Usage

result = Tempfile.string_as_file("id,name\n1,foo\n2,bar") do |file|
  FasterCSV.foreach(file) do |row|
    ....
  end
end

Code

class Tempfile
  def self.string_as_file(string)
    result = nil
    Tempfile.open('foo') do |f|
      f.print string
      f.close
      result = yield(f.path)
    end
    result
  end
end