Benchmarking all() vs for-loop

General Usage
,
2

I think you are paying the price of creating the view:

julia> function f1(v,idx)
           @inbounds for i in idx
               if v[i] ≠ 1
                   return false
               end
           end
           return true
       end
f1 (generic function with 1 method)

julia> f2(v,idx) = all(isequal(1), view(v,idx))
f2 (generic function with 1 method)

julia> function f3(v,idx)
           vv = @view(v[idx])
           for el in vv
               if el ≠ 1
                   return false
               end
           end
           return true
       end
f3 (generic function with 1 method)

julia> @btime f1($v, $idx)
  570.033 μs (0 allocations: 0 bytes)
true

julia> @btime f2($v, $idx)
  952.366 μs (0 allocations: 0 bytes)
true

julia> @btime f3($v, $idx)
  926.045 μs (0 allocations: 0 bytes)
true

which suggests this alternative:

julia> f4(v,idx) = all(@inbounds(v[i] == 1) for i in idx)
f4 (generic function with 1 method)

julia> f4(v,idx)
true

julia> @btime f4($v,$idx)
  567.193 μs (0 allocations: 0 bytes)
true
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