Scala Standard Library2.13.18 < 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 collection
  Definition Classes
    scala
-  trait MapOps[K, +V, +CC[_, _] <: IterableOps[_, AnyConstr, _], +C] extends IterableOps[(K, V), Iterable, C] with PartialFunction[K, V]

  Base Map implementation type

  Base Map implementation type

  K

    Type of keys

  V

    Type of values

  CC

    type constructor of the map (e.g. `HashMap`). Operations returning a collection with a different type of entries `(L, W)` (e.g. `map`) return a `CC[L, W]`.

  C

    type of the map (e.g. `HashMap[Int, String]`). Operations returning a collection with the same type of element (e.g. `drop`, `filter`) return a `C`.

  Definition Classes
    collection
- GenKeySet
- KeySet

c

scala.collection.MapOps

# KeySet

###

#### class KeySet extends AbstractSet[K] with GenKeySet with DefaultSerializable

The implementation class of the set returned by `keySet`.

Attributes
  protected
Source
  Map.scala

Linear Supertypes
DefaultSerializable, java.io.Serializable, GenKeySet, AbstractSet[K], Set[K], Equals, SetOps[K, Set, Set[K]], (K) => Boolean, AbstractIterable[K], Iterable[K], IterableFactoryDefaults[K, [x]Set[x]], IterableOps[K, [_]Set[_], Set[K]], IterableOnceOps[K, [_]Set[_], Set[K]], IterableOnce[K], AnyRef, Any
Known Subclasses
LinkedKeySet
Type Hierarchy

Ordering

1. Alphabetic
2. By Inheritance

Inherited

1. KeySet
2. DefaultSerializable
3. Serializable
4. GenKeySet
5. AbstractSet
6. Set
7. Equals
8. SetOps
9. Function1
10. AbstractIterable
11. Iterable
12. IterableFactoryDefaults
13. IterableOps
14. IterableOnceOps
15. IterableOnce
16. AnyRef
17. Any

Implicitly

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

1. Hide All
2. Show All

Visibility

1. Public
2. Protected

### Instance Constructors

1.  new KeySet()

### 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
     AnyRef → 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
     AnyRef → Any
3.  final def &(that: Set[K]): Set[K]

   Alias for `intersect`

   Alias for `intersect`

   Definition Classes
     SetOps
   Annotations
     @inline()
4.  final def &~(that: Set[K]): Set[K]

   Alias for `diff`

   Alias for `diff`

   Definition Classes
     SetOps
   Annotations
     @inline()
5.  final def ++(that: IterableOnce[K]): Set[K]

   Alias for `concat`

   Alias for `concat`

   Definition Classes
     SetOps
   Annotations
     @inline()
6.  final def ++[B >: K](suffix: IterableOnce[B]): Set[B]

   Alias for `concat`

   Alias for `concat`

   Definition Classes
     IterableOps
   Annotations
     @inline()
7.  def ->[B](y: B): (KeySet, B)
   Implicit
     This member is added by an implicit conversion from KeySet toArrowAssoc[KeySet] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()
8.  final def ==(arg0: Any): Boolean

   The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

   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
     AnyRef → Any
9.  final def addString(b: mutable.StringBuilder): b.type

   Appends all elements of this set to a string builder.

   Appends all elements of this set to a string builder. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this set without any separator string.

   Example:

       scala> val a = List(1,2,3,4)
       a: List[Int] = List(1, 2, 3, 4)

       scala> val b = new StringBuilder()
       b: StringBuilder =

       scala> val h = a.addString(b)
       h: StringBuilder = 1234

   b

     the string builder to which elements are appended.

   returns

     the string builder `b` to which elements were appended.

   Definition Classes
     IterableOnceOps
   Annotations
     @inline()
10.  final def addString(b: mutable.StringBuilder, sep: String): b.type

    Appends all elements of this set to a string builder using a separator string.

    Appends all elements of this set to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this set, separated by the string `sep`.

    Example:

        scala> val a = List(1,2,3,4)
        a: List[Int] = List(1, 2, 3, 4)

        scala> val b = new StringBuilder()
        b: StringBuilder =

        scala> a.addString(b, ", ")
        res0: StringBuilder = 1, 2, 3, 4

    b

      the string builder to which elements are appended.

    sep

      the separator string.

    returns

      the string builder `b` to which elements were appended.

    Definition Classes
      IterableOnceOps
    Annotations
      @inline()
11.  def addString(b: mutable.StringBuilder, start: String, sep: String, end: String): b.type

    Appends all elements of this set to a string builder using start, end, and separator strings.

    Appends all elements of this set to a string builder using start, end, and separator strings. The written text begins with the string `start` and ends with the string `end`. Inside, the string representations (w.r.t. the method `toString`) of all elements of this set are separated by the string `sep`.

    Example:

        scala> val a = List(1,2,3,4)
        a: List[Int] = List(1, 2, 3, 4)

        scala> val b = new StringBuilder()
        b: StringBuilder =

        scala> a.addString(b , "List(" , ", " , ")")
        res5: StringBuilder = List(1, 2, 3, 4)

    b

      the string builder to which elements are appended.

    start

      the starting string.

    sep

      the separator string.

    end

      the ending string.

    returns

      the string builder `b` to which elements were appended.

    Definition Classes
      IterableOnceOps
12.  def andThen[A](g: (Boolean) => A): (K) => A

    Composes two instances of `Function1` in a new `Function1`, with this function applied first.

    Composes two instances of `Function1` in a new `Function1`, with this function applied first.

    A

      the result type of function `g`

    g

      a function R => A

    returns

      a new function `f` such that `f(x) == g(apply(x))`

    Definition Classes
      Function1
    Annotations
      @unspecialized()
13.  final def apply(elem: K): Boolean

    Tests if some element is contained in this set.

    Tests if some element is contained in this set.

    This method is equivalent to `contains`. It allows sets to be interpreted as predicates.

    elem

      the element to test for membership.

    returns

      `true` if `elem` is contained in this set, `false` otherwise.

    Definition Classes
      SetOps → Function1
    Annotations
      @inline()
14.  final def asInstanceOf[T0]: T0

    Forces the compiler to treat the receiver object as having type `T0`, even though doing so may violate type safety.

    Forces the compiler to treat the receiver object as having type `T0`, even though doing so may violate type safety.

    This method is useful when you believe you have type information the compiler doesn't, and it also isn't possible to check the type at runtime. In such situations, skipping type safety is the only option.

    It is platform dependent whether `asInstanceOf` has any effect at runtime. It might do a runtime type test on the erasure of `T0`, insert a conversion (such as boxing/unboxing), fill in a default value, or do nothing at all.

    In particular, `asInstanceOf` is not a type test. It does **not** mean:

        this match {
         case x: T0 => x
         case _     => throw ClassCastException("...")

    Use pattern matching or isInstanceOf for type testing instead.

    Situations where `asInstanceOf` is useful:

    - when flow analysis fails to deduce `T0` automatically
    - when down-casting a type parameter or an abstract type member (which cannot be checked at runtime due to type erasure) If there is any doubt and you are able to type test instead, you should do so.

    Be careful of using `asInstanceOf` when `T0` is a primitive type. When `T0` is primitive, `asInstanceOf` may insert a conversion instead of a type test. If your intent is to convert, use a `toT` method (`x.toChar`, `x.toByte`, etc.).

    returns

      the receiver object.

    Definition Classes
      Any
    Exceptions thrown

      `ClassCastException` if the receiver is not an instance of the erasure of `T0`, if that can be checked on this platform

15.  def canEqual(that: Any): Boolean

    Checks whether this instance can possibly equal `that`.

    Checks whether this instance can possibly equal `that`.

    A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.

    that

      the value being probed for possible equality

    returns

      true if this instance can possibly equal `that`, otherwise false

    Definition Classes
      Set → Equals
16.  def className: String

    Defines the prefix of this object's `toString` representation.

    Defines the prefix of this object's `toString` representation.

    It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for `ListMap` this method should return `"ListMap"`, not `"Map"` (the supertype) or `"Node"` (an implementation subclass).

    The default implementation returns "Iterable". It is overridden for the basic collection kinds "Seq", "IndexedSeq", "LinearSeq", "Buffer", "Set", "Map", "SortedSet", "SortedMap" and "View".

    returns

      a string representation which starts the result of `toString` applied to this set. By default the string prefix is the simple name of the collection class set.

    Attributes
      protected[this]
    Definition Classes
      Iterable
17.  def clone(): AnyRef

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the `clone` method is platform dependent.

    returns

      a copy of the receiver object.

    Attributes
      protected[lang]
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.CloneNotSupportedException]) @native()
    Note

      not specified by SLS as a member of AnyRef

18.  final def coll: KeySet.this.type

    returns

      This collection as a `C`.

    Attributes
      protected
    Definition Classes
      Iterable → IterableOps
19.  def collect[B](pf: PartialFunction[K, B]): Set[B]

    Builds a new set by applying a partial function to all elements of this set on which the function is defined.

    Builds a new set by applying a partial function to all elements of this set on which the function is defined.

    B

      the element type of the returned set.

    pf

      the partial function which filters and maps the set.

    returns

      a new set resulting from applying the given partial function `pf` to each element on which it is defined and collecting the results. The order of the elements is preserved.

    Definition Classes
      IterableOps → IterableOnceOps
20.  def collectFirst[B](pf: PartialFunction[K, B]): Option[B]

    Finds the first element of the set for which the given partial function is defined, and applies the partial function to it.

    Finds the first element of the set for which the given partial function is defined, and applies the partial function to it.

    Note: may not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    pf

      the partial function

    returns

      an option value containing pf applied to the first value for which it is defined, or `None` if none exists.

    Definition Classes
      IterableOnceOps
    Example:

    1. `Seq("a", 1, 5L).collectFirst { case x: Int => x*10 } = Some(10)`

21.  def compose[A](g: (A) => K): (A) => Boolean

    Composes two instances of `Function1` in a new `Function1`, with this function applied last.

