Add support for using std::error_code when it's available.

asio/boostify.pl

@@ -71,231 +71,6 @@ sub source_contains_asio_include
   return 0;
 }
 
-sub source_contains_boostify_error_categories
-{
-  my ($from) = @_;
-
-  # Open the input file.
-  open(my $input, "<$from") or die("Can't open $from for reading");
-
-  # Check file for boostify error category directive.
-  while (my $line = <$input>)
-  {
-    chomp($line);
-    if ($line =~ /boostify: error category/)
-    {
-      close($input);
-      return 1;
-    }
-  }
-
-  close($input);
-  return 0;
-}
-
-my $error_cat_defns = <<"EOF";
-inline const boost::system::error_category& get_system_category()
-{
-  return boost::system::system_category();
-}
-
-#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-
-extern BOOST_ASIO_DECL
-const boost::system::error_category& get_netdb_category();
-
-extern BOOST_ASIO_DECL
-const boost::system::error_category& get_addrinfo_category();
-
-#else // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-
-inline const boost::system::error_category& get_netdb_category()
-{
-  return get_system_category();
-}
-
-inline const boost::system::error_category& get_addrinfo_category()
-{
-  return get_system_category();
-}
-
-#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-
-extern BOOST_ASIO_DECL
-const boost::system::error_category& get_misc_category();
-
-extern BOOST_ASIO_DECL
-const boost::system::error_category& get_ssl_category();
-
-static const boost::system::error_category& system_category
-  = boost::asio::error::get_system_category();
-static const boost::system::error_category& netdb_category
-  = boost::asio::error::get_netdb_category();
-static const boost::system::error_category& addrinfo_category
-  = boost::asio::error::get_addrinfo_category();
-static const boost::system::error_category& misc_category
-  = boost::asio::error::get_misc_category();
-static const boost::system::error_category& ssl_category
-  = boost::asio::error::get_ssl_category();
-
-} // namespace error
-} // namespace asio
-
-namespace system {
-
-template<> struct is_error_code_enum<boost::asio::error::basic_errors>
-{
-  static const bool value = true;
-};
-
-template<> struct is_error_code_enum<boost::asio::error::netdb_errors>
-{
-  static const bool value = true;
-};
-
-template<> struct is_error_code_enum<boost::asio::error::addrinfo_errors>
-{
-  static const bool value = true;
-};
-
-template<> struct is_error_code_enum<boost::asio::error::misc_errors>
-{
-  static const bool value = true;
-};
-
-template<> struct is_error_code_enum<boost::asio::error::ssl_errors>
-{
-  static const bool value = true;
-};
-
-} // namespace system
-
-namespace asio {
-namespace error {
-EOF
-
-my $error_cat_func_defns = <<"EOF";
-#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-
-namespace detail {
-
-class netdb_category : public boost::system::error_category
-{
-public:
-  const char* name() const
-  {
-    return "asio.netdb";
-  }
-
-  std::string message(int value) const
-  {
-    if (value == error::host_not_found)
-      return "Host not found (authoritative)";
-    if (value == error::host_not_found_try_again)
-      return "Host not found (non-authoritative), try again later";
-    if (value == error::no_data)
-      return "The query is valid, but it does not have associated data";
-    if (value == error::no_recovery)
-      return "A non-recoverable error occurred during database lookup";
-    return "asio.netdb error";
-  }
-};
-
-} // namespace detail
-
-const boost::system::error_category& get_netdb_category()
-{
-  static detail::netdb_category instance;
-  return instance;
-}
-
-namespace detail {
-
-class addrinfo_category : public boost::system::error_category
-{
-public:
-  const char* name() const
-  {
-    return "asio.addrinfo";
-  }
-
-  std::string message(int value) const
-  {
-    if (value == error::service_not_found)
-      return "Service not found";
-    if (value == error::socket_type_not_supported)
-      return "Socket type not supported";
-    return "asio.addrinfo error";
-  }
-};
-
-} // namespace detail
-
-const boost::system::error_category& get_addrinfo_category()
-{
-  static detail::addrinfo_category instance;
-  return instance;
-}
-
-#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-
-namespace detail {
-
-class misc_category : public boost::system::error_category
-{
-public:
-  const char* name() const
-  {
-    return "asio.misc";
-  }
-
-  std::string message(int value) const
-  {
-    if (value == error::already_open)
-      return "Already open";
-    if (value == error::eof)
-      return "End of file";
-    if (value == error::not_found)
-      return "Element not found";
-    if (value == error::fd_set_failure)
-      return "The descriptor does not fit into the select call's fd_set";
-    return "asio.misc error";
-  }
-};
-
-} // namespace detail
-
-const boost::system::error_category& get_misc_category()
-{
-  static detail::misc_category instance;
-  return instance;
-}
-
-namespace detail {
-
-class ssl_category : public boost::system::error_category
-{
-public:
-  const char* name() const
-  {
-    return "asio.ssl";
-  }
-
-  std::string message(int) const
-  {
-    return "asio.ssl error";
-  }
-};
-
-} // namespace detail
-
-const boost::system::error_category& get_ssl_category()
-{
-  static detail::ssl_category instance;
-  return instance;
-}
-EOF
-
 sub copy_source_file
 {
   my ($from, $to) = @_;
@@ -307,10 +82,11 @@ sub copy_source_file
 
