type19.rb

def self.coerce_to_float(obj, strict=false)
  case obj
  when Numeric
    coerce_to obj, Float, :to_f
  when Float
    return obj
  when String
    result = Rubinius.invoke_primitive :string_to_f, obj, strict
    raise ArgumentError, "invalid value for Float" if result.nil?
    result
  when nil, true, false
    raise TypeError, "can't convert #{obj.inspect} into Float"
  else
    raise TypeError, "can't convert #{obj.class} into Float"
  end
end