ceph/src/boost/boost/hana/fwd/max.hpp

   1 /*!
   2 @file
   3 Forward declares `boost::hana::max`.
   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_FWD_MAX_HPP
  11 #define BOOST_HANA_FWD_MAX_HPP
  12
  13 #include <boost/hana/config.hpp>
  14 #include <boost/hana/core/when.hpp>
  15
  16
  17 namespace boost { namespace hana {
  18     //! Returns the greatest of its arguments according to the `less` ordering.
  19     //! @ingroup group-Orderable
  20     //!
  21     //!
  22     //! @todo Can't specify the signature here either. See `min` for details.
  23     //!
  24     //! Example
  25     //! -------
  26     //! @include example/max.cpp
  27 #ifdef BOOST_HANA_DOXYGEN_INVOKED
  28     constexpr auto max = [](auto&& x, auto&& y) -> decltype(auto) {
  29         return tag-dispatched;
  30     };
  31 #else
  32     template <typename T, typename U, typename = void>
  33     struct max_impl : max_impl<T, U, when<true>> { };
  34
  35     struct max_t {
  36         template <typename X, typename Y>
  37         constexpr decltype(auto) operator()(X&& x, Y&& y) const;
  38     };
  39
  40     BOOST_HANA_INLINE_VARIABLE constexpr max_t max{};
  41 #endif
  42 }} // end namespace boost::hana
  43
  44 #endif // !BOOST_HANA_FWD_MAX_HPP