   # First determine whether the file makes any use of asio::thread.
   my $uses_asio_thread = source_contains_asio_thread_usage($from);
+
   my $includes_asio = source_contains_asio_include($from);
 
-  # Check whether the file includes error handling header files.
+  my $is_error_hpp = 0;
-  my $includes_boostify_ecats = source_contains_boostify_error_categories($from);
+  $is_error_hpp = 1 if ($from =~ /asio\/error\.hpp/);
 
   # Open the files.
   open(my $input, "<$from") or die("Can't open $from for reading");
@@ -367,33 +143,13 @@ sub copy_source_file
       }
       print_line($output, $line, $from, $lineno);
     }
-    elsif ($line =~ /^(# *include )[<"](asio\/detail\/config\.hpp)[>"]$/)
-    {
-      print_line($output, $1 . "<boost/" . $2 . ">", $from, $lineno);
-      if ($includes_boostify_ecats)
-      {
-        $includes_boostify_ecats = 0;
-        print_line($output, $1 . "<boost/cerrno.hpp>", $from, $lineno);
-        print_line($output, $1 . "<boost/system/error_code.hpp>", $from, $lineno);
-      }
-    }
-    elsif ($line =~ /# *include <cerrno>/)
-    {
-      if ($includes_boostify_ecats)
-      {
-        # Line is removed.
-      }
-      else
-      {
-        print_line($output, $line, $from, $lineno);
-      }
-    }
     elsif ($line =~ /# *include [<"]asio\/thread\.hpp[>"]/)
     {
       # Line is removed.
     }
     elsif ($line =~ /(# *include )[<"]asio\/error_code\.hpp[>"]/)
     {
+      print_line($output, $1 . "<boost/cerrno.hpp>", $from, $lineno) if ($is_error_hpp);
       print_line($output, $1 . "<boost/system/error_code.hpp>", $from, $lineno);
     }
     elsif ($line =~ /# *include [<"]asio\/impl\/error_code\.[hi]pp[>"]/)
@@ -408,28 +164,9 @@ sub copy_source_file
     {
       print_line($output, $1 . "<boost/" . $2 . ">" . $3, $from, $lineno);
     }
-    elsif ($line =~ /( *)op->Internal = asio::error::get_system_category\(\);/)
+    elsif ($line =~ /#.*defined\(.*ASIO_HAS_STD_SYSTEM_ERROR\)$/)
     {
-      my $indent = $1;
+      # Line is removed.
-      $line =~ s/asio.*$/reinterpret_cast<ulong_ptr_t>(/g;
-      print_line($output, $line, $from, $lineno);
-      $line = $indent . "    &boost::asio::error::get_system_category());";
-      print_line($output, $line, $from, $lineno);
-    }
-    elsif ($line =~ /op->Internal = ec\.category\(\);/)
-    {
-      $line =~ s/ec.*$/reinterpret_cast<ulong_ptr_t>(&ec.category());/g;
-      print_line($output, $line, $from, $lineno);
-    }
-    elsif ($line =~ /static_cast<asio::error_category>\(op->Internal\)\);/)
-    {
-      $line =~ s/static_cast<asio::error_category>/*reinterpret_cast<boost::system::error_category*>/g;
-      print_line($output, $line, $from, $lineno);
-    }
-    elsif ($line =~ /op->Internal = result_ec\.category\(\);/)
-    {
