Elixir: Set variable in if statement

In Elixir every statement returns the value. Instead of assigning variable in if you can assign whole if statement value into variable.

a = 0
a = if true do
      1 + 1
    else
      a + 1
    end

The warning is correct trying to prevent you from doing _ possibly dangerous_ thing. It is very well explained in the Elixir's 1.3 changelog.

Take a look at Deprecation of imperative assignment section, where it is explained (with example) here:

http://elixir-lang.org/blog/2016/06/21/elixir-v1-3-0-released/

Hope that helps!