Question

I am using the boost regex library in my code. I have a simple application that compiles and runs correctly on a machine that is running Fedora. When I compile the same code on SUSE linux, all but the first submatch string is empty.

The code is as follows

const string pattern = "(abc)(def)"; 
const string target = "abcdef";

boost::regex regexPattern(pattern, boost::regex::extended);
boost::smatch what;

bool isMatchFound = boost::regex_match(target, what, regexPattern);
if (isMatchFound)
{
    for (unsigned int i=0; i < what.size(); i++)
    {
        cout << "WHAT " << i << " " << what[i] << endl;
    }
}

The output on fedora is the following

WHAT 0 abcdef
WHAT 1 abc
WHAT 2 def

The output on SUSE is the following

WHAT 0 abcdef
WHAT 1 
WHAT 2 

I cannot seem to find any reference to a similar problem anywhere. I assume there is a simple fix, but I havent been able to find it despite days of scouring the web.

The compilers have the following versions.

Fedora : g++ (GCC) 4.5.1 20100924 (Red Hat 4.5.1-4)
SUSE : g++ (GCC) 4.1.2 20070115 (SUSE Linux)

I am using Boost version 1.48.0 in both cases. I don’t have root on either machine.

Answer 1

Updating the compiler to a later version fixed the issue. I am suprised compiling boost with the older 4.1 compiler silently broke the submatch functionality on that SUSE box.