    Composes two instances of `Function1` in a new `Function1`, with this function applied last.

    A

      the type to which function `g` can be applied

    g

      a function A => T1

    returns

      a new function `f` such that `f(x) == apply(g(x))`

    Definition Classes
      Function1
    Annotations
      @unspecialized()
22.  def concat(that: IterableOnce[K]): Set[K]

    Creates a new set by adding all elements contained in another collection to this set, omitting duplicates.

    Creates a new set by adding all elements contained in another collection to this set, omitting duplicates.

    Example:

        scala> val a = Set(1, 2) concat Set(2, 3)
        a: scala.collection.immutable.Set[Int] = Set(1, 2, 3)

    that

      the collection containing the elements to add.

    returns

      a new set with the given elements added, omitting duplicates.

    Definition Classes
      SetOps
23.  def concat[B >: K](suffix: IterableOnce[B]): Set[B]

    Returns a new set containing the elements from the left hand operand followed by the elements from the right hand operand.

    Returns a new set containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the set is the most specific superclass encompassing the element types of the two operands.

    B

      the element type of the returned collection.

    suffix

      the iterable to append.

    returns

      a new set which contains all elements of this set followed by all elements of `suffix`.

    Definition Classes
      IterableOps
24.  def contains(key: K): Boolean
    Definition Classes
      GenKeySet
25.  def copyToArray[B >: K](dest: Array[B], start: Int, n: Int): Int

    Copies elements to an array and returns the number of elements written.

    Copies elements to an array and returns the number of elements written.

    Fills the given array `dest` starting at index `start` with at most `n` elements of this set.

    Copying will stop once either all the elements of this set have been copied, or the end of the array is reached, or `n` elements have been copied.

    If `start` is less than zero, it is taken as zero.

    B

      the type of the elements of the array.

    dest

      the array to fill.

    start

      the starting index of xs.

    n

      the maximal number of elements to copy.

    returns

      the number of elements written to the array

    Definition Classes
      IterableOnceOps
    Note

      Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

26.  def copyToArray[B >: K](dest: Array[B], start: Int): Int

    Copies elements to an array, returning the number of elements written.

    Copies elements to an array, returning the number of elements written.

    Fills the given array `dest` starting at index `start` with values of this set.

    Copying will stop once either all the elements of this set have been copied, or the end of the array is reached.

    B

      the type of the elements of the array.

    dest

      the array to fill.

    start

      the starting index of xs.

    returns

      the number of elements written to the array

    Definition Classes
      IterableOnceOps
    Annotations
      @deprecatedOverriding()
    Note

      Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

27.  def copyToArray[B >: K](dest: Array[B]): Int

    Copies elements to an array, returning the number of elements written.

    Copies elements to an array, returning the number of elements written.

    Fills the given array `dest` starting at index `start` with values of this set.

    Copying will stop once either all the elements of this set have been copied, or the end of the array is reached.

    B

      the type of the elements of the array.

    dest

      the array to fill.

    returns

      the number of elements written to the array

    Definition Classes
      IterableOnceOps
    Annotations
      @deprecatedOverriding()
    Note

      Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

28.  def corresponds[B](that: IterableOnce[B])(p: (K, B) => Boolean): Boolean

    Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

    Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

    Note: will not terminate for infinite-sized collections.

    B

      the type of the elements of `that`

    that

      the other collection

    p

      the test predicate, which relates elements from both collections

    returns

      `true` if both collections have the same length and `p(x, y)` is `true` for all corresponding elements `x` of this iterator and `y` of `that`, otherwise `false`

    Definition Classes
      IterableOnceOps
29.  def count(p: (K) => Boolean): Int

    Counts the number of elements in the set which satisfy a predicate.

    Counts the number of elements in the set which satisfy a predicate.

    Note: will not terminate for infinite-sized collections.

    p

      the predicate used to test elements.

    returns

      the number of elements satisfying the predicate `p`.

    Definition Classes
      IterableOnceOps
30.  def diff(that: Set[K]): Set[K]

    Computes the difference of this set and another set.

    Computes the difference of this set and another set.

    that

      the set of elements to exclude.

    returns

      a set containing those elements of this set that are not also contained in the given set `that`.

    Definition Classes
      KeySet → SetOps
31.  def drop(n: Int): Set[K]

    Selects all elements except the first `n` ones.

    Selects all elements except the first `n` ones.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    n

      the number of elements to drop from this set.

    returns

      a set consisting of all elements of this set except the first `n` ones, or else the empty set, if this set has less than `n` elements. If `n` is negative, don't drop any elements.

    Definition Classes
      IterableOps → IterableOnceOps
32.  def dropRight(n: Int): Set[K]

    Selects all elements except last n ones.

    Selects all elements except last n ones.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    n

      the number of elements to drop from this set.

    returns

      a set consisting of all elements of this set except the last `n` ones, or else the empty set, if this set has less than `n` elements. If `n` is negative, don't drop any elements.

    Definition Classes
      IterableOps
33.  def dropWhile(p: (K) => Boolean): Set[K]

    Selects all elements except the longest prefix that satisfies a predicate.

    Selects all elements except the longest prefix that satisfies a predicate.

    The matching prefix starts with the first element of this set, and the element following the prefix is the first element that does not satisfy the predicate. The matching prefix may be empty, so that this method returns the entire set.

    Example:

        scala> List(1, 2, 3, 100, 4).dropWhile(n => n < 10)
        val res0: List[Int] = List(100, 4)

        scala> List(1, 2, 3, 100, 4).dropWhile(n => n == 0)
        val res1: List[Int] = List(1, 2, 3, 100, 4)

    Use span to obtain both the prefix and suffix. Use filterNot to drop all elements that satisfy the predicate.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    p

      The predicate used to test elements.

    returns

      the longest suffix of this set whose first element does not satisfy the predicate `p`.

    Definition Classes
      IterableOps → IterableOnceOps
34.  def empty: Set[K]

    The empty set.

    The empty set.

    returns

      an empty iterable of type `Set`.

    Definition Classes
      IterableFactoryDefaults → IterableOps
35.  def ensuring(cond: (KeySet) => Boolean, msg: => Any): KeySet
    Implicit
      This member is added by an implicit conversion from KeySet toEnsuring[KeySet] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
36.  def ensuring(cond: (KeySet) => Boolean): KeySet
    Implicit
      This member is added by an implicit conversion from KeySet toEnsuring[KeySet] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
37.  def ensuring(cond: Boolean, msg: => Any): KeySet
    Implicit
      This member is added by an implicit conversion from KeySet toEnsuring[KeySet] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
38.  def ensuring(cond: Boolean): KeySet
    Implicit
      This member is added by an implicit conversion from KeySet toEnsuring[KeySet] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
39.  final def eq(arg0: AnyRef): Boolean

    Tests whether the argument (`that`) is a reference to the receiver object (`this`).

    Tests whether the argument (`that`) is a reference to the receiver object (`this`).

    The `eq` method implements an equivalence relation on non-null instances of `AnyRef`, and has three additional properties:

    - It is consistent: for any non-null instances `x` and `y` of type `AnyRef`, multiple invocations of `x.eq(y)` consistently returns `true` or consistently returns `false`.
    - For any non-null instance `x` of type `AnyRef`, `x.eq(null)` and `null.eq(x)` returns `false`.
    - `null.eq(null)` returns `true`.

    When overriding the `equals` or `hashCode` methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (`o1 eq o2`), they should be equal to each other (`o1 == o2`) and they should hash to the same value (`o1.hashCode == o2.hashCode`).

    returns

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

    Definition Classes
      AnyRef
40.  def equals(that: Any): Boolean

    Equality of sets is implemented using the lookup method contains.

    Equality of sets is implemented using the lookup method contains. This method returns `true` if

    - the argument `that` is a `Set`,
    - the two sets have the same size, and
    - for every `element` this set, `other.contains(element) == true`.

    The implementation of `equals` checks the canEqual method, so subclasses of `Set` can narrow down the equality to specific set types. The `Set` implementations in the standard library can all be compared, their `canEqual` methods return `true`.

    Note: The `equals` method only respects the equality laws (symmetry, transitivity) if the two sets use the same element equivalence function in their lookup operation. For example, the element equivalence operation in a scala.collection.immutable.TreeSet is defined by its ordering. Comparing a `TreeSet` with a `HashSet` leads to unexpected results if `ordering.equiv(e1, e2)` (used for lookup in `TreeSet`) is different from `e1 == e2` (used for lookup in `HashSet`).

        scala> import scala.collection.immutable._
        scala> val ord: Ordering[String] = _ compareToIgnoreCase _

        scala> TreeSet("A")(ord) == HashSet("a")
        val res0: Boolean = false

        scala> HashSet("a") == TreeSet("A")(ord)
        val res1: Boolean = true

    that

      The set to which this set is compared

    returns

      `true` if the two sets are equal according to the description

    Definition Classes
      Set → Equals → AnyRef → Any
41.  def exists(p: (K) => Boolean): Boolean

    Tests whether a predicate holds for at least one element of this set.

    Tests whether a predicate holds for at least one element of this set.

    Note: may not terminate for infinite-sized collections.

    p

      the predicate used to test elements.

    returns

      `true` if the given predicate `p` is satisfied by at least one element of this set, otherwise `false`

    Definition Classes
      IterableOnceOps
42.  def filter(pred: (K) => Boolean): Set[K]

    Selects all elements of this set which satisfy a predicate.

    Selects all elements of this set which satisfy a predicate.

    returns

      a new set consisting of all elements of this set that satisfy the given predicate `p`. The order of the elements is preserved.

    Definition Classes
      IterableOps → IterableOnceOps
43.  def filterNot(pred: (K) => Boolean): Set[K]

    Selects all elements of this set which do not satisfy a predicate.

