ceph/src/boost/libs/hana/include/boost/hana/detail/operators/iterable.hpp

   1 /*!
   2 @file
   3 Defines operators for Iterables.
   4
   5 @copyright Louis Dionne 2013-2016
   6 Distributed under the Boost Software License, Version 1.0.
   7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   8  */
   9
  10 #ifndef BOOST_HANA_DETAIL_OPERATORS_ITERABLE_HPP
  11 #define BOOST_HANA_DETAIL_OPERATORS_ITERABLE_HPP
  12
  13 #include <boost/hana/config.hpp>
  14 #include <boost/hana/fwd/at.hpp>
  15
  16
  17 BOOST_HANA_NAMESPACE_BEGIN namespace detail {
  18     template <typename Derived>
  19     struct iterable_operators {
  20         template <typename N>
  21         constexpr decltype(auto) operator[](N&& n) & {
  22             return hana::at(static_cast<Derived&>(*this),
  23                             static_cast<N&&>(n));
  24         }
  25
  26         template <typename N>
  27         constexpr decltype(auto) operator[](N&& n) const& {
  28             return hana::at(static_cast<Derived const&>(*this),
  29                             static_cast<N&&>(n));
  30         }
  31
  32         template <typename N>
  33         constexpr decltype(auto) operator[](N&& n) && {
  34             return hana::at(static_cast<Derived&&>(*this),
  35                             static_cast<N&&>(n));
  36         }
  37     };
  38 } BOOST_HANA_NAMESPACE_END
  39
  40 #endif // !BOOST_HANA_DETAIL_OPERATORS_ITERABLE_HPP