toctave

t(iny)octave
git clone https://0xff.ir/g/toctave.git
Log | Files | Refs | README

utility.hpp (4342B)

      1 /*
      2     Copyright 2017 Adobe
      3     Distributed under the Boost Software License, Version 1.0.
      4     (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
      5 */
      6 
      7 /**************************************************************************************************/
      8 
      9 #ifndef STLAB_UTILITY_HPP
     10 #define STLAB_UTILITY_HPP
     11 
     12 /**************************************************************************************************/
     13 
     14 #include <array>
     15 #include <type_traits>
     16 
     17 /**************************************************************************************************/
     18 
     19 namespace stlab {
     20 
     21 /**************************************************************************************************/
     22 
     23 inline namespace v1 {
     24 /**************************************************************************************************/
     25 
     26 namespace detail {
     27 
     28 /**************************************************************************************************/
     29 
     30 template <bool, class T>
     31 struct move_if_helper;
     32 
     33 template <class T>
     34 struct move_if_helper<true, T> {
     35     using type = std::remove_reference_t<T>&&;
     36 };
     37 
     38 template <class T>
     39 struct move_if_helper<false, T> {
     40     using type = std::remove_reference_t<T>&;
     41 };
     42 
     43 template <bool P, class T>
     44 using move_if_helper_t = typename move_if_helper<P, T>::type;
     45 
     46 /**************************************************************************************************/
     47 
     48 } // namespace detail
     49 
     50 /**************************************************************************************************/
     51 
     52 template <class Seq1, class Seq2>
     53 struct index_sequence_cat;
     54 
     55 template <std::size_t... N1, std::size_t... N2>
     56 struct index_sequence_cat<std::index_sequence<N1...>, std::index_sequence<N2...>> {
     57     using type = std::index_sequence<N1..., N2...>;
     58 };
     59 
     60 template <class Seq1, class Seq2>
     61 using index_sequence_cat_t = typename index_sequence_cat<Seq1, Seq2>::type;
     62 
     63 /**************************************************************************************************/
     64 
     65 template <class Seq>
     66 struct index_sequence_to_array;
     67 
     68 template <std::size_t... N>
     69 struct index_sequence_to_array<std::index_sequence<N...>> {
     70     static constexpr std::array<std::size_t, sizeof...(N)> value{{N...}};
     71 };
     72 
     73 /**************************************************************************************************/
     74 
     75 template <class Seq, template <std::size_t> class F, std::size_t Index, std::size_t Count>
     76 struct index_sequence_transform;
     77 
     78 template <class Seq,
     79           template <std::size_t> class F,
     80           std::size_t Index = 0,
     81           std::size_t Count = Seq::size()>
     82 using index_sequence_transform_t = typename index_sequence_transform<Seq, F, Index, Count>::type;
     83 
     84 template <class Seq, template <std::size_t> class F, std::size_t Index, std::size_t Count>
     85 struct index_sequence_transform {
     86     using type = index_sequence_cat_t<
     87         index_sequence_transform_t<Seq, F, Index, Count / 2>,
     88         index_sequence_transform_t<Seq, F, Index + Count / 2, Count - Count / 2>>;
     89 };
     90 
     91 template <class Seq, template <std::size_t> class F, std::size_t Index>
     92 struct index_sequence_transform<Seq, F, Index, 0> {
     93     using type = std::index_sequence<>;
     94 };
     95 
     96 template <class Seq, template <std::size_t> class F, std::size_t Index>
     97 struct index_sequence_transform<Seq, F, Index, 1> {
     98     using type = typename F<index_sequence_to_array<Seq>::value[Index]>::type;
     99 };
    100 
    101 /**************************************************************************************************/
    102 
    103 template <bool P, class T>
    104 constexpr detail::move_if_helper_t<P, T> move_if(T&& t) noexcept {
    105     return static_cast<detail::move_if_helper_t<P, T>>(t);
    106 }
    107 
    108 /**************************************************************************************************/
    109 
    110 template <class F, class... Args>
    111 void for_each_argument(F&& f, Args&&... args) {
    112     return (void)std::initializer_list<int>{(std::forward<F>(f)(args), 0)...};
    113 }
    114 
    115 /**************************************************************************************************/
    116 
    117 } // namespace v1
    118 
    119 /**************************************************************************************************/
    120 
    121 } // namespace stlab
    122 
    123 /**************************************************************************************************/
    124 
    125 #endif
    126 
    127 /**************************************************************************************************/