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

   1 /*!
   2 @file
   3 Defines `boost::hana::detail::operators::adl`.
   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_ADL_HPP
  11 #define BOOST_HANA_DETAIL_OPERATORS_ADL_HPP
  12
  13 #include <boost/hana/config.hpp>
  14
  15
  16 BOOST_HANA_NAMESPACE_BEGIN namespace detail { namespace operators {
  17     //! @ingroup group-details
  18     //! Enables [ADL](http://en.cppreference.com/w/cpp/language/adl) in the
  19     //! `hana::detail::operators` namespace.
  20     //!
  21     //! This is used by containers in Hana as a quick way to automatically
  22     //! define the operators associated to some concepts, in conjunction
  23     //! with the `detail::xxx_operators` family of metafunctions.
  24     //!
  25     //! Note that `adl` can be passed template arguments to make it unique
  26     //! amongst a set of derived classes. This allows a set of derived classes
  27     //! not to possess a common base class, which would disable the EBO when
  28     //! many of these derived classes are stored in a Hana container. If EBO
  29     //! is not a concern, `adl<>` can simply be used.
  30     template <typename ...>
  31     struct adl { };
  32 }} BOOST_HANA_NAMESPACE_END
  33
  34 #endif // !BOOST_HANA_DETAIL_OPERATORS_ADL_HPP