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
10
11 // <tuple>
12
13 // template <class... Types> class tuple;
14
15 // template <class Alloc>
16 // explicit(see-below) tuple(allocator_arg_t, const Alloc& a);
17
18 // NOTE: this constructor does not currently support tags derived from
19 // allocator_arg_t because libc++ has to deduce the parameter as a template
20 // argument. See PR27684 (https://bugs.llvm.org/show_bug.cgi?id=27684)
21
22 #include <tuple>
23 #include <cassert>
24
25 #include "test_macros.h"
26 #include "DefaultOnly.h"
27 #include "allocators.h"
28 #include "../alloc_first.h"
29 #include "../alloc_last.h"
30
31 template <class T = void>
32 struct NonDefaultConstructible {
NonDefaultConstructibleNonDefaultConstructible33 constexpr NonDefaultConstructible() {
34 static_assert(!std::is_same<T, T>::value, "Default Ctor instantiated");
35 }
36
NonDefaultConstructibleNonDefaultConstructible37 explicit constexpr NonDefaultConstructible(int) {}
38 };
39
40
41 struct DerivedFromAllocArgT : std::allocator_arg_t {};
42
main(int,char **)43 int main(int, char**)
44 {
45 {
46 std::tuple<> t(std::allocator_arg, A1<int>());
47 }
48 {
49 std::tuple<int> t(std::allocator_arg, A1<int>());
50 assert(std::get<0>(t) == 0);
51 }
52 {
53 std::tuple<DefaultOnly> t(std::allocator_arg, A1<int>());
54 assert(std::get<0>(t) == DefaultOnly());
55 }
56 {
57 assert(!alloc_first::allocator_constructed);
58 std::tuple<alloc_first> t(std::allocator_arg, A1<int>(5));
59 assert(alloc_first::allocator_constructed);
60 assert(std::get<0>(t) == alloc_first());
61 }
62 {
63 assert(!alloc_last::allocator_constructed);
64 std::tuple<alloc_last> t(std::allocator_arg, A1<int>(5));
65 assert(alloc_last::allocator_constructed);
66 assert(std::get<0>(t) == alloc_last());
67 }
68 {
69 alloc_first::allocator_constructed = false;
70 std::tuple<DefaultOnly, alloc_first> t(std::allocator_arg, A1<int>(5));
71 assert(std::get<0>(t) == DefaultOnly());
72 assert(alloc_first::allocator_constructed);
73 assert(std::get<1>(t) == alloc_first());
74 }
75 {
76 alloc_first::allocator_constructed = false;
77 alloc_last::allocator_constructed = false;
78 std::tuple<DefaultOnly, alloc_first, alloc_last> t(std::allocator_arg,
79 A1<int>(5));
80 assert(std::get<0>(t) == DefaultOnly());
81 assert(alloc_first::allocator_constructed);
82 assert(std::get<1>(t) == alloc_first());
83 assert(alloc_last::allocator_constructed);
84 assert(std::get<2>(t) == alloc_last());
85 }
86 {
87 alloc_first::allocator_constructed = false;
88 alloc_last::allocator_constructed = false;
89 std::tuple<DefaultOnly, alloc_first, alloc_last> t(std::allocator_arg,
90 A2<int>(5));
91 assert(std::get<0>(t) == DefaultOnly());
92 assert(!alloc_first::allocator_constructed);
93 assert(std::get<1>(t) == alloc_first());
94 assert(!alloc_last::allocator_constructed);
95 assert(std::get<2>(t) == alloc_last());
96 }
97 {
98 // Test that the uses-allocator default constructor does not evaluate
99 // its SFINAE when it otherwise shouldn't be selected. Do this by
100 // using 'NonDefaultConstructible' which will cause a compile error
101 // if std::is_default_constructible is evaluated on it.
102 using T = NonDefaultConstructible<>;
103 T v(42);
104 std::tuple<T, T> t(v, v);
105 (void)t;
106 std::tuple<T, T> t2(42, 42);
107 (void)t2;
108 }
109
110 return 0;
111 }
112