julia> typealias SelfDict{T} Dict{T,T}
Dict{T,T}

julia> isself(d::Dict) = false
# methods for generic function isself
isself(d::Dict{K,V}) at none:1

julia> isself(d::SelfDict) = true
# methods for generic function isself
isself(d::Dict{T,T}) at none:1

julia> isself([1=>2])
true

julia> isself([1=>"foo"])
true