From: Fabian Senftenberg <senf@...>
Date: 2001-12-11T01:39:46+09:00
Subject: [ruby-talk:28099] Ensuring a specific type

Is there any way I can make sure that an expression (a block) is of a
specific type? Suppose, I have a fancy little class like the
following:

class Interval
  @start = Time.new()
  @duration = 0

  def initialize(s, d = 0)
    @start = s
    @duration = d
  end

  def end()
    return #{@start + @duration}.usec
  end
end

Now, the definition of the end method is not correct. Ruby complains
with "undefined method `usec' for 0:Fixnum (NameError)". How may I
tell the block "#{@start + @duration}" that is is of type Time and
nothing else?

-- 
  senf