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 // <algorithm>
10 
11 // UNSUPPORTED: c++03, c++11, c++14, c++17
12 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
13 
14 // template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
15 //   requires indirectly_movable<I, O>
16 //   constexpr ranges::move_result<I, O>
17 //     ranges::move(I first, S last, O result);
18 // template<input_range R, weakly_incrementable O>
19 //   requires indirectly_movable<iterator_t<R>, O>
20 //   constexpr ranges::move_result<borrowed_iterator_t<R>, O>
21 //     ranges::move(R&& r, O result);
22 
23 #include <algorithm>
24 #include <array>
25 #include <cassert>
26 #include <ranges>
27 
28 #include "almost_satisfies_types.h"
29 #include "MoveOnly.h"
30 #include "test_iterators.h"
31 
32 template <class In, class Out = In, class Sent = sentinel_wrapper<In>>
33 concept HasMoveIt = requires(In in, Sent sent, Out out) { std::ranges::move(in, sent, out); };
34 
35 static_assert(HasMoveIt<int*>);
36 static_assert(!HasMoveIt<InputIteratorNotDerivedFrom>);
37 static_assert(!HasMoveIt<InputIteratorNotIndirectlyReadable>);
38 static_assert(!HasMoveIt<InputIteratorNotInputOrOutputIterator>);
39 static_assert(!HasMoveIt<int*, WeaklyIncrementableNotMovable>);
40 struct NotIndirectlyMovable {};
41 static_assert(!HasMoveIt<int*, NotIndirectlyMovable*>);
42 static_assert(!HasMoveIt<int*, int*, SentinelForNotSemiregular>);
43 static_assert(!HasMoveIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
44 
45 template <class Range, class Out>
46 concept HasMoveR = requires(Range range, Out out) { std::ranges::move(range, out); };
47 
48 static_assert(HasMoveR<std::array<int, 10>, int*>);
49 static_assert(!HasMoveR<InputRangeNotDerivedFrom, int*>);
50 static_assert(!HasMoveR<InputRangeNotIndirectlyReadable, int*>);
51 static_assert(!HasMoveR<InputRangeNotInputOrOutputIterator, int*>);
52 static_assert(!HasMoveR<WeaklyIncrementableNotMovable, int*>);
53 static_assert(!HasMoveR<UncheckedRange<NotIndirectlyMovable*>, int*>);
54 static_assert(!HasMoveR<InputRangeNotSentinelSemiregular, int*>);
55 static_assert(!HasMoveR<InputRangeNotSentinelEqualityComparableWith, int*>);
56 static_assert(!HasMoveR<UncheckedRange<int*>, WeaklyIncrementableNotMovable>);
57 
58 static_assert(std::is_same_v<std::ranges::move_result<int, long>, std::ranges::in_out_result<int, long>>);
59 
60 template <class In, class Out, class Sent, int N>
61 constexpr void test(std::array<int, N> in) {
62   {
63     std::array<int, N> out;
64     std::same_as<std::ranges::in_out_result<In, Out>> decltype(auto) ret =
65       std::ranges::move(In(in.data()), Sent(In(in.data() + in.size())), Out(out.data()));
66     assert(in == out);
67     assert(base(ret.in) == in.data() + in.size());
68     assert(base(ret.out) == out.data() + out.size());
69   }
70   {
71     std::array<int, N> out;
72     auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
73     std::same_as<std::ranges::in_out_result<In, Out>> decltype(auto) ret =
74         std::ranges::move(range, Out(out.data()));
75     assert(in == out);
76     assert(base(ret.in) == in.data() + in.size());
77     assert(base(ret.out) == out.data() + out.size());
78   }
79 }
80 
81 template <class In, class Out, class Sent = In>
82 constexpr void test_iterators() {
83   // simple test
84   test<In, Out, Sent, 4>({1, 2, 3, 4});
85   // check that an empty range works
86   test<In, Out, Sent, 0>({});
87 }
88 
89 template <class Out>
90 constexpr void test_in_iterators() {
91   test_iterators<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
92   test_iterators<forward_iterator<int*>, Out>();
93   test_iterators<bidirectional_iterator<int*>, Out>();
94   test_iterators<random_access_iterator<int*>, Out>();
