copy.hpp

/****************************************************************************
 *  hipipe library
 *  Copyright (c) 2018, Iterait a.s.
 *  Author(s) Adam Blazek
 *
 *  This file is distributed under the MIT License.
 *  See the accompanying file LICENSE.txt for the complete license agreement.
 ****************************************************************************/
 
#pragma once
 
#include <hipipe/core/stream/transform.hpp>
 
namespace hipipe::stream {
 
template <typename... FromColumns, typename... ToColumns>
auto copy(from_t<FromColumns...> from_cols, to_t<ToColumns...> to_cols)
{
    static_assert(sizeof...(FromColumns) == sizeof...(ToColumns),
      "hipipe::stream::copy requires the same number of source and target columns.");
 
    static_assert(
      ((std::is_constructible_v<typename FromColumns::example_type,
                                const typename ToColumns::example_type&>) && ...),
      "hipipe::stream::copy target columns must be constructible "
      "from the respective source columns.");
 
    return stream::transform(from_cols, to_cols,
      [](const typename FromColumns::example_type&... vals) {
          return utility::maybe_tuple<typename ToColumns::example_type...>(vals...);
      });
}
 
}  // end namespace hipipe::stream