package com.temp.shared.utils;

/**
 * A Class, who's instances (usually a singleton) help a wrapper for an object
 * (<O>) that does NOT support Equals, HashCode, and Comparable to participate
 * in NoEquals... versions of collections
 *
 * @param <O>
 *            A class who's instances have a "ProxyValue" (of type C) that will
 *            be used for HashCode, Equals, & Comparability. If this value is
 *            null then then the HashCoe == 0, Equals will only be Equal to
 *            another null, and nulls will come ahead of Non-nulls during
 *            Compare operations.
 * @param <C>
 *            The class of the "ProxyValue" (from the instances of the type O)
 *            that will be used for HashCode, Equals, & Comparability. If this
 *            value is null then then the HashCoe == 0, Equals will only be
 *            Equal to another null, and nulls will come ahead of Non-nulls
 *            during Compare operations.
 */
public interface NoEqualsHelper<O, C extends Comparable<C>> {
    /**
     * Create an Array of type <O> for the toArray() methods.
     */
    public O[] createArray(int size);

    /**
     * Get the Comparable Proxy Value (usually a String) from a non-null
     * object.
     *
     * @return may be null!
     */
    public C getProxyValue(O object);
}