You can define a typespec for your struct but you cannot enforce it.

What you can do in your module is to use a constructor-like function:

def new(props) do
   ... validate the values
   struct(__MODULE__, props)
end

(new is not a special name)

I think that in this case struct!/2 (with bang) will make more sense.

I hesitated because if you validate the values beforehand you should not have to use it, but yes it may be safer.

@stevensonmt the difference is that struct!/2 will raise if the given props have extra properties or if keys declared with @enforce_keys are not defined.