Scala Standard Library2.13.5 < Back
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# Packages

-  package root

  This is the documentation for the Scala standard library.

  This is the documentation for the Scala standard library.

  #### Package structure

  The scala package contains core types like `Int`, `Float`, `Array` or `Option` which are accessible in all Scala compilation units without explicit qualification or imports.

  Notable packages include:

  - `scala.collection` and its sub-packages contain Scala's collections framework
    - `scala.collection.immutable` - Immutable, sequential data-structures such as `Vector`, `List`, `Range`, `HashMap` or `HashSet`
    - `scala.collection.mutable` - Mutable, sequential data-structures such as `ArrayBuffer`, `StringBuilder`, `HashMap` or `HashSet`
    - `scala.collection.concurrent` - Mutable, concurrent data-structures such as `TrieMap`
  - `scala.concurrent` - Primitives for concurrent programming such as `Futures` and `Promises`
  - `scala.io` - Input and output operations
  - `scala.math` - Basic math functions and additional numeric types like `BigInt` and `BigDecimal`
  - `scala.sys` - Interaction with other processes and the operating system
  - `scala.util.matching` - Regular expressions

  Other packages exist. See the complete list on the right.

  Additional parts of the standard library are shipped as separate libraries. These include:

  - `scala.reflect` - Scala's reflection API (scala-reflect.jar)
  - `scala.xml` - XML parsing, manipulation, and serialization (scala-xml.jar)
  - `scala.collection.parallel` - Parallel collections (scala-parallel-collections.jar)
  - `scala.util.parsing` - Parser combinators (scala-parser-combinators.jar)
  - `scala.swing` - A convenient wrapper around Java's GUI framework called Swing (scala-swing.jar)

  #### Automatic imports

  Identifiers in the scala package and the `scala.Predef` object are always in scope by default.

  Some of these identifiers are type aliases provided as shortcuts to commonly used classes. For example, `List` is an alias for `scala.collection.immutable.List`.

  Other aliases refer to classes provided by the underlying platform. For example, on the JVM, `String` is an alias for `java.lang.String`.

  Definition Classes
    root
-  package scala

  Core Scala types.

  Core Scala types. They are always available without an explicit import.

  Definition Classes
    root
-  package jdk

  The jdk package contains utilities to interact with JDK classes.

  The jdk package contains utilities to interact with JDK classes.

  This packages offers a number of converters, that are able to wrap or copy types from the scala library to equivalent types in the JDK class library and vice versa:

  - CollectionConverters, converting collections like scala.collection.Seq, scala.collection.Map, scala.collection.Set, scala.collection.mutable.Buffer, scala.collection.Iterator and scala.collection.Iterable to their JDK counterparts
  - OptionConverters, converting between Option and java.util.Optional and primitive variations
  - StreamConverters, to create JDK Streams from scala collections
  - DurationConverters, for conversions between scala scala.concurrent.duration.FiniteDuration and java.time.Duration
  - FunctionConverters, from scala Functions to java java.util.function.Function, java.util.function.UnaryOperator, java.util.function.Consumer and java.util.function.Predicate, as well as primitive variations and Bi-variations.

  By convention, converters that wrap an object to provide a different interface to the same underlying data structure use .asScala and .asJava extension methods, whereas converters that copy the underlying data structure use .toScala and .toJava.

  In the javaapi package, the same converters can be found with a java-friendly interface that don't rely on implicit enrichments.

  Additionally, this package offers Accumulators, capable of efficiently traversing JDK Streams.

