Still, the structure preserving Enum.map would be not possible in case like:

map = %{2 => 1, 3 => 7}

Enum.map(map, fn {a, b} -> a + b end)

As mentioned before, Enum.map on a map returns a list because this would fit better to pipes without the need to convert to a list and back behind the scenes in every step.

There used to be the Map.map/2 function in Elixir, which is now deprecated. But you get the same result with Map.new/2.

iex(1)> map = %{a: 1, b: 2, c: 3}
%{c: 3, a: 1, b: 2}
iex(2)> Map.map(map, fn {key, value} -> {key, value * value} end)
warning: Map.map/2 is deprecated. Use Map.new/2 instead (invoke Map.from_struct/1 before if you have a struct)
└─ iex:2

%{c: {:c, 9}, a: {:a, 1}, b: {:b, 4}}
iex(3)> Map.new(map, fn {key, value} -> {key, value * value} end)
%{c: 9, a: 1, b: 4}

One thing is that the result of your map operation is in a predictable order. I don’t have a real world example of where this would particularly useful, but in a pipeline it could be. Having each result getting converted back to a map would be pretty chaotic.