PassByAwesome

package com.skipifzero.superiority.utils;

import com.google.common.base.Objects;

/**
 * <p>Oh Oracle, why do thy smite me with lack of pass-by-reference?<br/>
 * I shallt redeem this injustice with providing me with C++ goodies.</p>
 *
 * @author Centril<twingoow@gmail.com> / Mazdak Farrokhzad.
 * @since 28 apr 2013
 * @version 1.0
 * @see http://stackoverflow.com/questions/430479/how-do-i-use-an-equivalent-to-c-reference-parameters-in-java
 */
public final class _<E> {
    private E ref;

    /**
     * Constructs the reference with null as value.
     */
    public _() {
    }

    /**
     * Constructs the reference with initial value.<br/>
     * Null is allowed.
     *
     * @param value the value to set.
     */
    public _( E value ) {
        this.ref = value;
    }

    /**
     * Returns the value of the reference.
     *
     * @return the value of the reference.
     */
    public E r() {
        return this.ref;
    }

    /**
     * Sets the value of the reference.
     *
     * @param value the value to set.
     */
    public void r( E value ) {
        this.ref = value;
    }

    /**
     * The given obj is equal to this iff one of the following:<br/>
     * this == obj, the {@link #r()} equals obj.r() if obj instanceof {@link _},<br/>
     * or if {@link #r()} equals obj.
     */
    public boolean equals( Object obj ) {
        return  this == obj || (obj != null && obj instanceof _
            ?   Objects.equal( this.r(), ((_<?>) obj).r() )
            :   Objects.equal( this.r(), obj ));
    }

    /**
     * If {@link #r()} == null => 0,<br/>
     * otherwise the hashcode of {@link #r()}.
     */
    @Override
    public int hashCode() {
        return this.r() == null ? 0 : this.r().hashCode();
    }

    /**
     * Relays to the values toString method.
     *
     * @return the value as string.
     */
    public String toString() {
        return ref.toString();
    }
}