ceph/src/boost/libs/exception/example/error_info_2.cpp

   1 //Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc.
   2
   3 //Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //This example shows how to add arbitrary data to active exception objects.
   7
   8 #include <boost/exception/all.hpp>
   9 #include <boost/shared_ptr.hpp>
  10 #include <stdio.h>
  11 #include <errno.h>
  12
  13 //
  14
  15 struct file_read_error: virtual boost::exception { };
  16
  17 void
  18 file_read( FILE * f, void * buffer, size_t size )
  19     {
  20     if( size!=fread(buffer,1,size,f) )
  21         throw file_read_error() << boost::errinfo_errno(errno);
  22     }
  23
  24 //
  25
  26 boost::shared_ptr<FILE> file_open( char const * file_name, char const * mode );
  27 void file_read( FILE * f, void * buffer, size_t size );
  28
  29 void
  30 parse_file( char const * file_name )
  31     {
  32     boost::shared_ptr<FILE> f = file_open(file_name,"rb");
  33     assert(f);
  34     try
  35         {
  36         char buf[1024];
  37         file_read( f.get(), buf, sizeof(buf) );
  38         }
  39     catch(
  40     boost::exception & e )
  41         {
  42         e << boost::errinfo_file_name(file_name);
  43         throw;
  44         }
  45     }