org.plumelib.util

Class WeakIdentityPair<T1,T2>

java.lang.Object

org.plumelib.util.WeakIdentityPair<T1,T2>

public class WeakIdentityPair<T1,T2>
extends java.lang.Object

Immutable pair class: type-safely holds two objects of possibly-different types.

Differs from Pair in the following ways: is immutable, cannot hold null, holds its elements with weak pointers, and its equals() method uses object equality to compare its elements.

Constructor Summary

Constructors

Constructor and Description
WeakIdentityPair(T1 a, T2 b) Creates a new weakly-held pair of a and b.

Method Summary

Modifier and Type	Method and Description
boolean	equals(@GuardSatisfied @Nullable java.lang.Object obj)
T1	getA() Return the first element of the pair, or null if it has been garbage-collected.
T2	getB() Return the second element of the pair, or null if it has been garbage-collected.
int	hashCode()
static <A,B> WeakIdentityPair<A,B>	of(A a, B b) Factory method with short name and no need to name type parameters.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

WeakIdentityPair

public WeakIdentityPair(T1 a,
                        T2 b)

Creates a new weakly-held pair of a and b.

Parameters:

a - the first element of the pair

b - the second element of the pair

Method Detail

of

public static <A,B> WeakIdentityPair<A,B> of(A a,
                                             B b)

Factory method with short name and no need to name type parameters.

Type Parameters:

A - type of first argument

B - type of second argument

Parameters:

a - first argument

b - second argument

Returns:

a WeakIdentityPair of (a, b)

getA

@SideEffectFree
public T1 getA(@GuardSatisfied WeakIdentityPair<T1,T2> this)

Return the first element of the pair, or null if it has been garbage-collected.

Returns:

the first element of the pail, or null if it has been garbage-collected

getB

@SideEffectFree
public T2 getB(@GuardSatisfied WeakIdentityPair<T1,T2> this)

Return the second element of the pair, or null if it has been garbage-collected.

Returns:

the second element of the pair, or null if it has been garbage-collected

toString

@SideEffectFree
public java.lang.String toString(@GuardSatisfied WeakIdentityPair<T1,T2> this)

Overrides:

toString in class java.lang.Object

equals

@SideEffectFree
public boolean equals(@GuardSatisfied WeakIdentityPair<T1,T2> this,
                                      @GuardSatisfied @Nullable java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

@Pure
public int hashCode(@GuardSatisfied WeakIdentityPair<T1,T2> this)

Overrides:

hashCode in class java.lang.Object