1 /*=============================================================================
2 Copyright (c) 2016 Lee Clagett
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 ==============================================================================*/
7 #include <boost/detail/lightweight_test.hpp>
8 #include <boost/fusion/container/vector.hpp>
9 #include <boost/fusion/tuple/tuple.hpp>
10 #include <boost/config.hpp>
11 #include <boost/type_traits/is_constructible.hpp>
12 #include <boost/type_traits/is_convertible.hpp>
13
14 #define FUSION_SEQUENCE boost::fusion::tuple
15 #define FUSION_ALT_SEQUENCE boost::fusion::vector
16 #include "traits.hpp"
17
18 struct not_convertible {};
19
20 /* Some construction differences in fusion::tuple from std::tuple:
21 - Construction from elements cannot call an explicit constructor.
22 - There is no implicit construction from elements.
23 - Construction from std::pair is _enabled_ when tuple is not of size 2.
24 - Construction from tuple is _enabled_ when destination tuple is of
25 different size.
26 - Implicit construction from std::pair can call explicit constructors on
27 elements.
28 - Implicit construction from tuple can call explicit constructors on
29 elements.
30
31 These differences are historical. Matching the behavior of std::tuple
32 could break existing code, however, switching to fusion::vector would
33 restore the historical behavior. */
34 int
main()35 main()
36 {
37 using namespace boost::fusion;
38
39 test_convertible(false /* no conversion construction */ );
40
41 BOOST_TEST((is_convertible<std::pair<int, int>, tuple<int, int> >(true)));
42 BOOST_TEST((
43 is_convertible<std::pair<int, int>, tuple<convertible, int> >(true)
44 ));
45 BOOST_TEST((
46 is_convertible<std::pair<int, int>, tuple<int, convertible> >(true)
47 ));
48 BOOST_TEST((
49 is_convertible<
50 std::pair<int, int>, tuple<convertible, convertible>
51 >(true)
52 ));
53
54 #if defined(FUSION_TEST_HAS_CONSTRUCTIBLE)
55 test_constructible();
56
57 BOOST_TEST((is_constructible< tuple<> >(true)));
58 BOOST_TEST((is_constructible<tuple<>, int>(false)));
59
60 BOOST_TEST((is_constructible< tuple<int> >(true)));
61 BOOST_TEST((is_constructible<tuple<int>, int>(true)));
62 BOOST_TEST((is_constructible<tuple<convertible>, int>(true)));
63 BOOST_TEST((is_constructible<tuple<not_convertible>, int>(false)));
64 BOOST_TEST((is_constructible< tuple<int>, vector<int> >(false)));
65 BOOST_TEST((is_constructible<tuple<int>, int, int>(false)));
66
67 BOOST_TEST((is_constructible< tuple<int, int> >(true)));
68 // boost::is_constructible always fail to test ctor which takes 2 or more arguments on GCC 4.7.
69 #if !BOOST_WORKAROUND(BOOST_GCC, < 40700)
70 BOOST_TEST((is_constructible<tuple<int, int>, int, int>(true)));
71 BOOST_TEST((
72 is_constructible<tuple<convertible, convertible>, int, int>(true)
73 ));
74 #endif // !(gcc < 4.7)
75 BOOST_TEST((is_constructible<tuple<int, not_convertible>, int, int>(false)));
76 BOOST_TEST((is_constructible<tuple<not_convertible, int>, int, int>(false)));
77 BOOST_TEST((
78 is_constructible<tuple<not_convertible, not_convertible>, int, int>(false)
79 ));
80 #if defined(BOOST_FUSION_HAS_VARIADIC_VECTOR)
81 // C++03 fusion::tuple has constructors that can never be used
82 BOOST_TEST((is_constructible<tuple<int, int>, int>(false)));
83 #endif
84 BOOST_TEST((is_constructible<tuple<int, int>, int, int, int>(false)));
85
86 #endif // FUSION_TEST_HAS_CONSTRUCTIBLE
87
88 return boost::report_errors();
89 }
90