[boost] About enums and exceptions

From: Daryle Walker (dwalker07_at_[hidden])
Date: 2002-11-24 18:13:45

I haven't the read list is a week, so I apologize if responses to 
earlier posts have been resolved already.

Someone (I think the serialization author) talked about how he didn't 
like the Standard exception philosophy and tried custom classes and 
enum values for exceptions instead.  I was thinking that the techniques 
could be combined.

Instead of this

class my_exception
{
public:
     enum problems { ... };

     //...

     problems  whats_up() const;

     //...
};

We could have

class my_exception_base
     : public std::exception
{
public:
     enum problems { ... };

     explicit  my_exception_base( problems p );

     virtual  const char *  what() const;
              problems      whats_up() const;
};

template < my_exception_base::problems P >
class my_exception
     : public my_exception_base
{
public:
     my_exception()
         : my_exception_base( P )
         {}
};

Now everyone can be happy.

Daryle