cycle.cpp 10 KB

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  1. // Range v3 library
  2. //
  3. // Copyright Eric Niebler 2013-present
  4. // Copyright Gonzalo Brito Gadeschi 2015
  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 <list>
  13. #include <array>
  14. #include <vector>
  15. #include <memory>
  16. #include <forward_list>
  17. #include <range/v3/range_for.hpp>
  18. #include <range/v3/algorithm/count_if.hpp>
  19. #include <range/v3/view/cycle.hpp>
  20. #include <range/v3/view/take.hpp>
  21. #include <range/v3/view/take_exactly.hpp>
  22. #include <range/v3/view/iota.hpp>
  23. #include <range/v3/view/reverse.hpp>
  24. #include <range/v3/view/slice.hpp>
  25. #include <range/v3/view/c_str.hpp>
  26. #include "../simple_test.hpp"
  27. #include "../test_utils.hpp"
  28. using namespace ranges;
  29. template<typename Rng>
  30. void test_const_forward_range(Rng const &rng)
  31. {
  32. auto r = rng | views::cycle;
  33. static_assert(is_infinite<decltype(r)>{}, "");
  34. static_assert(!common_range<decltype(r)>, "");
  35. CHECK(distance(r | views::take_exactly(0)) == 0);
  36. CHECK(distance(r | views::take_exactly(1)) == 1);
  37. CHECK(distance(r | views::take_exactly(2)) == 2);
  38. CHECK(distance(r | views::take_exactly(3)) == 3);
  39. CHECK(distance(r | views::take_exactly(4)) == 4);
  40. CHECK(distance(r | views::take_exactly(6)) == 6);
  41. CHECK(distance(r | views::take_exactly(7)) == 7);
  42. CHECK(count_if(r | views::take_exactly(7), [](int) { return true; }) == 7);
  43. ::check_equal(r | views::take_exactly(0), std::array<int, 0>{});
  44. ::check_equal(r | views::take_exactly(1), {0});
  45. ::check_equal(r | views::take_exactly(2), {0, 1});
  46. ::check_equal(r | views::take_exactly(3), {0, 1, 2});
  47. ::check_equal(r | views::take_exactly(4), {0, 1, 2, 0});
  48. ::check_equal(r | views::take_exactly(6), {0, 1, 2, 0, 1, 2});
  49. ::check_equal(r | views::take_exactly(7), {0, 1, 2, 0, 1, 2, 0});
  50. CHECK(distance(r | views::take(0)) == 0);
  51. CHECK(distance(r | views::take(1)) == 1);
  52. CHECK(distance(r | views::take(2)) == 2);
  53. CHECK(distance(r | views::take(3)) == 3);
  54. CHECK(distance(r | views::take(4)) == 4);
  55. CHECK(distance(r | views::take(6)) == 6);
  56. CHECK(distance(r | views::take(7)) == 7);
  57. CHECK(count_if(r | views::take(7), [](int) { return true; }) == 7);
  58. ::check_equal(r | views::take(0), std::array<int, 0>{});
  59. ::check_equal(r | views::take(1), {0});
  60. ::check_equal(r | views::take(2), {0, 1});
  61. ::check_equal(r | views::take(3), {0, 1, 2});
  62. ::check_equal(r | views::take(4), {0, 1, 2, 0});
  63. ::check_equal(r | views::take(6), {0, 1, 2, 0, 1, 2});
  64. ::check_equal(r | views::take(7), {0, 1, 2, 0, 1, 2, 0});
  65. }
  66. template<typename Rng>
  67. void test_const_forward_reversed_range(Rng const &rng)
  68. {
  69. test_const_forward_range(rng);
  70. auto r = rng | views::reverse | views::cycle;
  71. static_assert(is_infinite<decltype(r)>{}, "");
  72. static_assert(!common_range<decltype(r)>, "");
  73. CHECK(distance(r | views::take_exactly(0)) == 0);
  74. CHECK(distance(r | views::take_exactly(1)) == 1);
  75. CHECK(distance(r | views::take_exactly(2)) == 2);
  76. CHECK(distance(r | views::take_exactly(3)) == 3);
  77. CHECK(distance(r | views::take_exactly(4)) == 4);
  78. CHECK(distance(r | views::take_exactly(6)) == 6);
  79. CHECK(distance(r | views::take_exactly(7)) == 7);
  80. CHECK(count_if(r | views::take_exactly(7), [](int) { return true; }) == 7);
