[Boost-users] Win32 Non-greedy Regex "\w*?" matches whitespace (tab or space)

From: John F Meinel Jr (boost_at_[hidden])
Date: 2004-05-21 22:11:35

When changing the "search for word characters" from greedy to
non-greedy, it starts to match whitespace characters.
Attached is an example program.
If you remove the '?' to make the search greedy, then it (correctly)
doesn't match.

I am using boost 1.31.0, on WinXP using VC7.1.
I have confirmed that this does not occur on my Linux machine.

Also attached is my Jamfile to make sure I didn't just compile it wrong.
It occurs in both debug and release mode.

John
=:->

project-root ;

exe test 
        : test.cpp
          #unit_test_example1.cpp
        : <sysinclude>$(BOOST_ROOT)
          <stlport-iostream>on
      <library-path>$(BOOST_ROOT)/../../lib

          <vc7.1><debug><find-library>libboost_regex-vc71-mt-gd
          <vc7.1><release><find-library>libboost_regex-vc71-mt

          <gcc><debug><find-library>boost_regex-gcc-mt-d
          <gcc><release><find-library>boost_regex-gcc-mt
          <threading>multi
;

# vim: ts=4


#include <boost/regex.hpp>
#include <iostream>

boost::regex re("(\\w*?)");
void doesMatch(std::string s)  {
        boost::smatch m;
        std::cout << "String: \"" << s << "\"" << std::endl;
        if(boost::regex_match(s, m, re)) {
                std::cout << "Matched: ";
                std::cout << "\"" << std::string(m[1]) << "\"" << std::endl;
        } else {
                std::cout << "Didn't match" << std::endl;
        }
        std::cout << std::endl;
}

int main(int argc, char **argv)
{
    if(argc > 1)
        for(int i = 1; i < argc; ++i)
                        doesMatch(argv[i]);
    else {
        char *arg[] = {"", "should", "should\tnot", "shou_ld", "should not"
                        ," doesn't "
                };
        main(sizeof(arg)/sizeof(char*), arg);
    }
}