-      $line =~ s/res.*$/reinterpret_cast<ulong_ptr_t>(&result_ec.category());/g;
-      print_line($output, $line, $from, $lineno);
     }
     elsif ($line =~ /asio::thread/)
     {
@@ -448,21 +185,21 @@ sub copy_source_file
       }
       print_line($output, $1 . "boost::thread" . $2, $from, $lineno);
     }
-    elsif ($line =~ /boostify: error category definitions start here/)
+    elsif ($line =~ /namespace std {/)
     {
-      print($output $error_cat_defns);
+      print_line($output, "namespace boost {", $from, $lineno);
-      while ($line = <$input>)
+      print_line($output, "namespace system {", $from, $lineno);
-      {
-        last if $line =~ /boostify: error category definitions end here/;
     }
-    }
+    elsif ($line =~ /} \/\/ namespace std/)
-    elsif ($line =~ /boostify: error category function definitions go here/)
     {
-      print($output $error_cat_func_defns);
+      print_line($output, "} // namespace system", $from, $lineno);
+      print_line($output, "} // namespace boost", $from, $lineno);
     }
     elsif ($line =~ /asio::/ && !($line =~ /boost::asio::/))
     {
       $line =~ s/asio::error_code/boost::system::error_code/g;
+      $line =~ s/asio::error_category/boost::system::error_category/g;
+      $line =~ s/asio::system_category/boost::system::system_category/g;
       $line =~ s/asio::system_error/boost::system::system_error/g;
       $line =~ s/asio::/boost::asio::/g;
       print_line($output, $line, $from, $lineno);

asio/include/asio/detail/config.hpp

@@ -46,6 +46,22 @@
 # define ASIO_DECL
 #endif // !defined(ASIO_DECL)
 
+// Standard library support for system errors.
+#if !defined(ASIO_DISABLE_STD_SYSTEM_ERROR)
+# if defined(__GNUC__)
+#  if ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+#   if defined(__GXX_EXPERIMENTAL_CXX0X__)
+#    define ASIO_HAS_STD_SYSTEM_ERROR
+#   endif // defined(__GXX_EXPERIMENTAL_CXX0X__)
+#  endif // ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)) || (__GNUC__ > 4)
+# endif // defined(__GNUC__)
+# if defined(BOOST_MSVC)
+#  if (_MSC_VER >= 1600)
+#   define ASIO_HAS_STD_SYSTEM_ERROR
+#  endif // (_MSC_VER >= 1600)
+# endif // defined(BOOST_MSVC)
+#endif // !defined(ASIO_DISABLE_STD_SYSTEM_ERROR)
+
 // Windows: target OS version.
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
 # if !defined(_WIN32_WINNT) && !defined(_WIN32_WINDOWS)

asio/include/asio/detail/impl/win_iocp_io_service.ipp

@@ -284,7 +284,8 @@ void win_iocp_io_service::on_completion(win_iocp_operation* op,
   op->ready_ = 1;
 
   // Store results in the OVERLAPPED structure.
-  op->Internal = asio::error::get_system_category();
+  op->Internal = reinterpret_cast<ulong_ptr_t>(
+      &asio::error::get_system_category());
   op->Offset = last_error;
   op->OffsetHigh = bytes_transferred;
 
