[boost] lexical_cast with default value

From: Dave Dribin (dave-ml_at_[hidden])
Date: 2005-04-15 15:05:42

Hi all,

I recently discovered lexical_cast, and it's very nice and elegant.  
I'd like to put in a feature request, though: the ability to use a 
default value rather than throwing an exception on conversion failure.  
Basically, it would take a second argument that would be the value 
returned if the conversion fails.  This could be used directly in the 
example, like:

     std::vector<short> args;

     while(*++argv)
     {
         args.push_back(lexical_cast<short>(*argv, 0));
     }

This eliminates the throwing and catching of an exception for cases 
where conversion failure is not an exceptional.

I've attached a patch to lexical_cast.hpp found in Boost 1.32.0

-Dave