/*

 * 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.lang3.mutable;

/**

 * Provides mutable access to a value.

 * <p>

 * {@code Mutable} is used as a generic interface to the implementations in this package.

 * <p>

 * A typical use case would be to enable a primitive or string to be passed to a method and allow that method to

 * effectively change the value of the primitive/string. Another use case is to store a frequently changing primitive in

 * a collection (for example a total in a map) without needing to create new Integer/Long wrapper objects.

 *

 * @param <T> the type to set and get

 * @since 2.1

 */

public interface Mutable<T> {

    /**

     * Gets the value of this mutable.

     *

     * @return the stored value

     */

    T getValue();

    /**

     * Sets the value of this mutable.

     *

     * @param value

     *            the value to store

     * @throws NullPointerException

     *             if the object is null and null is invalid

     * @throws ClassCastException

     *             if the type is invalid

     */

    void setValue(T value);

}