identity.hpp

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

#include <atria/meta/utils.hpp>

namespace atria {
namespace prelude {

constexpr struct identity_t
{
  template <typename ArgT>
  constexpr auto operator() (ArgT&& x) const
    -> ABL_DECLTYPE_RETURN(
      std::forward<ArgT>(x))
} identity {};

constexpr struct identity_t_
{
  template <typename ArgT>
  constexpr auto operator() (ArgT x) const -> ArgT
  {
    return x;
  }
} identity_ {};

} // namespace prelude

using prelude::identity_t;
using prelude::identity;
using prelude::identity_t_;
using prelude::identity_;

} // namespace atria