class ActionView::PathSet

def typecast(paths)
  paths.map do |path|
    case path
    when Pathname, String
      # This path should only be reached by "direct" users of
      # ActionView::Base (not using the ViewPaths or Renderer modules).
      # We can't cache/de-dup the file system resolver in this case as we
      # don't know which compiled_method_container we'll be rendering to.
      FileSystemResolver.new(path)
    when Resolver
      path
    else
      raise TypeError, "#{path.inspect} is not a valid path: must be a String, Pathname, or Resolver"
    end
  end
end