Count the pattern matches with boost regex

boost_regex_count

int FindPatternInFile(const char * file)
{
    ifstream inFile;
    inFile.open(file);//open the input file

    stringstream strStream;
    strStream << inFile.rdbuf();//read the file
    string str = strStream.str();//str holds the content of the file

    boost::regex e("m{1000000}");

    boost::match_results<string::const_iterator> what;
    string::const_iterator begin = str.begin();
    string::const_iterator end = str.end();
    int count = 0;
    while(boost::regex_search(begin, end, what, e))
    {
        begin = what[0].second;
        ++count;
    }

    return count;
}