set_symmetric_difference.cpp 13 KB

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  1. // Range v3 library
  2. //
  3. // Copyright Eric Niebler 2014-present
  4. // Copyright Tomislav Ivek 2015-2016
  5. //
  6. // Use, modification and distribution is subject to the
  7. // Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at
  9. // http://www.boost.org/LICENSE_1_0.txt)
  10. //
  11. // Project home: https://github.com/ericniebler/range-v3
  12. #include <vector>
  13. #include <sstream>
  14. #include <range/v3/core.hpp>
  15. #include <range/v3/range_for.hpp>
  16. #include <range/v3/algorithm/set_algorithm.hpp>
  17. #include <range/v3/algorithm/move.hpp>
  18. #include <range/v3/utility/common_type.hpp>
  19. #include <range/v3/iterator/operations.hpp>
  20. #include <range/v3/iterator/insert_iterators.hpp>
  21. #include <range/v3/iterator/move_iterators.hpp>
  22. #include <range/v3/functional/identity.hpp>
  23. #include <range/v3/view/all.hpp>
  24. #include <range/v3/view/const.hpp>
  25. #include <range/v3/view/drop_while.hpp>
  26. #include <range/v3/view/empty.hpp>
  27. #include <range/v3/view/iota.hpp>
  28. #include <range/v3/view/reverse.hpp>
  29. #include <range/v3/view/set_algorithm.hpp>
  30. #include <range/v3/view/stride.hpp>
  31. #include <range/v3/view/take.hpp>
  32. #include <range/v3/view/transform.hpp>
  33. #include <range/v3/view/zip.hpp>
  34. #include <range/v3/utility/copy.hpp>
  35. #include "../simple_test.hpp"
  36. #include "../test_utils.hpp"
  37. int main()
  38. {
  39. using namespace ranges;
  40. int i1_finite[] = {1, 2, 2, 3, 3, 3, 4, 4, 4, 4};
  41. int i2_finite[] = { -3, 2, 4, 4, 6, 9};
  42. auto i1_infinite = views::ints | views::stride(3);
  43. auto i2_infinite = views::ints | views::transform([](int x)
  44. {
  45. return x * x;
  46. });
  47. // symmetric difference between two finite ranges/sets
  48. {
  49. auto res = views::set_symmetric_difference(i1_finite, i2_finite);
  50. CPP_assert(view_<decltype(res)>);
  51. CPP_assert(forward_range<decltype(res)>);
  52. CPP_assert(!random_access_range<decltype(res)>);
  53. CPP_assert(!common_range<decltype(res)>);
  54. using R = decltype(res);
  55. CPP_assert(same_as<range_value_t<R>, int>);
  56. CPP_assert(same_as<range_reference_t<R>, int&>);
  57. CPP_assert(same_as<decltype(iter_move(begin(res))), int&&>);
  58. static_assert(range_cardinality<R>::value == ranges::finite, "Cardinality of symmetric difference of finite ranges should be finite!");
  59. ::check_equal(res, {-3, 1, 2, 3, 3, 3, 4, 4, 6, 9});
  60. // check if the final result agrees with the greedy algorithm
  61. std::vector<int> greedy_sd;
  62. set_symmetric_difference(i1_finite, i2_finite, back_inserter(greedy_sd));
  63. ::check_equal(res, greedy_sd);
  64. auto it = begin(res);
  65. CHECK(&*it == &*(begin(i2_finite)));
  66. ++it;
  67. CHECK(&*it == &*(begin(i1_finite)));
  68. }
  69. // symmetric difference between two infinite ranges
  70. {
  71. auto res = views::set_symmetric_difference(i1_infinite, i2_infinite);
  72. CPP_assert(view_<decltype(res)>);
  73. CPP_assert(forward_range<decltype(res)>);
  74. CPP_assert(!random_access_range<decltype(res)>);
  75. CPP_assert(!common_range<decltype(res)>);
