com.google.common.base

Interface Equivalence<T>

@Beta
@GwtCompatible
public interface Equivalence<T>

A strategy for determining whether two instances are considered equivalent. Examples of equivalences are the identity equivalence and equals equivalence.

Since:

4

Author:

Bob Lee

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equivalent(T a, T b) Returns true if the given objects are considered equivalent.
int	hash(T t) Returns a hash code for object.

Method Detail

equivalent

boolean equivalent(@Nullable
                 T a,
                 @Nullable
                 T b)

Returns true if the given objects are considered equivalent.

The equivalent method implements an equivalence relation on object references:

• It is reflexive: for any reference x, including null, equivalent(x, x) should return true.
• It is symmetric: for any references x and y, equivalent(x, y) == equivalent(y, x).
• It is transitive: for any references x, y, and z, if equivalent(x, y) returns true and equivalent(y, z) returns true, then equivalent(x, z) should return true.
• It is consistent: for any references x and y, multiple invocations of equivalent(x, y) consistently return true or consistently return false (provided that neither x nor y is modified).

hash

int hash(@Nullable
       T t)

Returns a hash code for object. This function must return the same value for any two references which are equivalent(T, T), and should as often as possible return a distinct value for references which are not equivalent. It should support null references.

See Also:

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