Is `Vector{UInt8}(string)` the fastest way to convert String to bytes?

General Usage Performance
6 
julia>
  function roughhash(s::String)
       n = sizeof(s)
       if n >= 8
          return unsafe_load(Ptr{UInt64}(pointer(s)))
       else
          h = zero(UInt64)
          for i = 1:n
            @inbounds h = (h << 8) | codeunit(s, i)
          end
          return h
       end
  end

julia> @btime roughhash($("asldfj;asdjfsa"))
  3.473 ns (0 allocations: 0 bytes)
0x613b6a66646c7361

So, it is close to the 3ns you were hoping for.

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