The following example treats command line arguments as a sequence of numeric data:

int main(int argc, char * argv[])
{
    using boost::lexical_cast;
    using boost::bad_lexical_cast;

    std::vector<short> args;

    while(*++argv)
    {
        try
        {
            args.push_back(lexical_cast<short>(*argv));
        }
        catch(bad_lexical_cast &)
        {
            args.push_back(0);
        }
    }
    ...
}

The following example uses numeric data in a string expression:

void log_message(const std::string &);

void log_errno(int yoko)
{
    log_message("Error " + boost::lexical_cast<std::string>(yoko) + ": " + strerror(yoko));
}