  76. using R = decltype(res);
  77. CPP_assert(same_as<range_value_t<R>,
  78. common_type_t<range_value_t<decltype(i1_infinite)>,
  79. range_value_t<decltype(i2_infinite)>>>);
  80. CPP_assert(same_as<range_reference_t<R>,
  81. common_reference_t<range_reference_t<decltype(i1_infinite)>,
  82. range_reference_t<decltype(i2_infinite)>>
  83. >);
  84. CPP_assert(same_as<range_rvalue_reference_t<R>,
  85. common_reference_t<range_rvalue_reference_t<decltype(i1_infinite)>,
  86. range_rvalue_reference_t<decltype(i2_infinite)>>
  87. >);
  88. static_assert(range_cardinality<R>::value == ranges::unknown, "Cardinality of symmetric difference between infinite ranges should be unknown!");
  89. ::check_equal(res | views::take(6), {1, 3, 4, 6, 12, 15});
  90. // check if the final result agrees with the greedy algorithm
  91. std::vector<int> greedy_sd;
  92. set_symmetric_difference(i1_infinite | views::take(10), i2_infinite | views::take(10), back_inserter(greedy_sd));
  93. ::check_equal(res | views::take(6), greedy_sd | views::take(6));
  94. }
  95. // symmetric difference between a finite and an infinite range
  96. {
  97. auto res1 = views::set_symmetric_difference(i1_finite, i2_infinite);
  98. CPP_assert(view_<decltype(res1)>);
  99. CPP_assert(forward_range<decltype(res1)>);
  100. CPP_assert(!random_access_range<decltype(res1)>);
  101. CPP_assert(!common_range<decltype(res1)>);
  102. using R1 = decltype(res1);
  103. CPP_assert(same_as<range_value_t<R1>, int>);
  104. CPP_assert(same_as<range_reference_t<R1>, int>); // our infinite range does not give out references
  105. CPP_assert(same_as<range_rvalue_reference_t<R1>, int>);
  106. static_assert(range_cardinality<R1>::value == ranges::infinite, "Cardinality of symmetric difference between a finite and an infinite range should be infinite!");
  107. ::check_equal(res1 | views::take(10), {0, 2, 2, 3, 3, 3, 4, 4, 4, 9});
  108. // now swap the operands:
  109. auto res2 = views::set_symmetric_difference(i2_infinite, i1_finite);
  110. CPP_assert(view_<decltype(res2)>);
  111. CPP_assert(forward_range<decltype(res2)>);
  112. CPP_assert(!random_access_range<decltype(res2)>);
  113. CPP_assert(!common_range<decltype(res2)>);
  114. using R2 = decltype(res2);
  115. CPP_assert(same_as<range_value_t<R2>, int>);
  116. CPP_assert(same_as<range_reference_t<R2>, int>); // our infinite range does not give out references
  117. CPP_assert(same_as<range_rvalue_reference_t<R2>, int>);
  118. static_assert(range_cardinality<R2>::value == ranges::infinite, "Cardinality of symmetric difference between a finite and an infinite range should be infinite!");
  119. ::check_equal(res1 | views::take(10), res2 | views::take(10));
  120. }
  121. // symmetric differences involving unknown cardinalities
  122. {
  123. auto rng0 = views::iota(10) | views::drop_while([](int i)
  124. {
  125. return i < 25;
  126. });
  127. static_assert(range_cardinality<decltype(rng0)>::value == ranges::unknown, "");
  128. auto res1 = views::set_symmetric_difference(i2_finite, rng0);
  129. static_assert(range_cardinality<decltype(res1)>::value == ranges::unknown, "Symmetric difference between a finite and unknown cardinality set should have unknown cardinality!");
