How can I use Boost::regex.hpp library in C++?

Question

I tried to use Boost library but I failed, see my code:

#include "listy.h"
#include <boost/regex.hpp>
using namespace boost;

ListyCheck::ListyCheck() {

}

ListyCheck::~ListyCheck() {

}

bool ListyCheck::isValidItem(std::string &__item) {
    regex e("(\\d{4}[- ]){3}\\d{4}");

    return regex_match(__item, e);
}

When I tried to compile it I get those messages:

/usr/include/boost/regex/v4/regex_match.hpp:50: undefined reference to `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator, std::allocator > >, std::allocator, std::allocator > > > >, boost::regex_traits >

::match()'

/usr/include/boost/regex/v4/basic_regex.hpp:425: undefined reference to `boost::basic_regex >

::do_assign(char const*, char const*, unsigned int)'

/usr/include/boost/regex/v4/perl_matcher.hpp:366: undefined reference to `boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator, std::allocator > >, std::allocator, std::allocator > > > >, boost::regex_traits >

::construct_init(boost::basic_regex > > const&, boost::regex_constants::_match_flags)'

etc...

Answer 1

You need to link to libboost_regex. Add -lboost_regex to the compiler switch if you're using gcc.

Answer 2

Those are linker errors. The Boost regex library is not a header-only library like shared_ptr (for example) - you need to link against the .a or .lib or whatever binary library.

Answer 3

You have to link against boost_regex.