95   test_iterators<contiguous_iterator<int*>, Out>();
96 }
97 
98 template <class Out>
99 constexpr void test_proxy_in_iterators() {
100   test_iterators<ProxyIterator<cpp20_input_iterator<int*>>, Out, sentinel_wrapper<ProxyIterator<cpp20_input_iterator<int*>>>>();
101   test_iterators<ProxyIterator<forward_iterator<int*>>, Out>();
102   test_iterators<ProxyIterator<bidirectional_iterator<int*>>, Out>();
103   test_iterators<ProxyIterator<random_access_iterator<int*>>, Out>();
104   test_iterators<ProxyIterator<contiguous_iterator<int*>>, Out>();
105 }
106 
107 struct IteratorWithMoveIter {
108   using value_type = int;
109   using difference_type = int;
110   explicit IteratorWithMoveIter() = default;
111   int* ptr;
112   constexpr IteratorWithMoveIter(int* ptr_) : ptr(ptr_) {}
113 
114   constexpr int& operator*() const; // iterator with iter_move should not be dereferenced
115 
116   constexpr IteratorWithMoveIter& operator++() { ++ptr; return *this; }
117   constexpr IteratorWithMoveIter operator++(int) { auto ret = *this; ++*this; return ret; }
118 
119   friend constexpr int iter_move(const IteratorWithMoveIter&) { return 42; }
120 
121   constexpr bool operator==(const IteratorWithMoveIter& other) const = default;
122 };
123 
124 constexpr bool test() {
125   test_in_iterators<cpp17_output_iterator<int*>>();
126   test_in_iterators<cpp20_output_iterator<int*>>();
127   test_in_iterators<cpp17_input_iterator<int*>>();
128   test_in_iterators<cpp20_input_iterator<int*>>();
129   test_in_iterators<forward_iterator<int*>>();
130   test_in_iterators<bidirectional_iterator<int*>>();
131   test_in_iterators<random_access_iterator<int*>>();
132   test_in_iterators<contiguous_iterator<int*>>();
133 
134   test_proxy_in_iterators<ProxyIterator<cpp20_input_iterator<int*>>>();
135   test_proxy_in_iterators<ProxyIterator<forward_iterator<int*>>>();
136   test_proxy_in_iterators<ProxyIterator<bidirectional_iterator<int*>>>();
137   test_proxy_in_iterators<ProxyIterator<random_access_iterator<int*>>>();
138   test_proxy_in_iterators<ProxyIterator<contiguous_iterator<int*>>>();
139 
140   { // check that a move-only type works
141     {
142       MoveOnly a[] = {1, 2, 3};
143       MoveOnly b[3];
144       std::ranges::move(a, std::begin(b));
145       assert(b[0].get() == 1);
146       assert(b[1].get() == 2);
147       assert(b[2].get() == 3);
148     }
149     {
150       MoveOnly a[] = {1, 2, 3};
151       MoveOnly b[3];
152       std::ranges::move(std::begin(a), std::end(a), std::begin(b));
153       assert(b[0].get() == 1);
154       assert(b[1].get() == 2);
155       assert(b[2].get() == 3);
156     }
157   }
158 
159   { // check that a move-only type works for ProxyIterator
160     {
161       MoveOnly a[] = {1, 2, 3};
162       MoveOnly b[3];
163       ProxyRange proxyA{a};
164       ProxyRange proxyB{b};
165       std::ranges::move(proxyA, std::begin(proxyB));
166       assert(b[0].get() == 1);
167       assert(b[1].get() == 2);
168       assert(b[2].get() == 3);
169     }
170     {
171       MoveOnly a[] = {1, 2, 3};
172       MoveOnly b[3];
173       ProxyRange proxyA{a};
174       ProxyRange proxyB{b};
175       std::ranges::move(std::begin(proxyA), std::end(proxyA), std::begin(proxyB));
176       assert(b[0].get() == 1);
177       assert(b[1].get() == 2);
178       assert(b[2].get() == 3);
179     }
180   }
181 
182   { // check that ranges::dangling is returned
183     std::array<int, 4> out;
184     std::same_as<std::ranges::in_out_result<std::ranges::dangling, int*>> decltype(auto) ret =
185       std::ranges::move(std::array {1, 2, 3, 4}, out.data());
186     assert(ret.out == out.data() + 4);
187     assert((out == std::array{1, 2, 3, 4}));
188   }
