ceph/src/boost/libs/stl_interfaces/test/output.cpp

   1 // Copyright (C) 2019 T. Zachary Laine
   2 //
   3 // Distributed under the Boost Software License, Version 1.0. (See
   4 // accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6 #include <boost/stl_interfaces/iterator_interface.hpp>
   7
   8 #include <boost/core/lightweight_test.hpp>
   9
  10 #include <array>
  11 #include <numeric>
  12 #include <vector>
  13 #include <type_traits>
  14
  15
  16 struct basic_output_iter
  17     : boost::stl_interfaces::
  18           iterator_interface<basic_output_iter, std::output_iterator_tag, int>
  19 {
  20     basic_output_iter() : it_(nullptr) {}
  21     basic_output_iter(int * it) : it_(it) {}
  22
  23     int & operator*() noexcept { return *it_; }
  24     basic_output_iter & operator++() noexcept
  25     {
  26         ++it_;
  27         return *this;
  28     }
  29
  30     using base_type = boost::stl_interfaces::
  31         iterator_interface<basic_output_iter, std::output_iterator_tag, int>;
  32     using base_type::operator++;
  33
  34 private:
  35     int * it_;
  36 };
  37
  38 using output = basic_output_iter;
  39
  40 #if 201703L < __cplusplus && defined(__cpp_lib_concepts)
  41 static_assert(std::output_iterator<output, int>, "");
  42 #endif
  43 BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS(
  44     output,
  45     std::output_iterator_tag,
  46     std::output_iterator_tag,
  47     int,
  48     int &,
  49     void,
  50     std::ptrdiff_t)
  51
  52 template<typename Container>
  53 struct back_insert_iter : boost::stl_interfaces::iterator_interface<
  54                               back_insert_iter<Container>,
  55                               std::output_iterator_tag,
  56                               typename Container::value_type,
  57                               back_insert_iter<Container> &>
  58 {
  59     back_insert_iter() : c_(nullptr) {}
  60     back_insert_iter(Container & c) : c_(std::addressof(c)) {}
  61
  62     back_insert_iter & operator*() noexcept { return *this; }
  63     back_insert_iter & operator++() noexcept { return *this; }
  64
  65     back_insert_iter & operator=(typename Container::value_type const & v)
  66     {
  67         c_->push_back(v);
  68         return *this;
  69     }
  70     back_insert_iter & operator=(typename Container::value_type && v)
  71     {
  72         c_->push_back(std::move(v));
  73         return *this;
  74     }
  75
  76     using base_type = boost::stl_interfaces::iterator_interface<
  77         back_insert_iter<Container>,
  78         std::output_iterator_tag,
  79         typename Container::value_type,
  80         back_insert_iter<Container> &>;
  81     using base_type::operator++;
  82
  83 private:
  84     Container * c_;
  85 };
  86
  87 using back_insert = back_insert_iter<std::vector<int>>;
  88
  89 #if 201703L < __cplusplus && defined(__cpp_lib_concepts)
  90 static_assert(std::output_iterator<back_insert, int>, "");
  91 #endif
  92 BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS(
  93     back_insert,
  94     std::output_iterator_tag,
  95     std::output_iterator_tag,
  96     int,
  97     back_insert &,
  98     void,
  99     std::ptrdiff_t)
 100
 101
 102 std::vector<int> ints = {{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}};
 103
 104
 105 int main()
 106 {
 107
 108 {
 109     std::vector<int> ints_copy(ints.size());
 110     std::copy(ints.begin(), ints.end(), output(&ints_copy[0]));
 111     BOOST_TEST(ints_copy == ints);
 112 }
 113
 114
 115 {
 116     std::vector<int> ints_copy;
 117     std::copy(ints.begin(), ints.end(), back_insert(ints_copy));
 118     BOOST_TEST(ints_copy == ints);
 119 }
 120
 121
 122 {
 123     std::vector<int> ints_copy;
 124     back_insert out(ints_copy);
 125     for (int i = 0; i < 10; ++i)
 126         out++;
 127 }
 128
 129     return boost::report_errors();
 130 }