description

# UnmodifiableSetView<E> class

An unmodifiable Set view of another Set.

Methods that could change the set, such as `add` and `remove`, must not be called.

    final baseSet = <String>{'Mars', 'Mercury', 'Earth', 'Venus'};
    final unmodifiableSetView = UnmodifiableSetView(baseSet);

    // Remove an element from the original set.
    baseSet.remove('Venus');
    print(unmodifiableSetView); // {Mars, Mercury, Earth}

    unmodifiableSetView.remove('Earth'); // Throws.

Inheritance
  - Object
  - SetBase<E>
  - UnmodifiableSetView
Implemented types
  - Set<E>
Available extensions
  - EnumByName
  - FutureIterable
  - IterableExtensions
  - IterableToJSIterable
  - NullableIterableExtensions

## Constructors

UnmodifiableSetView(Set<E> source)
  Creates an UnmodifiableSetView of `source`.

## Properties

first → E
  The first element.
  no setter inherited
firstOrNull → T?

  Available on Iterable<T>, provided by the IterableExtensions extension

  The first element of this iterator, or `null` if the iterable is empty.
  no setter
hashCode → int
  The hash code for this object.
  no setter inherited
indexed → Iterable<(int, T)>

  Available on Iterable<T>, provided by the IterableExtensions extension

  Pairs of elements of the indices and elements of this iterable.
  no setter
isEmpty → bool
  Whether this collection has no elements.
  no setter inherited
isNotEmpty → bool
  Whether this collection has at least one element.
  no setter inherited
iterator → Iterator<E>
  An iterator that iterates over the elements of this set.
  no setter override
last → E
  The last element.
  no setter inherited
lastOrNull → T?

  Available on Iterable<T>, provided by the IterableExtensions extension

  The last element of this iterable, or `null` if the iterable is empty.
  no setter
length → int
  The number of elements in this Iterable.
  no setter override
nonNulls → Iterable<T>

  Available on Iterable<T?>, provided by the NullableIterableExtensions extension

  The non-`null` elements of this iterable.
  no setter
runtimeType → Type
  A representation of the runtime type of the object.
  no setter inherited
single → E
  Checks that this iterable has only one element, and returns that element.
  no setter inherited
singleOrNull → T?

  Available on Iterable<T>, provided by the IterableExtensions extension

  The single element of this iterator, or `null`.
  no setter
toJSIterable → JSIterable<T>

  Available on Iterable<T>, provided by the IterableToJSIterable extension

  A JSIterable wrapper that proxies to the Dart iterable API.
  no setter
wait → Future<List<T>>

  Available on Iterable<Future<T>>, provided by the FutureIterable extension

  Waits for futures in parallel.
  no setter

## Methods

add(E value) → bool
  This operation is not supported by an unmodifiable set.
  inherited
addAll(Iterable<E> elements) → void
  This operation is not supported by an unmodifiable set.
  inherited
any(bool test(E value)) → bool
  Checks whether any element of this iterable satisfies `test`.
  inherited
asNameMap() → Map<String, T>

  Available on Iterable<T>, provided by the EnumByName extension

  Creates a map from the names of enum values to the values.
byName(String name) → T

  Available on Iterable<T>, provided by the EnumByName extension

  Finds the enum value in this list with name `name`.
cast<R>() → Set<R>
  Provides a view of this set as a set of `R` instances.
  inherited
clear() → void
  This operation is not supported by an unmodifiable set.
  inherited
contains(Object? element) → bool
  Whether `value` is in the set.
  override
containsAll(Iterable<Object?> other) → bool
  Whether this set contains all the elements of `other`.
  inherited
difference(Set<Object?> other) → Set<E>
  Creates a new set with the elements of this that are not in `other`.
  inherited
elementAt(int index) → E
  Returns the `index`th element.
  inherited
elementAtOrNull(int index) → T?

  Available on Iterable<T>, provided by the IterableExtensions extension

  The element at position `index` of this iterable, or `null`.
every(bool f(E value)) → bool
  Checks whether every element of this iterable satisfies `test`.
  inherited
expand<T>(Iterable<T> f(E element)) → Iterable<T>
  Expands each element of this Iterable into zero or more elements.
  inherited
firstWhere(bool test(E value), {E orElse()?}) → E
  The first element that satisfies the given predicate `test`.
  inherited
fold<T>(T initialValue, T combine(T previousValue, E element)) → T
  Reduces a collection to a single value by iteratively combining each element of the collection with an existing value
  inherited
followedBy(Iterable<E> other) → Iterable<E>
  Creates the lazy concatenation of this iterable and `other`.
  inherited
forEach(void f(E element)) → void
  Invokes `action` on each element of this iterable in iteration order.
  inherited
intersection(Set<Object?> other) → Set<E>
  Creates a new set which is the intersection between this set and `other`.
  inherited
join([String separator = ""]) → String
  Converts each element to a String and concatenates the strings.
  inherited
lastWhere(bool test(E value), {E orElse()?}) → E
  The last element that satisfies the given predicate `test`.
  inherited
lookup(Object? element) → E?
  If an object equal to `object` is in the set, return it.
  override
map<T>(T f(E element)) → Iterable<T>
  The current elements of this iterable modified by `toElement`.
  inherited
noSuchMethod(Invocation invocation) → dynamic
  Invoked when a nonexistent method or property is accessed.
  inherited
reduce(E combine(E value, E element)) → E
  Reduces a collection to a single value by iteratively combining elements of the collection using the provided function.
  inherited
remove(Object? value) → bool
  This operation is not supported by an unmodifiable set.
  inherited
removeAll(Iterable<Object?> elements) → void
  This operation is not supported by an unmodifiable set.
  inherited
removeWhere(bool test(E value)) → void
  This operation is not supported by an unmodifiable set.
  inherited
retainAll(Iterable<Object?> elements) → void
  This operation is not supported by an unmodifiable set.
  inherited
retainWhere(bool test(E value)) → void
  This operation is not supported by an unmodifiable set.
  inherited
singleWhere(bool test(E value), {E orElse()?}) → E
  The single element that satisfies `test`.
  inherited
skip(int n) → Iterable<E>
  Creates an Iterable that provides all but the first `count` elements.
  inherited
skipWhile(bool test(E value)) → Iterable<E>
  Creates an `Iterable` that skips leading elements while `test` is satisfied.
  inherited
take(int n) → Iterable<E>
  Creates a lazy iterable of the `count` first elements of this iterable.
  inherited
takeWhile(bool test(E value)) → Iterable<E>
  Creates a lazy iterable of the leading elements satisfying `test`.
  inherited
toList({bool growable = true}) → List<E>
  Creates a List containing the elements of this Iterable.
  inherited
toSet() → Set<E>
  Creates a Set with the same elements and behavior as this `Set`.
  override
toString() → String
  A string representation of this object.
  inherited
union(Set<E> other) → Set<E>
  Creates a new set which contains all the elements of this set and `other`.
  inherited
where(bool f(E value)) → Iterable<E>
  Creates a new lazy Iterable with all elements that satisfy the predicate `test`.
  inherited
whereType<T>() → Iterable<T>
  Creates a new lazy Iterable with all elements that have type `T`.
  inherited

## Operators

operator ==(Object other) → bool
  The equality operator.
  inherited