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 // <queue>
10 // UNSUPPORTED: c++03, c++11, c++14
11 
12 // template<class Compare, class Container>
13 // priority_queue(Compare, Container)
14 //     -> priority_queue<typename Container::value_type, Container, Compare>;
15 //
16 // template<class InputIterator,
17 //          class Compare = less<typename iterator_traits<InputIterator>::value_type>,
18 //          class Container = vector<typename iterator_traits<InputIterator>::value_type>>
19 // priority_queue(InputIterator, InputIterator, Compare = Compare(), Container = Container())
20 //     -> priority_queue<typename iterator_traits<InputIterator>::value_type, Container, Compare>;
21 //
22 // template<class Compare, class Container, class Allocator>
23 // priority_queue(Compare, Container, Allocator)
24 //     -> priority_queue<typename Container::value_type, Container, Compare>;
25 
26 
27 #include <queue>
28 #include <vector>
29 #include <iterator>
30 #include <cassert>
31 #include <cstddef>
32 #include <climits> // INT_MAX
33 
34 #include "deduction_guides_sfinae_checks.h"
35 #include "test_macros.h"
36 #include "test_iterators.h"
37 #include "test_allocator.h"
38 
39 struct A {};
40 
main(int,char **)41 int main(int, char**)
42 {
43 
44 //  Test the explicit deduction guides
45     {
46     std::vector<int> v{0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
47     std::priority_queue pri(std::greater<int>(), v); // priority_queue(Compare, Container)
48 
49     static_assert(std::is_same_v<decltype(pri), std::priority_queue<int, std::vector<int>, std::greater<int>>>, "");
50     assert(pri.size() == v.size());
51     assert(pri.top() == 0);
52     }
53 
54     {
55     std::vector<long, test_allocator<long>> v{10, 11, 12, 13, 14, 15, 16, 17, 18, 19 };
56     std::priority_queue pri(std::greater<long>(), v, test_allocator<long>(2)); // priority_queue(Compare, Container, Allocator)
57 
58     static_assert(std::is_same_v<decltype(pri),
59                                  std::priority_queue<long, std::vector<long, test_allocator<long>>, std::greater<long>>>, "");
60     assert(pri.size() == v.size());
61     assert(pri.top() == 10);
62     }
63 
64     {
65     std::vector<short> v{10, 11, 12, 13, 14, 15, 28, 17, 18, 19 };
66     std::priority_queue pri(v.begin(), v.end()); // priority_queue(Iter, Iter)
67 
68     static_assert(std::is_same_v<decltype(pri), std::priority_queue<short>>, "");
69     assert(pri.size() == v.size());
70     assert(pri.top() == 28);
71     }
72 
73     {
74     std::vector<double> v{10, 11, 12, 13, 6, 15, 28, 17, 18, 19 };
75     std::priority_queue pri(v.begin(), v.end(), std::greater<double>()); // priority_queue(Iter, Iter, Comp)
76 
77     static_assert(std::is_same_v<decltype(pri), std::priority_queue<double, std::vector<double>, std::greater<double>>>, "");
78     assert(pri.size() == v.size());
79     assert(pri.top() == 6);
80     }
81 
82     {
83     std::vector<double> v{10, 6, 15, 28, 4, 18, 19 };
84     std::deque<double> deq;
85     std::priority_queue pri(v.begin(), v.end(), std::greater<double>(), deq); // priority_queue(Iter, Iter, Comp, Container)
86 
87     static_assert(std::is_same_v<decltype(pri), std::priority_queue<double, std::deque<double>, std::greater<double>>>, "");
88     assert(pri.size() == v.size());
89     assert(pri.top() == 4);
90     }
91 
92 //  Test the implicit deduction guides
93     {
94 //  We don't expect this one to work - no way to implicitly get value_type
95 //  std::priority_queue pri(std::allocator<int>()); // queue (allocator &)
96     }
97 
98     {
99     std::priority_queue<float> source;
100     std::priority_queue pri(source); // priority_queue(priority_queue &)
101     static_assert(std::is_same_v<decltype(pri)::value_type, float>, "");
102     static_assert(std::is_same_v<decltype(pri)::container_type, std::vector<float>>, "");
103     assert(pri.size() == 0);
104     }
105 
106     {
107         typedef short T;
108         typedef std::greater<T> Comp;
109         typedef test_allocator<T> Alloc;
110         typedef std::deque<T, Alloc> Cont;
111         typedef test_allocator<int> ConvertibleToAlloc;
112         static_assert(std::uses_allocator_v<Cont, ConvertibleToAlloc> &&
113                       !std::is_same_v<typename Cont::allocator_type, ConvertibleToAlloc>);
114 
115         {
116         Comp comp;
117         Cont cont;
118         std::priority_queue pri(comp, cont, Alloc(2));
119         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
120         }
121 
122         {
123         Comp comp;
124         Cont cont;
125         std::priority_queue pri(comp, cont, ConvertibleToAlloc(2));
126         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
127         }
128 
129         {
130         Comp comp;
131         Cont cont;
132         std::priority_queue pri(comp, std::move(cont), Alloc(2));
133         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
134         }
135 
136         {
137         Comp comp;
138         Cont cont;
139         std::priority_queue pri(comp, std::move(cont), ConvertibleToAlloc(2));
140         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
141         }
142     }
143 
144     {
145         typedef short T;
146         typedef signed char ConvertibleToT;