@@ -306,7 +307,7 @@ void win_iocp_io_service::on_completion(win_iocp_operation* op,
   op->ready_ = 1;
 
   // Store results in the OVERLAPPED structure.
-  op->Internal = ec.category();
+  op->Internal = reinterpret_cast<ulong_ptr_t>(&ec.category());
   op->Offset = ec.value();
   op->OffsetHigh = bytes_transferred;
 
@@ -358,7 +359,7 @@ size_t win_iocp_io_service::do_one(bool block, asio::error_code& ec)
       if (completion_key == overlapped_contains_result)
       {
         result_ec = asio::error_code(static_cast<int>(op->Offset),
-            static_cast<asio::error_category>(op->Internal));
+            *reinterpret_cast<asio::error_category*>(op->Internal));
         bytes_transferred = op->OffsetHigh;
       }
 
@@ -366,7 +367,7 @@ size_t win_iocp_io_service::do_one(bool block, asio::error_code& ec)
       // structure.
       else
       {
-        op->Internal = result_ec.category();
+        op->Internal = reinterpret_cast<ulong_ptr_t>(&result_ec.category());
         op->Offset = result_ec.value();
         op->OffsetHigh = bytes_transferred;
       }

asio/include/asio/error.hpp

@@ -16,6 +16,7 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include "asio/detail/config.hpp"
+#include "asio/error_code.hpp"
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
 # include <winerror.h>
 #else
@@ -212,22 +213,87 @@ enum ssl_errors
 {
 };
 
-// boostify: error category definitions start here.
+inline const asio::error_category& get_system_category()
+{
+  return asio::system_category();
+}
+
+#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+extern ASIO_DECL
+const asio::error_category& get_netdb_category();
+
+extern ASIO_DECL
+const asio::error_category& get_addrinfo_category();
+
+#else // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+inline const asio::error_category& get_netdb_category()
+{
+  return get_system_category();
+}
+
+inline const asio::error_category& get_addrinfo_category()
+{
+  return get_system_category();
+}
+
+#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+extern ASIO_DECL
+const asio::error_category& get_misc_category();
+
+extern ASIO_DECL
+const asio::error_category& get_ssl_category();
+
+static const asio::error_category& system_category
+  = asio::error::get_system_category();
+static const asio::error_category& netdb_category
+  = asio::error::get_netdb_category();
+static const asio::error_category& addrinfo_category
+  = asio::error::get_addrinfo_category();
+static const asio::error_category& misc_category
+  = asio::error::get_misc_category();
+static const asio::error_category& ssl_category
+  = asio::error::get_ssl_category();
 
 } // namespace error
 } // namespace asio
 
-#include "asio/detail/pop_options.hpp"
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
+namespace std {
 
-#include "asio/error_code.hpp"
+template<> struct is_error_code_enum<asio::error::basic_errors>
+{
+  static const bool value = true;
+};
 
-#include "asio/detail/push_options.hpp"
+template<> struct is_error_code_enum<asio::error::netdb_errors>
+{
+  static const bool value = true;
+};
+
+template<> struct is_error_code_enum<asio::error::addrinfo_errors>
+{
+  static const bool value = true;
+};
+
+template<> struct is_error_code_enum<asio::error::misc_errors>
+{
+  static const bool value = true;
+};
+
+template<> struct is_error_code_enum<asio::error::ssl_errors>
+{
+  static const bool value = true;
+};
+
+} // namespace std
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
 
 namespace asio {
 namespace error {
 
-// boostify: error category definitions end here.
-
 inline asio::error_code make_error_code(basic_errors e)
 {
   return asio::error_code(

asio/include/asio/error_code.hpp

@@ -16,71 +16,81 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include "asio/detail/config.hpp"
-#include <string>
 
