1 // Range v3 library
2 //
3 // Copyright Eric Niebler 2014-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
12 #include <list>
13 #include <vector>
14 #include <range/v3/core.hpp>
15 #include <range/v3/view/chunk.hpp>
16 #include <range/v3/view/drop.hpp>
17 #include <range/v3/view/iota.hpp>
18 #include <range/v3/view/join.hpp>
19 #include <range/v3/view/reverse.hpp>
20 #include <range/v3/view/take.hpp>
21 #include <range/v3/view/transform.hpp>
22 #include <range/v3/utility/copy.hpp>
23 #include "../simple_test.hpp"
24 #include "../test_utils.hpp"
25
main()26 int main()
27 {
28 using namespace ranges;
29
30 int rgi[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
31
32 {
33 auto rng0 = rgi | views::drop(6);
34 has_type<int &>(*begin(rng0));
35 CPP_assert(view_<decltype(rng0)>);
36 CPP_assert(common_range<decltype(rng0)>);
37 CPP_assert(sized_range<decltype(rng0)>);
38 CPP_assert(random_access_iterator<decltype(begin(rng0))>);
39 ::check_equal(rng0, {6, 7, 8, 9, 10});
40 CHECK(size(rng0) == 5u);
41
42 auto rng1 = rng0 | views::reverse;
43 has_type<int &>(*begin(rng1));
44 CPP_assert(view_<decltype(rng1)>);
45 CPP_assert(common_range<decltype(rng1)>);
46 CPP_assert(sized_range<decltype(rng1)>);
47 CPP_assert(random_access_iterator<decltype(begin(rng1))>);
48 ::check_equal(rng1, {10, 9, 8, 7, 6});
49 }
50
51 {
52 std::vector<int> v{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
53 auto rng2 = v | views::drop(6) | views::reverse;
54 has_type<int &>(*begin(rng2));
55 CPP_assert(view_<decltype(rng2)>);
56 CPP_assert(common_range<decltype(rng2)>);
57 CPP_assert(sized_range<decltype(rng2)>);
58 CPP_assert(random_access_iterator<decltype(begin(rng2))>);
59 ::check_equal(rng2, {10, 9, 8, 7, 6});
60 }
61
62 {
63 std::list<int> l{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
64 auto rng3 = l | views::drop(6);
65 has_type<int &>(*begin(rng3));
66 CPP_assert(view_<decltype(rng3)>);
67 CPP_assert(common_range<decltype(rng3)>);
68 CPP_assert(sized_range<decltype(rng3)>);
69 CPP_assert(bidirectional_iterator<decltype(begin(rng3))>);
70 CPP_assert(!random_access_iterator<decltype(begin(rng3))>);
71 ::check_equal(rng3, {6, 7, 8, 9, 10});
72 }
73
74 {
75 auto rng4 = views::iota(10) | views::drop(10);
76 CPP_assert(view_<decltype(rng4)>);
77 CPP_assert(!common_range<decltype(rng4)>);
78 CPP_assert(!sized_range<decltype(rng4)>);
79 static_assert(ranges::is_infinite<decltype(rng4)>::value, "");
80 auto b = ranges::begin(rng4);
81 CHECK(*b == 20);
82 CHECK(*(b+1) == 21);
83 }
84
85 {
86 auto rng5 = views::iota(10) | views::drop(10) | views::take(10) | views::reverse;
87 CPP_assert(view_<decltype(rng5)>);
88 CPP_assert(common_range<decltype(rng5)>);
89 CPP_assert(sized_range<decltype(rng5)>);
90 static_assert(!ranges::is_infinite<decltype(rng5)>::value, "");
91 ::check_equal(rng5, {29, 28, 27, 26, 25, 24, 23, 22, 21, 20});
92 CHECK(size(rng5) == 10u);
93 }
94
95 {
96 int some_ints[] = {0,1,2};
97 auto rng = make_subrange(some_ints + 0, some_ints + 1);
98 auto rng2 = views::drop(rng, 2);
99 CHECK(begin(rng2) == some_ints + 1);
100 CHECK(size(rng2) == 0u);
101 }
102
103 {
104 // Regression test for https://github.com/ericniebler/range-v3/issues/413
105 auto skips = [](std::vector<int> xs) {
106 return views::ints(0, (int)xs.size())
107 | views::transform([&](int n) {
108 return xs | views::chunk(n + 1)
109 | views::transform(views::drop(n))
110 | views::join;
111 })
112 | to<std::vector<std::vector<int>>>();
113 };
114 auto skipped = skips({1,2,3,4,5,6,7,8});
115 CHECK(skipped.size() == 8u);
116 if(skipped.size() >= 8u)
117 {
118 ::check_equal(skipped[0], {1,2,3,4,5,6,7,8});
119 ::check_equal(skipped[1], {2,4,6,8});
120 ::check_equal(skipped[2], {3,6});
121 ::check_equal(skipped[3], {4,8});
122 ::check_equal(skipped[4], {5});
123 ::check_equal(skipped[5], {6});
124 ::check_equal(skipped[6], {7});
125 ::check_equal(skipped[7], {8});
126 }
127 }
128
129 {
130 static int const some_ints[] = {0,1,2,3};
131 auto rng = debug_input_view<int const>{some_ints} | views::drop(2);
132 using R = decltype(rng);
133 CPP_assert(input_range<R> && view_<R>);
134 CPP_assert(!forward_range<R>);
135 CPP_assert(same_as<int const&, range_reference_t<R>>);
136 ::check_equal(rng, {2,3});
137 }
138
139 {
140 // regression test for #728
141 auto rng1 = views::iota(1) | views::chunk(6) | views::take(3);
142 int i = 2;
143 RANGES_FOR(auto o1, rng1)
144 {
145 auto rng2 = o1 | views::drop(1);
146 ::check_equal(rng2, {i, i+1, i+2, i+3, i+4});
147 i += 6;
148 }
149 }
150
151 {
152 // regression test for #813
153 static int const some_ints[] = {0,1,2,3};
154 auto rng = some_ints | views::drop(10);
155 CHECK(empty(rng));
156 }
157
158 return test_result();
159 }
160