libstdc++-v3/include/std/system_error

   1 // <system_error> -*- C++ -*-
   2
   3 // Copyright (C) 2007, 2008, 2009, 2010 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
  66   class error_category
  67   {
  68   protected:
  69     error_category();
  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   inline error_category::error_category() = default;
 106
 107   // DR 890.
 108   _GLIBCXX_CONST const error_category& system_category() throw();
 109   _GLIBCXX_CONST const error_category& generic_category() throw();
 110
 111   error_code make_error_code(errc);
 112
 113   template<typename _Tp>
 114     struct hash;
 115
 116   /// error_code
 117   // Implementation-specific error identification
 118   struct error_code
 119   {
 120     error_code()
 121     : _M_value(0), _M_cat(&system_category()) { }
 122
 123     error_code(int __v, const error_category& __cat)
 124     : _M_value(__v), _M_cat(&__cat) { }
 125
 126     template<typename _ErrorCodeEnum>
 127       error_code(_ErrorCodeEnum __e,
 128       typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type* = 0)
 129       { *this = make_error_code(__e); }
 130
 131     void
 132     assign(int __v, const error_category& __cat)
 133     {
 134       _M_value = __v;
 135       _M_cat = &__cat;
 136     }
 137
 138     void
 139     clear()
 140     { assign(0, system_category()); }
 141
 142     // DR 804.
 143     template<typename _ErrorCodeEnum>
 144       typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
 145                          error_code&>::type
 146       operator=(_ErrorCodeEnum __e)
 147       { return *this = make_error_code(__e); }
 148
 149     int
 150     value() const { return _M_value; }
 151
 152     const error_category&
 153     category() const { return *_M_cat; }
 154
 155     error_condition
 156     default_error_condition() const;
 157
 158     string
 159     message() const
 160     { return category().message(value()); }
 161
 162     explicit operator bool() const
 163     { return _M_value != 0 ? true : false; }
 164
 165     // DR 804.
 166   private:
 167     friend class hash<error_code>;
 168
 169     int                         _M_value;
 170     const error_category*       _M_cat;
 171   };
 172
 173   // 19.4.2.6 non-member functions
 174   inline error_code
 175   make_error_code(errc __e)
 176   { return error_code(static_cast<int>(__e), generic_category()); }
 177
 178   inline bool
 179   operator<(const error_code& __lhs, const error_code& __rhs)
 180   {
 181     return (__lhs.category() < __rhs.category()
 182             || (__lhs.category() == __rhs.category()
 183                 && __lhs.value() < __rhs.value()));
 184   }
 185
 186   template<typename _CharT, typename _Traits>
 187     basic_ostream<_CharT, _Traits>&
 188     operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
 189     { return (__os << __e.category().name() << ':' << __e.value()); }
 190
 191   error_condition make_error_condition(errc);
 192
 193   /// error_condition
 194   // Portable error identification
 195   struct error_condition
 196   {
 197     error_condition()
 198     : _M_value(0), _M_cat(&generic_category()) { }
 199
 200     error_condition(int __v, const error_category& __cat)
 201     : _M_value(__v), _M_cat(&__cat) { }
 202
 203     template<typename _ErrorConditionEnum>
 204       error_condition(_ErrorConditionEnum __e,
 205                       typename enable_if<is_error_condition_enum
 206                                       <_ErrorConditionEnum>::value>::type* = 0)
 207       { *this = make_error_condition(__e); }
 208
 209     void
 210     assign(int __v, const error_category& __cat)
 211     {
 212       _M_value = __v;
 213       _M_cat = &__cat;
 214     }
 215
 216     // DR 804.
 217     template<typename _ErrorConditionEnum>
 218       typename enable_if<is_error_condition_enum
 219                          <_ErrorConditionEnum>::value, error_condition&>::type
 220       operator=(_ErrorConditionEnum __e)
 221       { return *this = make_error_condition(__e); }
 222
 223     void
 224     clear()
 225     { assign(0, generic_category()); }
 226
 227     // 19.4.3.4 observers
 228     int
 229     value() const { return _M_value; }
 230
 231     const error_category&
 232     category() const { return *_M_cat; }
 233
 234     string
 235     message() const
 236     { return category().message(value()); }
 237
 238     explicit operator bool() const
 239     { return _M_value != 0 ? true : false; }
 240
 241     // DR 804.
 242   private:
 243     int                         _M_value;
 244     const error_category*       _M_cat;
 245   };
 246
 247   // 19.4.3.6 non-member functions
 248   inline error_condition
 249   make_error_condition(errc __e)
 250   { return error_condition(static_cast<int>(__e), generic_category()); }
 251
 252   inline bool
 253   operator<(const error_condition& __lhs, const error_condition& __rhs)
 254   {
 255     return (__lhs.category() < __rhs.category()
 256             || (__lhs.category() == __rhs.category()
 257                 && __lhs.value() < __rhs.value()));
 258   }
 259
 260   // 19.4.4 Comparison operators
 261   inline bool
 262   operator==(const error_code& __lhs, const error_code& __rhs)
 263   { return (__lhs.category() == __rhs.category()
 264             && __lhs.value() == __rhs.value()); }
 265
 266   inline bool
 267   operator==(const error_code& __lhs, const error_condition& __rhs)
 268   {
 269     return (__lhs.category().equivalent(__lhs.value(), __rhs)
 270             || __rhs.category().equivalent(__lhs, __rhs.value()));
 271   }
 272
 273   inline bool
 274   operator==(const error_condition& __lhs, const error_code& __rhs)
 275   {
 276     return (__rhs.category().equivalent(__rhs.value(), __lhs)
 277             || __lhs.category().equivalent(__rhs, __lhs.value()));
 278   }
 279
 280   inline bool
 281   operator==(const error_condition& __lhs, const error_condition& __rhs)
 282   {
 283     return (__lhs.category() == __rhs.category()
 284             && __lhs.value() == __rhs.value());
 285   }
 286
 287   inline bool
 288   operator!=(const error_code& __lhs, const error_code& __rhs)
 289   { return !(__lhs == __rhs); }
 290
 291   inline bool
 292   operator!=(const error_code& __lhs, const error_condition& __rhs)
 293   { return !(__lhs == __rhs); }
 294
 295   inline bool
 296   operator!=(const error_condition& __lhs, const error_code& __rhs)
 297   { return !(__lhs == __rhs); }
 298
 299   inline bool
 300   operator!=(const error_condition& __lhs, const error_condition& __rhs)
 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() throw();
 341
 342     const error_code&
 343     code() const throw() { 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
 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