1 | // Copyright Louis Dionne 2012. Use, modification and distribution is subject
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2 | // to the Boost Software License, Version 1.0. (See accompanying file
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3 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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4 |
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5 | #include <boost/iterator/transform_output_iterator.hpp>
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6 | #include <boost/concept/assert.hpp>
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7 | #include <boost/concept/usage.hpp>
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8 | #include <boost/concept_archetype.hpp>
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9 | #include <boost/concept_check.hpp>
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10 | #include <boost/iterator/counting_iterator.hpp>
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11 | #include <boost/iterator/iterator_concepts.hpp>
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12 | #include <boost/iterator/iterator_traits.hpp>
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13 |
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14 | #include <algorithm>
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15 | #include <cassert>
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16 | #include <iterator>
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17 | #include <string>
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18 | #include <vector>
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19 |
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20 |
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21 | namespace transform_output_iterator_test {
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22 |
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23 | template <typename Iterator, typename OutputType = typename
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24 | boost::iterator_value<Iterator>::type>
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25 | struct test_concepts {
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26 | BOOST_CONCEPT_USAGE(test_concepts) {
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27 | BOOST_CONCEPT_ASSERT((boost::OutputIterator<
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28 | boost::transform_output_iterator<
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29 | OutputType (*)(OutputType),
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30 | Iterator
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31 | >,
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32 | OutputType
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33 | >));
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34 |
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35 | BOOST_CONCEPT_ASSERT((boost_concepts::WritableIterator<
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36 | boost::transform_output_iterator<
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37 | OutputType (*)(OutputType),
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38 | Iterator
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39 | >,
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40 | OutputType
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41 | >));
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42 |
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43 | BOOST_CONCEPT_ASSERT((boost_concepts::IncrementableIterator<
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44 | boost::transform_output_iterator<
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45 | OutputType (*)(OutputType),
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46 | Iterator
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47 | >
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48 | >));
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49 | }
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50 | };
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51 |
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52 | struct dummy { };
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53 | BOOST_CONCEPT_ASSERT((
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54 | test_concepts<boost::output_iterator_archetype<dummy>, dummy>
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55 | ));
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56 | BOOST_CONCEPT_ASSERT((
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57 | test_concepts<boost::input_output_iterator_archetype<dummy>, dummy>
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58 | ));
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59 | BOOST_CONCEPT_ASSERT((
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60 | test_concepts<boost::mutable_forward_iterator_archetype<dummy> >
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61 | ));
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62 | BOOST_CONCEPT_ASSERT((
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63 | test_concepts<boost::mutable_bidirectional_iterator_archetype<dummy> >
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64 | ));
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65 | BOOST_CONCEPT_ASSERT((
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66 | test_concepts<boost::mutable_random_access_iterator_archetype<dummy> >
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67 | ));
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68 |
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69 | template <typename T = int>
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70 | struct Multiply {
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71 | T n_;
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72 | Multiply(T n) : n_(n) { }
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73 | T operator()(T val) const {
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74 | return val * n_;
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75 | }
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76 | };
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77 |
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78 | template <typename T = int>
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79 | struct Add {
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80 | T n_;
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81 | Add(T n) : n_(n) { }
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82 | T operator()(T val) const {
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83 | return val + n_;
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84 | }
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85 | };
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86 |
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87 | void should_transform_output() {
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88 | std::vector<int> actual, expected;
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89 | std::copy(boost::counting_iterator<int>(0),
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90 | boost::counting_iterator<int>(10),
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91 | boost::make_transform_output_iterator(
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92 | Add<>(10), std::back_inserter(actual)));
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93 |
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94 | std::copy(boost::counting_iterator<int>(10),
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95 | boost::counting_iterator<int>(20),
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96 | std::back_inserter(expected));
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97 |
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98 | assert(actual == expected);
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99 | }
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100 |
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101 | void should_allow_chaining() {
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102 | std::vector<int> actual, expected;
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103 |
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104 | boost::transform_output_iterator<Multiply<>,
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105 | boost::transform_output_iterator<Add<>,
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106 | std::back_insert_iterator<std::vector<int> > > > output =
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107 | boost::make_transform_output_iterator(
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108 | Multiply<>(2),std::back_inserter(actual)).and_then(Add<>(10));
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109 |
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110 | std::copy(boost::counting_iterator<int>(0),
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111 | boost::counting_iterator<int>(5),
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112 | output);
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113 |
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114 | expected.push_back(0 * 2 + 10);
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115 | expected.push_back(1 * 2 + 10);
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116 | expected.push_back(2 * 2 + 10);
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117 | expected.push_back(3 * 2 + 10);
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118 | expected.push_back(4 * 2 + 10);
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119 |
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120 | assert(actual == expected);
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121 | }
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122 |
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123 | void should_work_for_const_iterator_if_wrapped_iter_has_const_deref() {
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124 | typedef boost::transform_output_iterator<Multiply<>,
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125 | std::vector<int>::iterator> OutputIter;
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126 | std::vector<int> actual(1), expected;
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127 | OutputIter const out(Multiply<>(2), actual.begin());
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128 | *out = 3;
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129 |
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130 | expected.push_back(2 * 3);
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131 |
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132 | assert(actual == expected);
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133 | }
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134 |
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135 | void chain_performs_operation_in_right_order() {
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136 | std::string actual;
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137 | typedef Add<std::string> Append;
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138 | *boost::make_transform_output_iterator(Append("a"), &actual).
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139 | and_then(Append("b"))
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140 | .and_then(Append("c"))
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141 | .and_then(Append("d")) = "";
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142 |
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143 | assert(actual == "abcd");
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144 | }
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145 |
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146 | struct Input { };
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147 | struct First {
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148 | struct result { };
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149 | result operator()(Input) const { return result(); }
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150 | };
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151 | struct Second {
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152 | struct result { };
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153 | result operator()(First::result) const { return result(); }
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154 | };
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155 | struct Third {
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156 | struct result { };
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157 | result operator()(Second::result) const { return result(); }
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158 | };
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159 | struct Output {
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160 | Output& operator++() { return *this; }
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161 | Output operator++(int) { return *this; }
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162 | Output& operator=(Third::result) { return *this; }
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163 | Output& operator*() { return *this; }
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164 | };
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165 |
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166 | void test_ordering_of_operations_with_type_system() {
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167 | Output output;
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168 | *boost::make_transform_output_iterator<First>(output)
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169 | .and_then<Second>().and_then<Third>() = Input();
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170 | }
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171 |
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172 | } // end transform_output_iterator_test namespace
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173 |
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174 |
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175 | int main() {
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176 | using namespace transform_output_iterator_test;
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177 | should_transform_output();
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178 | should_allow_chaining();
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179 | should_work_for_const_iterator_if_wrapped_iter_has_const_deref();
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180 | chain_performs_operation_in_right_order();
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181 | test_ordering_of_operations_with_type_system();
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182 | return 0;
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183 | }
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