Trying to reference a struct field into an array

New to Julia
,
7

This part of StructArrays is less known, but works fine:

julia> foo = StructArray([Foo(SubFoo(1, 2, 3), 1), Foo(SubFoo(1, 2, 3), 2)]; unwrap=T -> fieldcount(T) > 0)
2-element StructArray(StructArray(::Vector{Int64}, ::Vector{Int64}, ::Vector{Int64}), ::Vector{Int64}) with eltype Foo{Int64}:
 Foo{Int64}(SubFoo{Int64}(1, 2, 3), 1)
 Foo{Int64}(SubFoo{Int64}(1, 2, 3), 2)

julia> foo.a.x
2-element Vector{Int64}:
 1
 1

And just in case you need something even fancier:

julia> using AccessorsExtra, SplitApplyCombine

julia> ax = mapview(@optic(_.a.x + 10), foo)
2-element <...>:
 11
 11

julia> ax[1] = 0
0

julia> foo
2-element <...>:
 Foo{Int64}(SubFoo{Int64}(-10, 2, 3), 1)
 Foo{Int64}(SubFoo{Int64}(1, 2, 3), 2)

Works with all arrays including Base Vectors.

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