libstdc++
system_error
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1 // <system_error> -*- C++ -*-
2 
3 // Copyright (C) 2007, 2008, 2009 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 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 <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 _GLIBCXX_BEGIN_NAMESPACE(std)
44 
45  class error_code;
46  class error_condition;
47  class error_category;
48  class system_error;
49 
50  /// is_error_code_enum
51  template<typename _Tp>
52  struct is_error_code_enum : public false_type { };
53 
54  /// is_error_condition_enum
55  template<typename _Tp>
56  struct is_error_condition_enum : public false_type { };
57 
58  template<>
59  struct is_error_condition_enum<errc>
60  : public true_type { };
61 
62 
63  /// error_category
65  {
66  protected:
67  error_category() = default;
68 
69  public:
70  virtual ~error_category() { }
71 
72  error_category(const error_category&) = delete;
73  error_category& operator=(const error_category&) = delete;
74 
75  virtual const char*
76  name() const = 0;
77 
78  virtual string
79  message(int) const = 0;
80 
81  virtual error_condition
82  default_error_condition(int __i) const;
83 
84  virtual bool
85  equivalent(int __i, const error_condition& __cond) const;
86 
87  virtual bool
88  equivalent(const error_code& __code, int __i) const;
89 
90  bool
91  operator<(const error_category& __other) const
92  { return less<const error_category*>()(this, &__other); }
93 
94  bool
95  operator==(const error_category& __other) const
96  { return this == &__other; }
97 
98  bool
99  operator!=(const error_category& __other) const
100  { return this != &__other; }
101  };
102 
103  // DR 890.
104  const error_category& system_category();
105  const error_category& generic_category();
106 
107  error_code make_error_code(errc);
108 
109  /// error_code
110  // Implementation-specific error identification
111  struct error_code
112  {
113  error_code()
114  : _M_value(0), _M_cat(&system_category()) { }
115 
116  error_code(int __v, const error_category& __cat)
117  : _M_value(__v), _M_cat(&__cat) { }
118 
119  template<typename _ErrorCodeEnum>
120  error_code(_ErrorCodeEnum __e,
121  typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type* = 0)
122  { *this = make_error_code(__e); }
123 
124  void
125  assign(int __v, const error_category& __cat)
126  {
127  _M_value = __v;
128  _M_cat = &__cat;
129  }
130 
131  void
132  clear()
133  { assign(0, system_category()); }
134 
135  // DR 804.
136  template<typename _ErrorCodeEnum>
137  typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
138  error_code&>::type
139  operator=(_ErrorCodeEnum __e)
140  { return *this = make_error_code(__e); }
141 
142  int
143  value() const { return _M_value; }
144 
145  const error_category&
146  category() const { return *_M_cat; }
147 
149  default_error_condition() const;
150 
151  string
152  message() const
153  { return category().message(value()); }
154 
155  // Safe bool idiom.
156  // explicit operator bool() const throw()
157  // { return _M_value != 0; }
158  typedef void (*__bool_type)();
159 
160  static void __not_bool_type() { }
161 
162  operator __bool_type() const
163  { return _M_value != 0 ? &__not_bool_type : false; }
164 
165  // DR 804.
166  private:
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)
174  { return error_code(static_cast<int>(__e), generic_category()); }
175 
176  inline bool
177  operator<(const error_code& __lhs, const error_code& __rhs)
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);
190 
191  /// error_condition
192  // Portable error identification
194  {
196  : _M_value(0), _M_cat(&generic_category()) { }
197 
198  error_condition(int __v, const error_category& __cat)
199  : _M_value(__v), _M_cat(&__cat) { }
200 
201  template<typename _ErrorConditionEnum>
202  error_condition(_ErrorConditionEnum __e,
203  typename enable_if<is_error_condition_enum
204  <_ErrorConditionEnum>::value>::type* = 0)
205  { *this = make_error_condition(__e); }
206 
207  void
208  assign(int __v, const error_category& __cat)
209  {
210  _M_value = __v;
211  _M_cat = &__cat;
212  }
213 
214  // DR 804.
