iterator_traits_test.cpp 7.8 KB

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  1. // (C) Copyright David Abrahams 2002.
  2. // Distributed under the Boost Software License, Version 1.0. (See
  3. // accompanying file LICENSE_1_0.txt or copy at
  4. // http://www.boost.org/LICENSE_1_0.txt)
  5. // See http://www.boost.org for most recent version including documentation.
  6. // Revision History
  7. // 04 Mar 2001 Patches for Intel C++ (Dave Abrahams)
  8. // 19 Feb 2001 Take advantage of improved iterator_traits to do more tests
  9. // on MSVC. Reordered some #ifdefs for coherency.
  10. // (David Abrahams)
  11. // 13 Feb 2001 Test new VC6 workarounds (David Abrahams)
  12. // 11 Feb 2001 Final fixes for Borland (David Abrahams)
  13. // 11 Feb 2001 Some fixes for Borland get it closer on that compiler
  14. // (David Abrahams)
  15. // 07 Feb 2001 More comprehensive testing; factored out static tests for
  16. // better reuse (David Abrahams)
  17. // 21 Jan 2001 Quick fix to my_iterator, which wasn't returning a
  18. // reference type from operator* (David Abrahams)
  19. // 19 Jan 2001 Initial version with iterator operators (David Abrahams)
  20. #include <boost/detail/iterator.hpp>
  21. #include <boost/type_traits/is_same.hpp>
  22. #include <boost/operators.hpp>
  23. #include <boost/static_assert.hpp>
  24. #include <iterator>
  25. #include <vector>
  26. #include <list>
  27. #include <boost/detail/lightweight_test.hpp>
  28. #include <iostream>
  29. // A UDT for which we can specialize std::iterator_traits<element*> on
  30. // compilers which don't support partial specialization. There's no
  31. // other reasonable way to test pointers on those compilers.
  32. struct element {};
  33. // An iterator for which we can get traits.
  34. struct my_iterator1
  35. : boost::forward_iterator_helper<my_iterator1, char, long, const char*, const char&>
  36. {
  37. my_iterator1(const char* p) : m_p(p) {}
  38. bool operator==(const my_iterator1& rhs) const
  39. { return this->m_p == rhs.m_p; }
  40. my_iterator1& operator++() { ++this->m_p; return *this; }
  41. const char& operator*() { return *m_p; }
  42. private:
  43. const char* m_p;
  44. };
  45. // Used to prove that we don't require std::iterator<> in the hierarchy under
  46. // MSVC6, and that we can compute all the traits for a standard-conforming UDT
  47. // iterator.
  48. struct my_iterator2
  49. : boost::equality_comparable<my_iterator2
  50. , boost::incrementable<my_iterator2
  51. , boost::dereferenceable<my_iterator2,const char*> > >
  52. {
  53. typedef char value_type;
  54. typedef long difference_type;
  55. typedef const char* pointer;
  56. typedef const char& reference;
  57. typedef std::forward_iterator_tag iterator_category;
  58. my_iterator2(const char* p) : m_p(p) {}
  59. bool operator==(const my_iterator2& rhs) const
  60. { return this->m_p == rhs.m_p; }
  61. my_iterator2& operator++() { ++this->m_p; return *this; }
  62. const char& operator*() { return *m_p; }
  63. private:
  64. const char* m_p;
  65. };
  66. // Used to prove that we're not overly confused by the existence of
  67. // std::iterator<> in the hierarchy under MSVC6 - we should find that
  68. // boost::detail::iterator_traits<my_iterator3>::difference_type is int.
