chunk_by.cpp 5.6 KB

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  1. // Range v3 library
  2. //
  3. // Copyright Hui Xie 2021
  4. //
  5. // Use, modification and distribution is subject to the
  6. // Boost Software License, Version 1.0. (See accompanying
  7. // file LICENSE_1_0.txt or copy at
  8. // http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. // Project home: https://github.com/ericniebler/range-v3
  11. #include <list>
  12. #include <vector>
  13. #include <range/v3/core.hpp>
  14. #include <range/v3/view/chunk_by.hpp>
  15. #include <range/v3/view/counted.hpp>
  16. #include <range/v3/view/cycle.hpp>
  17. #include <range/v3/view/remove_if.hpp>
  18. #include <range/v3/view/take.hpp>
  19. #include "../simple_test.hpp"
  20. #include "../test_iterators.hpp"
  21. #include "../test_utils.hpp"
  22. RANGES_DIAGNOSTIC_IGNORE_SIGN_CONVERSION
  23. int main()
  24. {
  25. using namespace ranges;
  26. using P = std::pair<int, int>;
  27. std::vector<std::pair<int, int>> v = {
  28. {1, 1},
  29. {1, 1},
  30. {1, 2},
  31. {1, 2},
  32. {1, 2},
  33. {1, 2},
  34. {2, 2},
  35. {2, 2},
  36. {2, 3},
  37. {2, 3},
  38. {2, 3},
  39. {2, 3},
  40. };
  41. {
  42. auto rng0 =
  43. v | views::chunk_by([](P p0, P p1) { return p0.second == p1.second; });
  44. CPP_assert(forward_range<decltype(rng0)>);
  45. CPP_assert(!bidirectional_range<decltype(rng0)>);
  46. CHECK(distance(rng0) == 3);
  47. check_equal(*rng0.begin(), {P{1, 1}, P{1, 1}});
  48. check_equal(*next(rng0.begin()),
  49. {P{1, 2}, P{1, 2}, P{1, 2}, P{1, 2}, P{2, 2}, P{2, 2}});
  50. check_equal(*next(rng0.begin(), 2), {P{2, 3}, P{2, 3}, P{2, 3}, P{2, 3}});
  51. auto rng1 = v | views::chunk_by([](P p0, P p1) { return p0.first == p1.first; });
  52. CPP_assert(forward_range<decltype(rng1)>);
  53. CPP_assert(!bidirectional_range<decltype(rng1)>);
  54. CHECK(distance(rng1) == 2);
  55. check_equal(*rng1.begin(),
  56. {P{1, 1}, P{1, 1}, P{1, 2}, P{1, 2}, P{1, 2}, P{1, 2}});
  57. check_equal(*next(rng1.begin()),
  58. {P{2, 2}, P{2, 2}, P{2, 3}, P{2, 3}, P{2, 3}, P{2, 3}});
  59. }
  60. {
  61. ForwardIterator<std::vector<P>::iterator> b{v.begin()};
  62. auto rng0 = views::counted(b, v.size()) |
  63. views::chunk_by([](P p0, P p1) { return p0.second == p1.second; });
  64. CPP_assert(forward_range<decltype(rng0)>);
  65. CPP_assert(!bidirectional_range<decltype(rng0)>);
  66. CHECK(distance(rng0) == 3);
  67. check_equal(*rng0.begin(), {P{1, 1}, P{1, 1}});
  68. check_equal(*next(rng0.begin()),
  69. {P{1, 2}, P{1, 2}, P{1, 2}, P{1, 2}, P{2, 2}, P{2, 2}});
  70. check_equal(*next(rng0.begin(), 2), {P{2, 3}, P{2, 3}, P{2, 3}, P{2, 3}});
  71. auto rng1 = views::counted(b, v.size()) |
  72. views::chunk_by([](P p0, P p1) { return p0.first == p1.first; });
  73. CPP_assert(forward_range<decltype(rng1)>);
