subrange.cpp 8.1 KB

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  1. // Range v3 library
  2. //
  3. // Copyright Eric Niebler 2017-present
  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/all.hpp>
  15. #include <range/v3/view/ref.hpp>
  16. #include <range/v3/view/subrange.hpp>
  17. #include "../simple_test.hpp"
  18. #include "../test_utils.hpp"
  19. #include "../test_iterators.hpp"
  20. CPP_template(class Rng)(
  21. requires ranges::range<Rng>)
  22. ranges::borrowed_subrange_t<Rng> algorithm(Rng &&rng);
  23. struct Base {};
  24. struct Derived : Base {};
  25. int main()
  26. {
  27. using namespace ranges;
  28. std::vector<int> vi{1,2,3,4};
  29. ////////////////////////////////////////////////////////////////////////////
  30. // borrowed_subrange_t tests:
  31. // lvalues are ReferenceableRanges and do not dangle:
  32. CPP_assert(same_as<subrange<int*>,
  33. decltype(::algorithm(std::declval<int(&)[42]>()))>);
  34. CPP_assert(same_as<subrange<std::vector<int>::iterator>,
  35. decltype(::algorithm(vi))>);
  36. // subrange and ref_view are ReferenceableRanges and do not dangle:
  37. CPP_assert(same_as<subrange<int*>,
  38. decltype(::algorithm(std::declval<subrange<int*>>()))>);
  39. CPP_assert(same_as<subrange<int*>,
  40. decltype(::algorithm(std::declval<ref_view<int[42]>>()))>);
  41. // non-ReferenceableRange rvalue ranges dangle:
  42. CPP_assert(same_as<dangling,
  43. decltype(::algorithm(std::declval<std::vector<int>>()))>);
  44. CPP_assert(same_as<dangling,
  45. decltype(::algorithm(std::move(vi)))>);
  46. // Test that slicing conversions are not allowed.
  47. CPP_assert(constructible_from<subrange<Base*, Base*>, Base*, Base*>);
  48. CPP_assert(!constructible_from<subrange<Base*, Base*>, Derived*, Derived*>);
  49. CPP_assert(constructible_from<subrange<const Base*, const Base*>, Base*, Base*>);
  50. CPP_assert(!constructible_from<subrange<const Base*, const Base*>, Derived*, Derived*>);
  51. CPP_assert(!constructible_from<subrange<Base*, Base*>, subrange<Derived*, Derived*>>);
  52. CPP_assert(constructible_from<subrange<Base*, unreachable_sentinel_t>, Base*, unreachable_sentinel_t>);
  53. CPP_assert(!constructible_from<subrange<Base*, unreachable_sentinel_t>, Derived*, unreachable_sentinel_t>);
  54. CPP_assert(constructible_from<subrange<const Base*, unreachable_sentinel_t>, Base*, unreachable_sentinel_t>);
  55. CPP_assert(!constructible_from<subrange<const Base*, unreachable_sentinel_t>, Derived*, unreachable_sentinel_t>);
  56. CPP_assert(!constructible_from<subrange<Base*, unreachable_sentinel_t>, subrange<Derived*, unreachable_sentinel_t>>);
  57. CPP_assert(constructible_from<subrange<Base*, Base*, subrange_kind::sized>, Base*, Base*, std::size_t>);
  58. CPP_assert(!constructible_from<subrange<Base*, Base*, subrange_kind::sized>, Derived*, Base*, std::size_t>);
  59. CPP_assert(constructible_from<subrange<const Base*, const Base*, subrange_kind::sized>, Base*, const Base*, std::size_t>);
  60. CPP_assert(!constructible_from<subrange<const Base*, const Base*, subrange_kind::sized>, Derived*, const Base*, std::size_t>);
  61. CPP_assert(!constructible_from<subrange<Base*, Base*, subrange_kind::sized>, subrange<Derived*, Base*>, std::size_t>);
  62. CPP_assert(convertible_to<subrange<Base*, Base*>, std::pair<const Base*, const Base*>>);
  63. CPP_assert(!convertible_to<subrange<Derived*, Derived*>, std::pair<Base*, Base*>>);
  64. subrange<std::vector<int>::iterator> r0 {vi.begin(), vi.end()};
  65. static_assert(std::tuple_size<decltype(r0)>::value == 2, "");
  66. CPP_assert(same_as<std::vector<int>::iterator,
  67. std::tuple_element<0, decltype(r0)>::type>);
  68. CPP_assert(same_as<std::vector<int>::iterator,
  69. std::tuple_element<1, decltype(r0)>::type>);
  70. CPP_assert(sized_range<decltype(r0)>);
  71. CHECK(r0.size() == 4u);
  72. CHECK(r0.begin() == vi.begin());
  73. CHECK(get<0>(r0) == vi.begin());
  74. CHECK(r0.end() == vi.end());
  75. CHECK(get<1>(r0) == vi.end());
  76. r0 = r0.next();
  77. CHECK(r0.size() == 3u);
  78. {
  79. subrange<std::vector<int>::iterator> rng {vi.begin(), vi.end(), ranges::size(vi)};
  80. CHECK(rng.size() == 4u);