  69. struct my_iterator3 : my_iterator1
  70. {
  71. typedef int difference_type;
  72. my_iterator3(const char* p)
  73. : my_iterator1(p) {}
  74. };
  75. //
  76. // Assertion tools. Used instead of BOOST_STATIC_ASSERT because that
  77. // doesn't give us a nice stack backtrace
  78. //
  79. template <bool = false> struct assertion;
  80. template <> struct assertion<true>
  81. {
  82. typedef char type;
  83. };
  84. template <class T, class U>
  85. struct assert_same
  86. : assertion<(::boost::is_same<T,U>::value)>
  87. {
  88. };
  89. // Iterator tests
  90. template <class Iterator,
  91. class value_type, class difference_type, class pointer, class reference, class category>
  92. struct non_portable_tests
  93. {
  94. typedef typename boost::detail::iterator_traits<Iterator>::pointer test_pt;
  95. typedef typename boost::detail::iterator_traits<Iterator>::reference test_rt;
  96. typedef typename assert_same<test_pt, pointer>::type a1;
  97. typedef typename assert_same<test_rt, reference>::type a2;
  98. };
  99. template <class Iterator,
  100. class value_type, class difference_type, class pointer, class reference, class category>
  101. struct portable_tests
  102. {
  103. typedef typename boost::detail::iterator_traits<Iterator>::difference_type test_dt;
  104. typedef typename boost::detail::iterator_traits<Iterator>::iterator_category test_cat;
  105. typedef typename assert_same<test_dt, difference_type>::type a1;
  106. typedef typename assert_same<test_cat, category>::type a2;
  107. };
  108. // Test iterator_traits
  109. template <class Iterator,
  110. class value_type, class difference_type, class pointer, class reference, class category>
  111. struct input_iterator_test
  112. : portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
  113. {
  114. typedef typename boost::detail::iterator_traits<Iterator>::value_type test_vt;
  115. typedef typename assert_same<test_vt, value_type>::type a1;
  116. };
  117. template <class Iterator,
  118. class value_type, class difference_type, class pointer, class reference, class category>
  119. struct non_pointer_test
  120. : input_iterator_test<Iterator,value_type,difference_type,pointer,reference,category>
  121. , non_portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
  122. {
  123. };
  124. template <class Iterator,
  125. class value_type, class difference_type, class pointer, class reference, class category>
  126. struct maybe_pointer_test
  127. : portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
  128. , non_portable_tests<Iterator,value_type,difference_type,pointer,reference,category>
  129. {
  130. };
  131. input_iterator_test<std::istream_iterator<int>, int, std::ptrdiff_t, int*, int&, std::input_iterator_tag>
  132. istream_iterator_test;
  133. #if BOOST_WORKAROUND(__BORLANDC__, <= 0x564) && !defined(__SGI_STL_PORT)
  134. typedef ::std::char_traits<char>::off_type distance;
  135. non_pointer_test<std::ostream_iterator<int>,int,
  136. distance,int*,int&,std::output_iterator_tag> ostream_iterator_test;
  137. #elif defined(BOOST_MSVC_STD_ITERATOR)
  138. non_pointer_test<std::ostream_iterator<int>,
  139. int, void, int*, int&, std::output_iterator_tag>
  140. ostream_iterator_test;
  141. #elif BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(70190006))
  142. non_pointer_test<std::ostream_iterator<int>,
  143. int, long, int*, int&, std::output_iterator_tag>
  144. ostream_iterator_test;
  145. #else
  146. non_pointer_test<std::ostream_iterator<int>,
  147. void, void, void, void, std::output_iterator_tag>
  148. ostream_iterator_test;
  149. #endif
  150. #ifdef __KCC
  151. typedef long std_list_diff_type;
  152. #else
  153. typedef std::ptrdiff_t std_list_diff_type;
  154. #endif
  155. non_pointer_test<std::list<int>::iterator, int, std_list_diff_type, int*, int&, std::bidirectional_iterator_tag>
  156. list_iterator_test;
  157. maybe_pointer_test<std::vector<int>::iterator, int, std::ptrdiff_t, int*, int&, std::random_access_iterator_tag>
  158. vector_iterator_test;
  159. maybe_pointer_test<int*, int, std::ptrdiff_t, int*, int&, std::random_access_iterator_tag>
  160. int_pointer_test;
  161. non_pointer_test<my_iterator1, char, long, const char*, const char&, std::forward_iterator_tag>
  162. my_iterator1_test;
  163. non_pointer_test<my_iterator2, char, long, const char*, const char&, std::forward_iterator_tag>
  164. my_iterator2_test;
  165. non_pointer_test<my_iterator3, char, int, const char*, const char&, std::forward_iterator_tag>
  166. my_iterator3_test;
  167. int main()
  168. {
  169. char chars[100];
  170. int ints[100];
  171. for (int length = 3; length < 100; length += length / 3)
  172. {
  173. std::list<int> l(length);
  174. BOOST_TEST(boost::detail::distance(l.begin(), l.end()) == length);
  175. std::vector<int> v(length);
  176. BOOST_TEST(boost::detail::distance(v.begin(), v.end()) == length);
  177. BOOST_TEST(boost::detail::distance(&ints[0], ints + length) == length);
  178. BOOST_TEST(boost::detail::distance(my_iterator1(chars), my_iterator1(chars + length)) == length);
  179. BOOST_TEST(boost::detail::distance(my_iterator2(chars), my_iterator2(chars + length)) == length);
  180. BOOST_TEST(boost::detail::distance(my_iterator3(chars), my_iterator3(chars + length)) == length);
  181. }
  182. return boost::report_errors();
  183. }