libstdc++

system_error
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1 // <system_error> -*- C++ -*-
2
3 // Copyright (C) 2007-2013 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 /** @file include/system_error
26 * This is a Standard C++ Library header.
27 */
28
29 #ifndef _GLIBCXX_SYSTEM_ERROR
30 #define _GLIBCXX_SYSTEM_ERROR 1
31
32 #pragma GCC system_header
33
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
36 #else
37
38 #include <bits/c++config.h>
39 #include <bits/error_constants.h>
40 #include <iosfwd>
41 #include <stdexcept>
42
43 namespace std _GLIBCXX_VISIBILITY(default)
44 {
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
46
47 class error_code;
48 class error_condition;
49 class error_category;
50 class system_error;
51
52 /// is_error_code_enum
53 template<typename _Tp>
54 struct is_error_code_enum : public false_type { };
55
56 /// is_error_condition_enum
57 template<typename _Tp>
58 struct is_error_condition_enum : public false_type { };
59
60 template<>
61 struct is_error_condition_enum<errc>
62 : public true_type { };
63
64
65 /// error_category
66 class error_category
67 {
68 protected:
69 error_category() noexcept;
70
71 public:
72 virtual ~error_category() noexcept;
73
74 error_category(const error_category&) = delete;
75 error_category& operator=(const error_category&) = delete;
76
77 virtual const char*
78 name() const noexcept = 0;
79
80 virtual string
81 message(int) const = 0;
82
83 virtual error_condition
84 default_error_condition(int __i) const noexcept;
85
86 virtual bool
87 equivalent(int __i, const error_condition& __cond) const noexcept;
88
89 virtual bool
90 equivalent(const error_code& __code, int __i) const noexcept;
91
92 bool
93 operator<(const error_category& __other) const noexcept
94 { return less<const error_category*>()(this, &__other); }
95
96 bool
97 operator==(const error_category& __other) const noexcept
98 { return this == &__other; }
99
100 bool
101 operator!=(const error_category& __other) const noexcept
102 { return this != &__other; }
103 };
104
105 // DR 890.
106 _GLIBCXX_CONST const error_category& system_category() noexcept;
107 _GLIBCXX_CONST const error_category& generic_category() noexcept;
108
109 error_code make_error_code(errc) noexcept;
110
111 template<typename _Tp>
112 struct hash;
113
114 /// error_code
115 // Implementation-specific error identification
116 struct error_code
117 {
118 error_code() noexcept
119 : _M_value(0), _M_cat(&system_category()) { }
120
121 error_code(int __v, const error_category& __cat) noexcept
122 : _M_value(__v), _M_cat(&__cat) { }
123
124 template<typename _ErrorCodeEnum, typename = typename
125 enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type>
126 error_code(_ErrorCodeEnum __e) noexcept
127 { *this = make_error_code(__e); }
128
129 void
130 assign(int __v, const error_category& __cat) noexcept
131 {
132 _M_value = __v;
133 _M_cat = &__cat;
134 }
135
136 void
137 clear() noexcept
138 { assign(0, system_category()); }
139
140 // DR 804.
141 template<typename _ErrorCodeEnum>
142 typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
143 error_code&>::type
144 operator=(_ErrorCodeEnum __e) noexcept
145 { return *this = make_error_code(__e); }
146
147 int
148 value() const noexcept { return _M_value; }
149
150 const error_category&
151 category() const noexcept { return *_M_cat; }
152
153 error_condition
154 default_error_condition() const noexcept;
155
156 string
157 message() const
158 { return category().message(value()); }
159
160 explicit operator bool() const noexcept
161 { return _M_value != 0 ? true : false; }
162
163 // DR 804.
164 private:
165 friend class hash<error_code>;
166
167 int _M_value;
168 const error_category* _M_cat;
169 };
170
171 // 19.4.2.6 non-member functions
172 inline error_code
173 make_error_code(errc __e) noexcept
174 { return error_code(static_cast<int>(__e), generic_category()); }
175
176 inline bool
177 operator<(const error_code& __lhs, const error_code& __rhs) noexcept
178 {
179 return (__lhs.category() < __rhs.category()
180 || (__lhs.category() == __rhs.category()
181 && __lhs.value() < __rhs.value()));
182 }
183
184 template<typename _CharT, typename _Traits>
185 basic_ostream<_CharT, _Traits>&
186 operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
187 { return (__os << __e.category().name() << ':' << __e.value()); }
188
189 error_condition make_error_condition(errc) noexcept;
190
191 /// error_condition
192 // Portable error identification
193 struct error_condition
194 {
195 error_condition() noexcept
196 : _M_value(0), _M_cat(&generic_category()) { }
197
198 error_condition(int __v, const error_category& __cat) noexcept
199 : _M_value(__v), _M_cat(&__cat) { }
200
201 template<typename _ErrorConditionEnum, typename = typename
202 enable_if<is_error_condition_enum<_ErrorConditionEnum>::value>::type>
203 error_condition(_ErrorConditionEnum __e) noexcept
204 { *this = make_error_condition(__e); }
205
206 void
207 assign(int __v, const error_category& __cat) noexcept
208 {
209 _M_value = __v;
210 _M_cat = &__cat;
211 }
212
213 // DR 804.
