JuliaArrays / JuliaArrays/StaticArrays.jl

`*` and `UniformScaling`

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Description

I'm seeing some strange typing when multiplying StaticArrays and UniformScaling. Is all of this expected?

N = 2

typeof(rand(SMatrix{N,N}) * I)  # SMatrix{N, N}

typeof(rand(SMatrix{N,N}) * I(N))  # Matrix

typeof(rand(SVector{N}) * I)  # Matrix

typeof(I * rand(SVector{N}))  # SVector{N}

typeof(rand(SVector{N}) * I(1))  # Matrix

typeof(I(N) * rand(SVector{N}))  # SizedVector{N}

Should all these be outputs <: StaticArray?

If not, what is the rule for expected output type of these operations?

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Research direction

Reproduce the six Julia expressions involving StaticArrays and UniformScaling, recording each resulting type. Read the existing multiplication and type-promotion behavior, then establish the intended rule for these combinations; done means the expected outputs are agreed and the behavior or documentation is updated accordingly.

Written by the indexing model from the issue text.

Assessment

Tech stack
julia
Domain
data
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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