215  template<typename _ErrorConditionEnum>
216  typename enable_if<is_error_condition_enum
217  <_ErrorConditionEnum>::value, error_condition&>::type
218  operator=(_ErrorConditionEnum __e)
219  { return *this = make_error_condition(__e); }
220 
221  void
222  clear()
223  { assign(0, generic_category()); }
224 
225  // 19.4.3.4 observers
226  int
227  value() const { return _M_value; }
228 
229  const error_category&
230  category() const { return *_M_cat; }
231 
232  string
233  message() const
234  { return category().message(value()); }
235 
236  // Safe bool idiom.
237  // explicit operator bool() const throw()
238  // { return _M_value != 0; }
239  typedef void (*__bool_type)();
240 
241  static void __not_bool_type() { }
242 
243  operator __bool_type() const
244  { return _M_value != 0 ? &__not_bool_type : false; }
245 
246  // DR 804.
247  private:
248  int _M_value;
249  const error_category* _M_cat;
250  };
251 
252  // 19.4.3.6 non-member functions
253  inline error_condition
254  make_error_condition(errc __e)
255  { return error_condition(static_cast<int>(__e), generic_category()); }
256 
257  inline bool
258  operator<(const error_condition& __lhs, const error_condition& __rhs)
259  {
260  return (__lhs.category() < __rhs.category()
261  || (__lhs.category() == __rhs.category()
262  && __lhs.value() < __rhs.value()));
263  }
264 
265  // 19.4.4 Comparison operators
266  inline bool
267  operator==(const error_code& __lhs, const error_code& __rhs)
268  { return (__lhs.category() == __rhs.category()
269  && __lhs.value() == __rhs.value()); }
270 
271  inline bool
272  operator==(const error_code& __lhs, const error_condition& __rhs)
273  {
274  return (__lhs.category().equivalent(__lhs.value(), __rhs)
275  || __rhs.category().equivalent(__lhs, __rhs.value()));
276  }
277 
278  inline bool
279  operator==(const error_condition& __lhs, const error_code& __rhs)
280  {
281  return (__rhs.category().equivalent(__rhs.value(), __lhs)
282  || __lhs.category().equivalent(__rhs, __lhs.value()));
283  }
284 
285  inline bool
286  operator==(const error_condition& __lhs, const error_condition& __rhs)
287  {
288  return (__lhs.category() == __rhs.category()
289  && __lhs.value() == __rhs.value());
290  }
291 
292  inline bool
293  operator!=(const error_code& __lhs, const error_code& __rhs)
294  { return !(__lhs == __rhs); }
295 
296  inline bool
297  operator!=(const error_code& __lhs, const error_condition& __rhs)
298  { return !(__lhs == __rhs); }
299 
300  inline bool
301  operator!=(const error_condition& __lhs, const error_code& __rhs)
302  { return !(__lhs == __rhs); }
303 
304  inline bool
305  operator!=(const error_condition& __lhs, const error_condition& __rhs)
306  { return !(__lhs == __rhs); }
307 
308 
309  /**
310  * @brief Thrown to indicate error code of underlying system.
311  *
312  * @ingroup exceptions
313  */
315  {
316  private:
317  error_code _M_code;
318 
319  public:
321  : runtime_error(""), _M_code(__ec) { }
322 
323  system_error(error_code __ec, const string& __what)
324  : runtime_error(__what), _M_code(__ec) { }
325 
326  /*
327  * TODO: Add const char* ctors to all exceptions.
328  *
329  * system_error(error_code __ec, const char* __what)
330  * : runtime_error(__what), _M_code(__ec) { }
331  *
332  * system_error(int __v, const error_category& __ecat, const char* __what)
333  * : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
334  */
335 
336  system_error(int __v, const error_category& __ecat)
337  : runtime_error(""), _M_code(error_code(__v, __ecat)) { }
338 
339  system_error(int __v, const error_category& __ecat, const string& __what)
340  : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
341 
342  virtual ~system_error() throw();
343 
344  const error_code&
345  code() const throw() { return _M_code; }
346  };
347 
348 _GLIBCXX_END_NAMESPACE
349 
350 #endif // __GXX_EXPERIMENTAL_CXX0X__
351 
352 #endif // _GLIBCXX_SYSTEM_ERROR
353