Many ambiguities

[timholy]

While it's not necessary to fix these unless they cause errors, this is a bit concerning:

julia> using StaticArrays

julia> Base.Test.detect_ambiguities(StaticArrays, Base, Core)
Skipping StaticArrays.MutableFieldVector
Skipping Base.<|
Skipping Base.>:
Skipping Base.cluster_manager
17-element Array{Tuple{Method,Method},1}:
 (+(a::Number, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:19,+(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:91)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
 (-(a::StaticArrays.StaticArray, b::AbstractArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:16,-(x::Union{Base.ReshapedArray{T<:Any,1,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{T<:Any,1},SubArray{T<:Any,1,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, y::AbstractSparseArray{Tv<:Any,Ti<:Any,1}) at sparse/sparsevector.jl:1184)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
 (.*(a1::Number, a2::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/arraymath.jl:19,.*{P<:Base.Dates.Period}(y::Real, X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at dates/periods.jl:91)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
 (+(a::StaticArrays.StaticArray, b::AbstractArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:12,+{P<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period},Q<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period}}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, Y::Union{Base.ReshapedArray{Q,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{Q,N<:Any},SubArray{Q,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at dates/periods.jl:338)
 (.*(a1::StaticArrays.StaticArray, a2::Number) at /home/tim/.julia/v0.6/StaticArrays/src/arraymath.jl:14,.*{P<:Base.Dates.Period}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, y::Real) at dates/periods.jl:101)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
 (+(a::StaticArrays.StaticArray, b::Number) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:20,+(A::AbstractArray{Bool,N<:Any}, x::Bool) at arraymath.jl:90)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
 (-(a::AbstractArray, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:15,-{P<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period},Q<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period}}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, Y::Union{Base.ReshapedArray{Q,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{Q,N<:Any},SubArray{Q,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at dates/periods.jl:338)
 (-(a::AbstractArray, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:15,-(x::AbstractSparseArray{Tv<:Any,Ti<:Any,1}, y::Union{Base.ReshapedArray{T<:Any,1,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{T<:Any,1},SubArray{T<:Any,1,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at sparse/sparsevector.jl:1185)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
 (+(a::AbstractArray, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:11,+(x::AbstractSparseArray{Tv<:Any,Ti<:Any,1}, y::Union{Base.ReshapedArray{T<:Any,1,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{T<:Any,1},SubArray{T<:Any,1,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at sparse/sparsevector.jl:1185)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
 (-(a::StaticArrays.StaticArray, b::Number) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:23,-(A::AbstractArray{Bool,N<:Any}, x::Bool) at arraymath.jl:92)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
 (-(a::Number, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:22,-(x::Bool, A::AbstractArray{Bool,N<:Any}) at arraymath.jl:93)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
 (./(a1::StaticArrays.StaticArray, a2::Number) at /home/tim/.julia/v0.6/StaticArrays/src/arraymath.jl:15,./{P<:Base.Dates.Period}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, y::Real) at dates/periods.jl:101)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
 (mapreduce(f, op, a1::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/mapreduce.jl:99,mapreduce(f, op::Union{Base.#&,Base.#|}, itr::AbstractArray) at reduce.jl:220)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
 (+(a::AbstractArray, b::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:11,+{P<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period},Q<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period}}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, Y::Union{Base.ReshapedArray{Q,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{Q,N<:Any},SubArray{Q,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at dates/periods.jl:338)
 (mapreduce(f, op, a1::StaticArrays.StaticArray) at /home/tim/.julia/v0.6/StaticArrays/src/mapreduce.jl:99,mapreduce(f, op::Union{Base.#&,Base.#|}, itr) at reduce.jl:221)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
 (+(a::StaticArrays.StaticArray, b::AbstractArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:12,+(x::Union{Base.ReshapedArray{T<:Any,1,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{T<:Any,1},SubArray{T<:Any,1,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, y::AbstractSparseArray{Tv<:Any,Ti<:Any,1}) at sparse/sparsevector.jl:1184)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
 (-(a::StaticArrays.StaticArray, b::AbstractArray) at /home/tim/.julia/v0.6/StaticArrays/src/linalg.jl:16,-{P<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period},Q<:Union{Base.Dates.CompoundPeriod,Base.Dates.Period}}(X::Union{Base.ReshapedArray{P,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{P,N<:Any},SubArray{P,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}, Y::Union{Base.ReshapedArray{Q,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray{Q,N<:Any},SubArray{Q,N<:Any,A<:Union{Base.ReshapedArray{T<:Any,N<:Any,A<:DenseArray,MI<:Tuple{Vararg{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64},N<:Any}}},DenseArray},I<:Tuple{Vararg{Union{Base.AbstractCartesianIndex,Colon,Int64,Range{Int64}},N<:Any}},L<:Any}}) at dates/periods.jl:338)

(In my packages' tests I'm starting to test that this returns an empty array. I can use setdiff to get rid of StaticArrays' ambiguities, but I thought I should let you know.)

[andyferris]

Ideally these should be fixed. It's really hard to predict these, and worse, people can add more definitions to any package that cause further ambiguities. Some of these are so esoteric that it seems a little silly to fix. I'm wondering if there is something that can be done at the Julia language level to simplify this explosion of possibilities... but maybe it's inherent to multiple dispatch?

On the other hand, I'm not sure I can prioritize this for this week at least, sorry @timholy :(

[timholy]

No problem. Like you, I think the fix for some of these is pointless and probably should be done in Base (see the "Dates module" link above).

I might tackle some of them at some point; this is just a TODO.

[andyferris]

Yes, I was just reading that - thanks. I'm sure we can cover the Bool ones if that makes sense.

Do you think there is much demand for a static bits array?

[timholy]

The good news is that Dates isn't loaded by default anymore, so most of the sillier ambiguities noted above are not present unless you load the Dates stdlib.

The bad news is we're now up to 114 ambiguities! This makes it hard for any package depending on StaticArrays to deliberately check for ambiguities in its tests. I will work on this, but gotta figure out what we want to do about #518 first.

[andyferris]

Okay, thanks... I haven't looked at this for quite some time, unfortunately.

[c42f]

It appears we're down to 5 ambiguities now if only LinearAlgebra and StaticArrays are loaded. Most of them look surprisingly fixable too.

[timholy]

Could conceivably drop the permitted number if you don't want to give up recent progress. Might be Julia version-dependent though.

[hyrodium]

The issue seems to have already been resolved.

julia> using StaticArrays, Test

julia> detect_ambiguities(StaticArrays)
Tuple{Method, Method}[]

x-ref: #1016 #1072