147         typedef std::greater<T> Comp;
148         typedef test_allocator<T> Alloc;
149         typedef std::deque<T, Alloc> Cont;
150         typedef test_allocator<int> ConvertibleToAlloc;
151         static_assert(std::uses_allocator_v<Cont, ConvertibleToAlloc> &&
152                       !std::is_same_v<typename Cont::allocator_type, ConvertibleToAlloc>);
153 
154         {
155         std::priority_queue<T, Cont, Comp> source;
156         std::priority_queue pri(source, Alloc(2));
157         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
158         }
159 
160         {
161         std::priority_queue<T, Cont, Comp> source;
162         std::priority_queue pri(source, ConvertibleToAlloc(2));
163         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
164         }
165 
166         {
167         std::priority_queue<T, Cont, Comp> source;
168         std::priority_queue pri(std::move(source), Alloc(2));
169         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
170         }
171 
172         {
173         std::priority_queue<T, Cont, Comp> source;
174         std::priority_queue pri(std::move(source), ConvertibleToAlloc(2));
175         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
176         }
177 
178         {
179         Cont cont;
180         std::priority_queue pri(Comp(), cont, Alloc(2));
181         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
182         }
183 
184         {
185         Cont cont;
186         std::priority_queue pri(Comp(), cont, ConvertibleToAlloc(2));
187         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
188         }
189 
190         {
191         Cont cont;
192         std::priority_queue pri(Comp(), std::move(cont), Alloc(2));
193         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
194         }
195 
196         {
197         Cont cont;
198         std::priority_queue pri(Comp(), std::move(cont), ConvertibleToAlloc(2));
199         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
200         }
201 
202         {
203         T a[2] = {};
204         std::priority_queue pri(a, a+2, Alloc(2));
205         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, std::vector<T, Alloc>>>);
206         }
207 
208         {
209         T a[2] = {};
210         std::priority_queue pri(a, a+2, Comp(), Alloc(2));
211         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, std::vector<T, Alloc>, Comp>>);
212         }
213 
214         {
215         Cont cont;
216         ConvertibleToT a[2] = {};
217         std::priority_queue pri(a, a+2, Comp(), cont, Alloc(2));
218         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
219         }
220 
221         {
222         Cont cont;
223         ConvertibleToT a[2] = {};
224         std::priority_queue pri(a, a+2, Comp(), cont, ConvertibleToAlloc(2));
225         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
226         }
227 
228         {
229         Cont cont;
230         ConvertibleToT a[2] = {};
231         std::priority_queue pri(a, a+2, Comp(), std::move(cont), Alloc(2));
232         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
233         }
234 
235         {
236         Cont cont;
237         ConvertibleToT a[2] = {};
238         std::priority_queue pri(a, a+2, Comp(), std::move(cont), ConvertibleToAlloc(2));
239         static_assert(std::is_same_v<decltype(pri), std::priority_queue<T, Cont, Comp>>);
240         }
241     }
242 
243     // Deduction guides should be SFINAE'd away when given:
244     // - "bad" input iterators (that is, a type not qualifying as an input
245     //   iterator);
246     // - a bad allocator;
247     // - an allocator instead of a comparator;
248     // - an allocator instead of a container;
249     // - an allocator and a container that uses a different allocator.
250     {
251         using Comp = std::less<int>;
252         using Cont = std::vector<int>;
253         using Alloc = std::allocator<int>;
254         using Iter = int*;
255 
256         // The only requirement in the Standard is that integral types cannot be
257         // considered input iterators, beyond that it is unspecified.
258         using BadIter = int;
259 #ifdef _LIBCPP_VERSION
260         struct OutputIter {
261           using iterator_category = std::output_iterator_tag;
262           using value_type = void;
263           using difference_type = void;
264           using pointer = void;
265           using reference = void;
266 
267           const OutputIter& operator*() const { return *this; }
268           const OutputIter& operator++() { return *this; }
269           OutputIter operator++(int) const { return *this; }
270         };
271 #endif // _LIBCPP_VERSION
272 
273         struct BadAlloc {};
274         using AllocAsComp = Alloc;
275         using AllocAsCont = Alloc;
276         using DiffAlloc = test_allocator<int>;
277 
278         // (iter, iter)
279         //
280         // Cannot deduce from (BAD_iter, BAD_iter)
281         static_assert(SFINAEs_away<std::priority_queue, BadIter, BadIter>);
282         // Note: (OutputIter, OutputIter) is interpreted as (comp, cont) and fails on accessing
283         // non-existent typedefs in `OutputIter` (as if it were a container). There is no
284         // requirement to SFINAE away bad containers.