189 
190   { // check that an iterator is returned with a borrowing range
191     std::array in {1, 2, 3, 4};
192     std::array<int, 4> out;
193     std::same_as<std::ranges::in_out_result<int*, int*>> decltype(auto) ret =
194         std::ranges::move(std::views::all(in), out.data());
195     assert(ret.in == in.data() + 4);
196     assert(ret.out == out.data() + 4);
197     assert(in == out);
198   }
199 
200   { // check that every element is moved exactly once
201     struct MoveOnce {
202       bool moved = false;
203       constexpr MoveOnce() = default;
204       constexpr MoveOnce(const MoveOnce& other) = delete;
205       constexpr MoveOnce& operator=(MoveOnce&& other) {
206         assert(!other.moved);
207         moved = true;
208         return *this;
209       }
210     };
211     {
212       std::array<MoveOnce, 4> in {};
213       std::array<MoveOnce, 4> out {};
214       auto ret = std::ranges::move(in.begin(), in.end(), out.begin());
215       assert(ret.in == in.end());
216       assert(ret.out == out.end());
217       assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.moved; }));
218     }
219     {
220       std::array<MoveOnce, 4> in {};
221       std::array<MoveOnce, 4> out {};
222       auto ret = std::ranges::move(in, out.begin());
223       assert(ret.in == in.end());
224       assert(ret.out == out.end());
225       assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.moved; }));
226     }
227   }
228 
229   { // check that the range is moved forwards
230     struct OnlyForwardsMovable {
231       OnlyForwardsMovable* next = nullptr;
232       bool canMove = false;
233       OnlyForwardsMovable() = default;
234       constexpr OnlyForwardsMovable& operator=(OnlyForwardsMovable&&) {
235         assert(canMove);
236         if (next != nullptr)
237           next->canMove = true;
238         return *this;
239       }
240     };
241     {
242       std::array<OnlyForwardsMovable, 3> in {};
243       std::array<OnlyForwardsMovable, 3> out {};
244       out[0].next = &out[1];
245       out[1].next = &out[2];
246       out[0].canMove = true;
247       auto ret = std::ranges::move(in.begin(), in.end(), out.begin());
248       assert(ret.in == in.end());
249       assert(ret.out == out.end());
250       assert(out[0].canMove);
251       assert(out[1].canMove);
252       assert(out[2].canMove);
253     }
254     {
255       std::array<OnlyForwardsMovable, 3> in {};
256       std::array<OnlyForwardsMovable, 3> out {};
257       out[0].next = &out[1];
258       out[1].next = &out[2];
259       out[0].canMove = true;
260       auto ret = std::ranges::move(in, out.begin());
261       assert(ret.in == in.end());
262       assert(ret.out == out.end());
263       assert(out[0].canMove);
264       assert(out[1].canMove);
265       assert(out[2].canMove);
266     }
267   }
268 
269   { // check that iter_move is used properly
270     {
271       int a[] = {1, 2, 3, 4};
272       std::array<int, 4> b;
273       auto ret = std::ranges::move(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4), b.data());
274       assert(ret.in == a + 4);
275       assert(ret.out == b.data() + 4);
276       assert((b == std::array {42, 42, 42, 42}));
277     }
278     {
279       int a[] = {1, 2, 3, 4};
280       std::array<int, 4> b;
281       auto range = std::ranges::subrange(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4));
282       auto ret = std::ranges::move(range, b.data());
283       assert(ret.in == a + 4);
284       assert(ret.out == b.data() + 4);
285       assert((b == std::array {42, 42, 42, 42}));
286     }
287   }
288 
289   return true;
290 }
291 
292 int main(int, char**) {
293   test();
294   static_assert(test());
295 
296   return 0;
297 }
298