ceph/src/boost/libs/hana/include/boost/hana/ext/std/vector.hpp

   1 /*!
   2 @file
   3 Adapts `std::vector` for use with Hana.
   4
   5 @copyright Louis Dionne 2013-2016
   6 @copyright Gonzalo Brito Gadeschi 2015
   7 Distributed under the Boost Software License, Version 1.0.
   8 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   9  */
  10
  11 #ifndef BOOST_HANA_EXT_STD_VECTOR_HPP
  12 #define BOOST_HANA_EXT_STD_VECTOR_HPP
  13
  14 #include <boost/hana/config.hpp>
  15 #include <boost/hana/equal.hpp>
  16 #include <boost/hana/fwd/core/tag_of.hpp>
  17 #include <boost/hana/less.hpp>
  18
  19 #include <algorithm>
  20 #include <iterator>
  21 #include <memory>
  22 #include <type_traits>
  23 #include <utility>
  24 #include <vector>
  25
  26
  27 BOOST_HANA_NAMESPACE_BEGIN
  28     namespace ext { namespace std { struct vector_tag; }}
  29
  30     template <typename T, typename Allocator>
  31     struct tag_of<std::vector<T, Allocator>> {
  32         using type = ext::std::vector_tag;
  33     };
  34
  35     //////////////////////////////////////////////////////////////////////////
  36     // Comparable
  37     //////////////////////////////////////////////////////////////////////////
  38     template <>
  39     struct equal_impl<ext::std::vector_tag, ext::std::vector_tag> {
  40         template <typename T1, typename A1, typename T2, typename A2>
  41         static bool apply(std::vector<T1, A1> const& v1,
  42                           std::vector<T2, A2> const& v2)
  43         {
  44             return std::equal(begin(v1), end(v1),
  45                               begin(v2), end(v2),
  46                               hana::equal);
  47         }
  48     };
  49
  50     //////////////////////////////////////////////////////////////////////////
  51     // Orderable
  52     //////////////////////////////////////////////////////////////////////////
  53     template <>
  54     struct less_impl<ext::std::vector_tag, ext::std::vector_tag> {
  55         template <typename T1, typename A1, typename T2, typename A2>
  56         static bool apply(std::vector<T1, A1> const& v1,
  57                           std::vector<T2, A2> const& v2)
  58         {
  59             return std::lexicographical_compare(begin(v1), end(v1),
  60                                                 begin(v2), end(v2),
  61                                                 hana::less);
  62         }
  63     };
  64
  65 #if 0
  66     //////////////////////////////////////////////////////////////////////////
  67     // Functor
  68     //////////////////////////////////////////////////////////////////////////
  69     template <>
  70     struct transform_impl<ext::std::vector_tag> {
  71         template <typename V, typename F>
  72         static auto apply(V&& v, F&& f) {
  73             using U = std::remove_cv_t<std::remove_reference_t<
  74                 decltype(f(*v.begin()))
  75             >>;
  76             using Alloc = typename std::remove_reference_t<V>::allocator_type;
  77             using NewAlloc = typename std::allocator_traits<Alloc>::
  78                              template rebind_alloc<U>;
  79             std::vector<U, NewAlloc> result; result.reserve(v.size());
  80
  81             std::transform(begin(v), end(v),
  82                            std::back_inserter(result), std::forward<F>(f));
  83             return result;
  84         }
  85
  86         template <typename T, typename Alloc, typename F>
  87         static auto apply(std::vector<T, Alloc>&& v, F&& f)
  88             -> std::enable_if_t<
  89                 std::is_same<
  90                     T,
  91                     std::remove_cv_t<std::remove_reference_t<
  92                         decltype(f(*v.begin()))
  93                     >>
  94                 >{}
  95                 , std::vector<T, Alloc>
  96             >
  97         {
  98             // If we receive a rvalue and the function returns elements of
  99             // the same type, we modify the vector in-place instead of
 100             // returning a new one.
 101             std::transform(std::make_move_iterator(begin(v)),
 102                            std::make_move_iterator(end(v)),
 103                            begin(v), std::forward<F>(f));
 104             return std::move(v);
 105         }
 106     };
 107 #endif
 108 BOOST_HANA_NAMESPACE_END
 109
 110 #endif // !BOOST_HANA_EXT_STD_VECTOR_HPP