1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
|
// <system_error> -*- C++ -*-
// Copyright (C) 2007-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file include/system_error
* This is a Standard C++ Library header.
*/
#ifndef _GLIBCXX_SYSTEM_ERROR
#define _GLIBCXX_SYSTEM_ERROR 1
#pragma GCC system_header
#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
#include <bits/c++config.h>
#include <bits/error_constants.h>
#include <iosfwd>
#include <stdexcept>
#if __cplusplus > 201703L
# include <compare>
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/** @addtogroup diagnostics
* @{
*/
class error_code;
class error_condition;
class system_error;
/// is_error_code_enum
template<typename _Tp>
struct is_error_code_enum : public false_type { };
/// is_error_condition_enum
template<typename _Tp>
struct is_error_condition_enum : public false_type { };
template<>
struct is_error_condition_enum<errc>
: public true_type { };
#if __cplusplus > 201402L
template <typename _Tp>
inline constexpr bool is_error_code_enum_v =
is_error_code_enum<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_error_condition_enum_v =
is_error_condition_enum<_Tp>::value;
#endif // C++17
/// @}
inline namespace _V2 {
/** @addtogroup diagnostics
* @{
*/
/** Abstract base class for types defining a category of error codes.
*
* An error category defines a context that give meaning to the integer
* stored in an `error_code` or `error_condition` object. For example,
* the standard `errno` constants such a `EINVAL` and `ENOMEM` are
* associated with the "generic" category and other OS-specific error
* numbers are associated with the "system" category, but a user-defined
* category might give different meanings to the same numerical values.
*
* @since C++11
*/
class error_category
{
public:
constexpr error_category() noexcept = default;
virtual ~error_category();
error_category(const error_category&) = delete;
error_category& operator=(const error_category&) = delete;
virtual const char*
name() const noexcept = 0;
// We need two different virtual functions here, one returning a
// COW string and one returning an SSO string. Their positions in the
// vtable must be consistent for dynamic dispatch to work, but which one
// the name "message()" finds depends on which ABI the caller is using.
#if _GLIBCXX_USE_CXX11_ABI
private:
_GLIBCXX_DEFAULT_ABI_TAG
virtual __cow_string
_M_message(int) const;
public:
_GLIBCXX_DEFAULT_ABI_TAG
virtual string
message(int) const = 0;
#else
virtual string
message(int) const = 0;
private:
virtual __sso_string
_M_message(int) const;
#endif
public:
virtual error_condition
default_error_condition(int __i) const noexcept;
virtual bool
equivalent(int __i, const error_condition& __cond) const noexcept;
virtual bool
equivalent(const error_code& __code, int __i) const noexcept;
bool
operator==(const error_category& __other) const noexcept
{ return this == &__other; }
#if __cpp_lib_three_way_comparison
strong_ordering
operator<=>(const error_category& __rhs) const noexcept
{ return std::compare_three_way()(this, &__rhs); }
#else
bool
operator!=(const error_category& __other) const noexcept
{ return this != &__other; }
bool
operator<(const error_category& __other) const noexcept
{ return less<const error_category*>()(this, &__other); }
#endif
};
// DR 890.
/// Error category for `errno` error codes.
_GLIBCXX_CONST const error_category& generic_category() noexcept;
/// Error category for other error codes defined by the OS.
_GLIBCXX_CONST const error_category& system_category() noexcept;
/// @}
} // end inline namespace
/** @addtogroup diagnostics
* @{
*/
error_code make_error_code(errc) noexcept;
/** Class error_code
*
* This class is a value type storing an integer error number and a
* category that gives meaning to the error number. Typically this is done
* close the the point where the error happens, to capture the original
* error value.
*
* An `error_code` object can be used to store the original error value
* emitted by some subsystem, with a category relevant to the subsystem.
* For example, errors from POSIX library functions can be represented by
* an `errno` value and the "generic" category, but errors from an HTTP
* library might be represented by an HTTP response status code (e.g. 404)
* and a custom category defined by the library.