  81. CHECK(rng.begin() == vi.begin());
  82. CHECK(rng.end() == vi.end());
  83. }
  84. std::pair<std::vector<int>::iterator, std::vector<int>::iterator> p0 = r0;
  85. CHECK(p0.first == vi.begin()+1);
  86. CHECK(p0.second == vi.end());
  87. subrange<std::vector<int>::iterator, unreachable_sentinel_t> r1 { r0.begin(), {} };
  88. static_assert(std::tuple_size<decltype(r1)>::value == 2, "");
  89. CPP_assert(same_as<std::vector<int>::iterator,
  90. std::tuple_element<0, decltype(r1)>::type>);
  91. CPP_assert(same_as<unreachable_sentinel_t,
  92. std::tuple_element<1, decltype(r1)>::type>);
  93. CPP_assert(view_<decltype(r1)>);
  94. CPP_assert(!sized_range<decltype(r1)>);
  95. CHECK(r1.begin() == vi.begin()+1);
  96. r1.end() = unreachable;
  97. r0 = r0.next();
  98. ++r0.begin();
  99. CHECK(r0.begin() == vi.begin()+2);
  100. CHECK(r0.size() == 2u);
  101. r0 = {r0.begin(), --r0.end()}; // --r0.end();
  102. CHECK(r0.end() == vi.end()-1);
  103. CHECK(r0.size() == 1u);
  104. CHECK(r0.front() == 3);
  105. CHECK(r0.back() == 3);
  106. std::pair<std::vector<int>::iterator, unreachable_sentinel_t> p1 = r1;
  107. CHECK(p1.first == vi.begin()+1);
  108. std::list<int> li{1,2,3,4};
  109. using LI = std::list<int>::iterator;
  110. subrange<LI, LI, subrange_kind::sized> l0 {li.begin(), li.end(), li.size()};
  111. CPP_assert(view_<decltype(l0)> && sized_range<decltype(l0)>);
  112. CHECK(l0.begin() == li.begin());
  113. CHECK(l0.end() == li.end());
  114. CHECK(l0.size() == li.size());
  115. l0 = l0.next();
  116. CHECK(l0.begin() == next(li.begin()));
  117. CHECK(l0.end() == li.end());
  118. CHECK(l0.size() == li.size() - 1u);
  119. l0 = views::all(li);
  120. subrange<std::list<int>::iterator> l1 = l0;
  121. CPP_assert(!sized_range<decltype(l1)>);
  122. CHECK(l1.begin() == li.begin());
  123. CHECK(l1.end() == li.end());
  124. #if RANGES_CXX_DEDUCTION_GUIDES >= RANGES_CXX_DEDUCTION_GUIDES_17
  125. #if defined(__clang__) && __clang_major__ < 6
  126. // Workaround https://bugs.llvm.org/show_bug.cgi?id=33314
  127. RANGES_DIAGNOSTIC_PUSH
  128. RANGES_DIAGNOSTIC_IGNORE_UNDEFINED_FUNC_TEMPLATE
  129. #endif
  130. {
  131. subrange s0{vi.begin(), vi.end()};
  132. subrange s1{li.begin(), li.end()};
  133. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  134. CPP_assert(same_as<decltype(l1), decltype(s1)>);
  135. }
  136. {
  137. subrange s0{vi.begin(), vi.end(), ranges::size(vi)};
  138. subrange s1{li.begin(), li.end(), ranges::size(li)};
  139. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  140. CPP_assert(same_as<decltype(l0), decltype(s1)>);
  141. }
  142. {
  143. subrange s0{vi};
  144. subrange s1{li};
  145. subrange s2{views::all(vi)};
  146. subrange s3{views::all(li)};
  147. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  148. CPP_assert(same_as<decltype(l0), decltype(s1)>);
  149. CPP_assert(same_as<decltype(r0), decltype(s2)>);
  150. CPP_assert(same_as<decltype(l0), decltype(s3)>);
  151. }
  152. {
  153. subrange s0{r0};
  154. subrange s1{l0};
  155. subrange s2{l1};
  156. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  157. CPP_assert(same_as<decltype(l0), decltype(s1)>);
  158. CPP_assert(same_as<decltype(l1), decltype(s2)>);
  159. }
  160. {
  161. subrange s0{vi, ranges::size(vi)};
  162. subrange s1{li, ranges::size(li)};
  163. subrange s2{views::all(vi), ranges::size(vi)};
  164. subrange s3{views::all(li), ranges::size(li)};
  165. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  166. CPP_assert(same_as<decltype(l0), decltype(s1)>);
  167. CPP_assert(same_as<decltype(r0), decltype(s2)>);
  168. CPP_assert(same_as<decltype(l0), decltype(s3)>);
  169. }
  170. {
  171. subrange s0{r0, size(r0)};
  172. subrange s1{l0, size(l0)};
  173. subrange s2{l1, size(l0)};
  174. CPP_assert(same_as<decltype(r0), decltype(s0)>);
  175. CPP_assert(same_as<decltype(l0), decltype(s1)>);
  176. CPP_assert(same_as<decltype(l0), decltype(s2)>);
  177. }
  178. #if defined(__clang__) && __clang_major__ < 6
  179. RANGES_DIAGNOSTIC_POP
  180. #endif // clang bug workaround
  181. #endif // use deduction guides
  182. return ::test_result();
  183. }