Re: try and catch

From:

Rolf Magnus <ramagnus@t-online.de>

Newsgroups:

comp.lang.c++

Date:

Sat, 03 Mar 2007 16:56:53 +0100

Message-ID:

<esc5s5$fn2$03$1@news.t-online.com>

Alf P. Steinbach wrote:

But if you have that low-level pattern occurring more than one place in
your code, consider abstracting it using the template pattern (nothing
to do with templates), like

Well, it could be combined with templates. I don't really see a need for
runtime polymorphism here.

   const unsigned untilDoomsday = unsigned(-1);

   struct Retry
   {
       bool operator( unsigned maxTries ) const

ITYM:

bool operator()( unsigned maxTries ) const

       {
           while( maxTries > 0 )
           {
               try
               {
                   doIt();
                   return true;
               }
               catch( std::exception const& x )
               {
                   onException( x );
               }
               if( maxTries != untilDoomsday ) { --maxTries; }
           }
           return false;
       }

       virtual void doIt() const = 0;
       virtual void onException( std::exception const& x ) const {}
   };