content: /*
   * Copyright (c) 2010, 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;
  
  import java.util.Objects;
  import java.util.Comparator;
  
  /**
   * Represents an operation upon two operands of the same type, producing a result
   * of the same type as the operands.  This is a specialization of
   * {@link BiFunction} for the case where the operands and the result are all of
   * the same type.
   *
   * <p>This is a <a href="package-summary.html">functional interface</a>
   * whose functional method is {@link #apply(Object, Object)}.
   *
   * @param <T> the type of the operands and result of the operator
   *
   * @see BiFunction
   * @see UnaryOperator
   * @since 1.8
   */
  @FunctionalInterface
  public interface BinaryOperator<T> extends BiFunction<T,T,T> {
      /**
       * Returns a {@link BinaryOperator} which returns the lesser of two elements
       * according to the specified {@code Comparator}.
       *
       * @param <T> the type of the input arguments of the comparator
       * @param comparator a {@code Comparator} for comparing the two values
       * @return a {@code BinaryOperator} which returns the lesser of its operands,
       *         according to the supplied {@code Comparator}
       * @throws NullPointerException if the argument is null
       */
      public static <T> BinaryOperator<T> minBy(Comparator<? super T> comparator) {
          Objects.requireNonNull(comparator);
          return (a, b) -> comparator.compare(a, b) <= 0 ? a : b;
      }
  
      /**
       * Returns a {@link BinaryOperator} which returns the greater of two elements
       * according to the specified {@code Comparator}.
       *
       * @param <T> the type of the input arguments of the comparator
       * @param comparator a {@code Comparator} for comparing the two values
       * @return a {@code BinaryOperator} which returns the greater of its operands,
       *         according to the supplied {@code Comparator}
       * @throws NullPointerException if the argument is null
       */
      public static <T> BinaryOperator<T> maxBy(Comparator<? super T> comparator) {
          Objects.requireNonNull(comparator);
          return (a, b) -> comparator.compare(a, b) >= 0 ? a : b;
      }
  }
  