#3 Make error

[Anonymous]

PXCore.cc: In member function âvoid PXCore::ParseArguments(int, char**)â:
PXCore.cc:96: error: âstrdupâ was not declared in this scope
make[3]: *** [PXCore.o] Erreur 1

I don't know why i get this error. And I add the #include <cassert> in PXCore.cc and not working either. Plz help me :)