You want
render{T<:AbstractString}(p::Dict{T})See the bit about "invariant" types in http://docs.julialang.org/en/latest/manual/types/#parametric-composite-types
You want
render{T<:AbstractString}(p::Dict{T})See the bit about "invariant" types in http://docs.julialang.org/en/latest/manual/types/#parametric-composite-types