int) => 0): OneEmptyConstructor // okay ((x: Int) => 0): OneEmptySecondaryConstructor // derived class must have an empty *primary* to call. ((x: Int) => 0): MultipleConstructorLists ((x: Int) => 0): MultipleMethodLists ((x: Int) => 0): ImplicitConstructorParam ((x: Int) => 0): ImplicitMethodParam ((x: Int) => 0): PolyClass[Int] // okay ((x: Int) => 0): PolyMethod }