A comparison for updating tuples and strucs

tuple_struc_bench.exs

defmodule TupleStructBench do
  defstruct name: nil, id: nil

  def update_struct(struct = %__MODULE__{}, new_name) do
    %{struct | name: new_name}
  end

  def update_tuple({id, _name}, new_name) do
    {id, new_name}
  end
end

my_struct = %TupleStructBench{id: 42, name: ""}
my_tuple = {42, ""}

inputs = %{
  "Small string" => Base.encode64(:crypto.strong_rand_bytes(1000)),
  "Middle string" => Base.encode64(:crypto.strong_rand_bytes(1_000_000)),
  "Big" => Base.encode64(:crypto.strong_rand_bytes(1_000_000_000))
}

Benchee.run %{
  "update name in struct" => fn(string) -> TupleStructBench.update_struct(my_struct, string) end,
  "update name in tuple" => fn(string) -> TupleStructBench.update_tuple(my_tuple, string) end
}, time: 25, warmup: 10, inputs: inputs