1 //  Boost system_error.hpp  --------------------------------------------------//

     2 

     3 //  Copyright Beman Dawes 2006

     4 

     5 //  Distributed under the Boost Software License, Version 1.0. (See accompanying

     6 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

     7 

     8 #ifndef BOOST_SYSTEM_ERROR_HPP

     9 #define BOOST_SYSTEM_ERROR_HPP

    10 

    11 #include <string>

    12 #include <stdexcept>

    13 #include <cassert>

    14 #include <boost/system/error_code.hpp>

    15 

    16 namespace boost

    17 {

    18   namespace system

    19   {

    20     //  class system_error  --------------------------------------------------//

    21 

    22     class system_error : public std::runtime_error

    23     {

    24     public:

    25       system_error( error_code ec )

    26           : std::runtime_error(""), m_error_code(ec) {}

    27 

    28       system_error( error_code ec, const std::string & what_arg )

    29           : std::runtime_error(what_arg), m_error_code(ec) {}

    30 

    31       system_error( error_code ec, const char* what_arg )

    32           : std::runtime_error(what_arg), m_error_code(ec) {}

    33 

    34       system_error( int ev, const error_category & ecat )

    35           : std::runtime_error(""), m_error_code(ev,ecat) {}

    36 

    37       system_error( int ev, const error_category & ecat,

    38         const std::string & what_arg )

    39           : std::runtime_error(what_arg), m_error_code(ev,ecat) {}

    40 

    41       system_error( int ev, const error_category & ecat,

    42         const char * what_arg )

    43           : std::runtime_error(what_arg), m_error_code(ev,ecat) {}

    44 

    45       virtual ~system_error() throw() {}

    46 

    47       const error_code &  code() const throw() { return m_error_code; }

    48       const char *        what() const throw();

    49 

    50     private:

    51       error_code           m_error_code;

    52       mutable std::string  m_what;

    53     };

    54 

    55     //  implementation  ------------------------------------------------------//

    56 

    57     inline const char * system_error::what() const throw()

    58     // see http://www.boost.org/more/error_handling.html for lazy build rationale

    59     {

    60       if ( m_what.empty() )

    61       {

    62         try

    63         {

    64           m_what = this->std::runtime_error::what();

    65           if ( m_error_code )

    66           {

    67             if ( !m_what.empty() ) m_what += ": ";

    68             m_what += m_error_code.message();

    69           }

    70         }

    71         catch (...) { return std::runtime_error::what(); }

    72       }

    73       return m_what.c_str();

    74     }

    75 

    76   } // namespace system

    77 } // namespace boost

    78 

    79 #endif // BOOST_SYSTEM_ERROR_HPP

    80 

    81