Broadcast Origin as a scalar by default?

[GregPlowman]

I often want to create several OffsetVectors with the same index offset.
For example, a vector of OffsetVectors.

This is a bit verbose:

OA = [ OffsetVector([1,2,3], 0:2), OffsetVector([4,5,6], 0:2) ]

This is better:

A = [ [1,2,3], [4,5,6] ]
OA = OffsetVector.(A, Ref(0:2))

Ref is required here to prevent indices 0:2 from being broadcast.

But I would like to specify just the starting index.
The following works but is also a bit too long.

A = [ [1,2,3], [4,5,6] ]
OA = OffsetVector.(A, Ref(OffsetArrays.Origin(0)))

Ideally I could omit Ref and OffsetArrays qualifiers:

A = [ [1,2,3], [4,5,6] ]
OA = OffsetVector.(A, Origin(0))

I can get what I want with this.

using OffsetArrays: Origin
Base.Broadcast.broadcastable(o::OffsetArrays.Origin) = Ref(o)

Are there problems with this approach?
Any better ways to reduce verbosity?
Could Origin be broadcast as a scalar by default?

EDIT:
I just realised using the offset directly will work:

A = [ [1,2,3], [4,5,6] ]
OA = OffsetVector.(A, -1)

Doesn't really capture the intent as clearly as OffsetVector.(A, Origin(0)) but it is most concise!

Perhaps the OffsetArray constructor should have taken starting index rather than offset? Then Origin wouldn't be needed? But I suppose then Offset would be wanted?

[johnnychen94]

Base.Broadcast.broadcastable(o::OffsetArrays.Origin) = Ref(o)

This sounds like a good patch to me. I don't see if there's any problem with making Origin a scalar since it doesn't get involved in any arithmetic computation.

Mind to submit a PR for this?

[jishnub]

Another solution that works now: you may wrap Origin in a Tuple to make it behave as a scalar in broadcasting:

julia> A = [ [1,2,3], [4,5,6] ];

julia> import OffsetArrays: Origin

julia> OA = OffsetVector.(A, (Origin(0),))
2-element Array{OffsetArray{Int64,1,Array{Int64,1}},1}:
 [1, 2, 3]
 [4, 5, 6]

julia> axes.(OA)
2-element Array{Tuple{OffsetArrays.IdOffsetRange{Int64,Base.OneTo{Int64}}},1}:
 (OffsetArrays.IdOffsetRange(0:2),)
 (OffsetArrays.IdOffsetRange(0:2),)

[jishnub]

Crossref: JuliaLang/julia#35591