Huge number of overwrite warnings on Julia 0.4

[tlnagy]

Just loading the Combinatorics package on 0.4 throws a huge number of warnings, which leads to pretty poor user experience:

julia> using Combinatorics
WARNING: Method definition levicivita(AbstractArray{#T<:Integer, 1}) in module Base at combinatorics.jl:611 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:188.
WARNING: Method definition partitions(Integer) in module Base at combinatorics.jl:252 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/partitions.jl:26.
WARNING: Method definition partitions(Integer, Integer) in module Base at combinatorics.jl:318 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/partitions.jl:93.
WARNING: Method definition partitions(AbstractArray{T<:Any, 1}) in module Base at combinatorics.jl:380 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/partitions.jl:158.
WARNING: Method definition partitions(AbstractArray{T<:Any, 1}, Int64) in module Base at combinatorics.jl:447 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/partitions.jl:228.
WARNING: Method definition permutations(Any) in module Base at combinatorics.jl:219 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:24.
WARNING: Method definition nthperm!(AbstractArray{T<:Any, 1}, Integer) in module Base at combinatorics.jl:70 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:136.
WARNING: Method definition prevprod(Array{Int64, 1}, Any) in module Base at combinatorics.jl:565 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/partitions.jl:354.
WARNING: Method definition combinations(Any, Integer) in module Base at combinatorics.jl:182 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/combinations.jl:42.
WARNING: Method definition nthperm(AbstractArray{#T<:Integer, 1}) in module Base at combinatorics.jl:92 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:161.
WARNING: Method definition nthperm(AbstractArray{T<:Any, 1}, Integer) in module Base at combinatorics.jl:89 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:157.
WARNING: Method definition factorial(#T<:Integer, #T<:Integer) in module Base at combinatorics.jl:56 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/factorials.jl:18.
WARNING: Method definition factorial(Integer, Integer) in module Base at combinatorics.jl:66 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/factorials.jl:28.
WARNING: Method definition parity(AbstractArray{#T<:Integer, 1}) in module Base at combinatorics.jl:642 overwritten in module Combinatorics at /Users/tamasnagy/.julia/v0.4/Combinatorics/src/permutations.jl:221.

I know that this was fixed in Base by JuliaLang/julia#16125, but 0.4 is still the official release.

[KristofferC]

I don't think anyone is going to put work into this when a new release that fixes this is not far away.

[mbauman]

A version check here https://github.com/JuliaLang/Combinatorics.jl/blob/44d815f1e2800d308407af70ea2195bfe135be81/src/Combinatorics.jl#L12 would probably make sense. You can use the workflow in Compat.jl to find the appropriate version number.

[KristofferC]

Oh, I didn't even notice these were not ambiguity but method overwrites. Yeah, then this should not be hard to fix like @mbauman says.

[tlnagy]

Oh yeah, they are overwrite warnings. My bad for using the wrong terminology. That fix seems easy enough to implement.

[tlnagy]

Based on @mbauman's suggestion, I made a quick PR fixing this: #27. There are still overwrite warnings for factorial, but my impression was that those should be there even on v0.4.