xref: /llvm-project/libcxx/test/std/algorithms/ranges_robust_against_dangling.pass.cpp (revision 04760bfadb399cc4ded9b32bd523ec7703aa7462)
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 // <algorithm>
12 //
13 // Range algorithms should return `std::ranges::dangling` when given a dangling range.
14 
15 #include <algorithm>
16 
17 #include <array>
18 #include <concepts>
19 #include <functional>
20 #include <iterator>
21 #include <ranges>
22 #include <random>
23 #include <utility>
24 
25 #include "test_iterators.h"
26 
27 struct NonBorrowedRange {
28   using Iter = int*;
29   using Sent = sentinel_wrapper<Iter>;
30 
31   int* data_;
32   std::size_t size_;
33 
34   template <std::size_t N>
35   constexpr explicit NonBorrowedRange(std::array<int, N>& arr) : data_{arr.data()}, size_{arr.size()} {}
36 
37   constexpr Iter begin() const { return data_; };
38   constexpr Sent end() const { return Sent{data_ + size_}; };
39 };
40 
41 using R = NonBorrowedRange;
42 
43 // (dangling_in, ...)
44 template <class ExpectedT = std::ranges::dangling, class Func, std::ranges::range Input, class ...Args>
45 constexpr void dangling_1st(Func&& func, Input& in, Args&& ...args) {
46   decltype(auto) result = func(R(in), std::forward<Args>(args)...);
47   static_assert(std::same_as<decltype(result), ExpectedT>);
48 }
49 
50 // (in, dangling_in, ...)
51 template <class ExpectedT = std::ranges::dangling, class Func, std::ranges::range Input, class ...Args>
52 constexpr void dangling_2nd(Func&& func, Input& in1, Input& in2, Args&& ...args) {
53   decltype(auto) result = func(in1, R(in2), std::forward<Args>(args)...);
54   static_assert(std::same_as<decltype(result), ExpectedT>);
55 }
56 
57 // (dangling_in1, dangling_in2, ...)
58 template <class ExpectedT = std::ranges::dangling, class Func, std::ranges::range Input, class ...Args>
59 constexpr void dangling_both(Func&& func, Input& in1, Input& in2, Args&& ...args) {
60   decltype(auto) result = func(R(in1), R(in2), std::forward<Args>(args)...);
61   static_assert(std::same_as<decltype(result), ExpectedT>);
62 }
63 
64 std::mt19937 rand_gen() { return std::mt19937(); }
65 
66 // TODO: also check the iterator values for algorithms that return `*_result` types.
67 constexpr bool test_all() {
68   using std::ranges::dangling;
69 
70   using std::ranges::binary_transform_result;
71   using std::ranges::copy_result;
72   using std::ranges::copy_backward_result;
73   using std::ranges::copy_if_result;
74   using std::ranges::for_each_result;
75   using std::ranges::merge_result;
76   using std::ranges::minmax_result;
77   using std::ranges::mismatch_result;
78   using std::ranges::move_result;
79   using std::ranges::move_backward_result;
80   using std::ranges::next_permutation_result;
81   using std::ranges::partial_sort_copy_result;
82   using std::ranges::partition_copy_result;
83   using std::ranges::prev_permutation_result;
84   using std::ranges::remove_copy_result;
85   using std::ranges::remove_copy_if_result;
86   using std::ranges::replace_copy_result;
87   using std::ranges::replace_copy_if_result;
88   using std::ranges::reverse_copy_result;
89   using std::ranges::rotate_copy_result;
90   using std::ranges::set_difference_result;
91   using std::ranges::set_intersection_result;
92   using std::ranges::set_symmetric_difference_result;
93   using std::ranges::set_union_result;
94   using std::ranges::swap_ranges_result;
95   using std::ranges::unary_transform_result;
96   using std::ranges::unique_copy_result;
97   using InIter = std::array<int, 3>::iterator;
98   using OutIter = std::array<int, 6>::iterator;
99 
100   auto unary_pred = [](int i) { return i > 0; };
101   auto binary_pred = [](int i, int j) { return i < j; };
102   auto gen = [] { return 42; };
103 
104   std::array in = {1, 2, 3};
