Undefined symbols for architecture x86_64:
"_Uzi_bang", referenced from:
  _Uzi_setup in ViewController.o
"_Uzi_class", referenced from:
  _Uzi_setup in ViewController.o
"_Uzi_float", referenced from:
  _Uzi_setup in ViewController.o
"_Uzi_new", referenced from:
  _Uzi_setup in ViewController.o
"_Uzi_pause", referenced from:
  _Uzi_setup in ViewController.o
"_Uzi_resume", referenced from:
  _Uzi_setup in ViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)