myop(::Int16, ::Int16) = Int32(1) myop(::Int16, ::Int32) = Int64(1) myop(::Int16, ::Int64) = Int128(1) myop(::Int16, ::Int128) = Int128(1)
foldr(myop, Int16[1]) |> typeof |> println foldr(myop, Int16[1,1]) |> typeof |> println foldr(myop, Int16[1,1,1]) |> typeof |> println foldr(myop, Int16[1,1,1,1]) |> typeof |> println gives Int32 Int64 Int128 Int128 Would it be better if the answer was typestable (always Int128)? See also here <https://github.com/JuliaLang/julia/issues/18960>.
