/*

* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.

*

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*/

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;

}

}