105   std::array in2 = {4, 5, 6};
106 
107   auto mid = in.data() + 1;
108 
109   std::array output = {7, 8, 9, 10, 11, 12};
110   auto out = output.begin();
111   auto out2 = output.begin() + 1;
112 
113   int x = 2;
114   std::size_t count = 1;
115 
116   dangling_1st(std::ranges::find, in, x);
117   dangling_1st(std::ranges::find_if, in, unary_pred);
118   dangling_1st(std::ranges::find_if_not, in, unary_pred);
119 #if TEST_STD_VER >= 23
120   dangling_1st(std::ranges::find_last, in, x);
121   dangling_1st(std::ranges::find_last_if, in, unary_pred);
122   dangling_1st(std::ranges::find_last_if_not, in, unary_pred);
123 #endif
124   dangling_1st(std::ranges::find_first_of, in, in2);
125   dangling_1st(std::ranges::adjacent_find, in);
126   dangling_1st<mismatch_result<dangling, InIter>>(std::ranges::mismatch, in, in2);
127   dangling_2nd<mismatch_result<InIter, dangling>>(std::ranges::mismatch, in, in2);
128   dangling_both<mismatch_result<dangling, dangling>>(std::ranges::mismatch, in, in2);
129   dangling_1st(std::ranges::partition_point, in, unary_pred);
130   dangling_1st(std::ranges::lower_bound, in, x);
131   dangling_1st(std::ranges::upper_bound, in, x);
132   dangling_1st(std::ranges::equal_range, in, x);
133   dangling_1st(std::ranges::min_element, in);
134   dangling_1st(std::ranges::max_element, in);
135   dangling_1st<minmax_result<dangling>>(std::ranges::minmax_element, in);
136   dangling_1st(std::ranges::search, in, in2);
137   dangling_1st(std::ranges::search_n, in, count, x);
138   dangling_1st(std::ranges::find_end, in, in2);
139   dangling_1st(std::ranges::is_sorted_until, in);
140   dangling_1st(std::ranges::is_heap_until, in);
141   dangling_1st<for_each_result<dangling, decltype(unary_pred)>>(std::ranges::for_each, in, unary_pred);
142   dangling_1st<copy_result<dangling, OutIter>>(std::ranges::copy, in, out);
143   dangling_1st<copy_backward_result<dangling, OutIter>>(std::ranges::copy_backward, in, output.end());
144   dangling_1st<copy_if_result<dangling, OutIter>>(std::ranges::copy_if, in, out, unary_pred);
145   dangling_1st<move_result<dangling, OutIter>>(std::ranges::move, in, out);
146   dangling_1st<move_backward_result<dangling, OutIter>>(std::ranges::move_backward, in, output.end());
147   dangling_1st(std::ranges::fill, in, x);
148   { // transform
149     using OutTransformIter = std::array<bool, 3>::iterator;
150     std::array out_transform = {false, true, true};
151     dangling_1st<unary_transform_result<dangling, OutTransformIter>>(std::ranges::transform, in, out_transform.begin(), unary_pred);
152     dangling_1st<binary_transform_result<dangling, InIter, OutTransformIter>>(
153         std::ranges::transform, in, in2, out_transform.begin(), binary_pred);
154     dangling_2nd<binary_transform_result<InIter, dangling, OutTransformIter>>(
155         std::ranges::transform, in, in2, out_transform.begin(), binary_pred);
156     dangling_both<binary_transform_result<dangling, dangling, OutTransformIter>>(
157         std::ranges::transform, in, in2, out_transform.begin(), binary_pred);
158   }
159   dangling_1st(std::ranges::generate, in, gen);
160   dangling_1st<remove_copy_result<dangling, OutIter>>(std::ranges::remove_copy, in, out, x);
161   dangling_1st<remove_copy_if_result<dangling, OutIter>>(std::ranges::remove_copy_if, in, out, unary_pred);
162   dangling_1st(std::ranges::replace, in, x, x);
163   dangling_1st(std::ranges::replace_if, in, std::identity{}, x);
164   dangling_1st<replace_copy_result<dangling, OutIter>>(std::ranges::replace_copy, in, out, x, x);
165   dangling_1st<replace_copy_if_result<dangling, OutIter>>(std::ranges::replace_copy_if, in, out, unary_pred, x);
166   dangling_1st<swap_ranges_result<dangling, InIter>>(std::ranges::swap_ranges, in, in2);
167   dangling_2nd<swap_ranges_result<InIter, dangling>>(std::ranges::swap_ranges, in, in2);