*
* @since C++11
* @ingroup diagnostics
*/
class error_code
{
public:
error_code() noexcept
: _M_value(0), _M_cat(&system_category()) { }
error_code(int __v, const error_category& __cat) noexcept
: _M_value(__v), _M_cat(&__cat) { }
template<typename _ErrorCodeEnum, typename = typename
enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type>
error_code(_ErrorCodeEnum __e) noexcept
{ *this = make_error_code(__e); }
void
assign(int __v, const error_category& __cat) noexcept
{
_M_value = __v;
_M_cat = &__cat;
}
void
clear() noexcept
{ assign(0, system_category()); }
// DR 804.
template<typename _ErrorCodeEnum>
typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
error_code&>::type
operator=(_ErrorCodeEnum __e) noexcept
{ return *this = make_error_code(__e); }
int
value() const noexcept { return _M_value; }
const error_category&
category() const noexcept { return *_M_cat; }
error_condition
default_error_condition() const noexcept;
_GLIBCXX_DEFAULT_ABI_TAG
string
message() const
{ return category().message(value()); }
explicit operator bool() const noexcept
{ return _M_value != 0; }
// DR 804.
private:
int _M_value;
const error_category* _M_cat;
};
// 19.4.2.6 non-member functions
/// @relates error_code @{
inline error_code
make_error_code(errc __e) noexcept
{ return error_code(static_cast<int>(__e), generic_category()); }
#if __cpp_lib_three_way_comparison
inline strong_ordering
operator<=>(const error_code& __lhs, const error_code& __rhs) noexcept
{
if (auto __c = __lhs.category() <=> __rhs.category(); __c != 0)
return __c;
return __lhs.value() <=> __rhs.value();
}
#else
inline bool
operator<(const error_code& __lhs, const error_code& __rhs) noexcept
{
return (__lhs.category() < __rhs.category()
|| (__lhs.category() == __rhs.category()
&& __lhs.value() < __rhs.value()));
}
#endif
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
{ return (__os << __e.category().name() << ':' << __e.value()); }
/// @}
error_condition make_error_condition(errc) noexcept;
/** Class error_condition
*
* This class represents error conditions that may be visible at an API
* boundary. Different `error_code` values that can occur within a library
* or module might map to the same `error_condition`.
*
* An `error_condition` represents something that the program can test for,
* and subsequently take appropriate action.
*
* @since C++11
*/
class error_condition
{
public:
error_condition() noexcept
: _M_value(0), _M_cat(&generic_category()) { }
error_condition(int __v, const error_category& __cat) noexcept
: _M_value(__v), _M_cat(&__cat) { }
template<typename _ErrorConditionEnum, typename = typename
enable_if<is_error_condition_enum<_ErrorConditionEnum>::value>::type>
error_condition(_ErrorConditionEnum __e) noexcept
{ *this = make_error_condition(__e); }
void
assign(int __v, const error_category& __cat) noexcept
{
_M_value = __v;
_M_cat = &__cat;
}
// DR 804.
template<typename _ErrorConditionEnum>
typename enable_if<is_error_condition_enum
<_ErrorConditionEnum>::value, error_condition&>::type
operator=(_ErrorConditionEnum __e) noexcept
{ return *this = make_error_condition(__e); }
void
clear() noexcept
{ assign(0, generic_category()); }
// 19.4.3.4 observers
int
value() const noexcept { return _M_value; }
const error_category&
category() const noexcept { return *_M_cat; }
_GLIBCXX_DEFAULT_ABI_TAG
string
message() const
{ return category().message(value()); }
explicit operator bool() const noexcept
{ return _M_value != 0; }
// DR 804.
private:
int _M_value;
const error_category* _M_cat;
};
// 19.4.3.6 non-member functions
/// Create an `error_condition` representing a standard `errc` condition.
