1 //  (C) Copyright Gennadiy Rozental 2001.
2 //  Distributed under the Boost Software License, Version 1.0.
3 //  (See accompanying file LICENSE_1_0.txt or copy at
4 //  http://www.boost.org/LICENSE_1_0.txt)
5 
6 //  See http://www.boost.org/libs/test for the library home page.
7 //
8 //! @file
9 //! Defines the is_cstring type trait
10 // ***************************************************************************
11 
12 #ifndef BOOST_TEST_UTILS_IS_CSTRING_HPP
13 #define BOOST_TEST_UTILS_IS_CSTRING_HPP
14 
15 // Boost
16 #include <boost/mpl/bool.hpp>
17 #include <boost/type_traits/is_same.hpp>
18 #include <boost/type_traits/decay.hpp>
19 #include <boost/type_traits/remove_pointer.hpp>
20 #include <boost/type_traits/remove_const.hpp>
21 #include <boost/type_traits/add_const.hpp>
22 
23 #include <boost/test/utils/basic_cstring/basic_cstring_fwd.hpp>
24 #include <string>
25 
26 #if defined(BOOST_TEST_STRING_VIEW)
27 #include <string_view>
28 #endif
29 
30 //____________________________________________________________________________//
31 
32 namespace boost {
33 namespace unit_test {
34 
35 // ************************************************************************** //
36 // **************                  is_cstring                  ************** //
37 // ************************************************************************** //
38 
39 namespace ut_detail {
40 
41 template<typename T>
42 struct is_cstring_impl : public mpl::false_ {};
43 
44 template<typename T>
45 struct is_cstring_impl<T const*> : public is_cstring_impl<T*> {};
46 
47 template<typename T>
48 struct is_cstring_impl<T const* const> : public is_cstring_impl<T*> {};
49 
50 template<>
51 struct is_cstring_impl<char*> : public mpl::true_ {};
52 
53 template<>
54 struct is_cstring_impl<wchar_t*> : public mpl::true_ {};
55 
56 template <typename T, bool is_cstring = is_cstring_impl<typename boost::decay<T>::type>::value >
57 struct deduce_cstring_transform_impl;
58 
59 template <typename T, bool is_cstring >
60 struct deduce_cstring_transform_impl<T&, is_cstring> : public deduce_cstring_transform_impl<T, is_cstring>{};
61 
62 template <typename T, bool is_cstring >
63 struct deduce_cstring_transform_impl<T const, is_cstring> : public deduce_cstring_transform_impl<T, is_cstring>{};
64 
65 template <typename T>
66 struct deduce_cstring_transform_impl<T, true> {
67     typedef typename boost::add_const<
68         typename boost::remove_pointer<
69             typename boost::decay<T>::type
70         >::type
71     >::type U;
72     typedef boost::unit_test::basic_cstring<U> type;
73 };
74 
75 template <typename T>
76 struct deduce_cstring_transform_impl< T, false > {
77     typedef typename
78         boost::remove_const<
79             typename boost::remove_reference<T>::type
80         >::type type;
81 };
82 
83 template <typename T>
84 struct deduce_cstring_transform_impl< std::basic_string<T, std::char_traits<T> >, false > {
85     typedef boost::unit_test::basic_cstring<typename boost::add_const<T>::type> type;
86 };
87 
88 #if defined(BOOST_TEST_STRING_VIEW)
89 template <typename T>
90 struct deduce_cstring_transform_impl< std::basic_string_view<T, std::char_traits<T> >, false > {
91 private:
92     using sv_t = std::basic_string_view<T, std::char_traits<T> > ;
93 
94 public:
95     using type = stringview_cstring_helper<typename boost::add_const<T>::type, sv_t>;
96 };
97 #endif
98 
99 } // namespace ut_detail
100 
101 template<typename T>
102 struct is_cstring : public ut_detail::is_cstring_impl<typename decay<T>::type> {};
103 
104 template<typename T, bool is_cstring = is_cstring<typename boost::decay<T>::type>::value >
105 struct is_cstring_comparable: public mpl::false_ {};
106 
107 template<typename T>
108 struct is_cstring_comparable< T, true > : public mpl::true_ {};
109 
110 template<typename T>
111 struct is_cstring_comparable< std::basic_string<T, std::char_traits<T> >, false > : public mpl::true_ {};
112 
113 #if defined(BOOST_TEST_STRING_VIEW)
114 template<typename T>
115 struct is_cstring_comparable< std::basic_string_view<T, std::char_traits<T> >, false > : public mpl::true_ {};
116 #endif
117 
118 template<typename T>
119 struct is_cstring_comparable< boost::unit_test::basic_cstring<T>, false > : public mpl::true_ {};
120 
121 template <class T>
122 struct deduce_cstring_transform {
123     typedef typename
124         boost::remove_const<
125             typename boost::remove_reference<T>::type
126         >::type U;
127     typedef typename ut_detail::deduce_cstring_transform_impl<typename boost::decay<U>::type>::type type;
128 };
129 
130 } // namespace unit_test
131 } // namespace boost
132 
133 #endif // BOOST_TEST_UTILS_IS_CSTRING_HPP
134