Question

I’ve got a program that uses tr1::regex, and while it compiles, it gives me very verbose linker errors.

Here’s my header file MapObject.hpp:

#include <iostream>
#include <string>
#include <tr1/regex>
#include "phBaseObject.hpp"
using std::string;

namespace phObject
{
    class MapObject: public phBaseObject
    {
        private:
            string color;  // must be a hex string represented as "#XXXXXX"
            static const std::tr1::regex colorRX;  // enforces the rule above
        public:
            void setColor(const string&);
        (...)
    };
}

Here’s my implementation:

#include <iostream>
#include <string>
#include <tr1/regex>
#include "MapObject.hpp"
using namespace std;


namespace phObject
{
    const tr1::regex MapObject::colorRX("#[a-fA-F0-9]{6}");

    void MapObject::setColor(const string& c)
    {
        if(tr1::regex_match(c.begin(), c.end(), colorRX))
        {
            color = c;
        }
        else cerr << "Invalid color assignment (" << c << ")" << endl;
     }

     (...)
}

and now for the errors:

max@max-desktop:~/Desktop/Development/CppPartyHack/PartyHack/lib$ g++ -Wall -std=c++0x MapObject.cpp
/tmp/cce5gojG.o: In function std::tr1::basic_regex<char, std::tr1::regex_traits<char> >::basic_regex(char const*, unsigned int)':
MapObject.cpp:(.text._ZNSt3tr111basic_regexIcNS_12regex_traitsIcEEEC1EPKcj[std::tr1::basic_regex<char, std::tr1::regex_traits<char> >::basic_regex(char const*, unsigned int)]+0x61): undefined reference tostd::tr1::basic_regex >::_M_compile()’
/tmp/cce5gojG.o: In function bool std::tr1::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, char, std::tr1::regex_traits<char> >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::tr1::basic_regex<char, std::tr1::regex_traits<char> > const&, std::bitset<11u>)':
MapObject.cpp:(.text._ZNSt3tr111regex_matchIN9__gnu_cxx17__normal_iteratorIPKcSsEEcNS_12regex_traitsIcEEEEbT_S8_RKNS_11basic_regexIT0_T1_EESt6bitsetILj11EE[bool std::tr1::regex_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, char, std::tr1::regex_traits<char> >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::tr1::basic_regex<char, std::tr1::regex_traits<char> > const&, std::bitset<11u>)]+0x53): undefined reference tobool std::tr1::regex_match<__gnu_cxx::__normal_iterator, std::allocator > >, std::allocator, std::allocator > > > >, char, std::tr1::regex_traits >(__gnu_cxx::__normal_iterator, std::allocator > >, __gnu_cxx::__normal_iterator, std::allocator > >, std::tr1::match_results<__gnu_cxx::__normal_iterator, std::allocator > >, std::allocator, std::allocator > > > > >&, std::tr1::basic_regex > const&, std::bitset<11u>)’
collect2: ld returned 1 exit status

I can’t really make heads or tails of this, except for the undefined reference to std::tr1::basic_regex near the beginning. Anyone know what’s going on?

Answer 1

Regex support for C++0x is incomplete and wasn’t there for TR1, see the implementation status page for C++0x/TR1.

Boost offers an alternative TR1 implementation as well as the original library it is based on.