  130. auto res2 = views::set_symmetric_difference(rng0, i2_finite);
  131. static_assert(range_cardinality<decltype(res2)>::value == ranges::unknown, "Symmetric difference between an unknown and finite cardinality set should have unknown cardinality!");
  132. auto res3 = views::set_symmetric_difference(i1_infinite, rng0);
  133. static_assert(range_cardinality<decltype(res3)>::value == ranges::unknown, "Symmetric difference between an infinite and unknown cardinality set should have unknown cardinality!");
  134. auto res4 = views::set_symmetric_difference(rng0, i1_infinite);
  135. static_assert(range_cardinality<decltype(res4)>::value == ranges::unknown, "Symmetric difference between an unknown and infinite cardinality set should have infinite cardinality!");
  136. auto res5 = views::set_symmetric_difference(rng0, rng0);
  137. static_assert(range_cardinality<decltype(res5)>::value == ranges::unknown, "Symmetric difference between two unknown cardinality sets should have unknown cardinality!");
  138. }
  139. // test const ranges
  140. {
  141. auto res1 = views::set_symmetric_difference(views::const_(i1_finite), views::const_(i2_finite));
  142. using R1 = decltype(res1);
  143. CPP_assert(same_as<range_value_t<R1>, int>);
  144. CPP_assert(same_as<range_reference_t<R1>, const int&>);
  145. CPP_assert(same_as<range_rvalue_reference_t<R1>, const int&&>);
  146. auto res2 = views::set_symmetric_difference(views::const_(i1_finite), i2_finite);
  147. using R2 = decltype(res2);
  148. CPP_assert(same_as<range_value_t<R2>, int>);
  149. CPP_assert(same_as<range_reference_t<R2>, const int&>);
  150. CPP_assert(same_as<range_rvalue_reference_t<R2>, const int&&>);
  151. }
  152. // test different orderings
  153. {
  154. auto res = views::set_symmetric_difference(views::reverse(i1_finite), views::reverse(i2_finite), [](int a, int b)
  155. {
  156. return a > b;
  157. });
  158. ::check_equal(res, {9, 6, 4, 4, 3, 3, 3, 2, 1, -3});
  159. CHECK(&*begin(res) == &*(begin(i2_finite) + 5));
  160. }
  161. struct B
  162. {
  163. int val;
  164. B(int i): val{i} {}
  165. bool operator==(const B& other) const
  166. {
  167. return val == other.val;
  168. }
  169. };
  170. struct D: public B
  171. {
  172. D(int i): B{i} {}
  173. D(B b): B{std::move(b)} {}
  174. };
  175. B b_finite[] = {B{-20}, B{-10}, B{1}, B{3}, B{3}, B{6}, B{8}, B{20}};
  176. D d_finite[] = {D{0}, D{2}, D{4}, D{6}};
  177. // sets with different element types, custom orderings
  178. {
  179. auto res = views::set_symmetric_difference(b_finite, d_finite, [](const B& a, const D& b){ return a.val < b.val; });
  180. CPP_assert(same_as<range_value_t<decltype(res)>, B>);
  181. CPP_assert(same_as<range_reference_t<decltype(res)>, B&>);
  182. CPP_assert(same_as<range_rvalue_reference_t<decltype(res)>, B&&>);
  183. ::check_equal(res, {B{-20}, B{-10}, B{0}, B{1}, B{2}, B{3}, B{3}, B{4}, B{8}, B{20}});
  184. auto it = begin(res);
  185. CHECK(&*it == &*begin(b_finite));
  186. advance(it, 2);
  187. CHECK(&*it == &*begin(d_finite));
  188. }
  189. // projections
  190. {
  191. auto res1 = views::set_symmetric_difference(b_finite, d_finite,
  192. less(),
  193. &B::val,
  194. &D::val
  195. );
  196. CPP_assert(same_as<range_value_t<decltype(res1)>, B>);
