libstdc++
system_error
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1 // <system_error> -*- C++ -*-
2 
3 // Copyright (C) 2007, 2008, 2009, 2010, 2011 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 #ifndef __GXX_EXPERIMENTAL_CXX0X__
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
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
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>
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 
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
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
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>
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  */
310  {
311  private:
312  error_code _M_code;
313 
314  public:
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 // __GXX_EXPERIMENTAL_CXX0X__
377 
378 #endif // _GLIBCXX_SYSTEM_ERROR