atelierspierrot/patterns

<?php
/**
 * This file is part of the Patterns package.
 *
 * Copyright (c) 2013-2016 Pierre Cassat <me@e-piwi.fr> and contributors
 * 
 * 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.
 *
 * The source code of this package is available online at 
 * <http://github.com/atelierspierrot/patterns>.
 */

namespace Patterns\Interfaces;

/**
 * A basic singleton interface
 *
 * The best practice is to render the constructor protected
 * to avoid direct object's creation:
 *
 *      protected function __construct() {}
 *
 * @author  piwi <me@e-piwi.fr>
 */
interface SingletonInterface
{

    /**
     * This must return (and create if necessary) the object's instance
     *
     * @return self
     */
    public static function getInstance();

    /**
     * This must throw an error as cloning a singleton is forbidden
     *
     * @return void
     * @throws \ErrorException
     */
    public function __clone();
}