/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.collections4;

import java.util.Map;

/**
 * The "write" subset of the {@link Map} interface.
 * <p>
 * NOTE: in the original {@link Map} interface, {@link Map#put(Object, Object)} is known
 * to have the same return type as {@link Map#get(Object)}, namely {@code V}. {@link Put}
 * makes no assumptions in this regard (there is no association with, nor even knowledge
 * of, a "reading" interface) and thus defines {@link #put(Object, Object)} as returning
 * {@link Object}.
 * </p>
 *
 * @param <K> the type of the keys in this map
 * @param <V> the type of the values in this map
 *
 * @since 4.0
 * @see Get
 */
public interface Put<K, V> {

    /**
     * @see Map#clear()
     */
    void clear();

    /**
     * Note that the return type is Object, rather than V as in the Map interface.
     * See the class Javadoc for further info.
     *
     * @param key key with which the specified value is to be associated
     * @param value value to be associated with the specified key
     * @return the previous value associated with <code>key</code>, or
     *         <code>null</code> if there was no mapping for <code>key</code>.
     *         (A <code>null</code> return can also indicate that the map
     *         previously associated <code>null</code> with <code>key</code>,
     *         if the implementation supports <code>null</code> values.)
     * @see Map#put(Object, Object)
     */
    Object put(K key, V value);

    /**
     * @param t mappings to be stored in this map
     * @see Map#putAll(Map)
     */
    void putAll(Map<? extends K, ? extends V> t);

}
