xref: /llvm-project/libcxx/test/std/utilities/variant/variant.get/get_if_index.pass.cpp (revision dfde6e89ecc10b1f1eebdb0e409ef1a084030a6c)
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, c++11, c++14
10 
11 // <variant>
12 
13 // template <size_t I, class... Types>
14 //  constexpr add_pointer_t<variant_alternative_t<I, variant<Types...>>>
15 //   get_if(variant<Types...>* v) noexcept;
16 // template <size_t I, class... Types>
17 //  constexpr add_pointer_t<const variant_alternative_t<I, variant<Types...>>>
18 //   get_if(const variant<Types...>* v) noexcept;
19 
20 #include "test_macros.h"
21 #include "variant_test_helpers.h"
22 #include <cassert>
23 #include <memory>
24 #include <variant>
25 
test_const_get_if()26 void test_const_get_if() {
27   {
28     using V = std::variant<int>;
29     constexpr const V *v = nullptr;
30     static_assert(std::get_if<0>(v) == nullptr, "");
31   }
32   {
33     using V = std::variant<int, const long>;
34     constexpr V v(42);
35     ASSERT_NOEXCEPT(std::get_if<0>(&v));
36     ASSERT_SAME_TYPE(decltype(std::get_if<0>(&v)), const int *);
37     static_assert(*std::get_if<0>(&v) == 42, "");
38     static_assert(std::get_if<1>(&v) == nullptr, "");
39   }
40   {
41     using V = std::variant<int, const long>;
42     constexpr V v(42l);
43     ASSERT_SAME_TYPE(decltype(std::get_if<1>(&v)), const long *);
44     static_assert(*std::get_if<1>(&v) == 42, "");
45     static_assert(std::get_if<0>(&v) == nullptr, "");
46   }
47 }
48 
test_get_if()49 void test_get_if() {
50   {
51     using V = std::variant<int>;
52     V *v = nullptr;
53     assert(std::get_if<0>(v) == nullptr);
54   }
55   {
56     using V = std::variant<int, long>;
57     V v(42);
58     ASSERT_NOEXCEPT(std::get_if<0>(&v));
59     ASSERT_SAME_TYPE(decltype(std::get_if<0>(&v)), int *);
60     assert(*std::get_if<0>(&v) == 42);
61     assert(std::get_if<1>(&v) == nullptr);
62   }
63   {
64     using V = std::variant<int, const long>;
65     V v(42l);
66     ASSERT_SAME_TYPE(decltype(std::get_if<1>(&v)), const long *);
67     assert(*std::get_if<1>(&v) == 42);
68     assert(std::get_if<0>(&v) == nullptr);
69   }
70 }
71 
main(int,char **)72 int main(int, char**) {
73   test_const_get_if();
74   test_get_if();
75 
76   return 0;
77 }
78