    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.io.function;
    019
    020import java.io.IOException;
    021import java.io.UncheckedIOException;
    022import java.util.function.UnaryOperator;
    023
    024/**
    025 * Like {@link UnaryOperator} but throws {@link IOException}.
    026 *
    027 * @param <T> the type of the operand and result of the operator.
    028 *
    029 * @see UnaryOperator
    030 * @see IOFunction
    031 * @since 2.12.0
    032 */
    033@FunctionalInterface
    034public interface IOUnaryOperator<T> extends IOFunction<T, T> {
    035
    036    /**
    037     * Creates a unary operator that always returns its input argument.
    038     *
    039     * @param <T> the type of the input and output of the operator.
    040     * @return a unary operator that always returns its input argument.
    041     */
    042    static <T> IOUnaryOperator<T> identity() {
    043        return t -> t;
    044    }
    045
    046    /**
    047     * Creates a {@link UnaryOperator} for this instance that throws {@link UncheckedIOException} instead of
    048     * {@link IOException}.
    049     *
    050     * @return an unchecked BiFunction.
    051     */
    052    default UnaryOperator<T> asUnaryOperator() {
    053        return t -> Uncheck.apply(this, t);
    054    }
    055
    056}