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:
70 
71  public:
72  virtual ~error_category();
73 
74  error_category(const error_category&) = delete;
75  error_category& operator=(const error_category&) = delete;
76 
77  virtual const char*
78  name() const = 0;
79 
80  virtual string
81  message(int) const = 0;
82 
83  virtual error_condition
84  default_error_condition(int __i) const;
85 
86  virtual bool
87  equivalent(int __i, const error_condition& __cond) const;
88 
89  virtual bool
90  equivalent(const error_code& __code, int __i) const;
91 
92  bool
93  operator<(const error_category& __other) const
94  { return less<const error_category*>()(this, &__other); }
95 
96  bool
97  operator==(const error_category& __other) const
98  { return this == &__other; }
99 
100  bool
101  operator!=(const error_category& __other) const
102  { return this != &__other; }
103  };
104 
105  // DR 890.
106  _GLIBCXX_CONST const error_category& system_category() throw();
107  _GLIBCXX_CONST const error_category& generic_category() throw();
108 
109  error_code make_error_code(errc);
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()
119  : _M_value(0), _M_cat(&system_category()) { }
120 
121  error_code(int __v, const error_category& __cat)
122  : _M_value(__v), _M_cat(&__cat) { }
123 
124  template<typename _ErrorCodeEnum>
125  error_code(_ErrorCodeEnum __e,
127  { *this = make_error_code(__e); }
128 
129  void
130  assign(int __v, const error_category& __cat)
131  {
132  _M_value = __v;
133  _M_cat = &__cat;
134  }
135 
136  void
137  clear()
138  { assign(0, system_category()); }
139 
140  // DR 804.
141  template<typename _ErrorCodeEnum>
143  error_code&>::type
144  operator=(_ErrorCodeEnum __e)
145  { return *this = make_error_code(__e); }
146 
147  int
148  value() const { return _M_value; }
149 
150  const error_category&
151  category() const { return *_M_cat; }
152 
154  default_error_condition() const;
155 
156  string
157  message() const
158  { return category().message(value()); }
159 
160  explicit operator bool() const
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)
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,
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>
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  explicit operator bool() const
237  { return _M_value != 0 ? true : false; }
238 
239  // DR 804.
240  private:
241  int _M_value;
242  const error_category* _M_cat;
243  };
244 
245  // 19.4.3.6 non-member functions
246  inline error_condition
247  make_error_condition(errc __e)
248  { return error_condition(static_cast<int>(__e), generic_category()); }
249 
250  inline bool
251  operator<(const error_condition& __lhs, const error_condition& __rhs)
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)
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)
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)
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, const error_condition& __rhs)
280  {
281  return (__lhs.category() == __rhs.category()
282  && __lhs.value() == __rhs.value());
283  }
284 
285  inline bool
286  operator!=(const error_code& __lhs, const error_code& __rhs)
287  { return !(__lhs == __rhs); }
288 
289  inline bool
290  operator!=(const error_code& __lhs, const error_condition& __rhs)
291  { return !(__lhs == __rhs); }
292 
293  inline bool
294  operator!=(const error_condition& __lhs, const error_code& __rhs)
295  { return !(__lhs == __rhs); }
296 
297  inline bool
298  operator!=(const error_condition& __lhs, const error_condition& __rhs)
299  { return !(__lhs == __rhs); }
300 
301 
302  /**
303  * @brief Thrown to indicate error code of underlying system.
304  *
305  * @ingroup exceptions
306  */
308  {
309  private:
310  error_code _M_code;
311 
312  public:
314  : runtime_error(__ec.message()), _M_code(__ec) { }
315 
316  system_error(error_code __ec, const string& __what)
317  : runtime_error(__what + ": " + __ec.message()), _M_code(__ec) { }
318 
319  /*
320  * TODO: Add const char* ctors to all exceptions.
321  *
322  * system_error(error_code __ec, const char* __what)
323  * : runtime_error(__what + (": " + __ec.message())), _M_code(__ec) { }
324  *
325  * system_error(int __v, const error_category& __ecat, const char* __what)
326  * : runtime_error(__what + (": " + __ec.message())),
327  * _M_code(error_code(__v, __ecat)) { }
328  */
329 
330  system_error(int __v, const error_category& __ecat)
331  : runtime_error(error_code(__v, __ecat).message()),
332  _M_code(__v, __ecat) { }
333 
334  system_error(int __v, const error_category& __ecat, const string& __what)
335  : runtime_error(__what + ": " + error_code(__v, __ecat).message()),
336  _M_code(__v, __ecat) { }
337 
338  virtual ~system_error() throw();
339 
340  const error_code&
341  code() const throw() { return _M_code; }
342  };
343 
344 _GLIBCXX_END_NAMESPACE_VERSION
345 } // namespace
346 
347 #ifndef _GLIBCXX_COMPATIBILITY_CXX0X
348 
349 #include <bits/functional_hash.h>
350 
351 namespace std _GLIBCXX_VISIBILITY(default)
352 {
353 _GLIBCXX_BEGIN_NAMESPACE_VERSION
354 
355  // DR 1182.
356  /// std::hash specialization for error_code.
357  template<>
358  struct hash<error_code>
359  : public __hash_base<size_t, error_code>
360  {
361  size_t
362  operator()(const error_code& __e) const
363  {
364  const size_t __tmp = std::_Hash_impl::hash(__e._M_value);
365  return std::_Hash_impl::__hash_combine(__e._M_cat, __tmp);
366  }
367  };
368 
369 _GLIBCXX_END_NAMESPACE_VERSION
370 } // namespace
371 
372 #endif // _GLIBCXX_COMPATIBILITY_CXX0X
373 
374 #endif // __GXX_EXPERIMENTAL_CXX0X__
375 
376 #endif // _GLIBCXX_SYSTEM_ERROR
Primary class template hash.
Definition: system_error:112
One of two subclasses of exception.
Definition: stdexcept:113
runtime_error(const string &__arg)
One of the comparison functors.
Definition: stl_function.h:232
error_code
Definition: system_error:116
enable_if
Definition: type_traits:836
is_error_condition_enum
Definition: system_error:58
Thrown to indicate error code of underlying system.
Definition: system_error:307
is_error_code_enum
Definition: system_error:54
error_condition
Definition: system_error:193
error_category
Definition: system_error:66