aspects/core-aspects/src/main/java/org/apache/axiom/core/Mappers.java

/*
 * 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.axiom.core;

public final class Mappers {
    @SuppressWarnings("rawtypes")
    private static final IdentityMapper IDENTITY = new IdentityMapper();
    
    private Mappers() {}
    
    @SuppressWarnings("unchecked")
    public static <S,T extends S> Mapper<S,T> upcast() {
        // This is an optimization for the following type safe instruction:
        // return new IdentityMapper<S,T>();
        return IDENTITY;
    }
    
    public static <T> Mapper<T,T> identity() {
        return upcast();
    }
}