214 template<typename _ErrorConditionEnum>
215 typename enable_if<is_error_condition_enum
216 <_ErrorConditionEnum>::value, error_condition&>::type
217 operator=(_ErrorConditionEnum __e) noexcept
218 { return *this = make_error_condition(__e); }
219
220 void
221 clear() noexcept
222 { assign(0, generic_category()); }
223
224 // 19.4.3.4 observers
225 int
226 value() const noexcept { return _M_value; }
227
228 const error_category&
229 category() const noexcept { return *_M_cat; }
230
231 string
232 message() const
233 { return category().message(value()); }
234
235 explicit operator bool() const noexcept
236 { return _M_value != 0 ? true : false; }
237
238 // DR 804.
239 private:
240 int _M_value;
241 const error_category* _M_cat;
242 };
243
244 // 19.4.3.6 non-member functions
245 inline error_condition
246 make_error_condition(errc __e) noexcept
247 { return error_condition(static_cast<int>(__e), generic_category()); }
248
249 inline bool
250 operator<(const error_condition& __lhs,
251 const error_condition& __rhs) noexcept
252 {
253 return (__lhs.category() < __rhs.category()
254 || (__lhs.category() == __rhs.category()
255 && __lhs.value() < __rhs.value()));
256 }
257
258 // 19.4.4 Comparison operators
259 inline bool
260 operator==(const error_code& __lhs, const error_code& __rhs) noexcept
261 { return (__lhs.category() == __rhs.category()
262 && __lhs.value() == __rhs.value()); }
263
264 inline bool
265 operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
266 {
267 return (__lhs.category().equivalent(__lhs.value(), __rhs)
268 || __rhs.category().equivalent(__lhs, __rhs.value()));
269 }
270
271 inline bool
272 operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
273 {
274 return (__rhs.category().equivalent(__rhs.value(), __lhs)
275 || __lhs.category().equivalent(__rhs, __lhs.value()));
276 }
277
278 inline bool
279 operator==(const error_condition& __lhs,
280 const error_condition& __rhs) noexcept
281 {
282 return (__lhs.category() == __rhs.category()
283 && __lhs.value() == __rhs.value());
284 }
285
286 inline bool
287 operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
288 { return !(__lhs == __rhs); }
289
290 inline bool
291 operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
292 { return !(__lhs == __rhs); }
293
294 inline bool
295 operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
296 { return !(__lhs == __rhs); }
297
298 inline bool
299 operator!=(const error_condition& __lhs,
300 const error_condition& __rhs) noexcept
301 { return !(__lhs == __rhs); }
302
303
304 /**
305 * @brief Thrown to indicate error code of underlying system.
306 *
307 * @ingroup exceptions
308 */
309 class system_error : public std::runtime_error
310 {
311 private:
312 error_code _M_code;
313
314 public:
315 system_error(error_code __ec = error_code())
316 : runtime_error(__ec.message()), _M_code(__ec) { }
317
318 system_error(error_code __ec, const string& __what)
319 : runtime_error(__what + ": " + __ec.message()), _M_code(__ec) { }
320
321 /*
322 * TODO: Add const char* ctors to all exceptions.
323 *
324 * system_error(error_code __ec, const char* __what)
325 * : runtime_error(__what + (": " + __ec.message())), _M_code(__ec) { }
326 *
327 * system_error(int __v, const error_category& __ecat, const char* __what)
328 * : runtime_error(__what + (": " + __ec.message())),
329 * _M_code(error_code(__v, __ecat)) { }
330 */
331
332 system_error(int __v, const error_category& __ecat)
333 : runtime_error(error_code(__v, __ecat).message()),
334 _M_code(__v, __ecat) { }
335
336 system_error(int __v, const error_category& __ecat, const string& __what)
337 : runtime_error(__what + ": " + error_code(__v, __ecat).message()),
338 _M_code(__v, __ecat) { }
339
340 virtual ~system_error() noexcept;
341
342 const error_code&
343 code() const noexcept { return _M_code; }
344 };
345
346 _GLIBCXX_END_NAMESPACE_VERSION
347 } // namespace
348
349 #ifndef _GLIBCXX_COMPATIBILITY_CXX0X
350
351 #include <bits/functional_hash.h>
352
353 namespace std _GLIBCXX_VISIBILITY(default)
354 {
355 _GLIBCXX_BEGIN_NAMESPACE_VERSION
356
357 // DR 1182.
358 /// std::hash specialization for error_code.
359 template<>
360 struct hash<error_code>
361 : public __hash_base<size_t, error_code>
362 {
363 size_t
364 operator()(const error_code& __e) const noexcept
365 {
366 const size_t __tmp = std::_Hash_impl::hash(__e._M_value);
367 return std::_Hash_impl::__hash_combine(__e._M_cat, __tmp);
368 }
369 };
370
371 _GLIBCXX_END_NAMESPACE_VERSION
372 } // namespace
373
374 #endif // _GLIBCXX_COMPATIBILITY_CXX0X
375
376 #endif // C++11
377
378 #endif // _GLIBCXX_SYSTEM_ERROR