1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 
11 #include <algorithm>
12 #include <array>
13 #include <cassert>
14 #include <concepts>
15 #include <deque>
16 #include <ranges>
17 #include <vector>
18 
19 #include "test_iterators.h"
20 #include "type_algorithms.h"
21 
22 template <class InContainer, class OutContainer>
test_containers()23 constexpr void test_containers() {
24   using InIter  = typename InContainer::iterator;
25   using OutIter = typename OutContainer::iterator;
26 
27   {
28     InContainer in{1, 2, 3, 4};
29     OutContainer out(4);
30 
31     std::same_as<std::ranges::in_out_result<InIter, OutIter>> auto ret =
32         std::ranges::copy_n(in.begin(), in.size(), out.begin());
33     assert(std::ranges::equal(in, out));
34     assert(ret.in == in.end());
35     assert(ret.out == out.end());
36   }
37 }
38 
39 template <class Iter, class Sent>
test_join_view()40 constexpr void test_join_view() {
41   auto to_subranges = std::views::transform([](auto& vec) {
42     return std::ranges::subrange(Iter(vec.data()), Sent(Iter(vec.data() + vec.size())));
43   });
44 
45   { // segmented -> contiguous
46     std::vector<std::vector<int>> vectors = {};
47     auto range                            = vectors | to_subranges;
48     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
49     std::array<int, 0> arr;
50 
51     std::ranges::copy_n((subrange_vector | std::views::join).begin(),
52                         std::ranges::distance(subrange_vector | std::views::join),
53                         arr.begin());
54     assert(std::ranges::equal(arr, std::array<int, 0>{}));
55   }
56   { // segmented -> contiguous
57     std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}};
58     auto range                            = vectors | to_subranges;
59     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
60     std::array<int, 10> arr;
61 
62     std::ranges::copy_n((subrange_vector | std::views::join).begin(),
63                         std::ranges::distance(subrange_vector | std::views::join),
64                         arr.begin());
65     assert(std::ranges::equal(arr, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
66   }
67   { // contiguous -> segmented
68     std::vector<std::vector<int>> vectors = {{0, 0, 0, 0}, {0, 0}, {0, 0, 0, 0}, {}};
69     auto range                            = vectors | to_subranges;
70     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
71     std::array arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
72 
73     std::ranges::copy_n(arr.begin(), arr.size(), (subrange_vector | std::views::join).begin());
74     assert(std::ranges::equal(subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
75   }
76   { // segmented -> segmented
77     std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}};
78     auto range1                           = vectors | to_subranges;
79     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range1.begin(), range1.end());
80     std::vector<std::vector<int>> to_vectors = {{0, 0, 0, 0}, {0, 0, 0, 0}, {}, {0, 0}};
81     auto range2                              = to_vectors | to_subranges;
82     std::vector<std::ranges::subrange<Iter, Sent>> to_subrange_vector(range2.begin(), range2.end());
83 
84     std::ranges::copy_n((subrange_vector | std::views::join).begin(),
85                         std::ranges::distance(subrange_vector | std::views::join),
86                         (to_subrange_vector | std::views::join).begin());
87     assert(std::ranges::equal(to_subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
88   }
89 }
90 
test_constexpr()91 constexpr bool test_constexpr() {
92   test_containers<std::vector<int>, std::vector<int>>();
93 
94   // TODO: this should be cpp20_input_iterator_list, not forward_iterator_list
95   types::for_each(types::forward_iterator_list<int*>{}, []<class Iter> {
96     test_join_view<Iter, Iter>();
97     test_join_view<Iter, sentinel_wrapper<Iter>>();
98     test_join_view<Iter, sized_sentinel<Iter>>();
99   });
100   return true;
101 }
102 
main(int,char **)103 int main(int, char**) {
104   test_containers<std::deque<int>, std::deque<int>>();
105   test_containers<std::deque<int>, std::vector<int>>();
106   test_containers<std::vector<int>, std::deque<int>>();
107 
108   test_constexpr();
109   static_assert(test_constexpr());
110 
111   return 0;
112 }
113