Indexing and assigning at once

[juliohm]

The following code shouldn't work?

julia> a=[3,2,1]
3-element Array{Int64,1}:
 3
 2
 1

julia> a[a]=[4:6]
WARNING: [a] concatenation is deprecated; use [a;] instead
 in depwarn at ./deprecated.jl:40
 in oldstyle_vcat_warning at ./abstractarray.jl:26
 in vect at abstractarray.jl:29
ERROR: BoundsError: attempt to access 3-element Array{Int64,1}:
 3
 5
 4
  at index [4]
 in setindex! at array.jl:377

[tkelman]

Maybe setindex! could do a sanity check that you aren't trying to use the same array for both the indices and the values to write into? a[copy(a)] = [4,5,6] works just fine, but I'd rather either error for setindex!(A, X, inds) when A === inds, or mark this as wontfix if that check would be too expensive.

[JeffBezanson]

At array.jl:382 this was already fixed if A === the RHS, but not for A === inds. I guess we should check that too.