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