```ruby
module SmartTitles
  module Helper
    MISSING_TRANSLATION = 0

    # <title><%= head_title %></title>
    # Will return title if it was set for the current page.
    # Otherwise will return :title translation.
    #
    # <title><%= head_title "My Blog" %></title>
    # The default title will be "My Blog" instead of :title translation.
    def head_title(*args)
      options = args.extract_options!
      custom_default_title = args.first
      default_title = custom_default_title || t(:title)

      if title = page_title
        t(:title_template, title: title, default: title)
      else
        default_title
      end
    end

    # This is a page title that was set by the #title helper method
    # It defaults to ".title" translation
    def page_title
      if content_for?(:page_title)
        content_for(:page_title)
      else
        translation = t('.title', default: MISSING_TRANSLATION)
        translation unless translation == MISSING_TRANSLATION
      end
    end

    # Convinient helper method that will:
    # * Set custom title for the current page if it is passed. Otherwise the title will be automatically set 
    # * Return the title passed or looked up from locale wrapped into h1 tag
    def title(custom_title = nil)
      provide(:page_title, custom_title)
      content_tag(:h1, page_title) if page_title
    end
  end
end
```

Use blank object as a missing translation so that it is unique.
user
```ruby
module SmartTitles
  module Helper
    MISSING_TRANSLATION = Object.new

    # <title><%= head_title %></title>
    # Will return title if it was set for the current page.
    # Otherwise will return :title translation.
    #
    # <title><%= head_title "My Blog" %></title>
    # The default title will be "My Blog" instead of :title translation.
    def head_title(*args)
      options = args.extract_options!
      custom_default_title = args.first
      default_title = custom_default_title || t(:title)

      if title = page_title
        t(:title_template, title: title, default: title)
      else
        default_title
      end
    end

    # This is a page title that was set by the #title helper method
    # It defaults to ".title" translation
    def page_title
      if content_for?(:page_title)
        content_for(:page_title)
      else
        translation = t('.title', default: MISSING_TRANSLATION)
        translation unless translation.equal? MISSING_TRANSLATION
      end
    end

    # Convinient helper method that will:
    # * Set custom title for the current page if it is passed. Otherwise the title will be automatically set 
    # * Return the title passed or looked up from locale wrapped into h1 tag
    def title(custom_title = nil)
      provide(:page_title, custom_title)
      content_tag(:h1, page_title) if page_title
    end
  end
end
```
assistant