Base promote for LArray with division by Float64

[jpfairbanks]

I found this while using LabelledArrays with OrdinaryDiffEq:

MWE:

using LabelledArrays
julia> Base.promote_op(/, typeof(LVector(a=1.0)), typeof(oneunit(1.0)))
Union{LArray{Float64, 1, Vector{Float64}, (:a,)}, Vector{Float64}}

When you promote LVector / Float64 you get a Union with Vector{Float64}.

Expected behavior

I expected to get LVector back as the promoted type, because that is the actual return type of the operation.

Minimal Reproducible Example 👇

MRE above

Error & Stacktrace ⚠️

No error and stacktrace, just the incorrect answer.

Environment (please complete the following information):

(julia_replication) pkg> st
Status `~/julia_replication/Project.toml`
  [2ee39098] LabelledArrays v1.16.0

• Output of using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)

julia> using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)
Status `~/julia_replication/Manifest.toml`
  [7d9f7c33] Accessors v0.1.36
  [79e6a3ab] Adapt v4.0.4
  [4fba245c] ArrayInterface v7.11.0
  [d360d2e6] ChainRulesCore v1.24.0
  [bbf7d656] CommonSubexpressions v0.3.0
  [34da2185] Compat v4.15.0
  [a33af91c] CompositionsBase v0.1.2
  [187b0558] ConstructionBase v1.5.5
  [9a962f9c] DataAPI v1.16.0
  [e2d170a0] DataValueInterfaces v1.0.0
  [163ba53b] DiffResults v1.1.0
  [b552c78f] DiffRules v1.15.1
  [ffbed154] DocStringExtensions v0.9.3
  [e2ba6199] ExprTools v0.1.10
  [f6369f11] ForwardDiff v0.10.36
  [46192b85] GPUArraysCore v0.1.6
  [3587e190] InverseFunctions v0.1.14
  [92d709cd] IrrationalConstants v0.2.2
  [82899510] IteratorInterfaceExtensions v1.0.0
  [692b3bcd] JLLWrappers v1.5.0
  [2ee39098] LabelledArrays v1.16.0 `~/.julia/dev/LabelledArrays`
  [2ab3a3ac] LogExpFunctions v0.3.28
  [1914dd2f] MacroTools v0.5.13
  [77ba4419] NaNMath v1.0.2
  [bac558e1] OrderedCollections v1.6.3
  [d236fae5] PreallocationTools v0.4.22
  [aea7be01] PrecompileTools v1.2.1
  [21216c6a] Preferences v1.4.3
  [3cdcf5f2] RecipesBase v1.3.4
  [731186ca] RecursiveArrayTools v3.23.0
  [ae029012] Requires v1.3.0
  [7e49a35a] RuntimeGeneratedFunctions v0.5.13
  [276daf66] SpecialFunctions v2.4.0
  [90137ffa] StaticArrays v1.9.5
  [1e83bf80] StaticArraysCore v1.4.3
  [2efcf032] SymbolicIndexingInterface v0.3.22
  [3783bdb8] TableTraits v1.0.1
  [bd369af6] Tables v1.11.1
  [efe28fd5] OpenSpecFun_jll v0.5.5+0
  [0dad84c5] ArgTools v1.1.1
  [56f22d72] Artifacts
  [2a0f44e3] Base64
  [ade2ca70] Dates
  [f43a241f] Downloads v1.6.0
  [7b1f6079] FileWatching
  [b77e0a4c] InteractiveUtils
  [b27032c2] LibCURL v0.6.4
  [76f85450] LibGit2
  [8f399da3] Libdl
  [37e2e46d] LinearAlgebra
  [56ddb016] Logging
  [d6f4376e] Markdown
  [ca575930] NetworkOptions v1.2.0
  [44cfe95a] Pkg v1.10.0
  [de0858da] Printf
  [3fa0cd96] REPL
  [9a3f8284] Random
  [ea8e919c] SHA v0.7.0
  [9e88b42a] Serialization
  [6462fe0b] Sockets
  [2f01184e] SparseArrays v1.10.0
  [10745b16] Statistics v1.10.0
  [4607b0f0] SuiteSparse
  [fa267f1f] TOML v1.0.3
  [a4e569a6] Tar v1.10.0
  [8dfed614] Test
  [cf7118a7] UUIDs
  [4ec0a83e] Unicode
  [e66e0078] CompilerSupportLibraries_jll v1.1.1+0
  [deac9b47] LibCURL_jll v8.4.0+0
  [e37daf67] LibGit2_jll v1.6.4+0
  [29816b5a] LibSSH2_jll v1.11.0+1
  [c8ffd9c3] MbedTLS_jll v2.28.2+1
  [14a3606d] MozillaCACerts_jll v2023.1.10
  [4536629a] OpenBLAS_jll v0.3.23+4
  [05823500] OpenLibm_jll v0.8.1+2
  [bea87d4a] SuiteSparse_jll v7.2.1+1
  [83775a58] Zlib_jll v1.2.13+1
  [8e850b90] libblastrampoline_jll v5.8.0+1
  [8e850ede] nghttp2_jll v1.52.0+1
  [3f19e933] p7zip_jll v17.4.0+2

• Output of versioninfo()

julia> versioninfo()
Julia Version 1.10.4
Commit 48d4fd48430 (2024-06-04 10:41 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (arm64-apple-darwin22.4.0)
  CPU: 20 × Apple M1 Ultra
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, apple-m1)
Threads: 1 default, 0 interactive, 1 GC (on 16 virtual cores)

Additional context

Came up from using ODE solvers, which use this to determine if the RHS of the ODE is type stable.

[ChrisRackauckas]

Yeah that's not quite intended.