  74. CPP_assert(!bidirectional_range<decltype(rng1)>);
  75. CHECK(distance(rng1) == 2);
  76. check_equal(*rng1.begin(),
  77. {P{1, 1}, P{1, 1}, P{1, 2}, P{1, 2}, P{1, 2}, P{1, 2}});
  78. check_equal(*next(rng1.begin()),
  79. {P{2, 2}, P{2, 2}, P{2, 3}, P{2, 3}, P{2, 3}, P{2, 3}});
  80. }
  81. {
  82. int a[] = {0, 1, 2, 3, 4, 5};
  83. auto rng = a | views::remove_if([](int n) { return n % 2 == 0; }) |
  84. views::chunk_by([](int, int) { return true; });
  85. check_equal(*rng.begin(), {1, 3, 5});
  86. }
  87. {
  88. std::vector<int> v2{0, 1, 2, 6, 8, 10, 15, 17, 18, 29};
  89. auto rng0 = ranges::views::chunk_by(v2, [](int i, int j) { return j - i < 3; });
  90. check_equal(*rng0.begin(), {0, 1, 2});
  91. check_equal(*next(rng0.begin()), {6, 8, 10});
  92. check_equal(*next(rng0.begin(), 2), {15, 17, 18});
  93. check_equal(*next(rng0.begin(), 3), {29});
  94. CHECK(distance(rng0) == 4);
  95. }
  96. {
  97. std::vector<int> v3{1, 2, 3, 4, 5};
  98. int count_invoc = 0;
  99. auto rng = views::chunk_by(v3, [&](int, int) {
  100. ++count_invoc;
  101. return false;
  102. });
  103. CHECK(distance(rng) == 5);
  104. CHECK(count_invoc == 4);
  105. auto it = rng.begin();
  106. check_equal(*it, {1});
  107. check_equal(*++it, {2});
  108. check_equal(*++it, {3});
  109. check_equal(*++it, {4});
  110. check_equal(*++it, {5});
  111. // 7, not 8, because caching in begin()
  112. CHECK(count_invoc == 7);
  113. }
  114. {
  115. std::vector<int> v4 = {2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 0};
  116. auto rng = v4 | views::chunk_by(std::less<>{});
  117. CHECK(distance(rng) == 4);
  118. check_equal(*rng.begin(), {2, 3, 4, 5});
  119. check_equal(*next(rng.begin()), {0, 1, 2, 3, 4, 5, 6});
  120. check_equal(*next(rng.begin(), 2), {0, 1, 2, 3});
  121. check_equal(*next(rng.begin(), 3), {0});
  122. }
  123. {
  124. std::vector<int> v5 = {0, 1, 2};
  125. auto rng = views::cycle(v5) | views::take(6) | views::chunk_by(std::less<>{});
  126. CHECK(distance(rng) == 2);
  127. check_equal(*rng.begin(), v5);
  128. check_equal(*next(rng.begin()), v5);
  129. }
  130. {
  131. std::vector<int> e;
  132. auto rng = e | views::chunk_by(std::less<>{});
  133. CHECK(distance(rng) == 0);
  134. }
  135. {
  136. std::vector<int> single{2};
  137. auto rng = single | views::chunk_by([](int, int) -> bool { throw 0; });
  138. CHECK(distance(rng) == 1);
  139. check_equal(*rng.begin(), {2});
  140. }
  141. {
  142. std::vector<int> v6 = {3, 6, 9, 4, 5, 0, 3, 2};
  143. auto rng = v6 | views::chunk_by(std::less<>{});
  144. check_equal(*rng.begin(), {3, 6, 9});
  145. check_equal(*next(rng.begin()), {4, 5});
  146. check_equal(*next(rng.begin(), 2), {0, 3});
  147. check_equal(*next(rng.begin(), 3), {2});
  148. CHECK(distance(rng) == 4);
  149. }
  150. return test_result();
  151. }