gistfile1.py

@typecheck
    def foo(bar:int) -> int:
    return bar * 2

>>> foo(3)
6

>>> foo('bar')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.3/dist-packages/typecheck/typecheck_decorator.py", line 332, in typecheck_invocation_proxy
    str(arg) == "" and "''" or arg))
typecheck.typecheck_decorator.InputParameterError: foo() has got an incompatible value for bar: bar