    Selects all elements of this set which do not satisfy a predicate.

    pred

      the predicate used to test elements.

    returns

      a new set consisting of all elements of this set that do not satisfy the given predicate `pred`. Their order may not be preserved.

    Definition Classes
      IterableOps → IterableOnceOps
44.  def finalize(): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the `finalize` method is invoked, as well as the interaction between `finalize` and non-local returns and exceptions, are all platform dependent.

    Attributes
      protected[lang]
    Definition Classes
      AnyRef
    Annotations
      @throws(classOf[java.lang.Throwable])
    Note

      not specified by SLS as a member of AnyRef

45.  def find(p: (K) => Boolean): Option[K]

    Finds the first element of the set satisfying a predicate, if any.

    Finds the first element of the set satisfying a predicate, if any.

    Note: may not terminate for infinite-sized collections.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    p

      the predicate used to test elements.

    returns

      an option value containing the first element in the set that satisfies `p`, or `None` if none exists.

    Definition Classes
      IterableOnceOps
46.  def flatMap[B](f: (K) => IterableOnce[B]): Set[B]

    Builds a new set by applying a function to all elements of this set and using the elements of the resulting collections.

    Builds a new set by applying a function to all elements of this set and using the elements of the resulting collections.

    For example:

        def getWords(lines: Seq[String]): Seq[String] = lines.flatMap(line => line.split("\\W+"))

    The type of the resulting collection is guided by the static type of this set. This might cause unexpected results sometimes. For example:

        // lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
        def lettersOf(words: Seq[String]) = words.flatMap(word => word.toSet)

        // lettersOf will return a Set[Char], not a Seq
        def lettersOf(words: Seq[String]) = words.toSet.flatMap(word => word.toSeq)

        // xs will be an Iterable[Int]
        val xs = Map("a" -> List(11, 111), "b" -> List(22, 222)).flatMap(_._2)

        // ys will be a Map[Int, Int]
        val ys = Map("a" -> List(1 -> 11, 1 -> 111), "b" -> List(2 -> 22, 2 -> 222)).flatMap(_._2)

    B

      the element type of the returned collection.

    f

      the function to apply to each element.

    returns

      a new set resulting from applying the given collection-valued function `f` to each element of this set and concatenating the results.

    Definition Classes
      IterableOps → IterableOnceOps
47.  def flatten[B](implicit asIterable: (K) => IterableOnce[B]): Set[B]

    Given that the elements of this collection are themselves iterable collections, converts this set into a set comprising the elements of these iterable collections.

    Given that the elements of this collection are themselves iterable collections, converts this set into a set comprising the elements of these iterable collections.

    The resulting collection's type will be guided by the type of set. For example:

        val xs = List(
                   Set(1, 2, 3),
                   Set(1, 2, 3)
                 ).flatten
        // xs == List(1, 2, 3, 1, 2, 3)

        val ys = Set(
                   List(1, 2, 3),
                   List(3, 2, 1)
                 ).flatten
        // ys == Set(1, 2, 3)

    B

      the type of the elements of each iterable collection.

    asIterable

      an implicit conversion which asserts that the element type of this set is an `Iterable`.

    returns

      a new set resulting from concatenating all element collections.

    Definition Classes
      IterableOps → IterableOnceOps
48.  def fold[A1 >: K](z: A1)(op: (A1, A1) => A1): A1

    Applies the given binary operator `op` to the given initial value `z` and all elements of this set.

    Applies the given binary operator `op` to the given initial value `z` and all elements of this set.

    For each application of the operator, each operand is either an element of this set, the initial value, or another such application of the operator.

    The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation. The initial value may be used an arbitrary number of times, but at least once.

    If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

    Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative. In either case, it is also necessary that the initial value be a neutral value for the operator, e.g. `Nil` for `List` concatenation or `1` for multiplication.

    The default implementation in `IterableOnce` is equivalent to `foldLeft` but may be overridden for more efficient traversal orders.

    Note: will not terminate for infinite-sized collections.

    A1

      The type parameter for the binary operator, a supertype of `A`.

    z

      An initial value; may be used an arbitrary number of times in the computation of the result; must be a neutral value for `op` for the result to always be the same across runs.

    op

      A binary operator; must be associative for the result to always be the same across runs.

    returns

      The result of applying `op` between all the elements and `z`, or `z` if this set is empty.

    Definition Classes
      IterableOnceOps
49.  def foldLeft[B](z: B)(op: (B, K) => B): B

    Applies the given binary operator `op` to the given initial value `z` and all elements of this set, going left to right.

    Applies the given binary operator `op` to the given initial value `z` and all elements of this set, going left to right. Returns the initial value if this set is empty.

    "Going left to right" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this set, the result is `op( op( ... op( op(z, x1), x2) ... ), xn)`.

    If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the initial value, and each other left operand is itself an application of the operator. The elements of this set and the initial value all appear exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator.

    z

      An initial value.

    op

      A binary operator.

    returns

      The result of applying `op` to `z` and all elements of this set, going left to right. Returns `z` if this set is empty.

    Definition Classes
      IterableOnceOps
50.  def foldRight[B](z: B)(op: (K, B) => B): B

    Applies the given binary operator `op` to all elements of this set and the given initial value `z`, going right to left.

    Applies the given binary operator `op` to all elements of this set and the given initial value `z`, going right to left. Returns the initial value if this set is empty.

    "Going right to left" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this set, the result is `op(x1, op(x2, op( ... op(xn, z) ... )))`.

    If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the initial value, and each other right operand is itself an application of the operator. The elements of this set and the initial value all appear exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator.

    z

      An initial value.

    op

      A binary operator.

    returns

      The result of applying `op` to all elements of this set and `z`, going right to left. Returns `z` if this set is empty.

    Definition Classes
      IterableOnceOps
51.  def forall(p: (K) => Boolean): Boolean

    Tests whether a predicate holds for all elements of this set.

    Tests whether a predicate holds for all elements of this set.

    Note: may not terminate for infinite-sized collections.

    p

      the predicate used to test elements.

    returns

      `true` if this set is empty or the given predicate `p` holds for all elements of this set, otherwise `false`.

    Definition Classes
      IterableOnceOps
52.  def foreach[U](f: (K) => U): Unit

    Applies `f` to each element for its side effects.

    Applies `f` to each element for its side effects. Note: `U` parameter needed to help scalac's type inference.

    Definition Classes
      IterableOnceOps
53.  def fromSpecific(coll: IterableOnce[K]): Set[K]

    Defines how to turn a given `Iterable[A]` into a collection of type `C`.

    Defines how to turn a given `Iterable[A]` into a collection of type `C`.

    This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.

    Attributes
      protected
    Definition Classes
      IterableFactoryDefaults → IterableOps
    Note

      When implementing a custom collection type and refining `C` to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case where `C =:= CC[A]`, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.

      ,

      As witnessed by the `@uncheckedVariance` annotation, using this method might be unsound. However, as long as it is called with an `Iterable[A]` obtained from `this` collection (as it is the case in the implementations of operations where we use a `View[A]`), it is safe.

54.  final def getClass(): Class[_ <: AnyRef]

    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
      AnyRef → Any
    Annotations
      @native()
55.  def groupBy[K](f: (K) => K): immutable.Map[K, Set[K]]

    Partitions this set into a map of sets according to some discriminator function.

    Partitions this set into a map of sets according to some discriminator function.

    Note: Even when applied to a view or a lazy collection it will always force the elements.

    K

      the type of keys returned by the discriminator function.

    f

      the discriminator function.

    returns

      A map from keys to sets such that the following invariant holds:

          (xs groupBy f)(k) = xs filter (x => f(x) == k)

      That is, every key `k` is bound to a set of those elements `x` for which `f(x)` equals `k`.

    Definition Classes
      IterableOps
56.  def groupMap[K, B](key: (K) => K)(f: (K) => B): immutable.Map[K, Set[B]]

    Partitions this set into a map of sets according to a discriminator function `key`.

    Partitions this set into a map of sets according to a discriminator function `key`. Each element in a group is transformed into a value of type `B` using the `value` function.

    It is equivalent to `groupBy(key).mapValues(_.map(f))`, but more efficient.

        case class User(name: String, age: Int)

        def namesByAge(users: Seq[User]): Map[Int, Seq[String]] =
          users.groupMap(_.age)(_.name)

    Note: Even when applied to a view or a lazy collection it will always force the elements.

    K

      the type of keys returned by the discriminator function

    B

      the type of values returned by the transformation function

    key

      the discriminator function

    f

      the element transformation function

    Definition Classes
      IterableOps
57.  def groupMapReduce[K, B](key: (K) => K)(f: (K) => B)(reduce: (B, B) => B): immutable.Map[K, B]

    Partitions this set into a map according to a discriminator function `key`.

    Partitions this set into a map according to a discriminator function `key`. All the values that have the same discriminator are then transformed by the `f` function and then reduced into a single value with the `reduce` function.

    It is equivalent to `groupBy(key).mapValues(_.map(f).reduce(reduce))`, but more efficient.

        def occurrences[A](as: Seq[A]): Map[A, Int] =
          as.groupMapReduce(identity)(_ => 1)(_ + _)

    Note: Even when applied to a view or a lazy collection it will always force the elements.

    Definition Classes
      IterableOps
58.  def grouped(size: Int): Iterator[Set[K]]

    Partitions elements in fixed size sets.

    Partitions elements in fixed size sets.

    size

      the number of elements per group

    returns

      An iterator producing sets of size `size`, except the last will be less than size `size` if the elements don't divide evenly.

    Definition Classes
      IterableOps
    See also

      scala.collection.Iterator, method `grouped`

59.  def hashCode(): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in scala.Any.

    returns

      the hash code value for this object.

    Definition Classes
      Set → AnyRef → Any
60.  def head: K

    Selects the first element of this set.

    Selects the first element of this set.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the first element of this set.

