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 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 _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
  64   class error_category
  65   {
  66   protected:
  67     error_category();
  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   inline error_category::error_category() = default;
 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   /// error_code
 112   // Implementation-specific error identification
 113   struct error_code
 114   {
 115     error_code()
 116     : _M_value(0), _M_cat(&system_category()) { }
 117
 118     error_code(int __v, const error_category& __cat)
 119     : _M_value(__v), _M_cat(&__cat) { }
 120
 121     template<typename _ErrorCodeEnum>
 122       error_code(_ErrorCodeEnum __e,
 123       typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type* = 0)
 124       { *this = make_error_code(__e); }
 125
 126     void
 127     assign(int __v, const error_category& __cat)
 128     {
 129       _M_value = __v;
 130       _M_cat = &__cat;
 131     }
 132
 133     void
 134     clear()
 135     { assign(0, system_category()); }
 136
 137     // DR 804.
 138     template<typename _ErrorCodeEnum>
 139       typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
 140                          error_code&>::type
 141       operator=(_ErrorCodeEnum __e)
 142       { return *this = make_error_code(__e); }
 143
 144     int
 145     value() const { return _M_value; }
 146
 147     const error_category&
 148     category() const { return *_M_cat; }
 149
 150     error_condition
 151     default_error_condition() const;
 152
 153     string
 154     message() const
 155     { return category().message(value()); }
 156
 157     explicit operator bool() const
 158     { return _M_value != 0 ? true : false; }
 159
 160     // DR 804.
 161   private:
 162     int                         _M_value;
 163     const error_category*       _M_cat;
 164   };
 165
 166   // 19.4.2.6 non-member functions
 167   inline error_code
 168   make_error_code(errc __e)
 169   { return error_code(static_cast<int>(__e), generic_category()); }
 170
 171   inline bool
 172   operator<(const error_code& __lhs, const error_code& __rhs)
 173   {
 174     return (__lhs.category() < __rhs.category()
 175             || (__lhs.category() == __rhs.category()
 176                 && __lhs.value() < __rhs.value()));
 177   }
 178
 179   template<typename _CharT, typename _Traits>
 180     basic_ostream<_CharT, _Traits>&
 181     operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
 182     { return (__os << __e.category().name() << ':' << __e.value()); }
 183
 184   error_condition make_error_condition(errc);
 185
 186   /// error_condition
 187   // Portable error identification
 188   struct error_condition
 189   {
 190     error_condition()
 191     : _M_value(0), _M_cat(&generic_category()) { }
 192
 193     error_condition(int __v, const error_category& __cat)
 194     : _M_value(__v), _M_cat(&__cat) { }
 195
 196     template<typename _ErrorConditionEnum>
 197       error_condition(_ErrorConditionEnum __e,
 198                       typename enable_if<is_error_condition_enum
 199                                       <_ErrorConditionEnum>::value>::type* = 0)
 200       { *this = make_error_condition(__e); }
 201
 202     void
 203     assign(int __v, const error_category& __cat)
 204     {
 205       _M_value = __v;
 206       _M_cat = &__cat;
 207     }
 208
 209     // DR 804.
 210     template<typename _ErrorConditionEnum>
 211       typename enable_if<is_error_condition_enum
 212                          <_ErrorConditionEnum>::value, error_condition&>::type
 213       operator=(_ErrorConditionEnum __e)
 214       { return *this = make_error_condition(__e); }
 215
 216     void
 217     clear()
 218     { assign(0, generic_category()); }
 219
 220     // 19.4.3.4 observers
 221     int
 222     value() const { return _M_value; }
 223
 224     const error_category&
 225     category() const { return *_M_cat; }
 226
 227     string
 228     message() const
 229     { return category().message(value()); }
 230
 231     explicit operator bool() const
 232     { return _M_value != 0 ? true : false; }
 233
 234     // DR 804.
 235   private:
 236     int                         _M_value;
 237     const error_category*       _M_cat;
 238   };
 239
 240   // 19.4.3.6 non-member functions
 241   inline error_condition
 242   make_error_condition(errc __e)
 243   { return error_condition(static_cast<int>(__e), generic_category()); }
 244
 245   inline bool
 246   operator<(const error_condition& __lhs, const error_condition& __rhs)
 247   {
 248     return (__lhs.category() < __rhs.category()
 249             || (__lhs.category() == __rhs.category()
 250                 && __lhs.value() < __rhs.value()));
 251   }
 252
 253   // 19.4.4 Comparison operators
 254   inline bool
 255   operator==(const error_code& __lhs, const error_code& __rhs)
 256   { return (__lhs.category() == __rhs.category()
 257             && __lhs.value() == __rhs.value()); }
 258
 259   inline bool
 260   operator==(const error_code& __lhs, const error_condition& __rhs)
 261   {
 262     return (__lhs.category().equivalent(__lhs.value(), __rhs)
 263             || __rhs.category().equivalent(__lhs, __rhs.value()));
 264   }
 265
 266   inline bool
 267   operator==(const error_condition& __lhs, const error_code& __rhs)
 268   {
 269     return (__rhs.category().equivalent(__rhs.value(), __lhs)
 270             || __lhs.category().equivalent(__rhs, __lhs.value()));
 271   }
 272
 273   inline bool
 274   operator==(const error_condition& __lhs, const error_condition& __rhs)
 275   {
 276     return (__lhs.category() == __rhs.category()
 277             && __lhs.value() == __rhs.value());
 278   }
 279
 280   inline bool
 281   operator!=(const error_code& __lhs, const error_code& __rhs)
 282   { return !(__lhs == __rhs); }
 283
 284   inline bool
 285   operator!=(const error_code& __lhs, const error_condition& __rhs)
 286   { return !(__lhs == __rhs); }
 287
 288   inline bool
 289   operator!=(const error_condition& __lhs, const error_code& __rhs)
 290   { return !(__lhs == __rhs); }
 291
 292   inline bool
 293   operator!=(const error_condition& __lhs, const error_condition& __rhs)
 294   { return !(__lhs == __rhs); }
 295
 296
 297   /**
 298    *  @brief Thrown to indicate error code of underlying system.
 299    *
 300    *  @ingroup exceptions
 301    */
 302   class system_error : public std::runtime_error
 303   {
 304   private:
 305     error_code  _M_code;
 306
 307   public:
 308     system_error(error_code __ec = error_code())
 309     : runtime_error(""), _M_code(__ec) { }
 310
 311     system_error(error_code __ec, const string& __what)
 312     : runtime_error(__what), _M_code(__ec) { }
 313
 314     /*
 315      * TODO: Add const char* ctors to all exceptions.
 316      *
 317      * system_error(error_code __ec, const char* __what)
 318      * : runtime_error(__what), _M_code(__ec) { }
 319      *
 320      * system_error(int __v, const error_category& __ecat, const char* __what)
 321      * : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
 322      */
 323
 324     system_error(int __v, const error_category& __ecat)
 325     : runtime_error(""), _M_code(error_code(__v, __ecat)) { }
 326
 327     system_error(int __v, const error_category& __ecat, const string& __what)
 328     : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
 329
 330     virtual ~system_error() throw();
 331
 332     const error_code&
 333     code() const throw() { return _M_code; }
 334   };
 335
 336 _GLIBCXX_END_NAMESPACE
 337
 338 #endif // __GXX_EXPERIMENTAL_CXX0X__
 339
 340 #endif // _GLIBCXX_SYSTEM_ERROR
 341