Rails设计:user_signed_in ?不工作

I have this in my view:

我认为:

<% if user_signed_in? %>
<%= current_user.email %>
<% else %>
<%= link_to "Sign in", new_user_session_path %><br />
<%= link_to "Opret", new_user_session_path %><br />
<% end %>
<% if user_sig