ceph/src/boost/libs/hana/include/boost/hana/fwd/basic_tuple.hpp

   1 /*!
   2 @file
   3 Forward declares `boost::hana::basic_tuple`.
   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_FWD_BASIC_TUPLE_HPP
  11 #define BOOST_HANA_FWD_BASIC_TUPLE_HPP
  12
  13 #include <boost/hana/config.hpp>
  14 #include <boost/hana/fwd/core/make.hpp>
  15
  16
  17 BOOST_HANA_NAMESPACE_BEGIN
  18     //! @ingroup group-datatypes
  19     //! Stripped down version of `hana::tuple`.
  20     //!
  21     //! Whereas `hana::tuple` aims to provide an interface somewhat close to a
  22     //! `std::tuple`, `basic_tuple` provides the strict minimum required to
  23     //! implement a closure with maximum compile-time efficiency.
  24     //!
  25     //!
  26     //! Modeled concepts
  27     //! ----------------
  28     //! `Sequence`, and all the concepts it refines
  29     template <typename ...Xs>
  30     struct basic_tuple;
  31
  32     //! Tag representing `hana::basic_tuple`.
  33     //! @relates hana::basic_tuple
  34     struct basic_tuple_tag { };
  35
  36 #ifdef BOOST_HANA_DOXYGEN_INVOKED
  37     //! Function object for creating a `basic_tuple`.
  38     //! @relates hana::basic_tuple
  39     //!
  40     //! Given zero or more objects `xs...`, `make<basic_tuple_tag>` returns a
  41     //! new `basic_tuple` containing those objects. The elements are held by
  42     //! value inside the resulting tuple, and they are hence copied or moved
  43     //! in. This is analogous to `std::make_tuple` for creating `basic_tuple`s.
  44     //!
  45     //!
  46     //! Example
  47     //! -------
  48     //! @include example/basic_tuple/make.cpp
  49     template <>
  50     constexpr auto make<basic_tuple_tag> = [](auto&& ...xs) {
  51         return basic_tuple<std::decay_t<decltype(xs)>...>{forwarded(xs)...};
  52     };
  53 #endif
  54
  55     //! Alias to `make<basic_tuple_tag>`; provided for convenience.
  56     //! @relates hana::basic_tuple
  57     //!
  58     //!
  59     //! Example
  60     //! -------
  61     //! @include example/basic_tuple/make.cpp
  62     constexpr auto make_basic_tuple = make<basic_tuple_tag>;
  63 BOOST_HANA_NAMESPACE_END
  64
  65 #endif // !BOOST_HANA_FWD_BASIC_TUPLE_HPP