Re: [Boost-users] Undefined reference

Carl Wainwright wrote:

Hi all,

I've started just recently to use boost in my C++ application to manage some threads. However, when I link my application I get strange undefined references

g++ -g -O -o test_exe -lcppunit -ldl -lpthread -lboost_thread Main.o test.o test.o(.text+0x874): In function `threadTestCases::spawnThread()': : undefined reference to `boost::thread::thread(boost::function0boost::function_base > const&)' test.o(.text+0x8b7): In function `threadTestCases::spawnThread()': : undefined reference to `boost::thread::join()' test.o(.text+0x8ce): In function `threadTestCases::spawnThread()': : undefined reference to `boost::thread::~thread()' test.o(.text+0x8eb): In function `threadTestCases::spawnThread()': : undefined reference to `boost::thread::~thread()' collect2: ld returned 1 exit status make: *** [test_exe] Error 1

As you can see I have linked in the boost_thread and pthread but still I get the problem. My LD_LIBRARY_PATH is correctly setup to define the path where boost is installed (/usr/lib/)

Hi Carl, Try changing the order that you specify the arguments to g++. You'll want to put Main.o and test.o before the request to link in the libraries. Here is a link that has some more information (it is about DJGPP, but should hold true for your version of g++): http://www.delorie.com/djgpp/v2faq/faq8_10.html David