Re: [Boost-users] assert when using cregex_iterator

From: John Maddock (john_at_[hidden])
Date: 2006-08-05 04:43:10

Winson Yung wrote:
>> I have a very simple test program using the latest 1.33 version of
>> regex library. As soon as I run it, it assert (crash) at the line
>> where std::string s = (*m1)[0]. I am doing something wrong?

Yes.

>>    regex header_expr(matchpattern, regex_constants::basic |
>> regex_constants::icase);

POSIX Basic expression don't support \s or the + operator so the regex 
doesn't do what you think it does and does *not* match the string.

>>    cregex_iterator m1(astring, astring + strlen(astring),
>> header_expr);
>>
>>    std::string s = (*m1)[0];   <==== crash here
>>    return 0;

You should always check to see if the iterator is equal to the end of 
sequence iterator: as it stands you're dereferencing an iterator that 
doesn't point to anything since no match was found.

John.