ceph/src/boost/boost/hana/suffix.hpp

   1 /*!
   2 @file
   3 Defines `boost::hana::suffix`.
   4
   5 @copyright Louis Dionne 2013-2017
   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_SUFFIX_HPP
  11 #define BOOST_HANA_SUFFIX_HPP
  12
  13 #include <boost/hana/fwd/suffix.hpp>
  14
  15 #include <boost/hana/chain.hpp>
  16 #include <boost/hana/concept/monad_plus.hpp>
  17 #include <boost/hana/config.hpp>
  18 #include <boost/hana/core/dispatch.hpp>
  19 #include <boost/hana/functional/partial.hpp>
  20 #include <boost/hana/lift.hpp>
  21 #include <boost/hana/prepend.hpp>
  22
  23
  24 BOOST_HANA_NAMESPACE_BEGIN
  25     //! @cond
  26     template <typename Xs, typename Sfx>
  27     constexpr auto suffix_t::operator()(Xs&& xs, Sfx&& sfx) const {
  28         using M = typename hana::tag_of<Xs>::type;
  29         using Suffix = BOOST_HANA_DISPATCH_IF(suffix_impl<M>,
  30             hana::MonadPlus<M>::value
  31         );
  32
  33     #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
  34         static_assert(hana::MonadPlus<M>::value,
  35         "hana::suffix(xs, sfx) requires 'xs' to be a MonadPlus");
  36     #endif
  37
  38         return Suffix::apply(static_cast<Xs&&>(xs), static_cast<Sfx&&>(sfx));
  39     }
  40     //! @endcond
  41
  42     template <typename M, bool condition>
  43     struct suffix_impl<M, when<condition>> : default_ {
  44         template <typename Xs, typename Z>
  45         static constexpr auto apply(Xs&& xs, Z&& z) {
  46             return hana::chain(static_cast<Xs&&>(xs),
  47                 hana::partial(hana::prepend, hana::lift<M>(static_cast<Z&&>(z))));
  48         }
  49     };
  50 BOOST_HANA_NAMESPACE_END
  51
  52 #endif // !BOOST_HANA_SUFFIX_HPP