    Definition Classes
      IterableOps
    Exceptions thrown

      `NoSuchElementException` if the set is empty.

61.  def headOption: Option[K]

    Optionally selects the first element.

    Optionally selects the first element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the first element of this set if it is nonempty, `None` if it is empty.

    Definition Classes
      IterableOps
62.  def init: Set[K]

    The initial part of the collection without its last element.

    The initial part of the collection without its last element.

    Note: Even when applied to a view or a lazy collection it will always force the elements.

    Definition Classes
      IterableOps
63.  def inits: Iterator[Set[K]]

    Iterates over the inits of this set.

    Iterates over the inits of this set. The first value will be this set and the final one will be an empty set, with the intervening values the results of successive applications of `init`.

    Note: Even when applied to a view or a lazy collection it will always force the elements.

    returns

      an iterator over all the inits of this set

    Definition Classes
      IterableOps
    Example:

    1. `List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)`

64.  def intersect(that: Set[K]): Set[K]

    Computes the intersection between this set and another set.

    Computes the intersection between this set and another set.

    that

      the set to intersect with.

    returns

      a new set consisting of all elements that are both in this set and in the given set `that`.

    Definition Classes
      SetOps
65.  def isEmpty: Boolean
    Definition Classes
      GenKeySet
66.  final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object has the same erasure as `T0`.

    Test whether the dynamic type of the receiver object has the same erasure as `T0`.

    Depending on what `T0` is, the test is done in one of the below ways:

    - `T0` is a non-parameterized class type, e.g. `BigDecimal`: this method returns `true` if the value of the receiver object is a `BigDecimal` or a subtype of `BigDecimal`.
    - `T0` is a parameterized class type, e.g. `List[Int]`: this method returns `true` if the value of the receiver object is some `List[X]` for any `X`. For example, `List(1, 2, 3).isInstanceOf[List[String]]` will return true.
    - `T0` is some singleton type `x.type` or literal `x`: this method returns `this.eq(x)`. For example, `x.isInstanceOf[1]` is equivalent to `x.eq(1)`
    - `T0` is an intersection `X with Y` or `X & Y: this method is equivalent to` x.isInstanceOf[X] && x.isInstanceOf[Y]``
    - `T0` is a union `X | Y`: this method is equivalent to `x.isInstanceOf[X] || x.isInstanceOf[Y]`
    - `T0` is a type parameter or an abstract type member: this method is equivalent to `isInstanceOf[U]` where `U` is `T0`'s upper bound, `Any` if `T0` is unbounded. For example, `x.isInstanceOf[A]` where `A` is an unbounded type parameter will return true for any value of `x`.

    This is exactly equivalent to the type pattern `_: T0`

    returns

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

    Definition Classes
      Any
    Note

      due to the unexpectedness of `List(1, 2, 3).isInstanceOf[List[String]]` returning true and `x.isInstanceOf[A]` where `A` is a type parameter or abstract member returning true, these forms issue a warning.

67.  def isTraversableAgain: Boolean

    Tests whether this set can be repeatedly traversed.

    Tests whether this set can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.

    returns

      `true` if it is repeatedly traversable, `false` otherwise.

    Definition Classes
      IterableOps → IterableOnceOps
68.  def iterableFactory: IterableFactory[Set]

    The companion object of this set, providing various factory methods.

    The companion object of this set, providing various factory methods.

    Definition Classes
      Set → Iterable → IterableOps
    Note

      When implementing a custom collection type and refining `CC` to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).

69.  def iterator: Iterator[K]
    Definition Classes
      GenKeySet
70.  def knownSize: Int
    Definition Classes
      GenKeySet
71.  def last: K

    Selects the last element.

    Selects the last element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      The last element of this set.

    Definition Classes
      IterableOps
    Exceptions thrown

      `NoSuchElementException` If the set is empty.

72.  def lastOption: Option[K]

    Optionally selects the last element.

    Optionally selects the last element.

    Note: might return different results for different runs, unless the underlying collection type is ordered.

    returns

      the last element of this set if it is nonempty, `None` if it is empty.

    Definition Classes
      IterableOps
73.  def lazyZip[B](that: Iterable[B]): LazyZip2[K, B, KeySet.this.type]

    Analogous to `zip` except that the elements in each collection are not consumed until a strict operation is invoked on the returned `LazyZip2` decorator.

    Analogous to `zip` except that the elements in each collection are not consumed until a strict operation is invoked on the returned `LazyZip2` decorator.

    Calls to `lazyZip` can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.

        val xs = List(1, 2, 3)
        val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d)
        // res == List(4, 8, 12)

    B

      the type of the second element in each eventual pair

    that

      the iterable providing the second element of each eventual pair

    returns

      a decorator `LazyZip2` that allows strict operations to be performed on the lazily evaluated pairs or chained calls to `lazyZip`. Implicit conversion to `Iterable[(A, B)]` is also supported.

    Definition Classes
      Iterable
74.  def map[B](f: (K) => B): Set[B]

    Builds a new set by applying a function to all elements of this set.

    Builds a new set by applying a function to all elements of this set.

    B

      the element type of the returned set.

    f

      the function to apply to each element.

    returns

      a new set resulting from applying the given function `f` to each element of this set and collecting the results.

    Definition Classes
      IterableOps → IterableOnceOps
75.  def max[B >: K](implicit ord: math.Ordering[B]): K

    Finds the largest element.

    Finds the largest element.

    Note: will not terminate for infinite-sized collections.

    B

      The type over which the ordering is defined.

    ord

      An ordering to be used for comparing elements.

    returns

      the largest element of this set with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

76.  def maxBy[B](f: (K) => B)(implicit ord: math.Ordering[B]): K

    Finds the first element which yields the largest value measured by function `f`.

    Finds the first element which yields the largest value measured by function `f`.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the function `f`.

    f

      The measuring function.

    ord

      An ordering to be used for comparing elements.

    returns

      the first element of this set with the largest value measured by function `f` with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

77.  def maxByOption[B](f: (K) => B)(implicit ord: math.Ordering[B]): Option[K]

    Finds the first element which yields the largest value measured by function `f`.

    Finds the first element which yields the largest value measured by function `f`.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the function `f`.

    f

      The measuring function.

    ord

      An ordering to be used for comparing elements.

    returns

      an option value containing the first element of this set with the largest value measured by function `f` with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
78.  def maxOption[B >: K](implicit ord: math.Ordering[B]): Option[K]

    Finds the largest element.

    Finds the largest element.

    Note: will not terminate for infinite-sized collections.

    B

      The type over which the ordering is defined.

    ord

      An ordering to be used for comparing elements.

    returns

      an option value containing the largest element of this set with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
79.  def min[B >: K](implicit ord: math.Ordering[B]): K

    Finds the smallest element.

    Finds the smallest element.

    Note: will not terminate for infinite-sized collections.

    B

      The type over which the ordering is defined.

    ord

      An ordering to be used for comparing elements.

    returns

      the smallest element of this set with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

80.  def minBy[B](f: (K) => B)(implicit ord: math.Ordering[B]): K

    Finds the first element which yields the smallest value measured by function `f`.

    Finds the first element which yields the smallest value measured by function `f`.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the function `f`.

    f

      The measuring function.

    ord

      An ordering to be used for comparing elements.

    returns

      the first element of this set with the smallest value measured by function `f` with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

81.  def minByOption[B](f: (K) => B)(implicit ord: math.Ordering[B]): Option[K]

    Finds the first element which yields the smallest value measured by function `f`.

    Finds the first element which yields the smallest value measured by function `f`.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the function `f`.

    f

      The measuring function.

    ord

      An ordering to be used for comparing elements.

    returns

      an option value containing the first element of this set with the smallest value measured by function `f` with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
82.  def minOption[B >: K](implicit ord: math.Ordering[B]): Option[K]

    Finds the smallest element.

    Finds the smallest element.

    Note: will not terminate for infinite-sized collections.

    B

      The type over which the ordering is defined.

    ord

      An ordering to be used for comparing elements.

    returns

      an option value containing the smallest element of this set with respect to the ordering `ord`.

    Definition Classes
      IterableOnceOps
83.  final def mkString: String

    Displays all elements of this set in a string.

    Displays all elements of this set in a string.

    Delegates to addString, which can be overridden.

    returns

      a string representation of this set. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this set follow each other without any separator string.

    Definition Classes
      IterableOnceOps
    Annotations
      @inline()
84.  final def mkString(sep: String): String

    Displays all elements of this set in a string using a separator string.

    Displays all elements of this set in a string using a separator string.

    Delegates to addString, which can be overridden.

    sep

      the separator string.

    returns

      a string representation of this set. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this set are separated by the string `sep`.

    Definition Classes
      IterableOnceOps
    Annotations
      @inline()
    Example:

    1. `List(1, 2, 3).mkString("|") = "1|2|3"`

85.  final def mkString(start: String, sep: String, end: String): String

    Displays all elements of this set in a string using start, end, and separator strings.

    Displays all elements of this set in a string using start, end, and separator strings.

    Delegates to addString, which can be overridden.

    start

      the starting string.

    sep

      the separator string.

    end

      the ending string.

    returns

      a string representation of this set. The resulting string begins with the string `start` and ends with the string `end`. Inside, the string representations (w.r.t. the method `toString`) of all elements of this set are separated by the string `sep`.

    Definition Classes
      IterableOnceOps
    Example:

    1. `List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"`

86.  final def ne(arg0: AnyRef): Boolean

    Equivalent to `!(this eq that)`.

    Equivalent to `!(this eq that)`.

    returns

      `true` if the argument is not a reference to the receiver object; `false` otherwise.

    Definition Classes
      AnyRef
87.  def newSpecificBuilder: Builder[K, Set[K]]

    returns

      a strict builder for the same collection type. Note that in the case of lazy collections (e.g. scala.collection.View or scala.collection.immutable.LazyList), it is possible to implement this method but the resulting `Builder` will break laziness. As a consequence, operations should preferably be implemented with `fromSpecific` instead of this method.

