Class Sets.SetView<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractSet<E>
com.google.common.collect.Sets.SetView<E>
All Implemented Interfaces:
Iterable<E>, Collection<E>, Set<E>
Enclosing class:
Sets
public abstract static class Sets.SetView<E> extends AbstractSet<E>
An unmodifiable view of a set which may be backed by other sets; this view will change as the backing sets do. Contains methods to copy the data into a new set which will then remain stable. There is usually no reason to retain a reference of type SetView; typically, you either use it as a plain Set, or immediately invoke immutableCopy() or copyInto(S) and forget the SetView itself.
Since:
2.0

  • Method Details

    • immutableCopy

      public ImmutableSet<E> immutableCopy()
      Returns an immutable copy of the current contents of this set view. Does not support null elements.

      Warning: this may have unexpected results if a backing set of this view uses a nonstandard notion of equivalence, for example if it is a TreeSet using a comparator that is inconsistent with Object.equals(Object).

    • copyInto

      public <S extends Set<E>> S copyInto(S set)
      Copies the current contents of this set view into an existing set. This method has equivalent behavior to set.addAll(this), assuming that all the sets involved are based on the same notion of equivalence.
      Returns:
      a reference to set, for convenience

    • iterator

      public abstract UnmodifiableIterator<E> iterator()
      Scope the return type to UnmodifiableIterator to ensure this is an unmodifiable view.
      Specified by:
      iterator in interface Collection<E>
      Specified by:
      iterator in interface Iterable<E>
      Specified by:
      iterator in interface Set<E>
      Specified by:
      iterator in class AbstractCollection<E>
      Since:
      20.0 (present with return type Iterator since 2.0)