g++ -o TestReponse TestReponse.o Reponse.o -L/usr/local/lib -lcppunit -ldl Undefined first referenced symbol in file Envoi::~Envoi() Reponse.o Envoi::Envoi() Reponse.o Utilisateur::Utilisateur(std::basic_string, std::allocator > const&, std::basic_string, std::allocator > const&)TestReponse.o Utilisateur::~Utilisateur() TestReponse.o Envoi::Envoi(Utilisateur const&, std::basic_string, std::allocator > const&)Reponse.o Envoi::getTexte() const TestReponse.o ld: fatal: Symbol referencing errors. No output written to TestReponse collect2: ld returned 1 exit status make: *** [TestReponse] Error 1