get_non_const.pass.cpp revision da0a0e8a1be285d18870955cffc1b51982675dd8 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <tuple>
11
12// template <class... Types> class tuple;
13
14// template <size_t I, class... Types>
15//   typename tuple_element<I, tuple<Types...> >::type&
16//   get(tuple<Types...>& t);
17
18#include <tuple>
19#include <string>
20#include <cassert>
21
22#if __cplusplus > 201103L
23
24struct Empty {};
25
26struct S {
27   std::tuple<int, Empty> a;
28   int k;
29   Empty e;
30   constexpr S() : a{1,Empty{}}, k(std::get<0>(a)), e(std::get<1>(a)) {}
31   };
32
33constexpr std::tuple<int, int> getP () { return { 3, 4 }; }
34#endif
35
36int main()
37{
38    {
39        typedef std::tuple<int> T;
40        T t(3);
41        assert(std::get<0>(t) == 3);
42        std::get<0>(t) = 2;
43        assert(std::get<0>(t) == 2);
44    }
45    {
46        typedef std::tuple<std::string, int> T;
47        T t("high", 5);
48        assert(std::get<0>(t) == "high");
49        assert(std::get<1>(t) == 5);
50        std::get<0>(t) = "four";
51        std::get<1>(t) = 4;
52        assert(std::get<0>(t) == "four");
53        assert(std::get<1>(t) == 4);
54    }
55    {
56        typedef std::tuple<double&, std::string, int> T;
57        double d = 1.5;
58        T t(d, "high", 5);
59        assert(std::get<0>(t) == 1.5);
60        assert(std::get<1>(t) == "high");
61        assert(std::get<2>(t) == 5);
62        std::get<0>(t) = 2.5;
63        std::get<1>(t) = "four";
64        std::get<2>(t) = 4;
65        assert(std::get<0>(t) == 2.5);
66        assert(std::get<1>(t) == "four");
67        assert(std::get<2>(t) == 4);
68        assert(d == 2.5);
69    }
70#if _LIBCPP_STD_VER > 11
71    { // get on an rvalue tuple
72        static_assert ( std::get<0> ( std::make_tuple ( 0.0f, 1, 2.0, 3L )) == 0, "" );
73        static_assert ( std::get<1> ( std::make_tuple ( 0.0f, 1, 2.0, 3L )) == 1, "" );
74        static_assert ( std::get<2> ( std::make_tuple ( 0.0f, 1, 2.0, 3L )) == 2, "" );
75        static_assert ( std::get<3> ( std::make_tuple ( 0.0f, 1, 2.0, 3L )) == 3, "" );
76        static_assert(S().k == 1, "");
77        static_assert(std::get<1>(getP()) == 4, "");
78    }
79#endif
80
81}
82