add void type for returning nothing

[raabf]

It would be nice to have voidas an alias for type(None), e.g for returning Nothing, so that you can write something like:

@typechecked
def function(a: int) -> void:
    pass

voidis a very common keyword to indicate that a function returns no value, so for most users it is clear what voidindicates. It is faster to write and in my opinion better to read then type(None).

[dahlia]

+1

[jan-matejka]

Should use just None to be consistent with pep 484

[raabf]

You mean Using None right? Automatically it does not work. Mhmm I personally find that strange since None (=instance) and type(None) (=type) is not the same and you had to detect the context. But yea you're right if PEP484 defines that we should follow this guideline. So lets change this MR to #10 .