  Definition Classes
    scala
-  object FunctionWrappers
  Definition Classes
    jdk
- AsJavaBiConsumer
- AsJavaBiFunction
- AsJavaBiPredicate
- AsJavaBinaryOperator
- AsJavaBooleanSupplier
- AsJavaConsumer
- AsJavaDoubleBinaryOperator
- AsJavaDoubleConsumer
- AsJavaDoubleFunction
- AsJavaDoublePredicate
- AsJavaDoubleSupplier
- AsJavaDoubleToIntFunction
- AsJavaDoubleToLongFunction
- AsJavaDoubleUnaryOperator
- AsJavaFunction
- AsJavaIntBinaryOperator
- AsJavaIntConsumer
- AsJavaIntFunction
- AsJavaIntPredicate
- AsJavaIntSupplier
- AsJavaIntToDoubleFunction
- AsJavaIntToLongFunction
- AsJavaIntUnaryOperator
- AsJavaLongBinaryOperator
- AsJavaLongConsumer
- AsJavaLongFunction
- AsJavaLongPredicate
- AsJavaLongSupplier
- AsJavaLongToDoubleFunction
- AsJavaLongToIntFunction
- AsJavaLongUnaryOperator
- AsJavaObjDoubleConsumer
- AsJavaObjIntConsumer
- AsJavaObjLongConsumer
- AsJavaPredicate
- AsJavaSupplier
- AsJavaToDoubleBiFunction
- AsJavaToDoubleFunction
- AsJavaToIntBiFunction
- AsJavaToIntFunction
- AsJavaToLongBiFunction
- AsJavaToLongFunction
- AsJavaUnaryOperator
- FromJavaBiConsumer
- FromJavaBiFunction
- FromJavaBiPredicate
- FromJavaBinaryOperator
- FromJavaBooleanSupplier
- FromJavaConsumer
- FromJavaDoubleBinaryOperator
- FromJavaDoubleConsumer
- FromJavaDoubleFunction
- FromJavaDoublePredicate
- FromJavaDoubleSupplier
- FromJavaDoubleToIntFunction
- FromJavaDoubleToLongFunction
- FromJavaDoubleUnaryOperator
- FromJavaFunction
- FromJavaIntBinaryOperator
- FromJavaIntConsumer
- FromJavaIntFunction
- FromJavaIntPredicate
- FromJavaIntSupplier
- FromJavaIntToDoubleFunction
- FromJavaIntToLongFunction
- FromJavaIntUnaryOperator
- FromJavaLongBinaryOperator
- FromJavaLongConsumer
- FromJavaLongFunction
- FromJavaLongPredicate
- FromJavaLongSupplier
- FromJavaLongToDoubleFunction
- FromJavaLongToIntFunction
- FromJavaLongUnaryOperator
- FromJavaObjDoubleConsumer
- FromJavaObjIntConsumer
- FromJavaObjLongConsumer
- FromJavaPredicate
- FromJavaSupplier
- FromJavaToDoubleBiFunction
- FromJavaToDoubleFunction
- FromJavaToIntBiFunction
- FromJavaToIntFunction
- FromJavaToLongBiFunction
- FromJavaToLongFunction
- FromJavaUnaryOperator
- RichBiConsumerAsFunction2
- RichBiFunctionAsFunction2
- RichBiPredicateAsFunction2
- RichBinaryOperatorAsFunction2
- RichBooleanSupplierAsFunction0
- RichConsumerAsFunction1
- RichDoubleBinaryOperatorAsFunction2
- RichDoubleConsumerAsFunction1
- RichDoubleFunctionAsFunction1
- RichDoublePredicateAsFunction1
- RichDoubleSupplierAsFunction0
- RichDoubleToIntFunctionAsFunction1
- RichDoubleToLongFunctionAsFunction1
- RichDoubleUnaryOperatorAsFunction1
- RichFunction0AsBooleanSupplier
- RichFunction0AsDoubleSupplier
- RichFunction0AsIntSupplier
- RichFunction0AsLongSupplier
- RichFunction0AsSupplier
- RichFunction1AsConsumer
- RichFunction1AsDoubleConsumer
- RichFunction1AsDoubleFunction
- RichFunction1AsDoublePredicate
- RichFunction1AsDoubleToIntFunction
- RichFunction1AsDoubleToLongFunction
- RichFunction1AsDoubleUnaryOperator
- RichFunction1AsFunction
- RichFunction1AsIntConsumer
- RichFunction1AsIntFunction
- RichFunction1AsIntPredicate
- RichFunction1AsIntToDoubleFunction
- RichFunction1AsIntToLongFunction
- RichFunction1AsIntUnaryOperator
- RichFunction1AsLongConsumer
- RichFunction1AsLongFunction
- RichFunction1AsLongPredicate
- RichFunction1AsLongToDoubleFunction
- RichFunction1AsLongToIntFunction
- RichFunction1AsLongUnaryOperator
- RichFunction1AsPredicate
- RichFunction1AsToDoubleFunction
- RichFunction1AsToIntFunction
- RichFunction1AsToLongFunction
- RichFunction1AsUnaryOperator
- RichFunction2AsBiConsumer
- RichFunction2AsBiFunction
- RichFunction2AsBiPredicate
- RichFunction2AsBinaryOperator
- RichFunction2AsDoubleBinaryOperator
- RichFunction2AsIntBinaryOperator
- RichFunction2AsLongBinaryOperator
- RichFunction2AsObjDoubleConsumer
- RichFunction2AsObjIntConsumer
- RichFunction2AsObjLongConsumer
- RichFunction2AsToDoubleBiFunction
- RichFunction2AsToIntBiFunction
- RichFunction2AsToLongBiFunction
- RichFunctionAsFunction1
- RichIntBinaryOperatorAsFunction2
- RichIntConsumerAsFunction1
- RichIntFunctionAsFunction1
- RichIntPredicateAsFunction1
- RichIntSupplierAsFunction0
- RichIntToDoubleFunctionAsFunction1
- RichIntToLongFunctionAsFunction1
- RichIntUnaryOperatorAsFunction1
- RichLongBinaryOperatorAsFunction2
- RichLongConsumerAsFunction1
- RichLongFunctionAsFunction1
- RichLongPredicateAsFunction1
- RichLongSupplierAsFunction0
- RichLongToDoubleFunctionAsFunction1
- RichLongToIntFunctionAsFunction1
- RichLongUnaryOperatorAsFunction1
- RichObjDoubleConsumerAsFunction2
- RichObjIntConsumerAsFunction2
- RichObjLongConsumerAsFunction2
- RichPredicateAsFunction1
- RichSupplierAsFunction0
- RichToDoubleBiFunctionAsFunction2
- RichToDoubleFunctionAsFunction1
- RichToIntBiFunctionAsFunction2
- RichToIntFunctionAsFunction1
- RichToLongBiFunctionAsFunction2
- RichToLongFunctionAsFunction1
- RichUnaryOperatorAsFunction1

