1 | // Copyright Kevlin Henney, 2000-2005. |
2 | // Copyright Alexander Nasonov, 2006-2010. |
3 | // Copyright Antony Polukhin, 2011-2014. |
4 | // |
5 | // Distributed under the Boost Software License, Version 1.0. (See |
6 | // accompanying file LICENSE_1_0.txt or copy at |
7 | // http://www.boost.org/LICENSE_1_0.txt) |
8 | // |
9 | // what: lexical_cast custom keyword cast |
10 | // who: contributed by Kevlin Henney, |
11 | // enhanced with contributions from Terje Slettebo, |
12 | // with additional fixes and suggestions from Gennaro Prota, |
13 | // Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov, |
14 | // Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann, |
15 | // Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters |
16 | // when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014 |
17 | |
18 | #ifndef BOOST_LEXICAL_CAST_TRY_LEXICAL_CONVERT_HPP |
19 | #define BOOST_LEXICAL_CAST_TRY_LEXICAL_CONVERT_HPP |
20 | |
21 | #include <boost/config.hpp> |
22 | #ifdef BOOST_HAS_PRAGMA_ONCE |
23 | # pragma once |
24 | #endif |
25 | |
26 | #if defined(__clang__) || (defined(__GNUC__) && \ |
27 | !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && \ |
28 | (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))) |
29 | #pragma GCC diagnostic push |
30 | #pragma GCC diagnostic ignored "-Wuninitialized" |
31 | #endif |
32 | |
33 | #include <string> |
34 | #include <boost/mpl/bool.hpp> |
35 | #include <boost/mpl/identity.hpp> |
36 | #include <boost/mpl/if.hpp> |
37 | #include <boost/type_traits/is_same.hpp> |
38 | #include <boost/type_traits/is_arithmetic.hpp> |
39 | |
40 | #include <boost/lexical_cast/detail/is_character.hpp> |
41 | #include <boost/lexical_cast/detail/converter_numeric.hpp> |
42 | #include <boost/lexical_cast/detail/converter_lexical.hpp> |
43 | |
44 | #include <boost/range/iterator_range_core.hpp> |
45 | #include <boost/container/container_fwd.hpp> |
46 | |
47 | namespace boost { |
48 | namespace detail |
49 | { |
50 | template<typename T> |
51 | struct is_stdstring |
52 | : boost::false_type |
53 | {}; |
54 | |
55 | template<typename CharT, typename Traits, typename Alloc> |
56 | struct is_stdstring< std::basic_string<CharT, Traits, Alloc> > |
57 | : boost::true_type |
58 | {}; |
59 | |
60 | template<typename CharT, typename Traits, typename Alloc> |
61 | struct is_stdstring< boost::container::basic_string<CharT, Traits, Alloc> > |
62 | : boost::true_type |
63 | {}; |
64 | |
65 | template<typename Target, typename Source> |
66 | struct is_arithmetic_and_not_xchars |
67 | { |
68 | typedef boost::mpl::bool_< |
69 | !(boost::detail::is_character<Target>::value) && |
70 | !(boost::detail::is_character<Source>::value) && |
71 | boost::is_arithmetic<Source>::value && |
72 | boost::is_arithmetic<Target>::value |
73 | > type; |
74 | |
75 | BOOST_STATIC_CONSTANT(bool, value = ( |
76 | type::value |
77 | )); |
78 | }; |
79 | |
80 | /* |
81 | * is_xchar_to_xchar<Target, Source>::value is true, |
82 | * Target and Souce are char types of the same size 1 (char, signed char, unsigned char). |
83 | */ |
84 | template<typename Target, typename Source> |
85 | struct is_xchar_to_xchar |
86 | { |
87 | typedef boost::mpl::bool_< |
88 | sizeof(Source) == sizeof(Target) && |
89 | sizeof(Source) == sizeof(char) && |
90 | boost::detail::is_character<Target>::value && |
91 | boost::detail::is_character<Source>::value |
92 | > type; |
93 | |
94 | BOOST_STATIC_CONSTANT(bool, value = ( |
95 | type::value |
96 | )); |
97 | }; |
98 | |
99 | template<typename Target, typename Source> |
100 | struct is_char_array_to_stdstring |
101 | : boost::false_type |
102 | {}; |
103 | |
104 | template<typename CharT, typename Traits, typename Alloc> |
105 | struct is_char_array_to_stdstring< std::basic_string<CharT, Traits, Alloc>, CharT* > |
106 | : boost::true_type |
107 | {}; |
108 | |
109 | template<typename CharT, typename Traits, typename Alloc> |
110 | struct is_char_array_to_stdstring< std::basic_string<CharT, Traits, Alloc>, const CharT* > |