  81. ::check_equal(r | views::take_exactly(0), std::array<int, 0>{});
  82. ::check_equal(r | views::take_exactly(1), {2});
  83. ::check_equal(r | views::take_exactly(2), {2, 1});
  84. ::check_equal(r | views::take_exactly(3), {2, 1, 0});
  85. ::check_equal(r | views::take_exactly(4), {2, 1, 0, 2});
  86. ::check_equal(r | views::take_exactly(6), {2, 1, 0, 2, 1, 0});
  87. ::check_equal(r | views::take_exactly(7), {2, 1, 0, 2, 1, 0, 2});
  88. CHECK(distance(r | views::take(0)) == 0);
  89. CHECK(distance(r | views::take(1)) == 1);
  90. CHECK(distance(r | views::take(2)) == 2);
  91. CHECK(distance(r | views::take(3)) == 3);
  92. CHECK(distance(r | views::take(4)) == 4);
  93. CHECK(distance(r | views::take(6)) == 6);
  94. CHECK(distance(r | views::take(7)) == 7);
  95. CHECK(count_if(r | views::take(7), [](int) { return true; }) == 7);
  96. ::check_equal(r | views::take(0), std::array<int, 0>{});
  97. ::check_equal(r | views::take(1), {2});
  98. ::check_equal(r | views::take(2), {2, 1});
  99. ::check_equal(r | views::take(3), {2, 1, 0});
  100. ::check_equal(r | views::take(4), {2, 1, 0, 2});
  101. ::check_equal(r | views::take(6), {2, 1, 0, 2, 1, 0});
  102. ::check_equal(r | views::take(7), {2, 1, 0, 2, 1, 0, 2});
  103. }
  104. template<typename Rng>
  105. void test_mutable_forward_range_reversed(Rng &rng)
  106. {
  107. test_const_forward_reversed_range(rng);
  108. int count = 2;
  109. RANGES_FOR(auto &&i, rng | views::cycle | views::take_exactly(6)) { i = ++count; }
  110. ::check_equal(rng | views::take_exactly(3), {6, 7, 8});
  111. }
  112. template<typename Rng>
  113. void test_forward_it(Rng const &rng)
  114. {
  115. auto r = rng | views::cycle;
  116. static_assert(forward_range<decltype(r)>, "");
  117. auto f = begin(r);
  118. static_assert(forward_iterator<decltype(f)>, "");
  119. CHECK((*f) == 0);
  120. auto n = next(f, 1);
  121. CHECK((*n) == 1);
  122. }
  123. template<typename Rng>
  124. void test_bidirectional_it(Rng const &rng)
  125. {
  126. test_forward_it(rng);
  127. auto r = rng | views::cycle;
  128. static_assert(bidirectional_range<decltype(r)>, "");
  129. auto f = begin(r);
  130. static_assert(bidirectional_iterator<decltype(f)>, "");
  131. CHECK((*f) == 0);
  132. auto n = next(f, 1);
  133. CHECK((*n) == 1);
  134. CHECK((--n) == f);
  135. }
  136. template<typename Rng>
  137. void test_random_access_it(Rng const &rng)
  138. {
  139. test_bidirectional_it(rng);
  140. auto r = rng | views::cycle;
  141. static_assert(random_access_range<decltype(r)>, "");
  142. auto f = begin(r);
  143. static_assert(random_access_iterator<decltype(f)>, "");
  144. auto m = begin(r) + 1;
  145. auto l = begin(r) + 2;
  146. auto f1 = begin(r) + 3;
  147. auto f2 = begin(r) + 6;
  148. CHECK(r[0] == 0);
  149. CHECK(r[1] == 1);
  150. CHECK(r[2] == 2);
  151. CHECK(r[3] == 0);
  152. CHECK(r[4] == 1);
  153. CHECK(r[5] == 2);
  154. CHECK((f + 3) == f1);
  155. CHECK((f + 6) == f2);
  156. CHECK((f1 + 3) == f2);
  157. CHECK((f2 - 3) == f1);
  158. CHECK((f2 - 6) == f);
  159. auto e = end(r);
  160. CHECK(*f == 0);
  161. CHECK(f[0] == 0);
  162. CHECK(f[1] == 1);
  163. CHECK(f[2] == 2);
  164. CHECK(f[3] == 0);
  165. CHECK(f[4] == 1);
  166. CHECK(f[5] == 2);
  167. CHECK(*m == 1);
  168. CHECK(m[0] == 1);
  169. CHECK(m[1] == 2);
  170. CHECK(m[2] == 0);
  171. CHECK(m[3] == 1);
  172. CHECK(m[4] == 2);
  173. CHECK(m[5] == 0);
  174. CHECK(m[-1] == 0);
  175. CHECK(*l == 2);
  176. CHECK(l[0] == 2);
  177. CHECK(l[1] == 0);
  178. CHECK(l[2] == 1);