c

scala.jdk.FunctionWrappers

# RichFunction1AsUnaryOperator

###

#### final class RichFunction1AsUnaryOperator[T] extends AnyVal

Source
  FunctionWrappers.scala

Linear Supertypes
AnyVal, Any
Type Hierarchy

Ordering

1. Alphabetic
2. By Inheritance

Inherited

1. RichFunction1AsUnaryOperator
2. AnyVal
3. Any

Implicitly

1. by any2stringadd
2. by StringFormat
3. by Ensuring
4. by ArrowAssoc

1. Hide All
2. Show All

Visibility

1. Public
2. Protected

### Instance Constructors

1.  new RichFunction1AsUnaryOperator(underlying: (T) => T)

### Value Members

1.  final def !=(arg0: Any): Boolean

   Test two objects for inequality.

   Test two objects for inequality.

   returns

     `true` if !(this == that), false otherwise.

   Definition Classes
     Any
2.  final def ##: Int

   Equivalent to `x.hashCode` except for boxed numeric types and `null`.

   Equivalent to `x.hashCode` except for boxed numeric types and `null`. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For `null` returns a hashcode where `null.hashCode` throws a `NullPointerException`.

   returns

     a hash value consistent with ==

   Definition Classes
     Any
3.  def +(other: String): String
   Implicit
     This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toany2stringadd[RichFunction1AsUnaryOperator[T]] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
4.  def ->[B](y: B): (RichFunction1AsUnaryOperator[T], B)
   Implicit
     This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toArrowAssoc[RichFunction1AsUnaryOperator[T]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()
5.  final def ==(arg0: Any): Boolean

   Test two objects for equality.

