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 // TODO: make `join_view` non-experimental once D2770 is implemented.
11 // UNSUPPORTED: !c++experimental
12 
13 #include <algorithm>
14 #include <array>
15 #include <cassert>
16 #include <concepts>
17 #include <deque>
18 #include <ranges>
19 #include <vector>
20 
21 #include "test_iterators.h"
22 #include "type_algorithms.h"
23 
24 template <class InContainer, class OutContainer>
25 constexpr void test_containers() {
26   using InIter  = typename InContainer::iterator;
27   using OutIter = typename OutContainer::iterator;
28 
29   {
30     InContainer in{1, 2, 3, 4};
31     OutContainer out(4);
32 
33     std::same_as<std::ranges::in_out_result<InIter, OutIter>> auto ret =
34         std::ranges::copy(in.begin(), in.end(), out.begin());
35     assert(std::ranges::equal(in, out));
36     assert(ret.in == in.end());
37     assert(ret.out == out.end());
38   }
39   {
40     InContainer in{1, 2, 3, 4};
41     OutContainer out(4);
42     std::same_as<std::ranges::in_out_result<InIter, OutIter>> auto ret = std::ranges::copy(in, out.begin());
43     assert(std::ranges::equal(in, out));
44     assert(ret.in == in.end());
45     assert(ret.out == out.end());
46   }
47 }
48 
49 template <class Iter, class Sent>
50 constexpr void test_join_view() {
51   auto to_subranges = std::views::transform([](auto& vec) {
52     return std::ranges::subrange(Iter(vec.data()), Sent(Iter(vec.data() + vec.size())));
53   });
54 
55   { // segmented -> contiguous
56     std::vector<std::vector<int>> vectors = {};
57     auto range                            = vectors | to_subranges;
58     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
59     std::array<int, 0> arr;
60 
61     std::ranges::copy(subrange_vector | std::views::join, arr.begin());
62     assert(std::ranges::equal(arr, std::array<int, 0>{}));
63   }
64   { // segmented -> contiguous
65     std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}};
66     auto range                            = vectors | to_subranges;
67     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
68     std::array<int, 10> arr;
69 
70     std::ranges::copy(subrange_vector | std::views::join, arr.begin());
71     assert(std::ranges::equal(arr, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
72   }
73   { // contiguous -> segmented
74     std::vector<std::vector<int>> vectors = {{0, 0, 0, 0}, {0, 0}, {0, 0, 0, 0}, {}};
75     auto range                            = vectors | to_subranges;
76     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end());
77     std::array arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
78 
79     std::ranges::copy(arr, (subrange_vector | std::views::join).begin());
80     assert(std::ranges::equal(subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
81   }
82   { // segmented -> segmented
83     std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}};
84     auto range1                           = vectors | to_subranges;
85     std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range1.begin(), range1.end());
86     std::vector<std::vector<int>> to_vectors = {{0, 0, 0, 0}, {0, 0, 0, 0}, {}, {0, 0}};
87     auto range2                              = to_vectors | to_subranges;
88     std::vector<std::ranges::subrange<Iter, Sent>> to_subrange_vector(range2.begin(), range2.end());
89 
90     std::ranges::copy(subrange_vector | std::views::join, (to_subrange_vector | std::views::join).begin());
91     assert(std::ranges::equal(to_subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}));
92   }
93 }
94 
95 int main(int, char**) {
96   if (!std::is_constant_evaluated()) {
97     test_containers<std::deque<int>, std::deque<int>>();
98     test_containers<std::deque<int>, std::vector<int>>();
99     test_containers<std::vector<int>, std::deque<int>>();
100     test_containers<std::vector<int>, std::vector<int>>();
101   }
102 
103   types::for_each(types::forward_iterator_list<int*>{}, []<class Iter> {
104     test_join_view<Iter, Iter>();
105     test_join_view<Iter, sentinel_wrapper<Iter>>();
106     test_join_view<Iter, sized_sentinel<Iter>>();
107   });
108 
109   return 0;
110 }
111