Case-insensitive match with Boost Xpressive

Question

I just can't get the regex_match function to find case-insensitive matches. Even though boost::xpressive::regex_constants::icase is defined and I use a cast (so there is no ambiguity to the icase method of Xpressive), I get a compilation error (VS2010):

error C2440: 'type cast' : cannot convert from 'const boost::xpressive::detail::modifier_op' to 'boost::xpressive::regex_constants::match_flag_type'

Some code to reproduce:

#include <stdio.h>
#include <boost/xpressive/xpressive.hpp>

int main(){
    std::string str("FOO");
    boost::xpressive::sregex re = boost::xpressive::sregex_compiler().compile("foo");
    bool result = regex_match(str,re,(boost::xpressive::regex_constants::match_flag_type)boost::xpressive::regex_constants::icase);
    if(result){
        std::cout << "Match!";
    }else{
        std::cout << "No match!";
    }
    return 0;
}

Do you know what the problem might be?

Answer 1

Try to use

boost::xpressive::sregex re = boost::xpressive::sregex_compiler().
compile("foo", boost::xpressive::icase);

syntax_options_type (that is boost::xpressive::regex_constants::icase_) is not match_flag_type (3 argument for regex_match should have this type).