   Test two objects for equality. The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

   returns

     `true` if the receiver object is equivalent to the argument; `false` otherwise.

   Definition Classes
     Any
6.  final def asInstanceOf[T0]: T0

   Cast the receiver object to be of type `T0`.

   Cast the receiver object to be of type `T0`.

   Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression `1.asInstanceOf[String]` will throw a `ClassCastException` at runtime, while the expression `List(1).asInstanceOf[List[String]]` will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

   returns

     the receiver object.

   Definition Classes
     Any
   Exceptions thrown

     `ClassCastException` if the receiver object is not an instance of the erasure of type `T0`.

7.  def asJava: UnaryOperator[T]
   Annotations
     @inline()
8.  def asJavaUnaryOperator: UnaryOperator[T]
   Annotations
     @inline()
9.  def ensuring(cond: (RichFunction1AsUnaryOperator[T]) => Boolean, msg: => Any): RichFunction1AsUnaryOperator[T]
   Implicit
     This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toEnsuring[RichFunction1AsUnaryOperator[T]] performed by method Ensuring in scala.Predef.
   Definition Classes
     Ensuring
10.  def ensuring(cond: (RichFunction1AsUnaryOperator[T]) => Boolean): RichFunction1AsUnaryOperator[T]
    Implicit
      This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toEnsuring[RichFunction1AsUnaryOperator[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
11.  def ensuring(cond: Boolean, msg: => Any): RichFunction1AsUnaryOperator[T]
    Implicit
      This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toEnsuring[RichFunction1AsUnaryOperator[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
12.  def ensuring(cond: Boolean): RichFunction1AsUnaryOperator[T]
    Implicit
      This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toEnsuring[RichFunction1AsUnaryOperator[T]] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
13.  def formatted(fmtstr: String): String

    Returns string formatted according to given `format` string.

    Returns string formatted according to given `format` string. Format strings are as for `String.format` (@see java.lang.String.format).

    Implicit
      This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toStringFormat[RichFunction1AsUnaryOperator[T]] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @inline()
14.  def getClass(): Class[_ <: AnyVal]

    Returns the runtime class representation of the object.

    Returns the runtime class representation of the object.

    returns

      a class object corresponding to the runtime type of the receiver.

    Definition Classes
      AnyVal → Any
15.  final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object is `T0`.

    Test whether the dynamic type of the receiver object is `T0`.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression `1.isInstanceOf[String]` will return `false`, while the expression `List(1).isInstanceOf[List[String]]` will return `true`. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

      `true` if the receiver object is an instance of erasure of type `T0`; `false` otherwise.

    Definition Classes
      Any
16.  def toString(): String

    Returns a string representation of the object.

    Returns a string representation of the object.

    The default representation is platform dependent.

    returns

      a string representation of the object.

    Definition Classes
      Any

### Deprecated Value Members

1.  def →[B](y: B): (RichFunction1AsUnaryOperator[T], B)
   Implicit
     This member is added by an implicit conversion from RichFunction1AsUnaryOperator[T] toArrowAssoc[RichFunction1AsUnaryOperator[T]] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use `->` instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

### Inherited from AnyVal

### Inherited from Any

### Inherited by implicit conversion any2stringadd fromRichFunction1AsUnaryOperator[T] to any2stringadd[RichFunction1AsUnaryOperator[T]]

### Inherited by implicit conversion StringFormat fromRichFunction1AsUnaryOperator[T] to StringFormat[RichFunction1AsUnaryOperator[T]]

### Inherited by implicit conversion Ensuring fromRichFunction1AsUnaryOperator[T] to Ensuring[RichFunction1AsUnaryOperator[T]]

### Inherited by implicit conversion ArrowAssoc fromRichFunction1AsUnaryOperator[T] to ArrowAssoc[RichFunction1AsUnaryOperator[T]]

### Ungrouped