Elixir allows to rebind the variables, so this is perfectly possible to do:
a = 1
a = 2
Which will then be translated to Erlang as a something like:
A@1 = 1
A@2 = 2
To have the same behaviour as in Erlang, you need to use pin operator (^):
a = 1
^a = 2 # will fail with no match
So in your case you need to write it as:
receive do
{:DOWN, ^ref, :process, ^pid, why} -> why
end
To “pin down” the variables to their current binding instead of creating new ones.
