boost::program_options undefined reference

Question

I use ubuntu 10.04 and libboost1.40.

ls -l /usr/lib | grep boost_pro
    -rw-r--r--  1 root root   640800 2010-04-01 05:19 libboost_program_options.a
    lrwxrwxrwx  1 root root       26 2011-11-03 22:40 libboost_program_options-mt.a ->                  libboost_program_options.a
    lrwxrwxrwx  1 root root       34 2011-11-03 22:40 libboost_program_options-mt.so ->                libboost_program_options.so.1.40.0
    lrwxrwxrwx  1 root root       34 2011-11-03 22:40 libboost_program_options.so ->    libboost_program_options.so.1.40.0
    -rw-r--r--  1 root root   289336 2010-04-01 05:19 libboost_program_options.so.1.40.0

this is main.cpp(just for testing)

     #include <string> 
#include <iostream> 
#include <boost/date_time/gregorian/gregorian.hpp> 
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/program_options/options_description.hpp>
//--------------------------------------------------------------------- 
int main(int argc,char** argv) 
{ 
 boost::gregorian::date now(boost::gregorian::day_clock::local_day());
 //is works fine 
 std::cout<<boost::gregorian::to_iso_string(now)<<std::endl;
 boost::program_options::options_description a; //but here i get an error when the                constructor have started
 return 0; 
 }

    g++ -o main -lboost_date_time -lboost_program_options   main.cpp && ./main
    /tmp/cc3RJHsG.o: In function `main':
    main.cpp:(.text+0x81): undefined reference to   `boost::program_options::options_description::options_description(unsigned int, unsigned     int)'
    collect2: ld returned 1 exit status

i do

    find /usr/include/ -name "*description*"
/usr/include/boost/program_options/options_description.hpp

and there's only a prototype ofcouse. Any ideas?

Answer 1

Apparently, there is a prototype for a two-arg constructor that takes two unsigned ints, both with a default value. Hence, this becomes the default constructor, that is used when a is created. It's this constructor:

  options_description(unsigned = m_default_line_length, 
                      unsigned = m_default_line_length/2);

However, this was added in Boost 1.42 and does not exist in your version, 1.40.

So I think you somehow managed to overwrite the headers that Ubuntu installed for you, with a more recent version, but did not update the libraries in /usr/lib. Try uninstalling and reinstalling the package.

If you need a newer Boost than 1.40, either upgrade your Ubuntu, or uninstall all Boost-related packages and reinstall from source in /usr/local. The package manager will stay away from anything in /usr/local, so this will ensure that this kind of trouble does not happen again.