[julia-users] Another (basic) parameterization question

[Seth]

I have

abstract AbstractGraph{T<:Integer}

type Graph{T}<:AbstractGraph{T}
    vertices::UnitRange{T}
    edges::Set{Edge{T}}
    finclist::Vector{Vector{Edge{T}}} # [src]: ((src,dst), (src,dst), 
(src,dst))
    binclist::Vector{Vector{Edge{T}}} # [dst]: ((src,dst), (src,dst), 
(src,dst))
end

function Graph{T<:Integer}(n::T)





and g = Graph(5) works and produces a graph of type Graph{Int64}, but g = 
Graph{Int64}(5) produces

ERROR: MethodError: `convert` has no method matching 
convert(::Type{LightGraphs.Graph{Int64}}, ::Int64)

This is a problem because I have 

function union{T<:AbstractGraph}(g::T, h::T)
    gnv = nv(g)
    r = T(gnv + nv(h))
    for e in edges(g)
        add_edge!(r,e)
    end
    for e in edges(h)
        add_edge!(r, gnv+src(e), gnv+dst(e))
    end
    return r
end



Which is failing on line 3 (in the creation of the graph).

What's the proper way of creating the object from a parameterized type? 
Thanks.