Is this what you want?
julia> abstract ABC
julia> type A <: ABC end
julia> type B <: ABC end
julia>
julia> type TestType{T <:ABC}
a::Float64
b::T
TestType(a::Float64) = new(a)
end
julia> myT = TestType{A}(4.0)
TestType{A}(4.0,#undef)
julia> myT.b = A()
A()
julia> myT
TestType{A}(4.0,A())
On Friday, March 4, 2016 at 9:19:42 AM UTC-8, Christopher Alexander wrote:
>
> Hi all,
>
> Is there anyway to do something like the following?
>
> abstract ABC
>
> type A <: ABC end
>
> type B <: ABC end
>
> type TestType{T <:ABC}
> a::Float64
> b::T
>
> TestType(a::Float64) = new(a)
> end
>
> myT = TestType(4.0)
> myT.b = A()
>
> I am wondering if you can incompletely initialize a parametric type, and
> then set the actual value needed later. The above code doesn't work, but
> that is what I'm trying to do. The alternative is I guess to have some
> default Null Type, but then to get the performance gains I have to copy the
> object when I want to actually set it with the value that I want.
>
> Thanks!
>
> Chris
>
