xref: /llvm-project/libcxx/test/std/containers/container.adaptors/stack/stack.cons/deduct.pass.cpp (revision f3aed3698185dd4a03b210a9d73be4dc1efc580f)
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 // <stack>
10 // UNSUPPORTED: c++03, c++11, c++14
11 
12 // template<class Container>
13 //   stack(Container) -> stack<typename Container::value_type, Container>;
14 //
15 // template<class Container, class Allocator>
16 //   stack(Container, Allocator) -> stack<typename Container::value_type, Container>;
17 
18 
19 #include <array>
20 #include <stack>
21 #include <deque>
22 #include <vector>
23 #include <list>
24 #include <iterator>
25 #include <cassert>
26 #include <cstddef>
27 #include <climits> // INT_MAX
28 
29 #include "deduction_guides_sfinae_checks.h"
30 #include "test_macros.h"
31 #include "test_iterators.h"
32 #include "test_allocator.h"
33 
34 struct A {};
35 
36 int main(int, char**)
37 {
38 
39 //  Test the explicit deduction guides
40     {
41     std::vector<int> v{0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
42     std::stack stk(v);
43 
44     static_assert(std::is_same_v<decltype(stk), std::stack<int, std::vector<int>>>, "");
45     assert(stk.size() == v.size());
46     assert(stk.top() == v.back());
47     }
48 
49     {
50     std::list<long, test_allocator<long>> l{10, 11, 12, 13, 14, 15, 16, 17, 18, 19 };
51     std::stack stk(l, test_allocator<long>(0,2)); // different allocator
52     static_assert(std::is_same_v<decltype(stk)::container_type, std::list<long, test_allocator<long>>>, "");
53     static_assert(std::is_same_v<decltype(stk)::value_type, long>, "");
54     assert(stk.size() == 10);
55     assert(stk.top() == 19);
56 //  I'd like to assert that we've gotten the right allocator in the stack, but
57 //  I don't know how to get at the underlying container.
58     }
59 
60 //  Test the implicit deduction guides
61 
62     {
63 //  We don't expect this one to work - no way to implicitly get value_type
64 //  std::stack stk(std::allocator<int>()); // stack (allocator &)
65     }
66 
67     {
68     std::stack<A> source;
69     std::stack stk(source); // stack(stack &)
70     static_assert(std::is_same_v<decltype(stk)::value_type, A>, "");
71     static_assert(std::is_same_v<decltype(stk)::container_type, std::deque<A>>, "");
72     assert(stk.size() == 0);
73     }
74 
75     {
76         typedef short T;
77         typedef test_allocator<T> Alloc;
78         typedef std::list<T, Alloc> Cont;
79         typedef test_allocator<int> ConvertibleToAlloc;
80         static_assert(std::uses_allocator_v<Cont, ConvertibleToAlloc> &&
81                       !std::is_same_v<typename Cont::allocator_type, ConvertibleToAlloc>);
82 
83         {
84         Cont cont;
85         std::stack stk(cont, Alloc(2));
86         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
87         }
88 
89         {
90         Cont cont;
91         std::stack stk(cont, ConvertibleToAlloc(2));
92         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
93         }
94 
95         {
96         Cont cont;
97         std::stack stk(std::move(cont), Alloc(2));
98         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
99         }
100 
101         {
102         Cont cont;
103         std::stack stk(std::move(cont), ConvertibleToAlloc(2));
104         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
105         }
106     }
107 
108     {
109         typedef short T;
110         typedef test_allocator<T> Alloc;
111         typedef std::list<T, Alloc> Cont;
112         typedef test_allocator<int> ConvertibleToAlloc;
113         static_assert(std::uses_allocator_v<Cont, ConvertibleToAlloc> &&
114                       !std::is_same_v<typename Cont::allocator_type, ConvertibleToAlloc>);
115 
116         {
117         std::stack<T, Cont> source;
118         std::stack stk(source, Alloc(2));
119         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
120         }
121 
122         {
123         std::stack<T, Cont> source;
124         std::stack stk(source, ConvertibleToAlloc(2));
125         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
126         }
127 
128         {
129         std::stack<T, Cont> source;
130         std::stack stk(std::move(source), Alloc(2));
131         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
132         }
133 
134         {
135         std::stack<T, Cont> source;
136         std::stack stk(std::move(source), ConvertibleToAlloc(2));
137         static_assert(std::is_same_v<decltype(stk), std::stack<T, Cont>>);
138         }
139     }
140 
141     // Deduction guides should be SFINAE'd away when given:
142     // - a "bad" allocator (that is, a type not qualifying as an allocator);
143     // - an allocator instead of a container;
144     // - an allocator and a container that uses a different allocator.
145     {
146         using Cont = std::list<int>;
147         using Alloc = std::allocator<int>;
148         using DiffAlloc = test_allocator<int>;
149         using Iter = int;
150 
151         struct NotIter {};
152         struct NotAlloc {};
153 
154         static_assert(SFINAEs_away<std::stack, Alloc, Alloc>);
155         static_assert(SFINAEs_away<std::stack, Cont, NotAlloc>);
156         static_assert(SFINAEs_away<std::stack, Cont, DiffAlloc>);
157         static_assert(SFINAEs_away<std::stack, Iter, NotIter>);
158 #if TEST_STD_VER > 20
159         static_assert(SFINAEs_away<std::stack, Iter, NotIter, Alloc>);
160         static_assert(SFINAEs_away<std::stack, Iter, Iter, NotAlloc>);
161 #endif
162     }
163 
164 #if TEST_STD_VER > 20
165     {
166         typedef short T;
167         typedef test_allocator<T> Alloc;
168         std::list<T> a;
169         {
170         std::stack s(a.begin(), a.end());
171         static_assert(std::is_same_v<decltype(s), std::stack<T>>);
172         }
173         {
174         std::stack s(a.begin(), a.end(), Alloc());
175         static_assert(std::is_same_v<decltype(s), std::stack<T, std::deque<T, Alloc>>>);
176         }
177     }
178 #endif
179 
180     return 0;
181 }
182