Trait/Object

shapeless

Default

Related Docs: object Default | package shapeless

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trait Default[T] extends DepFn0 with Serializable

Provides default values of case class-like types.

The Out type parameter is an HList type whose length is the number of fields of T. Its elements correspond to the fields of T, in their original order. It is made of None.type (no default value for this field) and Some[...] (default value available for this field, with ... the type of the field). Note that None.type and Some[...] are more precise than simply Option[...], so that the availability of default values can be used in type level calculations.

The apply method returns an HList of type Out, with None elements corresponding to no default value available, and Some(defaultValue) to default value available for the corresponding fields.

Use like

case class CC(i: Int, s: String = "b")

val default = Default[CC]

// default.Out is  None.type :: Some[String] :: HNil

// default() returns
//   None :: Some("b") :: HNil,
// typed as default.Out
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Type Members

  1. abstract type Out <: HList

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    DefaultDepFn0

Abstract Value Members

  1. abstract def apply(): Out

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    DepFn0

Concrete Value Members

  1. final def !=(arg0: Any): Boolean

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  2. final def ##(): Int

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  3. final def ==(arg0: Any): Boolean

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  4. final def asInstanceOf[T0]: T0

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  5. def clone(): AnyRef

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    protected[java.lang]
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    @throws( ... )
  6. final def eq(arg0: AnyRef): Boolean

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  7. def equals(arg0: Any): Boolean

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  8. def finalize(): Unit

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    protected[java.lang]
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    @throws( classOf[java.lang.Throwable] )
  9. final def getClass(): Class[_]

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  10. def hashCode(): Int

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  11. final def isInstanceOf[T0]: Boolean

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  12. final def ne(arg0: AnyRef): Boolean

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  13. final def notify(): Unit

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  14. final def notifyAll(): Unit

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  15. final def synchronized[T0](arg0: ⇒ T0): T0

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  16. def toString(): String

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  17. final def wait(): Unit

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    @throws( ... )
  18. final def wait(arg0: Long, arg1: Int): Unit

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    @throws( ... )
  19. final def wait(arg0: Long): Unit

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Inherited from Serializable

Inherited from Serializable

Inherited from DepFn0

Inherited from AnyRef

Inherited from Any

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