ArraySetJvmUtil.java

/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed 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 androidx.collection;

import java.lang.reflect.Array;

class ArraySetJvmUtil {
    private ArraySetJvmUtil() {
    }

    // Necessary to implement in Java to allow allocating a typed array without a callback for
    // initialization. We also need to ignore the nullity of the type in order to null out the
    // (n+1)'th item for behavior compatibility.
    @SuppressWarnings("unchecked")
    static <T> T[] resizeForToArray(T[] destination, int size) {
        if (destination.length < size) {
            return (T[]) Array.newInstance(destination.getClass().getComponentType(), size);
        } else {
            if (destination.length > size) {
                destination[size] = null;
            }
            return destination;
        }
    }
}