111 | : boost::true_type |
112 | {}; |
113 | |
114 | template<typename CharT, typename Traits, typename Alloc> |
115 | struct is_char_array_to_stdstring< boost::container::basic_string<CharT, Traits, Alloc>, CharT* > |
116 | : boost::true_type |
117 | {}; |
118 | |
119 | template<typename CharT, typename Traits, typename Alloc> |
120 | struct is_char_array_to_stdstring< boost::container::basic_string<CharT, Traits, Alloc>, const CharT* > |
121 | : boost::true_type |
122 | {}; |
123 | |
124 | template <typename Target, typename Source> |
125 | struct copy_converter_impl |
126 | { |
127 | // MSVC fail to forward an array (DevDiv#555157 "SILENT BAD CODEGEN triggered by perfect forwarding", |
128 | // fixed in 2013 RTM). |
129 | #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && (!defined(BOOST_MSVC) || BOOST_MSVC >= 1800) |
130 | template <class T> |
131 | static inline bool try_convert(T&& arg, Target& result) { |
132 | result = static_cast<T&&>(arg); // eqaul to `result = std::forward<T>(arg);` |
133 | return true; |
134 | } |
135 | #else |
136 | static inline bool try_convert(const Source& arg, Target& result) { |
137 | result = arg; |
138 | return true; |
139 | } |
140 | #endif |
141 | }; |
142 | } |
143 | |
144 | namespace conversion { namespace detail { |
145 | |
146 | template <typename Target, typename Source> |
147 | inline bool try_lexical_convert(const Source& arg, Target& result) |
148 | { |
149 | typedef BOOST_DEDUCED_TYPENAME boost::detail::array_to_pointer_decay<Source>::type src; |
150 | |
151 | typedef boost::mpl::bool_< |
152 | boost::detail::is_xchar_to_xchar<Target, src >::value || |
153 | boost::detail::is_char_array_to_stdstring<Target, src >::value || |
154 | ( |
155 | boost::is_same<Target, src >::value && |
156 | boost::detail::is_stdstring<Target >::value |
157 | ) || |
158 | ( |
159 | boost::is_same<Target, src >::value && |
160 | boost::detail::is_character<Target >::value |
161 | ) |
162 | > shall_we_copy_t; |
163 | |
164 | typedef boost::detail::is_arithmetic_and_not_xchars<Target, src > |
165 | shall_we_copy_with_dynamic_check_t; |
166 | |
167 | // We do evaluate second `if_` lazily to avoid unnecessary instantiations |
168 | // of `shall_we_copy_with_dynamic_check_t` and improve compilation times. |
169 | typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_c< |
170 | shall_we_copy_t::value, |
171 | boost::mpl::identity<boost::detail::copy_converter_impl<Target, src > >, |
172 | boost::mpl::if_< |
173 | shall_we_copy_with_dynamic_check_t, |
174 | boost::detail::dynamic_num_converter_impl<Target, src >, |
175 | boost::detail::lexical_converter_impl<Target, src > |
176 | > |
177 | >::type caster_type_lazy; |
178 | |
179 | typedef BOOST_DEDUCED_TYPENAME caster_type_lazy::type caster_type; |
180 | |
181 | return caster_type::try_convert(arg, result); |
182 | } |
183 | |
184 | template <typename Target, typename CharacterT> |
185 | inline bool try_lexical_convert(const CharacterT* chars, std::size_t count, Target& result) |
186 | { |
187 | BOOST_STATIC_ASSERT_MSG( |
188 | boost::detail::is_character<CharacterT>::value, |
189 | "This overload of try_lexical_convert is meant to be used only with arrays of characters." |
190 | ); |
191 | return ::boost::conversion::detail::try_lexical_convert( |
192 | ::boost::iterator_range<const CharacterT*>(chars, chars + count), result |
193 | ); |
194 | } |
195 | |
196 | }} // namespace conversion::detail |
197 | |
198 | namespace conversion { |
199 | // ADL barrier |
200 | using ::boost::conversion::detail::try_lexical_convert; |
201 | } |
202 | |
203 | } // namespace boost |
204 | |
205 | #if defined(__clang__) || (defined(__GNUC__) && \ |
206 | !(defined(__INTEL_COMPILER) || defined(__ICL) || defined(__ICC) || defined(__ECC)) && \ |
207 | (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))) |
208 | #pragma GCC diagnostic pop |
209 | #endif |
210 | |
211 | #endif // BOOST_LEXICAL_CAST_TRY_LEXICAL_CONVERT_HPP |
212 | |
213 | |