285 
286         // (iter, iter, comp)
287         //
288         // Cannot deduce from (BAD_iter, BAD_iter, comp)
289         static_assert(SFINAEs_away<std::priority_queue, BadIter, BadIter, Comp>);
290         LIBCPP_STATIC_ASSERT(SFINAEs_away<std::priority_queue, OutputIter, OutputIter, Comp>);
291         // Note: (iter, iter, ALLOC_as_comp) is allowed -- it just calls (iter, iter, alloc).
292 
293         // (iter, iter, comp, cont)
294         //
295         // Cannot deduce from (BAD_iter, BAD_iter, comp, cont)
296         static_assert(SFINAEs_away<std::priority_queue, BadIter, BadIter, Comp, Cont>);
297         LIBCPP_STATIC_ASSERT(SFINAEs_away<std::priority_queue, OutputIter, OutputIter, Comp, Cont>);
298         // Cannot deduce from (iter, iter, ALLOC_as_comp, cont)
299         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, AllocAsComp, Cont>);
300         // Note: (iter, iter, comp, ALLOC_as_cont) is allowed -- it just calls (iter, iter, comp,
301         // alloc).
302 
303         // (iter, iter, alloc)
304         //
305         // Cannot deduce from (BAD_iter, BAD_iter, alloc)
306         static_assert(SFINAEs_away<std::priority_queue, BadIter, BadIter, Alloc>);
307         LIBCPP_STATIC_ASSERT(SFINAEs_away<std::priority_queue, OutputIter, OutputIter, Alloc>);
308         // Note: (iter, iter, BAD_alloc) is interpreted as (iter, iter, comp) instead and fails upon
309         // instantiation. There is no requirement to SFINAE away bad comparators.
310 
311         // (iter, iter, comp, alloc)
312         //
313         // Cannot deduce from (iter, iter, ALLOC_as_comp, alloc)
314         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, AllocAsComp, Alloc>);
315         // Note: (iter, iter, comp, BAD_alloc) is interpreted as (iter, iter, comp, cont) instead
316         // and fails upon instantiation. There is no requirement to SFINAE away bad containers.
317 
318         // (iter, iter, comp, cont, alloc)
319         //
320         // Cannot deduce from (BAD_iter, BAD_iter, comp, cont, alloc)
321         static_assert(SFINAEs_away<std::priority_queue, BadIter, BadIter, Comp, Cont, Alloc>);
322         LIBCPP_STATIC_ASSERT(
323             SFINAEs_away<std::priority_queue, OutputIter, OutputIter, Comp, Cont, Alloc>);
324         // Cannot deduce from (iter, iter, ALLOC_as_comp, cont, alloc)
325         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, AllocAsComp, Cont, Alloc>);
326         // Cannot deduce from (iter, iter, comp, ALLOC_as_cont, alloc)
327         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, Comp, AllocAsCont, Alloc>);
328         // Cannot deduce from (iter, iter, comp, cont, BAD_alloc)
329         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, Comp, Cont, BadAlloc>);
330         // Cannot deduce from (iter, iter, comp, cont, DIFFERENT_alloc)
331         static_assert(SFINAEs_away<std::priority_queue, Iter, Iter, Comp, Cont, DiffAlloc>);
332 
333         // (comp, alloc)
334         //
335         // Cannot deduce from (ALLOC_as_comp, alloc)
336         static_assert(SFINAEs_away<std::priority_queue, AllocAsComp, Alloc>);
337         // Cannot deduce from (comp, BAD_alloc)
338         static_assert(SFINAEs_away<std::priority_queue, Comp, BadAlloc>);
339 
340         // (comp, cont, alloc)
341         //
342         // Cannot deduce from (ALLOC_as_comp, cont, alloc)
343         static_assert(SFINAEs_away<std::priority_queue, AllocAsComp, Cont, Alloc>);
344         // Cannot deduce from (comp, ALLOC_as_cont, alloc)
345         static_assert(SFINAEs_away<std::priority_queue, Comp, AllocAsCont, Alloc>);
346         // Cannot deduce from (comp, cont, BAD_alloc)
347         static_assert(SFINAEs_away<std::priority_queue, Comp, Cont, BadAlloc>);
348         // Cannot deduce from (comp, cont, DIFFERENT_alloc)
349         static_assert(SFINAEs_away<std::priority_queue, Comp, Cont, DiffAlloc>);
350 
351         // (comp, cont)
352         //
353         // Cannot deduce from (ALLOC_as_comp, cont)
354         static_assert(SFINAEs_away<std::priority_queue, AllocAsComp, Cont>);
355         // Cannot deduce from (comp, ALLOC_as_cont)
356         static_assert(SFINAEs_away<std::priority_queue, Comp, AllocAsCont>);
357     }
358 
359     return 0;
360 }
361