similar with IdOffsetRanges may use the parent axes types

[jishnub]

Currently

julia> s = @SVector[i for i in 1:3]
3-element SArray{Tuple{3},Int64,1,3} with indices SOneTo(3):
 1
 2
 3

julia> so = OffsetArray(s, 4);

julia> similar(so)
3-element OffsetArray(::Array{Int64,1}, 5:7) with eltype Int64 with indices 5:7:
 139957917106072
 139957916617440
 139957916868864

After this PR:

julia> similar(so)
3-element OffsetArray(::MArray{Tuple{3},Int64,1,3}, 5:7) with eltype Int64 with indices 5:7:
 139957418956176
               4
               0

The new array type is also statically sized, as the information about the size is preserved in the axes.

[codecov]

Codecov Report

Merging #213 (2691937) into master (7a1e2b9) will decrease coverage by 3.70%.
The diff coverage is 70.00%.

@@            Coverage Diff             @@
##           master     #213      +/-   ##
==========================================
- Coverage   98.28%   94.57%   -3.71%     
==========================================
  Files           5        5              
  Lines         291      332      +41     
==========================================
+ Hits          286      314      +28     
- Misses          5       18      +13     

Impacted Files	Coverage Δ
src/OffsetArrays.jl	98.21% <62.50%> (+0.27%)	⬆️
src/utils.jl	100.00% <100.00%> (ø)
src/precompile.jl	0.00% <0.00%> (-92.86%)	⬇️
src/axes.jl	100.00% <0.00%> (ø)
src/origin.jl	100.00% <0.00%> (ø)

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[jishnub]

Now a mix of SOneTo and IdOffsetRange(::SOneTo) axis types as arguments to similar leads to a StaticArray

Before:

julia> s = SArray{Tuple{2,2},Int,2,4}((1,2,3,4))
2×2 SArray{Tuple{2,2},Int64,2,4} with indices SOneTo(2)×SOneTo(2):
 1  3
 2  4

julia> so = OffsetArray(s, 2, 2);

julia> similar(so, axes(so,1), axes(s,2))
2×2 OffsetArray(::Array{Int64,2}, 3:4, 1:2) with eltype Int64 with indices 3:4×1:2:
 281474976710656  140349019967488
               0  140348924690432

After 8992fc9:

julia> similar(so, axes(so,1), axes(s,2))
2×2 OffsetArray(::MArray{Tuple{2,2},Int64,2,4}, 3:4, 1:2) with eltype Int64 with indices 3:4×1:2:
             139  19
 140348215528848   5

[jishnub]

Before 8abaae2:

julia> s = SArray{Tuple{2,2},Int,2,4}((1,2,3,4));

julia> so = OffsetArray(s, 2, 2);

julia> so .+ 1
2×2 OffsetArray(::Array{Int64,2}, 3:4, 3:4) with eltype Int64 with indices 3:4×3:4:
 2  4
 3  5

After 8abaae2:

julia> so .+ 1
2×2 OffsetArray(::SizedArray{Tuple{2,2},Int64,2,2,Array{Int64,2}}, 3:4, 3:4) with eltype Int64 with indices 3:4×3:4:
 2  4
 3  5

julia> parent(so .+ 1) isa StaticArray
true

So now broadcasting preserves the static sizes.

[johnnychen94]

No objection to the fix. You always write good test cases.

[johnnychen94]

It's a little bit unintuitive to understand what _similar does, so how about:

new_inds = _strip_IdOffsetRange(inds)
B = similar(A, T, new_inds)