How does @forward handle abstract type?

[Azzaare]

I am sorry for the basic question, but I am not good at reading meta-programming (yet?!).

I can use the @forward macro to generate methods (let's say mylazy here) that applies to a field of all the subtypes of an abstract type. However, how is the method generated? In the following code, the second and third options are definitely better.

function mylazy(lazystruct::AbstractLazyStruct) 
# method body
end

function mylazy(lazystruct::S) where {S <: AbstractLazyStruct}
# method body
end

function mylazy(lazystruct)
# method body
end