-#if defined(GENERATING_DOCUMENTATION)
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
-# define ASIO_WIN_OR_POSIX(e_win, e_posix) implementation_defined
+# include <system_error>
-#elif defined(BOOST_WINDOWS) || defined(__CYGWIN__)
+#else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-# define ASIO_WIN_OR_POSIX(e_win, e_posix) e_win
+# include <string>
-#else
+# include "asio/detail/noncopyable.hpp"
-# define ASIO_WIN_OR_POSIX(e_win, e_posix) e_posix
+# if !defined(BOOST_NO_IOSTREAM)
-#endif
+#  include <iosfwd>
+# endif // !defined(BOOST_NO_IOSTREAM)
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
 
 #include "asio/detail/push_options.hpp"
 
 namespace asio {
 
-namespace error
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
+typedef std::error_category error_category;
+
+#else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
+/// Base class for all error categories.
+class error_category : private noncopyable
 {
-  /// Available error code categories.
+public:
-  enum error_category
+  /// Destructor.
+  virtual ~error_category()
   {
-    /// System error codes.
+  }
-    system_category = ASIO_WIN_OR_POSIX(0, 0),
 
-    /// Error codes from NetDB functions.
+  /// Returns a string naming the error gategory.
-    netdb_category = ASIO_WIN_OR_POSIX(system_category, 1),
+  virtual const char* name() const = 0;
 
-    /// Error codes from getaddrinfo.
+  /// Returns a string describing the error denoted by @c value.
-    addrinfo_category = ASIO_WIN_OR_POSIX(system_category, 2),
+  virtual std::string message(int value) const = 0;
 
-    /// Miscellaneous error codes.
+  /// Equality operator to compare two error categories.
-    misc_category = ASIO_WIN_OR_POSIX(3, 3),
+  bool operator==(const error_category& rhs) const
+  {
+    return this == &rhs;
+  }
 
-    /// SSL error codes.
+  /// Inequality operator to compare two error categories.
-    ssl_category = ASIO_WIN_OR_POSIX(4, 4)
+  bool operator!=(const error_category& rhs) const
-  };
+  {
+    return !(*this == rhs);
+  }
+};
 
-  // Category getters.
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-  inline error_category get_system_category() { return system_category; }
-  inline error_category get_netdb_category() { return netdb_category; }
-  inline error_category get_addrinfo_category() { return addrinfo_category; }
-  inline error_category get_misc_category() { return misc_category; }
-  inline error_category get_ssl_category() { return ssl_category; }
 
-} // namespace error
+/// Returns the error category used for the system errors produced by asio.
+extern ASIO_DECL const error_category& system_category();
 
-/// Bring error category type into the asio namespace.
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
-typedef asio::error::error_category error_category;
+
+typedef std::error_code error_code;
+
+#else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
 
 /// Class to represent an error code value.
 class error_code
 {
 public:
-  /// The underlying representation of an error code.
-  typedef int value_type;
-
   /// Default constructor.
   error_code()
     : value_(0),
-      category_(error::system_category)
+      category_(&system_category())
   {
   }
 
   /// Construct with specific error code and category.
-  error_code(value_type v, error_category c)
+  error_code(int v, const error_category& c)
     : value_(v),
-      category_(c)
+      category_(&c)
   {
   }
 
@@ -92,19 +102,22 @@ public:
   }
 
   /// Get the error value.
-  value_type value() const
+  int value() const
   {
     return value_;
   }
 
   /// Get the error category.
-  error_category category() const
+  const error_category& category() const
   {
-    return category_;
+    return *category_;
   }
 
   /// Get the message associated with the error.
-  ASIO_DECL std::string message() const;
+  std::string message() const
+  {
+    return category_->message(value_);
+  }
 
   struct unspecified_bool_type_t
   {
@@ -143,18 +156,31 @@ public:
 
 private:
   // The value associated with the error code.
-  value_type value_;
+  int value_;
 
   // The category associated with the error code.
-  error_category category_;
+  const error_category* category_;
 };
 
+# if !defined(BOOST_NO_IOSTREAM)
+
+/// Output an error code.
+template <typename Elem, typename Traits>
+std::basic_ostream<Elem, Traits>& operator<<(
+    std::basic_ostream<Elem, Traits>& os, const error_code& ec)
+{
+  os << ec.category().name() << ':' << ec.value();
+  return os;
+}
+
+# endif // !defined(BOOST_NO_IOSTREAM)
+
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
 } // namespace asio
 
