java.lang.Object
- java.lang.Enum<CollectionFeature>
- - com.google.common.collect.testing.features.CollectionFeature

All Implemented Interfaces:

Feature<Collection>, Serializable, Comparable<CollectionFeature>
```
@GwtCompatible
public enum CollectionFeature
extends Enum<CollectionFeature>
implements Feature<Collection>
```
Optional features of classes derived from Collection.

Author:

George van den Driessche

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface CollectionFeature.Require

Enum Constant Summary

Enum Constants
Enum Constant	Description
`ALLOWS_NULL_QUERIES`	The collection must not throw `NullPointerException` on calls such as `contains(null)` or `remove(null)`, but instead must return a simple `false`.
`ALLOWS_NULL_VALUES`
`DESCENDING_VIEW`
`FAILS_FAST_ON_CONCURRENT_MODIFICATION`
`GENERAL_PURPOSE`	Features supported by general-purpose collections - everything but `RESTRICTS_ELEMENTS`.
`KNOWN_ORDER`	Indicates that a collection has a well-defined ordering of its elements.
`NON_STANDARD_TOSTRING`	Indicates that a collection has a different `Object.toString()` representation than most collections.
`NONE`	For documenting collections that support no optional features, such as `Collections.emptySet()`
`REJECTS_DUPLICATES_AT_CREATION`	Indicates that the constructor or factory method of a collection, usually an immutable set, throws an `IllegalArgumentException` when presented with duplicate elements instead of collapsing them to a single element or including duplicate instances in the collection.
`REMOVE_OPERATIONS`	Features supported by collections where only removal is allowed.
`RESTRICTS_ELEMENTS`	Indicates that a collection disallows certain elements (other than `null`, whose validity as an element is indicated by the presence or absence of `ALLOWS_NULL_VALUES`).
`SERIALIZABLE`
`SERIALIZABLE_INCLUDING_VIEWS`
`SUBSET_VIEW`
`SUPPORTS_ADD`
`SUPPORTS_ITERATOR_REMOVE`
`SUPPORTS_REMOVE`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Set<Feature<? super Collection>>`	`getImpliedFeatures()`	Returns the set of features that are implied by this feature.
`static CollectionFeature`	`valueOf(String name)`	Returns the enum constant of this type with the specified name.
`static CollectionFeature[]`	`values()`	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

- Enum Constant Detail
  - ALLOWS_NULL_QUERIES
```
public static final CollectionFeature ALLOWS_NULL_QUERIES
```
    The collection must not throw NullPointerException on calls such as contains(null) or remove(null), but instead must return a simple false.
  - ALLOWS_NULL_VALUES
```
public static final CollectionFeature ALLOWS_NULL_VALUES
```
  - RESTRICTS_ELEMENTS
```
public static final CollectionFeature RESTRICTS_ELEMENTS
```
    Indicates that a collection disallows certain elements (other than null, whose validity as an element is indicated by the presence or absence of ALLOWS_NULL_VALUES). From the documentation for Collection:
    "Some collection implementations have restrictions on the elements that they may contain. For example, some implementations prohibit null elements, and some have restrictions on the types of their elements."
  - KNOWN_ORDER
```
public static final CollectionFeature KNOWN_ORDER
```
    Indicates that a collection has a well-defined ordering of its elements. The ordering may depend on the element values, such as a SortedSet, or on the insertion ordering, such as a LinkedHashSet. All list tests and sorted-collection tests automatically specify this feature.
  - NON_STANDARD_TOSTRING
```
public static final CollectionFeature NON_STANDARD_TOSTRING
```
    Indicates that a collection has a different Object.toString() representation than most collections. If not specified, the collection tests will examine the value returned by Object.toString().
  - REJECTS_DUPLICATES_AT_CREATION
```
public static final CollectionFeature REJECTS_DUPLICATES_AT_CREATION
```
    Indicates that the constructor or factory method of a collection, usually an immutable set, throws an IllegalArgumentException when presented with duplicate elements instead of collapsing them to a single element or including duplicate instances in the collection.
  - SUPPORTS_ADD
```
public static final CollectionFeature SUPPORTS_ADD
```
  - SUPPORTS_REMOVE
```
public static final CollectionFeature SUPPORTS_REMOVE
```
  - SUPPORTS_ITERATOR_REMOVE
```
public static final CollectionFeature SUPPORTS_ITERATOR_REMOVE
```
  - FAILS_FAST_ON_CONCURRENT_MODIFICATION
```
public static final CollectionFeature FAILS_FAST_ON_CONCURRENT_MODIFICATION
```
  - GENERAL_PURPOSE
```
public static final CollectionFeature GENERAL_PURPOSE
```
    Features supported by general-purpose collections - everything but RESTRICTS_ELEMENTS.
    
    See Also:
    
    the definition of general-purpose collections.
  - REMOVE_OPERATIONS
```
public static final CollectionFeature REMOVE_OPERATIONS
```
    Features supported by collections where only removal is allowed.
  - SERIALIZABLE
```
public static final CollectionFeature SERIALIZABLE
```
  - SERIALIZABLE_INCLUDING_VIEWS
```
public static final CollectionFeature SERIALIZABLE_INCLUDING_VIEWS
```
  - SUBSET_VIEW
```
public static final CollectionFeature SUBSET_VIEW
```
  - DESCENDING_VIEW
```
public static final CollectionFeature DESCENDING_VIEW
```
  - NONE
```
public static final CollectionFeature NONE
```
    For documenting collections that support no optional features, such as Collections.emptySet()
- Method Detail
  - values
```
public static CollectionFeature[] values()
```
    Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
    for (CollectionFeature c : CollectionFeature.values()) System.out.println(c);
    Returns:
    
    an array containing the constants of this enum type, in the order they are declared
  - valueOf
```
public static CollectionFeature valueOf(String name)
```
    Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
    
    Parameters:
    
    name - the name of the enum constant to be returned.
    
    Returns:
    
    the enum constant with the specified name
    
    Throws:
    
    IllegalArgumentException - if this enum type has no constant with the specified name
    
    NullPointerException - if the argument is null
  - getImpliedFeatures
```
public Set<Feature<? super Collection>> getImpliedFeatures()
```
    Description copied from interface: Feature
    
    Returns the set of features that are implied by this feature.
    
    Specified by:
    
    getImpliedFeatures in interface Feature<Collection>

Enum CollectionFeature

Nested Class Summary

Enum Constant Summary

Method Summary

Methods inherited from class java.lang.Enum

Methods inherited from class java.lang.Object

Enum Constant Detail

ALLOWS_NULL_QUERIES

ALLOWS_NULL_VALUES

RESTRICTS_ELEMENTS

KNOWN_ORDER

NON_STANDARD_TOSTRING

REJECTS_DUPLICATES_AT_CREATION

SUPPORTS_ADD

SUPPORTS_REMOVE

SUPPORTS_ITERATOR_REMOVE

FAILS_FAST_ON_CONCURRENT_MODIFICATION

GENERAL_PURPOSE

REMOVE_OPERATIONS

SERIALIZABLE

SERIALIZABLE_INCLUDING_VIEWS

SUBSET_VIEW

DESCENDING_VIEW

NONE

Method Detail

values

valueOf

getImpliedFeatures