tuple_utils.hpp

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//
// Copyright (C) 2014, 2015 Ableton AG, Berlin. All rights reserved.
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#pragma once

#include <atria/estd/type_traits.hpp>
#include <tuple>

namespace atria {
namespace xform {
namespace detail {

template <std::size_t Index, std::size_t Max>
struct tuple_all_neq_t
{
  template <typename Tuple1T, typename Tuple2T>
  bool operator()(Tuple1T&& t1, Tuple2T&& t2)
  {
    return
      std::get<Index>(std::forward<Tuple1T>(t1)) !=
      std::get<Index>(std::forward<Tuple2T>(t2)) &&
      tuple_all_neq_t<Index + 1, Max>{} (
        std::forward<Tuple1T>(t1),
        std::forward<Tuple2T>(t2));
  }
};

template <std::size_t Max>
struct tuple_all_neq_t<Max, Max>
{
  template <typename Tuple1T, typename Tuple2T>
  bool operator()(Tuple1T&&, Tuple2T&&)
  {
    return true;
  }
};

template <typename Tuple1T, typename Tuple2T>
bool tuple_all_neq(Tuple1T&& t1, Tuple2T&& t2)
{
  constexpr auto size1 = std::tuple_size<estd::decay_t<Tuple1T> >{};
  constexpr auto size2 = std::tuple_size<estd::decay_t<Tuple2T> >{};
  static_assert(size1 == size2, "");

  using impl_t = tuple_all_neq_t<0u, (size1 > size2 ? size2 : size1)>;

  return impl_t{} (
    std::forward<Tuple1T>(t1),
    std::forward<Tuple2T>(t2));
}

} // namespace detail
} // namespace xform
} // namespace atria