  179. CHECK(l[3] == 2);
  180. CHECK(l[4] == 0);
  181. CHECK(l[5] == 1);
  182. CHECK(l[-1] == 1);
  183. CHECK(l[-2] == 0);
  184. CHECK(f != e);
  185. auto cur = f;
  186. for (int i = 0; i < 100; ++i, ++cur)
  187. {
  188. CHECK((next(begin(r), i) - f) == i);
  189. CHECK((cur - f) == i);
  190. if(i > 0)
  191. CHECK((cur - m) == i - 1);
  192. if(i > 1)
  193. CHECK((cur - l) == i - 2);
  194. }
  195. }
  196. int main()
  197. {
  198. // initializer list
  199. {
  200. auto il = {0, 1, 2};
  201. test_random_access_it(il);
  202. test_const_forward_reversed_range(il);
  203. const auto cil = {0, 1, 2};
  204. test_random_access_it(cil);
  205. test_const_forward_reversed_range(cil);
  206. }
  207. // array
  208. {
  209. std::array<int, 3> a = {{0, 1, 2}};
  210. test_random_access_it(a);
  211. test_mutable_forward_range_reversed(a);
  212. const std::array<int, 3> ca = {{0, 1, 2}};
  213. test_random_access_it(ca);
  214. test_const_forward_reversed_range(ca);
  215. }
  216. // list
  217. {
  218. std::list<int> l = {0, 1, 2};
  219. test_bidirectional_it(l);
  220. test_mutable_forward_range_reversed(l);
  221. const std::list<int> cl = {0, 1, 2};
  222. test_bidirectional_it(cl);
  223. test_const_forward_reversed_range(cl);
  224. }
  225. // forward list
  226. {
  227. std::forward_list<int> l = {0, 1, 2};
  228. test_forward_it(l);
  229. test_const_forward_range(l);
  230. const std::forward_list<int> cl = {0, 1, 2};
  231. test_forward_it(cl);
  232. test_const_forward_range(cl);
  233. }
  234. // move-only types
  235. {
  236. std::array<std::unique_ptr<int>, 3> a = {{
  237. std::unique_ptr<int>(new int(0)),
  238. std::unique_ptr<int>(new int(1)),
  239. std::unique_ptr<int>(new int(2))
  240. }};
  241. auto r = a | views::cycle;
  242. auto b = iter_move(r.begin() + 4);
  243. CHECK((*(b)) == 1);
  244. }
  245. // infinite
  246. {
  247. int count = 0;
  248. auto il = {0, 1, 2};
  249. auto v = 10;
  250. RANGES_FOR(auto&& i, il | views::cycle)
  251. {
  252. if (count == 42) { break; }
  253. v = i;
  254. ++count;
  255. }
  256. CHECK(count == 42);
  257. CHECK(v == 2);
  258. }
  259. // non-bounded
  260. {
  261. auto sz = views::c_str((char const *)"hi! ");
  262. ::check_equal(
  263. sz | views::cycle | views::take(10),
  264. {'h','i','!',' ','h','i','!',' ','h','i'} );
  265. auto rng = sz | views::cycle;
  266. auto it = ranges::begin(rng);
  267. CHECK(*it == 'h');
  268. CHECK(*++it == 'i');
  269. CHECK(*++it == '!');
  270. CHECK(*++it == ' ');
  271. CHECK(*++it == 'h');
  272. CHECK(*--it == ' ');
  273. CHECK(*--it == '!');
  274. CHECK(*--it == 'i');
  275. CHECK(*--it == 'h');
  276. rng = sz | views::cycle;
  277. it = ranges::begin(rng);
  278. it += 4;
  279. CHECK(*it == 'h');
  280. }
  281. // Cycle of an infinite range,
  282. // https://github.com/ericniebler/range-v3/issues/780
  283. {
  284. auto view = ranges::views::iota(0)
  285. | ranges::views::cycle;
  286. CHECK(view[5] == 5);
  287. }
  288. // Composing ranges::views::cycle with ranges::views::slice
  289. // https://github.com/ericniebler/range-v3/issues/778
  290. {
  291. const auto length = 512;
  292. const auto k = 16;
  293. std::vector<int> input(length);
  294. auto output = ranges::views::cycle(input)
  295. | ranges::views::slice(length + k, 2 * length + k);
  296. CHECK(bool(ranges::begin(output) != ranges::end(output)));
  297. CHECK(ranges::size(output) == 512u);
  298. CHECK(ranges::distance(output) == 512);
  299. }
  300. return test_result();
  301. }