File tuple_size.h

File List > code_source > templat > include > TempLat > util > tuple_size.h

Go to the documentation of this file

#ifndef TEMPLAT_UTIL_TUPLE_SIZE_H
#define TEMPLAT_UTIL_TUPLE_SIZE_H

/* This file is part of TempLat, available at https://cosmolattice.github.io/templat .
   Copyright 2021-2026 The TempLat authors, see AUTHORS.md.
   Released under the MIT license, see LICENSE.md. */

// File info: Main contributor(s): Adrien Florio, Year: 2019

#include <cstddef>
#include <tuple>
#include <type_traits>

namespace TempLat
{
  template <typename Tuple, class = std::void_t<>> struct tuple_size_helper {
    static const size_t value = 1;
  };

  template <typename Tuple> struct tuple_size_helper<Tuple, std::void_t<decltype(std::tuple_size<Tuple>::value)>> {
    static const size_t value = std::tuple_size<Tuple>::value;
  };

  template <typename Tuple, class = std::void_t<>> struct tuple_size {
    static const size_t value = tuple_size_helper<Tuple>::value;
  };

  template <typename Tuple> struct tuple_size<Tuple, std::void_t<decltype(Tuple::size)>> {
    static const size_t value = Tuple::size;
  };
} // namespace TempLat

#endif