package it.unimi.dsi.fastutil;

/*		 
 * Copyright (C) 2010-2013 Sebastiano Vigna 
 *
 * 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. 
 */

import java.util.Collection;

/** An interface for data structures whose size can exceed {@link Integer#MAX_VALUE}.
 *
 * <P>The only methods specified by this interfaces are {@link #size64()}, and 
 * a deprecated {@link #size()} identical to {@link Collection#size()}. Implementations
 * can work around the type problem of {@link java.util.Collection#size()}
 * (e.g., not being able to return more than {@link Integer#MAX_VALUE}) by implementing this
 * interface. Callers interested in large structures
 * can use a reflective call to <code>instanceof</code> to check for the presence of {@link #size64()}.
 * 
 * <p>We remark that it is always a good idea to implement both {@link #size()} <em>and</em> {@link #size64()},
 * as the former might be implemented by a superclass in an incompatible way. If you implement this interface,
 * just implement {@link #size()} as a <em>deprecated</em> method returning <code>Math.min(Integer.MAX_VALUE, size64())</code>.
 */

public interface Size64 {
	/** Returns the size of this data structure as a long.
	 *
	 * @return  the size of this data structure.
	 */
	long size64();

	/** Returns the size of this data structure, minimized with {@link Integer#MAX_VALUE}.
	 * 
	 * @return the size of this data structure, minimized with {@link Integer#MAX_VALUE}.
	 * @see java.util.Collection#size()
	 * @deprecated Use {@link #size64()} instead.
	 */
	@Deprecated
	int size();
}
