identity.h

/*
 * Copyright (c) 2014, Siemens AG. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef EMBB_ALGORITHMS_IDENTITY_H_
#define EMBB_ALGORITHMS_IDENTITY_H_

namespace embb {
namespace algorithms {

/**
 * Unary identity functor.
 *
 * \ingroup CPP_ALGORITHMS_SCAN
 * \ingroup CPP_ALGORITHMS_REDUCTION
 * \ingroup CPP_ALGORITHMS_FOREACH
 * \ingroup CPP_ALGORITHMS_COUNT
 * \ingroup CPP_ALGORITHMS_SORTING
 */
struct Identity {
  /**
   * Returns \c value unchanged.
   *
   * \return \c value
   * \tparam Type Any type
   */
  template<typename Type>
  Type& operator()(
    Type& value
    /**< [IN] Value that is returned unchanged */
    ) {
    return value;
  }

  /**
   * Returns \c value unchanged.
   *
   * \return \c value
   * \tparam Type Any type
   */
  template<typename Type>
  const Type& operator()(
    const Type& value
    /**< [IN] Value that is returned unchanged */
    ) {
    return value;
  }
};

}  // namespace algorithms
}  // namespace embb

#endif  // EMBB_ALGORITHMS_IDENTITY_H_