 #include "asio/detail/pop_options.hpp"
 
-#undef ASIO_WIN_OR_POSIX
-
 #if defined(ASIO_HEADER_ONLY)
 # include "asio/impl/error_code.ipp"
 #endif // defined(ASIO_HEADER_ONLY)

asio/include/asio/impl/error.ipp

@@ -23,7 +23,125 @@
 namespace asio {
 namespace error {
 
-// boostify: error category function definitions go here.
+#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+namespace detail {
+
+class netdb_category : public asio::error_category
+{
+public:
+  const char* name() const
+  {
+    return "asio.netdb";
+  }
+
+  std::string message(int value) const
+  {
+    if (value == error::host_not_found)
+      return "Host not found (authoritative)";
+    if (value == error::host_not_found_try_again)
+      return "Host not found (non-authoritative), try again later";
+    if (value == error::no_data)
+      return "The query is valid, but it does not have associated data";
+    if (value == error::no_recovery)
+      return "A non-recoverable error occurred during database lookup";
+    return "asio.netdb error";
+  }
+};
+
+} // namespace detail
+
+const asio::error_category& get_netdb_category()
+{
+  static detail::netdb_category instance;
+  return instance;
+}
+
+namespace detail {
+
+class addrinfo_category : public asio::error_category
+{
+public:
+  const char* name() const
+  {
+    return "asio.addrinfo";
+  }
+
+  std::string message(int value) const
+  {
+    if (value == error::service_not_found)
+      return "Service not found";
+    if (value == error::socket_type_not_supported)
+      return "Socket type not supported";
+    return "asio.addrinfo error";
+  }
+};
+
+} // namespace detail
+
+const asio::error_category& get_addrinfo_category()
+{
+  static detail::addrinfo_category instance;
+  return instance;
+}
+
+#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
+
+namespace detail {
+
+class misc_category : public asio::error_category
+{
+public:
+  const char* name() const
+  {
+    return "asio.misc";
+  }
+
+  std::string message(int value) const
+  {
+    if (value == error::already_open)
+      return "Already open";
+    if (value == error::eof)
+      return "End of file";
+    if (value == error::not_found)
+      return "Element not found";
+    if (value == error::fd_set_failure)
+      return "The descriptor does not fit into the select call's fd_set";
+    return "asio.misc error";
+  }
+};
+
+} // namespace detail
+
+const asio::error_category& get_misc_category()
+{
+  static detail::misc_category instance;
+  return instance;
+}
+
+namespace detail {
+
+class ssl_category : public asio::error_category
+{
+public:
+  const char* name() const
+  {
+    return "asio.ssl";
+  }
+
+  std::string message(int) const
+  {
+    return "asio.ssl error";
+  }
+};
+
+} // namespace detail
+
+const asio::error_category& get_ssl_category()
+{
+  static detail::ssl_category instance;
+  return instance;
+}
 
 } // namespace error
 } // namespace asio

asio/include/asio/impl/error_code.ipp

@@ -16,40 +16,31 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include "asio/detail/config.hpp"
+#if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
+# include <winerror.h>
+#else
+# include <cerrno>
+#endif
 #include "asio/detail/local_free_on_block_exit.hpp"
 #include "asio/detail/socket_types.hpp"
-#include "asio/error.hpp"
 #include "asio/error_code.hpp"
 
