/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Iterator;

An iterator which forwards all its method calls to another iterator. Subclasses should override
one or more methods to modify the behavior of the backing iterator as desired per the decorator pattern.
default method warning: This class forwards calls to only some 
default methods. Specifically, it forwards calls only for methods that existed before default methods were introduced. For newer methods, like forEachRemaining, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingIterator. 
Author:
Kevin Bourrillion
Since:
2.0/**
 * An iterator which forwards all its method calls to another iterator. Subclasses should override
 * one or more methods to modify the behavior of the backing iterator as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code
 * default} methods. Specifically, it forwards calls only for methods that existed <a
 * href="https://docs.oracle.com/javase/7/docs/api/java/util/Iterator.html">before {@code default}
 * methods were introduced</a>. For newer methods, like {@code forEachRemaining}, it inherits their
 * default implementations. When those implementations invoke methods, they invoke methods on the
 * {@code ForwardingIterator}.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingIterator<T> extends ForwardingObject implements Iterator<T> {

  
Constructor for use by subclasses. /** Constructor for use by subclasses. */
  protected ForwardingIterator() {}

  @Override
  protected abstract Iterator<T> delegate();

  @Override
  public boolean hasNext() {
    return delegate().hasNext();
  }

  @CanIgnoreReturnValue
  @Override
  public T next() {
    return delegate().next();
  }

  @Override
  public void remove() {
    delegate().remove();
  }
}