/// @relates error_condition
inline error_condition
make_error_condition(errc __e) noexcept
{ return error_condition(static_cast<int>(__e), generic_category()); }
// 19.4.4 Comparison operators
/// @relates error_code
inline bool
operator==(const error_code& __lhs, const error_code& __rhs) noexcept
{ return (__lhs.category() == __rhs.category()
&& __lhs.value() == __rhs.value()); }
/// @relates error_code
inline bool
operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
{
return (__lhs.category().equivalent(__lhs.value(), __rhs)
|| __rhs.category().equivalent(__lhs, __rhs.value()));
}
/// @relates error_condition
inline bool
operator==(const error_condition& __lhs,
const error_condition& __rhs) noexcept
{
return (__lhs.category() == __rhs.category()
&& __lhs.value() == __rhs.value());
}
#if __cpp_lib_three_way_comparison
/// Define an ordering for error_condition objects.
/// @relates error_condition
inline strong_ordering
operator<=>(const error_condition& __lhs,
const error_condition& __rhs) noexcept
{
if (auto __c = __lhs.category() <=> __rhs.category(); __c != 0)
return __c;
return __lhs.value() <=> __rhs.value();
}
#else
/// Define an ordering for error_condition objects.
/// @relates error_condition
inline bool
operator<(const error_condition& __lhs,
const error_condition& __rhs) noexcept
{
return (__lhs.category() < __rhs.category()
|| (__lhs.category() == __rhs.category()
&& __lhs.value() < __rhs.value()));
}
/// @relates error_condition
inline bool
operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
{
return (__rhs.category().equivalent(__rhs.value(), __lhs)
|| __lhs.category().equivalent(__rhs, __lhs.value()));
}
/// @relates error_code
inline bool
operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
{ return !(__lhs == __rhs); }
/// @relates error_code
inline bool
operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
{ return !(__lhs == __rhs); }
/// @relates error_condition
inline bool
operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
{ return !(__lhs == __rhs); }
/// @relates error_condition
inline bool
operator!=(const error_condition& __lhs,
const error_condition& __rhs) noexcept
{ return !(__lhs == __rhs); }
#endif // three_way_comparison
/// @}
/**
* @brief An exception type that includes an `error_code` value.
*
* Typically used to report errors from the operating system and other
* low-level APIs.
*
* @since C++11
* @ingroup exceptions
*/
class system_error : public std::runtime_error
{
private:
error_code _M_code;
public:
system_error(error_code __ec = error_code())
: runtime_error(__ec.message()), _M_code(__ec) { }
system_error(error_code __ec, const string& __what)
: runtime_error(__what + ": " + __ec.message()), _M_code(__ec) { }
system_error(error_code __ec, const char* __what)
: runtime_error(__what + (": " + __ec.message())), _M_code(__ec) { }
system_error(int __v, const error_category& __ecat, const char* __what)
: system_error(error_code(__v, __ecat), __what) { }
system_error(int __v, const error_category& __ecat)
: runtime_error(error_code(__v, __ecat).message()),
_M_code(__v, __ecat) { }
system_error(int __v, const error_category& __ecat, const string& __what)
: runtime_error(__what + ": " + error_code(__v, __ecat).message()),
_M_code(__v, __ecat) { }
#if __cplusplus >= 201103L
system_error (const system_error &) = default;
system_error &operator= (const system_error &) = default;
#endif
virtual ~system_error() noexcept;
const error_code&
code() const noexcept { return _M_code; }
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#include <bits/functional_hash.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
// DR 1182.
/// std::hash specialization for error_code.
/// @relates error_code
template<>
struct hash<error_code>
: public __hash_base<size_t, error_code>
{
size_t
operator()(const error_code& __e) const noexcept
{
const size_t __tmp = std::_Hash_impl::hash(__e.value());
return std::_Hash_impl::__hash_combine(&__e.category(), __tmp);
}
};
#endif // _GLIBCXX_COMPATIBILITY_CXX0X
#if __cplusplus >= 201703L
// DR 2686.
/// std::hash specialization for error_condition.
/// @relates error_condition
template<>
struct hash<error_condition>
: public __hash_base<size_t, error_condition>
{
size_t
operator()(const error_condition& __e) const noexcept
{
const size_t __tmp = std::_Hash_impl::hash(__e.value());
return std::_Hash_impl::__hash_combine(&__e.category(), __tmp);
}
};
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#endif // _GLIBCXX_SYSTEM_ERROR
|