Re: [boost] [Regex] Avoid exceptions when using invalid regularexpressions

From: Joe Gottman (jgottman_at_[hidden])
Date: 2006-04-03 20:03:35

"Anne Martens" <mail_at_[hidden]> wrote in message 
news:443140C5.6020007_at_anne-martens.de...
> Hi,
>
> I'm trying to use boost-regex in my project that doesn't support
> exceptions. Thus, when constructing a regular expression with
> boost::regex expression(expr); and passig an invalid regular expression,
> my program crashes.
>
> What can I do to make sure my regular expression is valid before passing
> it to exception-throwing methods like that one?
>

   One possibility is to use a try-catch inside your function that produces 
the regex, and return optional<regex>

optional<regex> maybe_make_regex(const string &s)
{
    try {
        return regex(s);
    } catch (...) {
        return none;
   }
}

Joe Gottman