    Attributes
      protected
    Definition Classes
      IterableFactoryDefaults → IterableOps
    Note

      When implementing a custom collection type and refining `C` to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case where `C =:= CC[A]`, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.

      ,

      As witnessed by the `@uncheckedVariance` annotation, using this method might be unsound. However, as long as the returned builder is only fed with `A` values taken from `this` instance, it is safe.

88.  def nonEmpty: Boolean

    Tests whether the set is not empty.

    Tests whether the set is not empty.

    returns

      `true` if the set contains at least one element, `false` otherwise.

    Definition Classes
      IterableOnceOps
    Annotations
      @deprecatedOverriding()
89.  final def notify(): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Definition Classes
      AnyRef
    Annotations
      @native()
    Note

      not specified by SLS as a member of AnyRef

90.  final def notifyAll(): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Definition Classes
      AnyRef
    Annotations
      @native()
    Note

      not specified by SLS as a member of AnyRef

91.  def partition(p: (K) => Boolean): (Set[K], Set[K])

    A pair of, first, all elements that satisfy predicate `p` and, second, all elements that do not.

    A pair of, first, all elements that satisfy predicate `p` and, second, all elements that do not.

    The two set correspond to the result of filter and filterNot, respectively.

    The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of `partition` in `StrictOptimizedIterableOps`, which requires only a single traversal.

    Definition Classes
      IterableOps
92.  def partitionMap[A1, A2](f: (K) => Either[A1, A2]): (Set[A1], Set[A2])

    Applies a function `f` to each element of the set and returns a pair of sets: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

    Applies a function `f` to each element of the set and returns a pair of sets: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

    Example:

        val xs = `Set`(1, "one", 2, "two", 3, "three") partitionMap {
         case i: Int => Left(i)
         case s: String => Right(s)
        }
        // xs == (`Set`(1, 2, 3),
        //        `Set`(one, two, three))

    A1

      the element type of the first resulting collection

    A2

      the element type of the second resulting collection

    f

      the 'split function' mapping the elements of this set to an scala.util.Either

    returns

      a pair of sets: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

    Definition Classes
      IterableOps
93.  def product[B >: K](implicit num: math.Numeric[B]): B

    Multiplies together the elements of this collection.

    Multiplies together the elements of this collection.

    The default implementation uses `reduce` for a known non-empty collection, `foldLeft` otherwise.

    Note: will not terminate for infinite-sized collections.

    B

      the result type of the `*` operator.

    num

      an implicit parameter defining a set of numeric operations which includes the `*` operator to be used in forming the product.

    returns

      the product of all elements of this set with respect to the `*` operator in `num`.

    Definition Classes
      IterableOnceOps
94.  def reduce[B >: K](op: (B, B) => B): B

    Applies the given binary operator `op` to all elements of this set.

    Applies the given binary operator `op` to all elements of this set.

    For each application of the operator, each operand is either an element of this set or another such application of the operator. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

    If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

    Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      The type parameter for the binary operator, a supertype of `A`.

    op

      A binary operator; must be associative for the result to always be the same across runs.

    returns

      The result of applying `op` between all the elements if the set is nonempty.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

95.  def reduceLeft[B >: K](op: (B, K) => B): B

    Applies the given binary operator `op` to all elements of this set, going left to right.

    Applies the given binary operator `op` to all elements of this set, going left to right.

    "Going left to right" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this set, the result is `op( op( op( ... op(x1, x2) ... ), xn-1), xn)`.

    If this collection is not ordered, then for each application of the operator, each right operand is an element. In addition, the leftmost operand is the first element of this set and each other left operand is itself an application of the operator. Each element appears exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator, a supertype of `A`.

    op

      A binary operator.

    returns

      The result of applying `op` to all elements of this set, going left to right.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

96.  def reduceLeftOption[B >: K](op: (B, K) => B): Option[B]

    If this set is nonempty, reduces it with the given binary operator `op`, going left to right.

    If this set is nonempty, reduces it with the given binary operator `op`, going left to right.

    The behavior is the same as reduceLeft except that the value is `None` if the set is empty. Each element appears exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator, a supertype of `A`.

    op

      A binary operator.

    returns

      The result of reducing this set with `op` going left to right if the set is nonempty, inside a `Some`, and `None` otherwise.

    Definition Classes
      IterableOnceOps
97.  def reduceOption[B >: K](op: (B, B) => B): Option[B]

    If this set is nonempty, reduces it with the given binary operator `op`.

    If this set is nonempty, reduces it with the given binary operator `op`.

    The behavior is the same as reduce except that the value is `None` if the set is empty. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

    Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      A type parameter for the binary operator, a supertype of `A`.

    op

      A binary operator; must be associative for the result to always be the same across runs.

    returns

      The result of reducing this set with `op` if the set is nonempty, inside a `Some`, and `None` otherwise.

    Definition Classes
      IterableOnceOps
98.  def reduceRight[B >: K](op: (K, B) => B): B

    Applies the given binary operator `op` to all elements of this set, going right to left.

    Applies the given binary operator `op` to all elements of this set, going right to left.

    "Going right to left" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this set, the result is `op(x1, op(x2, op( ... op(xn-1, xn) ... )))`.

    If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the last element of this set and each other right operand is itself an application of the operator. Each element appears exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator, a supertype of `A`.

    op

      A binary operator.

    returns

      The result of applying `op` to all elements of this set, going right to left.

    Definition Classes
      IterableOnceOps
    Exceptions thrown

      `UnsupportedOperationException` if this set is empty.

99.  def reduceRightOption[B >: K](op: (K, B) => B): Option[B]

    If this set is nonempty, reduces it with the given binary operator `op`, going right to left.

    If this set is nonempty, reduces it with the given binary operator `op`, going right to left.

    The behavior is the same as reduceRight except that the value is `None` if the set is empty. Each element appears exactly once in the computation.

    Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.

    Note: will not terminate for infinite-sized collections.

    B

      The result type of the binary operator, a supertype of `A`.

    op

      A binary operator.

    returns

      The result of reducing this set with `op` going right to left if the set is nonempty, inside a `Some`, and `None` otherwise.

    Definition Classes
      IterableOnceOps
100.  def reversed: Iterable[K]
     Attributes
       protected
     Definition Classes
       IterableOnceOps
101.  def scan[B >: K](z: B)(op: (B, B) => B): Set[B]

     Computes a prefix scan of the elements of the collection.

     Computes a prefix scan of the elements of the collection.

     Note: The neutral element `z` may be applied more than once.

     B

       element type of the resulting collection

     z

       neutral element for the operator `op`

     op

       the associative operator for the scan

     returns

       a new set containing the prefix scan of the elements in this set

     Definition Classes
       IterableOps
102.  def scanLeft[B](z: B)(op: (B, K) => B): Set[B]

     Produces a set containing cumulative results of applying the operator going left to right, including the initial value.

     Produces a set containing cumulative results of applying the operator going left to right, including the initial value.

     Note: will not terminate for infinite-sized collections.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     B

       the type of the elements in the resulting collection

     z

       the initial value

     op

       the binary operator applied to the intermediate result and the element

     returns

       collection with intermediate results

     Definition Classes
       IterableOps → IterableOnceOps
103.  def scanRight[B](z: B)(op: (K, B) => B): Set[B]

     Produces a collection containing cumulative results of applying the operator going right to left.

     Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.

     Note: will not terminate for infinite-sized collections.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     Note: Even when applied to a view or a lazy collection it will always force the elements.

     Example:

         List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

     B

       the type of the elements in the resulting collection

     z

       the initial value

     op

       the binary operator applied to the intermediate result and the element

     returns

       collection with intermediate results

     Definition Classes
       IterableOps
104.  def size: Int
     Definition Classes
       GenKeySet
105.  def sizeCompare(that: Iterable[_]): Int

     Compares the size of this set to the size of another `Iterable`.

     Compares the size of this set to the size of another `Iterable`.

     that

       the `Iterable` whose size is compared with this set's size.

     returns

       A value `x` where

           x <  0       if this.size <  that.size
           x == 0       if this.size == that.size
           x >  0       if this.size >  that.size

       The method as implemented here does not call `size` directly; its running time is `O(this.size min that.size)` instead of `O(this.size + that.size)`. The method should be overridden if computing `size` is cheap and `knownSize` returns `-1`.

     Definition Classes
       IterableOps
106.  def sizeCompare(otherSize: Int): Int

     Compares the size of this set to a test value.

     Compares the size of this set to a test value.

     otherSize

       the test value that gets compared with the size.

     returns

       A value `x` where

           x <  0       if this.size <  otherSize
           x == 0       if this.size == otherSize
           x >  0       if this.size >  otherSize

       The method as implemented here does not call `size` directly; its running time is `O(size min otherSize)` instead of `O(size)`. The method should be overridden if computing `size` is cheap and `knownSize` returns `-1`.

     Definition Classes
       IterableOps
     See also

       sizeIs

107.  final def sizeIs: SizeCompareOps

     Returns a value class containing operations for comparing the size of this set to a test value.

     Returns a value class containing operations for comparing the size of this set to a test value.

     These operations are implemented in terms of `sizeCompare(Int)`, and allow the following more readable usages:

         this.sizeIs < size     // this.sizeCompare(size) < 0
         this.sizeIs <= size    // this.sizeCompare(size) <= 0
         this.sizeIs == size    // this.sizeCompare(size) == 0
         this.sizeIs != size    // this.sizeCompare(size) != 0
         this.sizeIs >= size    // this.sizeCompare(size) >= 0
         this.sizeIs > size     // this.sizeCompare(size) > 0

     Definition Classes
       IterableOps
     Annotations
       @inline()
108.  def slice(from: Int, until: Int): Set[K]

     Selects an interval of elements.

