LinearMaps 3.0: Incompatibility with StaticArrays due to generic _cat

[mfherbst]

I observed the issue when using LinearMaps and StaticArrays at the same time. Could be more general and effect other generic Array types as well, but I have not tested.

Reproducer

Works fine:

using LinearMaps
using StaticArrays
rotations = [ones(3,3), ones(3,3)]
cat(rotations..., dims=3)

Not working any more with LinearMaps 3.0:

using LinearMaps
using StaticArrays
rotations = SMatrix{3,3,Float64}[ones(3,3), ones(3,3)]
cat(rotations..., dims=3)

Stacktrace:

ERROR: TypeError: in typeassert, expected Tuple{Int64,Int64}, got a value of type Int64
Stacktrace:
 [1] _cat(::Int64, ::SArray{Tuple{3,3},Float64,2,9}, ::Vararg{SArray{Tuple{3,3},Float64,2,9},N} where N) at /packages/LinearMaps/OwJoG/src/blockmap.jl:455
 [2] cat(::SArray{Tuple{3,3},Float64,2,9}, ::Vararg{SArray{Tuple{3,3},Float64,2,9},N} where N; dims::Int64) at ./abstractarray.jl:1654
 [3] top-level scope at REPL[19]:1

[dkarrasch]

Thanks for reporting this. I guess I'll need to revert that _cat overload then. Tricky concatenation business.

[mfherbst]

Thanks for your quick reply ... yes patching these sort of things in Base is always a bit tricky.