Well, the previous listing worked only for Int vectors. Following is a more
properly typed version.
Various optimizations are possible: @inbounds, reducing allocations, etc.
function uniquepermutations(base)
zpos = Vector{Vector{Vector{Int}}}()
zval = Vector{eltype(base)}()
left = length(base)
for (v,c) in countmap(base)
push!(zpos,collect(subsets(collect(1:left),c)))
push!(zval,v)
left -= c
end
res = Vector{Vector{eltype(base)}}()
for a in product(zpos...)
slots = collect(1:length(base))
perm = similar(base)
for (val,b) in zip(zval,a)
perm[slots[b]] = val
slots[b] = 0
slots = filter(x->x>0,slots)
end
push!(res,perm)
end
res
end
