/*
 * This file is part of ELKI:
 * Environment for Developing KDD-Applications Supported by Index-Structures
 *
 * Copyright (C) 2022
 * ELKI Development Team
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package elki.utilities.datastructures.arraylike;

import elki.data.FeatureVector;

/**
 * Adapter to use a feature vector as an array of features.
 * <p>
 * Use the static instance from {@link ArrayLikeUtil}!
 *
 * @author Erich Schubert
 * @since 0.5.0
 *
 * @param <F> Feature type
 */
public final class FeatureVectorAdapter<F> implements ArrayAdapter<F, FeatureVector<F>> {
  /**
   * Static instance.
   */
  public static final FeatureVectorAdapter<?> STATIC = new FeatureVectorAdapter<>();

  /**
   * Constructor.
   * <p>
   * Use the static instance from {@link ArrayLikeUtil}!
   */
  private FeatureVectorAdapter() {
    super();
  }

  @Override
  public int size(FeatureVector<F> array) {
    return array.getDimensionality();
  }

  @Override
  public F get(FeatureVector<F> array, int off) {
    return array.getValue(off);
  }
}
