Undefined symbols for architecture x86_64:
  "sf::String::String(char const*, std::__1::locale const&)", referenced from:
      _main in intro-to-sfml-e17192.o
  "sf::Window::Window(sf::VideoMode, sf::String const&, unsigned int, sf::ContextSettings const&)", referenced from:
      _main in intro-to-sfml-e17192.o
  "sf::Window::~Window()", referenced from:
      _main in intro-to-sfml-e17192.o
  "sf::VideoMode::VideoMode(unsigned int, unsigned int, unsigned int)", referenced from:
      _main in intro-to-sfml-e17192.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)