| /* |
| * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package java.util.function; |
| |
| /** |
| * Represents an operation on a single operand that produces a result of the |
| * same type as its operand. This is a specialization of {@code Function} for |
| * the case where the operand and result are of the same type. |
| * |
| * <p>This is a <a href="package-summary.html">functional interface</a> |
| * whose functional method is {@link #apply(Object)}. |
| * |
| * @param <T> the type of the operand and result of the operator |
| * |
| * @see Function |
| * @since 1.8 |
| */ |
| @FunctionalInterface |
| public interface UnaryOperator<T> extends Function<T, T> { |
| |
| /** |
| * Returns a unary operator that always returns its input argument. |
| * |
| * @param <T> the type of the input and output of the operator |
| * @return a unary operator that always returns its input argument |
| */ |
| static <T> UnaryOperator<T> identity() { |
| return t -> t; |
| } |
| } |