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
43namespace 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
353namespace 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
379