 #include "asio/detail/push_options.hpp"
 
 namespace asio {
+namespace detail {
 
-std::string error_code::message() const
+class system_category : public error_category
 {
-  if (category_ == error::get_misc_category())
+public:
+  const char* name() const
   {
-    if (value_ == error::already_open)
+    return "asio.system";
-      return "Already open.";
-    if (value_ == error::not_found)
-      return "Not found.";
-    if (value_ == error::fd_set_failure)
-      return "The descriptor does not fit into the select call's fd_set.";
-    if (value_ == error::not_found)
-      return "Element not found.";
-#if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
-    if (value_ == error::eof)
-      return "End of file.";
-#endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
   }
-  if (category_ == error::get_ssl_category())
+
-    return "SSL error.";
+  std::string message(int value) const
+  {
 #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
-  value_type value = value_;
-  if (category_ == error::get_misc_category() && value_ == error::eof)
-    value = ERROR_HANDLE_EOF;
-  else if (category_ != error::get_system_category())
-    return "asio error";
     char* msg = 0;
     DWORD length = ::FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER
         | FORMAT_MESSAGE_FROM_SYSTEM
@@ -63,46 +54,35 @@ std::string error_code::message() const
     if (length)
       return msg;
     else
-    return "asio error";
+      return "asio.system error";
 #else // defined(BOOST_WINDOWS)
-  if (category_ == error::get_netdb_category())
-  {
-    if (value_ == error::host_not_found)
-      return "Host not found (authoritative).";
-    if (value_ == error::host_not_found_try_again)
-      return "Host not found (non-authoritative), try again later.";
-    if (value_ == error::no_recovery)
-      return "A non-recoverable error occurred during database lookup.";
-    if (value_ == error::no_data)
-      return "The query is valid, but it does not have associated data.";
-  }
-  if (category_ == error::get_addrinfo_category())
-  {
-    if (value_ == error::service_not_found)
-      return "Service not found.";
-    if (value_ == error::socket_type_not_supported)
-      return "Socket type not supported.";
-  }
-  if (category_ != error::get_system_category())
-    return "asio error";
 #if !defined(__sun)
-  if (value_ == error::operation_aborted)
+    if (value == ECANCELED)
       return "Operation aborted.";
 #endif // !defined(__sun)
 #if defined(__sun) || defined(__QNX__) || defined(__SYMBIAN32__)
     using namespace std;
-  return strerror(value_);
+    return strerror(value);
 #elif defined(__MACH__) && defined(__APPLE__) \
-|| defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) \
+  || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) \
-|| defined(_AIX) || defined(__hpux) || defined(__osf__)
+  || defined(_AIX) || defined(__hpux) || defined(__osf__)
     char buf[256] = "";
-  strerror_r(value_, buf, sizeof(buf));
+    strerror_r(value, buf, sizeof(buf));
     return buf;
 #else
     char buf[256] = "";
-  return strerror_r(value_, buf, sizeof(buf));
+    return strerror_r(value, buf, sizeof(buf));
 #endif
 #endif // defined(BOOST_WINDOWS)
+  }
+};
+
+} // namespace detail
+
+const error_category& system_category()
+{
+  static detail::system_category instance;
+  return instance;
 }
 
 } // namespace asio

asio/include/asio/system_error.hpp

@@ -2,7 +2,7 @@
 // system_error.hpp
 // ~~~~~~~~~~~~~~~~
 //
-// Copyright (c) 2003-2011 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2003-2010 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -16,16 +16,27 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include "asio/detail/config.hpp"
-#include <boost/scoped_ptr.hpp>
+
-#include <cerrno>
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
-#include <exception>
+# include <system_error>
-#include <string>
+#else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
-#include "asio/error_code.hpp"
+# include <boost/scoped_ptr.hpp>
+# include <cerrno>
+# include <exception>
+# include <string>
+# include "asio/error_code.hpp"
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
 
 #include "asio/detail/push_options.hpp"
 
 namespace asio {
 
+#if defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
+typedef std::system_error system_error;
+
+#else // defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
 /// The system_error class is used to represent system conditions that
 /// prevent the library from operating correctly.
 class system_error
@@ -111,6 +122,8 @@ private:
   mutable boost::scoped_ptr<std::string> what_;
 };
 
+#endif // defined(ASIO_HAS_STD_SYSTEM_ERROR)
+
 } // namespace asio
 
 #include "asio/detail/pop_options.hpp"