Julia is pretty good at dealing with this now though

    julia> @btime test1(10^5)
      147.427 μs (0 allocations: 0 bytes)
    99999.1

    julia> @btime test2(10^5)
      88.472 μs (0 allocations: 0 bytes)
    99999.1

In earlier versions of Julia, the penalty here would be order of magnitudes worse.