You are signed
<% if user_signed_in? %>
    in as <%= current_user.email %>.
    <form method="post" action="<%= destroy_user_session_path %>">
        <input type="hidden" name="_method" value="delete" />
        <input type="submit" value="Sign out" />
    </form>
<% else %>
    out.  <%= link_to "Sign in", new_user_session_path %>
<% end %>