     Selects an interval of elements. The returned set is made up of all elements `x` which satisfy the invariant:

         from <= indexOf(x) < until

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     from

       the lowest index to include from this set.

     until

       the lowest index to EXCLUDE from this set.

     returns

       a set containing the elements greater than or equal to index `from` extending up to (but not including) index `until` of this set.

     Definition Classes
       IterableOps → IterableOnceOps
     Example:

     1. `List('a', 'b', 'c', 'd', 'e').slice(1, 3) == List('b', 'c')`

109.  def sliding(size: Int, step: Int): Iterator[Set[K]]

     Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in `grouped`).

     Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in `grouped`).

     The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.

     size

       the number of elements per group

     step

       the distance between the first elements of successive groups

     returns

       An iterator producing sets of size `size`, except the last element (which may be the only element) will be smaller if there are fewer than `size` elements remaining to be grouped.

     Definition Classes
       IterableOps
     Examples:

     1. `List(1, 2, 3, 4, 5).sliding(2, 2) = Iterator(List(1, 2), List(3, 4), List(5))`

     ,

     2. `List(1, 2, 3, 4, 5, 6).sliding(2, 3) = Iterator(List(1, 2), List(4, 5))`

     See also

       scala.collection.Iterator, method `sliding`

110.  def sliding(size: Int): Iterator[Set[K]]

     Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in `grouped`).

     Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in `grouped`).

     An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.

     size

       the number of elements per group

     returns

       An iterator producing sets of size `size`, except for a non-empty collection with less than `size` elements, which returns an iterator that produces the source collection itself as its only element.

     Definition Classes
       IterableOps
     Examples:

     1. `List().sliding(2) = empty iterator`

     ,

     2. `List(1).sliding(2) = Iterator(List(1))`

     ,

     3. `List(1, 2).sliding(2) = Iterator(List(1, 2))`

     ,

     4. `List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))`

     See also

       scala.collection.Iterator, method `sliding`

111.  def span(p: (K) => Boolean): (Set[K], Set[K])

     Splits this set into a prefix/suffix pair according to a predicate.

     Splits this set into a prefix/suffix pair according to a predicate.

     Note: `c span p` is equivalent to (but possibly more efficient than) `(c takeWhile p, c dropWhile p)`, provided the evaluation of the predicate `p` does not cause any side effects.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     p

       the test predicate

     returns

       a pair consisting of the longest prefix of this set whose elements all satisfy `p`, and the rest of this set.

     Definition Classes
       IterableOps → IterableOnceOps
112.  def splitAt(n: Int): (Set[K], Set[K])

     Splits this set into a prefix/suffix pair at a given position.

     Splits this set into a prefix/suffix pair at a given position.

     Note: `c splitAt n` is equivalent to (but possibly more efficient than) `(c take n, c drop n)`.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     n

       the position at which to split.

     returns

       a pair of sets consisting of the first `n` elements of this set, and the other elements.

     Definition Classes
       IterableOps → IterableOnceOps
113.  def stepper[S <: Stepper[_]](implicit shape: StepperShape[K, S]): S

     Returns a scala.collection.Stepper for the elements of this collection.

     Returns a scala.collection.Stepper for the elements of this collection.

     The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.

     The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.

     - For collections of `Int`, `Short`, `Byte` or `Char`, an scala.collection.IntStepper is returned
     - For collections of `Double` or `Float`, a scala.collection.DoubleStepper is returned
     - For collections of `Long` a scala.collection.LongStepper is returned
     - For any other element type, an scala.collection.AnyStepper is returned

     Note that this method is overridden in subclasses and the return type is refined to `S with EfficientSplit`, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.

     Definition Classes
       IterableOnce
114.  def stringPrefix: String
     Attributes
       protected[this]
     Definition Classes
       Set → Iterable
     Annotations
       @nowarn()
115.  def subsetOf(that: Set[K]): Boolean

     Tests whether this set is a subset of another set.

     Tests whether this set is a subset of another set.

     that

       the set to test.

     returns

       `true` if this set is a subset of `that`, i.e. if every element of this set is also an element of `that`.

     Definition Classes
       SetOps
116.  def subsets(): Iterator[Set[K]]

     An iterator over all subsets of this set.

     An iterator over all subsets of this set.

     returns

       the iterator.

     Definition Classes
       SetOps
117.  def subsets(len: Int): Iterator[Set[K]]

     An iterator over all subsets of this set of the given size.

     An iterator over all subsets of this set of the given size. If the requested size is impossible, an empty iterator is returned.

     len

       the size of the subsets.

     returns

       the iterator.

     Definition Classes
       SetOps
118.  def sum[B >: K](implicit num: math.Numeric[B]): B

     Sums the elements of this collection.

     Sums the elements of this collection.

     The default implementation uses `reduce` for a known non-empty collection, `foldLeft` otherwise.

     Note: will not terminate for infinite-sized collections.

     B

       the result type of the `+` operator.

     num

       an implicit parameter defining a set of numeric operations which includes the `+` operator to be used in forming the sum.

     returns

       the sum of all elements of this set with respect to the `+` operator in `num`.

     Definition Classes
       IterableOnceOps
119.  final def synchronized[T0](arg0: => T0): T0

     Executes the code in `body` with an exclusive lock on `this`.

     Executes the code in `body` with an exclusive lock on `this`.

     returns

       the result of `body`

     Definition Classes
       AnyRef
120.  def tail: Set[K]

     The rest of the collection without its first element.

     The rest of the collection without its first element.

     Definition Classes
       IterableOps
121.  def tails: Iterator[Set[K]]

     Iterates over the tails of this set.

     Iterates over the tails of this set. The first value will be this set and the final one will be an empty set, with the intervening values the results of successive applications of `tail`.

     returns

       an iterator over all the tails of this set

     Definition Classes
       IterableOps
     Example:

     1. `List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)`

122.  def take(n: Int): Set[K]

     Selects the first `n` elements.

     Selects the first `n` elements.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     n

       the number of elements to take from this set.

     returns

       a set consisting only of the first `n` elements of this set, or else the whole set, if it has less than `n` elements. If `n` is negative, returns an empty set.

     Definition Classes
       IterableOps → IterableOnceOps
123.  def takeRight(n: Int): Set[K]

     Selects the last n elements.

     Selects the last n elements.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     n

       the number of elements to take from this set.

     returns

       a set consisting only of the last `n` elements of this set, or else the whole set, if it has less than `n` elements. If `n` is negative, returns an empty set.

     Definition Classes
       IterableOps
124.  def takeWhile(p: (K) => Boolean): Set[K]

     Takes longest prefix of elements that satisfy a predicate.

     Takes longest prefix of elements that satisfy a predicate.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     p

       The predicate used to test elements.

     returns

       the longest prefix of this set whose elements all satisfy the predicate `p`.

     Definition Classes
       IterableOps → IterableOnceOps
125.  def tapEach[U](f: (K) => U): Set[K]

     Applies a side-effecting function to each element in this collection.

     Applies a side-effecting function to each element in this collection. Strict collections will apply `f` to their elements immediately, while lazy collections like Views and LazyLists will only apply `f` on each element if and when that element is evaluated, and each time that element is evaluated.

     U

       the return type of f

     f

       a function to apply to each element in this set

     returns

       The same logical collection as this

     Definition Classes
       IterableOps → IterableOnceOps
126.  def to[C1](factory: Factory[K, C1]): C1

     Given a collection factory `factory`, converts this set to the appropriate representation for the current element type `A`.

     Given a collection factory `factory`, converts this set to the appropriate representation for the current element type `A`. Example uses:

         xs.to(List)
         xs.to(ArrayBuffer)
         xs.to(BitSet) // for xs: Iterable[Int]

     Definition Classes
       IterableOnceOps
127.  def toArray[B >: K](implicit arg0: ClassTag[B]): Array[B]

     Converts this set to an `Array`.

     Converts this set to an `Array`.

     Implementation note: DO NOT call Array.from from this method.

     B

       The type of elements of the result, a supertype of `A`.

     returns

       This set as an `Array[B]`.

     Definition Classes
       IterableOnceOps
128.  final def toBuffer[B >: K]: Buffer[B]

     Converts this set to a `Buffer`.

     Converts this set to a `Buffer`.

     B

       The type of elements of the result, a supertype of `A`.

     returns

       This set as a `Buffer[B]`.

     Definition Classes
       IterableOnceOps
     Annotations
       @inline()
129.  def toIndexedSeq: immutable.IndexedSeq[K]

     Converts this set to an `IndexedSeq`.

     Converts this set to an `IndexedSeq`.

     returns

       This set as an `IndexedSeq[A]`.

     Definition Classes
       IterableOnceOps
130.  def toList: immutable.List[K]

     Converts this set to a `List`.

     Converts this set to a `List`.

     returns

       This set as a `List[A]`.

     Definition Classes
       IterableOnceOps
131.  def toMap[K, V](implicit ev: <:<[K, (K, V)]): immutable.Map[K, V]

     Converts this set to a `Map`, given an implicit coercion from the set's type to a key-value tuple.

     Converts this set to a `Map`, given an implicit coercion from the set's type to a key-value tuple.

     K

       The key type for the resulting map.

     V

       The value type for the resulting map.

     ev

       An implicit coercion from `A` to `[K, V]`.

     returns

       This set as a `Map[K, V]`.

     Definition Classes
       IterableOnceOps
132.  def toSeq: immutable.Seq[K]

     returns

       This set as a `Seq[A]`. This is equivalent to `to(Seq)` but might be faster.

     Definition Classes
       IterableOnceOps
133.  def toSet[B >: K]: immutable.Set[B]

     Converts this set to a `Set`.

     Converts this set to a `Set`.

     B

       The type of elements of the result, a supertype of `A`.

     returns

       This set as a `Set[B]`.

     Definition Classes
       IterableOnceOps
134.  def toString(): String

     Creates a String representation of this object.

     Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

     returns

       a String representation of the object.

