What about ( 0.5miles + 0.3km ).to_meters?

I do know how this can be done, but I'd like this to be a standard. As
for Tk. 

And what about percents?

# -----Original Message-----
# From: Avi Bryant [mailto:avi / beta4.com] 
# Sent: 8 ???? 2001 ?. 13:42
# To: ruby-talk ML
# Subject: [ruby-talk:17485] Re: %
# 
# 
# On Sun, 8 Jul 2001, Aleksei Guzev wrote:
# 
# > And what about types for meters, miles, feets etc. Automatic 
# > convertion while assignment whould be useful. But language should 
# > support constants of that type. Maybe use letters after 
# digits: 10mm, 
# > 15cm, 5,8miles, 4.45kg, 35%.
# 
# class Numeric
# 	def mm
# 		Millimeters.new(self)
# 	end
# 	def cm
# 		Centimeters.new(self)
# 	end
# 	...
# end
# 
# 10.mm
# 15.cm
# 5.8.miles
# ...
# 
# 
# Good enough?
#