// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements. See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership. The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License. You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied. See the License for the

// specific language governing permissions and limitations

// under the License.

package org.apache.impala.common;

/**

* The equivalent of C++'s std::pair<>.

*/

public class Pair<F, S> {

public F first;

public S second;

public Pair(F first, S second) {

this.first = first;

this.second = second;

}

public F getFirst() {

return first;

}

public S getSecond() {

return second;

}

@Override

/**

* A pair is equal if both parts are equal().

*/

public boolean equals(Object o) {

if (o instanceof Pair) {

Pair<F,S> other = (Pair<F,S>) o;

return this.first.equals(other.first) && this.second.equals(other.second);

}

return false;

}

@Override

public int hashCode() {

int hashFirst = first != null ? first.hashCode() : 0;

int hashSecond = second != null ? second.hashCode() : 0;

return (hashFirst + hashSecond) * hashSecond + hashFirst;

}

static public <F, S> Pair<F, S> create(F first, S second) {

return new Pair<F, S>(first, second);

}

@Override

public String toString() {

return String.format("<%s, %s>", first, second);

}

}