     Definition Classes
       Set → Function1 → Iterable → AnyRef → Any
135.  def toVector: immutable.Vector[K]

     Converts this set to a `Vector`.

     Converts this set to a `Vector`.

     returns

       This set as a `Vector[A]`.

     Definition Classes
       IterableOnceOps
136.  def transpose[B](implicit asIterable: (K) => Iterable[B]): Set[Set[B]]

     Transposes this set of iterable collections into a set of sets.

     Transposes this set of iterable collections into a set of sets.

     The resulting collection's type will be guided by the static type of set. For example:

         val xs = List(
                    Set(1, 2, 3),
                    Set(4, 5, 6)).transpose
         // xs == List(
         //         List(1, 4),
         //         List(2, 5),
         //         List(3, 6))

         val ys = Vector(
                    List(1, 2, 3),
                    List(4, 5, 6)).transpose
         // ys == Vector(
         //         Vector(1, 4),
         //         Vector(2, 5),
         //         Vector(3, 6))

     Note: Even when applied to a view or a lazy collection it will always force the elements.

     B

       the type of the elements of each iterable collection.

     asIterable

       an implicit conversion which asserts that the element type of this set is an `Iterable`.

     returns

       a two-dimensional set of sets which has as nth row the nth column of this set.

     Definition Classes
       IterableOps
     Exceptions thrown

       `IllegalArgumentException` if all collections in this set are not of the same size.

137.  final def union(that: Set[K]): Set[K]

     Computes the union between of set and another set.

     Computes the union between of set and another set.

     that

       the set to form the union with.

     returns

       a new set consisting of all elements that are in this set or in the given set `that`.

     Definition Classes
       SetOps
     Annotations
       @inline()
138.  def unzip[A1, A2](implicit asPair: (K) => (A1, A2)): (Set[A1], Set[A2])

     Converts this set of pairs into two collections of the first and second half of each pair.

     Converts this set of pairs into two collections of the first and second half of each pair.

         val xs = `Set`(
                    (1, "one"),
                    (2, "two"),
                    (3, "three")).unzip
         // xs == (`Set`(1, 2, 3),
         //        `Set`(one, two, three))

     A1

       the type of the first half of the element pairs

     A2

       the type of the second half of the element pairs

     asPair

       an implicit conversion which asserts that the element type of this set is a pair.

     returns

       a pair of sets, containing the first, respectively second half of each element pair of this set.

     Definition Classes
       IterableOps
139.  def unzip3[A1, A2, A3](implicit asTriple: (K) => (A1, A2, A3)): (Set[A1], Set[A2], Set[A3])

     Converts this set of triples into three collections of the first, second, and third element of each triple.

     Converts this set of triples into three collections of the first, second, and third element of each triple.

         val xs = `Set`(
                    (1, "one", '1'),
                    (2, "two", '2'),
                    (3, "three", '3')).unzip3
         // xs == (`Set`(1, 2, 3),
         //        `Set`(one, two, three),
         //        `Set`(1, 2, 3))

     A1

       the type of the first member of the element triples

     A2

       the type of the second member of the element triples

     A3

       the type of the third member of the element triples

     asTriple

       an implicit conversion which asserts that the element type of this set is a triple.

     returns

       a triple of sets, containing the first, second, respectively third member of each element triple of this set.

     Definition Classes
       IterableOps
140.  def view: View[K]

     A view over the elements of this collection.

     A view over the elements of this collection.

     Definition Classes
       IterableOps
141.  final def wait(): Unit

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--.

     Definition Classes
       AnyRef
     Annotations
       @throws(classOf[java.lang.InterruptedException])
     Note

       not specified by SLS as a member of AnyRef

142.  final def wait(arg0: Long, arg1: Int): Unit

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-

     Definition Classes
       AnyRef
     Annotations
       @throws(classOf[java.lang.InterruptedException])
     Note

       not specified by SLS as a member of AnyRef

143.  final def wait(arg0: Long): Unit

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.

     See https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-.

     Definition Classes
       AnyRef
     Annotations
       @throws(classOf[java.lang.InterruptedException]) @native()
     Note

       not specified by SLS as a member of AnyRef

144.  def withFilter(p: (K) => Boolean): WithFilter[K, [_]Set[_]]

     Creates a non-strict filter of this set.

     Creates a non-strict filter of this set.

     Note: the difference between `c filter p` and `c withFilter p` is that the former creates a new collection, whereas the latter only restricts the domain of subsequent `map`, `flatMap`, `foreach`, and `withFilter` operations.

     Note: might return different results for different runs, unless the underlying collection type is ordered.

     p

       the predicate used to test elements.

     returns

       an object of class `WithFilter`, which supports `map`, `flatMap`, `foreach`, and `withFilter` operations. All these operations apply to those elements of this set which satisfy the predicate `p`.

     Definition Classes
       IterableOps
145.  def writeReplace(): AnyRef
     Attributes
       protected[this]
     Definition Classes
       DefaultSerializable
146.  def zip[B](that: IterableOnce[B]): Set[(K, B)]

     Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs.

     Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

     B

       the type of the second half of the returned pairs

     that

       The iterable providing the second half of each result pair

     returns

       a new set containing pairs consisting of corresponding elements of this set and `that`. The length of the returned collection is the minimum of the lengths of this set and `that`.

     Definition Classes
       IterableOps
147.  def zipAll[A1 >: K, B](that: Iterable[B], thisElem: A1, thatElem: B): Set[(A1, B)]

     Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs.

     Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

     that

       the iterable providing the second half of each result pair

     thisElem

       the element to be used to fill up the result if this set is shorter than `that`.

     thatElem

       the element to be used to fill up the result if `that` is shorter than this set.

     returns

       a new set containing pairs consisting of corresponding elements of this set and `that`. The length of the returned collection is the maximum of the lengths of this set and `that`. If this set is shorter than `that`, `thisElem` values are used to pad the result. If `that` is shorter than this set, `thatElem` values are used to pad the result.

     Definition Classes
       IterableOps
148.  def zipWithIndex: Set[(K, Int)]

     Zips this set with its indices.

     Zips this set with its indices.

     returns

       A new set containing pairs consisting of all elements of this set paired with their index. Indices start at `0`.

     Definition Classes
       IterableOps → IterableOnceOps
     Example:

     1. `List("a", "b", "c").zipWithIndex == List(("a", 0), ("b", 1), ("c", 2))`

149.  final def |(that: Set[K]): Set[K]

     Alias for `union`

     Alias for `union`

     Definition Classes
       SetOps
     Annotations
       @inline()

### Shadowed Implicit Value Members

1.  def +(other: String): String
   Implicit
     This member is added by an implicit conversion from KeySet toany2stringadd[KeySet] performed by method any2stringadd in scala.Predef.
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   Definition Classes
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### Deprecated Value Members

1.  def +(elem1: K, elem2: K, elems: K*): Set[K]
   Definition Classes
     SetOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use ++ with an explicit collection argument instead of + with varargs

2.  def +(elem: K): Set[K]
   Definition Classes
     SetOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Consider requiring an immutable Set or fall back to Set.union

3.  def ++:[B >: K](that: IterableOnce[B]): Set[B]
   Definition Classes
     IterableOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use ++ instead of ++: for collections of type Iterable

4.  def -(elem1: K, elem2: K, elems: K*): Set[K]
   Definition Classes
     SetOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Use &- with an explicit collection argument instead of - with varargs

5.  def -(elem: K): Set[K]
   Definition Classes
     SetOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Consider requiring an immutable Set or fall back to Set.diff

6.  def --(that: IterableOnce[K]): Set[K]
   Definition Classes
     SetOps
   Annotations
     @deprecated
   Deprecated

     (Since version 2.13.0) Consider requiring an immutable Set

7.  def /:[B](z: B)(op: (B, K) => B): B
   Implicit
     This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
   Shadowing
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         (keySet: IterableOnceExtensionMethods[K])./:(z)(op)

   Definition Classes
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   Annotations
     @deprecated @inline()
   Deprecated

     (Since version 2.13.0) Use .iterator.foldLeft instead

8.  final def /:[B](z: B)(op: (B, K) => B): B
   Definition Classes
     IterableOnceOps
   Annotations
     @deprecated @inline()
   Deprecated

     (Since version 2.13.0) Use foldLeft instead of /:

9.  def :\[B](z: B)(op: (K, B) => B): B
   Implicit
     This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
   Shadowing
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   Definition Classes
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   Annotations
     @deprecated @inline()
   Deprecated

     (Since version 2.13.0) Use .iterator.foldRight instead

10.  final def :\[B](z: B)(op: (K, B) => B): B
    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use foldRight instead of :\

11.  def aggregate[B](z: => B)(seqop: (B, K) => B, combop: (B, B) => B): B

    Aggregates the results of applying an operator to subsequent elements.

    Aggregates the results of applying an operator to subsequent elements.

    Since this method degenerates to `foldLeft` for sequential (non-parallel) collections, where the combining operation is ignored, it is advisable to prefer `foldLeft` for that case.

    For parallel collections, use the `aggregate` method specified by `scala.collection.parallel.ParIterableLike`.

    B

      the result type, produced by `seqop`, `combop`, and by this function as a final result.

    z

      the start value, a neutral element for `seqop`.

    seqop

      the binary operator used to accumulate the result.

    combop

      an associative operator for combining sequential results, unused for sequential collections.

    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) For sequential collections, prefer `foldLeft(z)(seqop)`. For parallel collections, use `ParIterableLike#aggregate`.