168   dangling_both<swap_ranges_result<dangling, dangling>>(std::ranges::swap_ranges, in, in2);
169   dangling_1st<reverse_copy_result<dangling, OutIter>>(std::ranges::reverse_copy, in, out);
170   dangling_1st<rotate_copy_result<dangling, OutIter>>(std::ranges::rotate_copy, in, mid, out);
171   dangling_1st<unique_copy_result<dangling, OutIter>>(std::ranges::unique_copy, in, out);
172   dangling_1st<partition_copy_result<dangling, OutIter, OutIter>>(std::ranges::partition_copy, in, out, out2, unary_pred);
173   dangling_1st<partial_sort_copy_result<dangling, InIter>>(std::ranges::partial_sort_copy, in, in2);
174   dangling_2nd<partial_sort_copy_result<InIter, dangling>>(std::ranges::partial_sort_copy, in, in2);
175   dangling_both<partial_sort_copy_result<dangling, dangling>>(std::ranges::partial_sort_copy, in, in2);
176   dangling_1st<merge_result<dangling, InIter, OutIter>>(std::ranges::merge, in, in2, out);
177   dangling_2nd<merge_result<InIter, dangling, OutIter>>(std::ranges::merge, in, in2, out);
178   dangling_both<merge_result<dangling, dangling, OutIter>>(std::ranges::merge, in, in2, out);
179   dangling_1st<set_difference_result<dangling, OutIter>>(std::ranges::set_difference, in, in2, out);
180   dangling_1st<set_intersection_result<dangling, InIter, OutIter>>(std::ranges::set_intersection, in, in2, out);
181   dangling_2nd<set_intersection_result<InIter, dangling, OutIter>>(std::ranges::set_intersection, in, in2, out);
182   dangling_both<set_intersection_result<dangling, dangling, OutIter>>(std::ranges::set_intersection, in, in2, out);
183   dangling_1st<set_symmetric_difference_result<dangling, InIter, OutIter>>(
184       std::ranges::set_symmetric_difference, in, in2, out);
185   dangling_2nd<set_symmetric_difference_result<InIter, dangling, OutIter>>(
186       std::ranges::set_symmetric_difference, in, in2, out);
187   dangling_both<set_symmetric_difference_result<dangling, dangling, OutIter>>(
188       std::ranges::set_symmetric_difference, in, in2, out);
189   dangling_1st<set_union_result<dangling, InIter, OutIter>>(std::ranges::set_union, in, in2, out);
190   dangling_2nd<set_union_result<InIter, dangling, OutIter>>(std::ranges::set_union, in, in2, out);
191   dangling_both<set_union_result<dangling, dangling, OutIter>>(std::ranges::set_union, in, in2, out);
192   dangling_1st(std::ranges::remove, in, x);
193   dangling_1st(std::ranges::remove_if, in, unary_pred);
194   dangling_1st(std::ranges::reverse, in);
195   dangling_1st(std::ranges::rotate, in, mid);
196   if (!std::is_constant_evaluated()) // `shuffle` isn't `constexpr`.
197     dangling_1st(std::ranges::shuffle, in, rand_gen());
198   dangling_1st(std::ranges::unique, in);
199   dangling_1st(std::ranges::partition, in, unary_pred);
200   if (!std::is_constant_evaluated())
201     dangling_1st(std::ranges::stable_partition, in, unary_pred);
202   dangling_1st(std::ranges::sort, in);
203   if (!std::is_constant_evaluated())
204     dangling_1st(std::ranges::stable_sort, in);
205   dangling_1st(std::ranges::partial_sort, in, mid);
206   dangling_1st(std::ranges::nth_element, in, mid);
207   if (!std::is_constant_evaluated())
208     dangling_1st(std::ranges::inplace_merge, in, mid);
209   dangling_1st(std::ranges::make_heap, in);
210   dangling_1st(std::ranges::push_heap, in);
211   dangling_1st(std::ranges::pop_heap, in);
212   dangling_1st(std::ranges::make_heap, in);
213   dangling_1st(std::ranges::sort_heap, in);
214   dangling_1st<prev_permutation_result<dangling>>(std::ranges::prev_permutation, in);
215   dangling_1st<next_permutation_result<dangling>>(std::ranges::next_permutation, in);
216 
217   return true;
218 }
219 
220 int main(int, char**) {
221   test_all();
222   static_assert(test_all());
223 
224   return 0;
225 }
226