ceph/src/boost/libs/hana/include/boost/hana/remove_if.hpp

   1 /*!
   2 @file
   3 Defines `boost::hana::remove_if`.
   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_REMOVE_IF_HPP
  11 #define BOOST_HANA_REMOVE_IF_HPP
  12
  13 #include <boost/hana/fwd/remove_if.hpp>
  14
  15 #include <boost/hana/concept/monad_plus.hpp>
  16 #include <boost/hana/config.hpp>
  17 #include <boost/hana/core/dispatch.hpp>
  18 #include <boost/hana/filter.hpp>
  19 #include <boost/hana/functional/compose.hpp>
  20 #include <boost/hana/not.hpp>
  21
  22
  23 BOOST_HANA_NAMESPACE_BEGIN
  24     //! @cond
  25     template <typename Xs, typename Pred>
  26     constexpr auto remove_if_t::operator()(Xs&& xs, Pred&& pred) const {
  27         using M = typename hana::tag_of<Xs>::type;
  28         using RemoveIf = BOOST_HANA_DISPATCH_IF(remove_if_impl<M>,
  29             hana::MonadPlus<M>::value
  30         );
  31
  32         #ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
  33             static_assert(hana::MonadPlus<M>::value,
  34             "hana::remove_if(xs, predicate) requires 'xs' to be a MonadPlus");
  35         #endif
  36
  37         return RemoveIf::apply(static_cast<Xs&&>(xs),
  38                                static_cast<Pred&&>(pred));
  39     }
  40     //! @endcond
  41
  42     template <typename M, bool condition>
  43     struct remove_if_impl<M, when<condition>> : default_ {
  44         template <typename Xs, typename Pred>
  45         static constexpr auto apply(Xs&& xs, Pred&& pred) {
  46             return hana::filter(static_cast<Xs&&>(xs),
  47                         hana::compose(hana::not_, static_cast<Pred&&>(pred)));
  48         }
  49     };
  50 BOOST_HANA_NAMESPACE_END
  51
  52 #endif // !BOOST_HANA_REMOVE_IF_HPP