Undefined reference to QuantLib::Date::Date()

  c++, quantlib

Hi I am trying to compile my first QuantLib program.
–> quantlib-sample.cpp

#include <ql/time/all.hpp>
using namespace QuantLib;

int main()
  Date d1(14, February, 2014);
  return 0;

when I am running on the windows command prompt:
g++.exe -o quantlib-sample-1.exe -g quantlib-sample-1.cpp -I ‘path_to_QuantLib_folder’ -I ‘path_to_boost_folder’
it is showing me the following:
undefined reference to QuantLib::Date::Date(int, QuantLib::Month, in).
What am I doing wrong? Please help as I have been spending days figuring this out….

Source: Windows Questions C++