12.  def collectFirst[B](f: PartialFunction[K, B]): Option[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).collectFirst(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.collectFirst(...) instead

13.  def companion: IterableFactory[[_]Set[_]]
    Definition Classes
      IterableOps
    Annotations
      @deprecated @deprecatedOverriding() @inline()
    Deprecated

      (Since version 2.13.0) Use iterableFactory instead

14.  def copyToBuffer(dest: Buffer[K]): Unit
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
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          (keySet: IterableOnceExtensionMethods[K]).copyToBuffer(dest)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.copyToBuffer(...) instead

15.  final def copyToBuffer[B >: K](dest: Buffer[B]): Unit
    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use `dest ++= coll` instead

16.  def count(f: (K) => Boolean): Int
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
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          (keySet: IterableOnceExtensionMethods[K]).count(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.count(...) instead

17.  def exists(f: (K) => Boolean): Boolean
    Implicit
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          (keySet: IterableOnceExtensionMethods[K]).exists(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.exists(...) instead

18.  def filter(f: (K) => Boolean): Iterator[K]
    Implicit
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          (keySet: IterableOnceExtensionMethods[K]).filter(f)

    Definition Classes
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    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.filter(...) instead

19.  def find(p: (K) => Boolean): Option[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
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          (keySet: IterableOnceExtensionMethods[K]).find(p)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.find instead

20.  def flatMap[B](f: (K) => IterableOnce[B]): IterableOnce[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).flatMap(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.flatMap instead or consider requiring an Iterable

21.  def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).fold(z)(op)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.fold instead

22.  def foldLeft[B](z: B)(op: (B, K) => B): B
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).foldLeft(z)(op)

    Definition Classes
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    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.foldLeft instead

23.  def foldRight[B](z: B)(op: (K, B) => B): B
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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    Definition Classes
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    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.foldRight instead

24.  def forall(f: (K) => Boolean): Boolean
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).forall(f)

    Definition Classes
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    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.forall(...) instead

25.  def foreach[U](f: (K) => U): Unit
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).foreach(f)

    Definition Classes
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    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.foreach(...) instead

26.  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 KeySet toStringFormat[KeySet] performed by method StringFormat in scala.Predef.
    Definition Classes
      StringFormat
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.12.16) Use `formatString.format(value)` instead of `value.formatted(formatString)`, or use the `f""` string interpolator. In Java 15 and later, `formatted` resolves to the new method in String which has reversed parameters.

27.  def hasDefiniteSize: Boolean

    Tests whether this set is known to have a finite size.

    Tests whether this set is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as `Stream`, the predicate returns `true` if all elements have been computed. It returns `false` if the stream is not yet evaluated to the end. Non-empty Iterators usually return `false` even if they were created from a collection with a known finite size.

    Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that `hasDefiniteSize` returns `true`. However, checking `hasDefiniteSize` can provide an assurance that size is well-defined and non-termination is not a concern.

    returns

      `true` if this collection is known to have finite size, `false` otherwise.

    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)

    See also

      method `knownSize` for a more useful alternative

28.  def isEmpty: Boolean
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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      This implicitly inherited member is shadowed by one or more members in this class.
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          (keySet: IterableOnceExtensionMethods[K]).isEmpty

    Definition Classes
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    Annotations
      @deprecated
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      (Since version 2.13.0) Use .iterator.isEmpty instead

29.  def map[B](f: (K) => B): IterableOnce[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).map(f)

    Definition Classes
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      (Since version 2.13.0) Use .iterator.map instead or consider requiring an Iterable

30.  def max(implicit ord: math.Ordering[K]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).max(ord)

    Definition Classes
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    Annotations
      @deprecated
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      (Since version 2.13.0) Use .iterator.max instead

31.  def maxBy[B](f: (K) => B)(implicit cmp: math.Ordering[B]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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      (Since version 2.13.0) Use .iterator.maxBy(...) instead

32.  def min(implicit ord: math.Ordering[K]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).min(ord)

    Definition Classes
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    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.min instead

33.  def minBy[B](f: (K) => B)(implicit cmp: math.Ordering[B]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).minBy(f)(cmp)

    Definition Classes
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    Annotations
      @deprecated
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      (Since version 2.13.0) Use .iterator.minBy(...) instead

34.  def mkString: String
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).mkString

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      (Since version 2.13.0) Use .iterator.mkString instead

35.  def mkString(sep: String): String
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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      This implicitly inherited member is shadowed by one or more members in this class.
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          (keySet: IterableOnceExtensionMethods[K]).mkString(sep)

    Definition Classes
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      (Since version 2.13.0) Use .iterator.mkString instead

36.  def mkString(start: String, sep: String, end: String): String
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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          (keySet: IterableOnceExtensionMethods[K]).mkString(start, sep, end)

    Definition Classes
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      (Since version 2.13.0) Use .iterator.mkString instead

37.  def nonEmpty: Boolean
    Implicit
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          (keySet: IterableOnceExtensionMethods[K]).nonEmpty

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      (Since version 2.13.0) Use .iterator.nonEmpty instead

38.  def product(implicit num: math.Numeric[K]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).product(num)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.product instead

39.  def reduce(f: (K, K) => K): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduce(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduce(...) instead

40.  def reduceLeft(f: (K, K) => K): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduceLeft(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduceLeft(...) instead

41.  def reduceLeftOption(f: (K, K) => K): Option[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduceLeftOption(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduceLeftOption(...) instead

42.  def reduceOption(f: (K, K) => K): Option[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduceOption(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduceOption(...) instead

43.  def reduceRight(f: (K, K) => K): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduceRight(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduceRight(...) instead

44.  def reduceRightOption(f: (K, K) => K): Option[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).reduceRightOption(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.reduceRightOption(...) instead

45.  final def repr: Set[K]
    Definition Classes
      IterableOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use coll instead of repr in a collection implementation, use the collection value itself from the outside

46.  def sameElements[B >: A](that: IterableOnce[B]): Boolean
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.sameElements instead

47.  def seq: KeySet.this.type
    Definition Classes
      Iterable
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Iterable.seq always returns the iterable itself

48.  def size: Int
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).size

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.size instead

49.  def sum(implicit num: math.Numeric[K]): K
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).sum(num)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.sum instead

50.  def to[C1](factory: Factory[K, C1]): C1
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).to(factory)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.to(factory) instead

51.  def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toArray(arg0)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.toArray

52.  def toBuffer[B >: A]: Buffer[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toBuffer

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.to(ArrayBuffer) instead

53.  def toIndexedSeq: IndexedSeq[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toIndexedSeq

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.toIndexedSeq instead

54.  final def toIterable: Iterable[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toIterable

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Iterable) instead

55.  final def toIterable: KeySet.this.type

    returns

      This collection as an `Iterable[A]`. No new collection will be built if `this` is already an `Iterable[A]`.

    Definition Classes
      Iterable → IterableOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.7) toIterable is internal and will be made protected; its name is similar to `toList` or `toSeq`, but it doesn't copy non-immutable collections

56.  def toIterator: Iterator[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toIterator

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator instead

57.  final def toIterator: Iterator[K]
    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator instead of .toIterator

58.  def toList: immutable.List[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toList

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.to(List) instead

59.  def toMap[K, V](implicit ev: <:<[K, (K, V)]): immutable.Map[K, V]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toMap(ev)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Map) instead

60.  def toSeq: immutable.Seq[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toSeq

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Seq) instead

61.  def toSet[B >: A]: immutable.Set[B]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toSet

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Set) instead

62.  def toStream: immutable.Stream[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toStream

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(LazyList) instead

63.  final def toStream: immutable.Stream[K]
    Definition Classes
      IterableOnceOps
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .to(LazyList) instead of .toStream

64.  final def toTraversable: Traversable[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toTraversable

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Iterable) instead

65.  final def toTraversable: Traversable[K]

    Converts this set to an unspecified Iterable.

    Converts this set to an unspecified Iterable. Will return the same collection if this instance is already Iterable.

    returns

      An Iterable containing all elements of this set.

    Definition Classes
      IterableOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) toTraversable is internal and will be made protected; its name is similar to `toList` or `toSeq`, but it doesn't copy non-immutable collections

66.  def toVector: immutable.Vector[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).toVector

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated @inline()
    Deprecated

      (Since version 2.13.0) Use .iterator.to(Vector) instead

67.  def view(from: Int, until: Int): View[K]

    A view over a slice of the elements of this collection.

    A view over a slice of the elements of this collection.

    Definition Classes
      IterableOps
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)

68.  def withFilter(f: (K) => Boolean): Iterator[K]
    Implicit
      This member is added by an implicit conversion from KeySet toIterableOnceExtensionMethods[K] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
    Shadowing
      This implicitly inherited member is shadowed by one or more members in this class.
      To access this member you can use a type ascription:

          (keySet: IterableOnceExtensionMethods[K]).withFilter(f)

    Definition Classes
      IterableOnceExtensionMethods
    Annotations
      @deprecated
    Deprecated

      (Since version 2.13.0) Use .iterator.withFilter(...) instead

69.  def →[B](y: B): (KeySet, B)
    Implicit
      This member is added by an implicit conversion from KeySet toArrowAssoc[KeySet] 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 DefaultSerializable

### Inherited from java.io.Serializable

### Inherited from GenKeySet

### Inherited from AbstractSet[K]

### Inherited from Set[K]

### Inherited from Equals

### Inherited from SetOps[K, Set, Set[K]]

### Inherited from (K) => Boolean

### Inherited from AbstractIterable[K]

### Inherited from Iterable[K]

### Inherited from IterableFactoryDefaults[K, [x]Set[x]]

### Inherited from IterableOps[K, [_]Set[_], Set[K]]

### Inherited from IterableOnceOps[K, [_]Set[_], Set[K]]

### Inherited from IterableOnce[K]

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion iterableOnceExtensionMethods fromKeySet to IterableOnceExtensionMethods[K]

### Inherited by implicit conversion any2stringadd fromKeySet to any2stringadd[KeySet]

### Inherited by implicit conversion StringFormat fromKeySet to StringFormat[KeySet]

### Inherited by implicit conversion Ensuring fromKeySet to Ensuring[KeySet]

### Inherited by implicit conversion ArrowAssoc fromKeySet to ArrowAssoc[KeySet]

### Ungrouped