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 // UNSUPPORTED: clang-5, apple-clang-9
12 // UNSUPPORTED: libcpp-no-deduction-guides
13 // Clang 5 will generate bad implicit deduction guides
14 //	Specifically, for the copy constructor.
15 
16 
17 // template<class Container>
18 //   stack(Container) -> stack<typename Container::value_type, Container>;
19 //
20 // template<class Container, class Allocator>
21 //   stack(Container, Allocator) -> stack<typename Container::value_type, Container>;
22 
23 
24 #include <stack>
25 #include <vector>
26 #include <list>
27 #include <iterator>
28 #include <cassert>
29 #include <cstddef>
30 #include <climits> // INT_MAX
31 
32 #include "test_macros.h"
33 #include "test_iterators.h"
34 #include "test_allocator.h"
35 
36 struct A {};
37 
main(int,char **)38 int main(int, char**)
39 {
40 
41 //  Test the explicit deduction guides
42     {
43     std::vector<int> v{0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
44     std::stack stk(v);
45 
46     static_assert(std::is_same_v<decltype(stk), std::stack<int, std::vector<int>>>, "");
47     assert(stk.size() == v.size());
48     assert(stk.top() == v.back());
49     }
50 
51     {
52     std::list<long, test_allocator<long>> l{10, 11, 12, 13, 14, 15, 16, 17, 18, 19 };
53     std::stack stk(l, test_allocator<long>(0,2)); // different allocator
54     static_assert(std::is_same_v<decltype(stk)::container_type, std::list<long, test_allocator<long>>>, "");
55     static_assert(std::is_same_v<decltype(stk)::value_type, long>, "");
56     assert(stk.size() == 10);
57     assert(stk.top() == 19);
58 //  I'd like to assert that we've gotten the right allocator in the stack, but
59 //  I don't know how to get at the underlying container.
60     }
61 
62 //  Test the implicit deduction guides
63 
64     {
65 //  We don't expect this one to work - no way to implicitly get value_type
66 //  std::stack stk(std::allocator<int>()); // stack (allocator &)
67     }
68 
69     {
70     std::stack<A> source;
71     std::stack stk(source); // stack(stack &)
72     static_assert(std::is_same_v<decltype(stk)::value_type, A>, "");
73     static_assert(std::is_same_v<decltype(stk)::container_type, std::deque<A>>, "");
74     assert(stk.size() == 0);
75     }
76 
77     {
78 //  This one is odd - you can pass an allocator in to use, but the allocator
79 //  has to match the type of the one used by the underlying container
80     typedef short T;
81     typedef test_allocator<T> Alloc;
82     typedef std::deque<T, Alloc> Container;
83 
84     Container c{0,1,2,3};
85     std::stack<T, Container> source(c);
86     std::stack stk(source, Alloc(2)); // stack(stack &, allocator)
87     static_assert(std::is_same_v<decltype(stk)::value_type, T>, "");
88     static_assert(std::is_same_v<decltype(stk)::container_type, Container>, "");
89     assert(stk.size() == 4);
90     assert(stk.top() == 3);
91     }
92 
93 
94   return 0;
95 }
96