  197. CPP_assert(same_as<range_reference_t<decltype(res1)>, B&>);
  198. CPP_assert(same_as<range_rvalue_reference_t<decltype(res1)>, B&&>);
  199. ::check_equal(res1, {B{-20}, B{-10}, B{0}, B{1}, B{2}, B{3}, B{3}, B{4}, B{8}, B{20}});
  200. auto res2 = views::set_symmetric_difference(views::ints(-2, 10), b_finite,
  201. less(),
  202. identity(),
  203. [](const B& x){ return x.val; }
  204. );
  205. CPP_assert(same_as<range_value_t<decltype(res2)>, B>);
  206. CPP_assert(same_as<range_reference_t<decltype(res2)>, B>);
  207. CPP_assert(same_as<range_rvalue_reference_t<decltype(res2)>, B>);
  208. ::check_equal(res2, {B{-20}, B{-10}, B{-2}, B{-1}, B{0}, B{2}, B{3}, B{4}, B{5}, B{7}, B{9}, B{20}});
  209. }
  210. // move
  211. {
  212. auto v0 = to<std::vector<MoveOnlyString>>({"a","b","b","c","x","x"});
  213. auto v1 = to<std::vector<MoveOnlyString>>({"b","x","y","z"});
  214. auto res = views::set_symmetric_difference(v0, v1, [](const MoveOnlyString& a, const MoveOnlyString& b){return a<b;});
  215. std::vector<MoveOnlyString> expected;
  216. move(res, back_inserter(expected));
  217. ::check_equal(expected, {"a","b","c","x","y","z"});
  218. ::check_equal(v1, {"b","x","",""});
  219. ::check_equal(v0, {"","b","","","x",""});
  220. auto v0_greedy = to<std::vector<MoveOnlyString>>({"a","b","b","c","x","x"});
  221. auto v1_greedy = to<std::vector<MoveOnlyString>>({"b","x","y","z"});
  222. std::vector<MoveOnlyString> expected_greedy;
  223. set_symmetric_difference(v0_greedy, v1_greedy,
  224. move_into(back_inserter(expected_greedy)),
  225. [](const MoveOnlyString& a, const MoveOnlyString& b){return a<b;});
  226. ::check_equal(expected_greedy, expected);
  227. ::check_equal(v0_greedy, v0);
  228. ::check_equal(v1_greedy, v1);
  229. using R = decltype(res);
  230. CPP_assert(same_as<range_value_t<R>, MoveOnlyString>);
  231. CPP_assert(same_as<range_reference_t<R>, MoveOnlyString &>);
  232. CPP_assert(same_as<range_rvalue_reference_t<R>, MoveOnlyString &&>);
  233. }
  234. // WARNING: set_symmetric_difference between two infinite ranges can create infinite loops!
  235. // {
  236. // auto empty_range = views::set_symmetric_difference(views::ints, views::ints);
  237. // begin(empty_range); // infinite loop!
  238. // }
  239. // iterator (in)equality
  240. {
  241. int r1[] = {1, 2, 3};
  242. int r2[] = { 2, 3, 4, 5};
  243. auto res = views::set_symmetric_difference(r1, r2); // 1, 4, 5
  244. auto it1 = ranges::next(res.begin()); // *it1 == 4, member iterator into r1 points to r1.end()
  245. auto it2 = ranges::next(it1); // *it2 == 5, member iterator into r1 also points to r1.end()
  246. auto sentinel = res.end();
  247. CHECK(*it1 == 4);
  248. CHECK(*it2 == 5);
  249. CHECK(it1 != it2); // should be different even though member iterators into r1 are the same
  250. CHECK(it1 != sentinel);
  251. CHECK(ranges::next(it1, 2) == sentinel);
  252. CHECK(it2 != sentinel);
  253. CHECK(ranges::next(it2, 1) == sentinel);
  254. }
  255. {
  256. auto rng = views::set_symmetric_difference(
  257. debug_input_view<int const>{i1_finite},
  258. debug_input_view<int const>{i2_finite}
  259. );
  260. ::check_equal(rng, {-3, 1, 2, 3, 3, 3, 4, 4, 6, 9});
  261. }
  262. return test_result();
  263. }