From: Henrik Horneber <ryco@...>
Date: 2004-10-02T08:09:10+09:00
Subject: BigDecimal Float worries

Hi!

I stumbled over something while toying around with BigDecimal

require 'bigdecimal'
     ==>true

a = 2.12
     ==>2.12
b = BigDecimal.new(a.to_s).to_f
     ==>2.12
a == b
     ==>true
a = 20.12
     ==>20.12
b = BigDecimal.new(a.to_s).to_f
     ==>20.12
a == b
     ==>false
a.class == b.class
     ==>true
a.to_s == b.to_s
     ==>true

# in short
a == b
     ==>false  # and then sometimes its true
a == b.to_s.to_f
     ==>true
b == b.to_s.to_f
     ==>false
#even though
b.class == b.to_s.to_f.class
     ==>true
a.class == b.class
     ==>true


seems a little strange to me.
what's going on? :)

Henrik

D:\>ruby -v
ruby 1.8.2 (2004-07-29) [i386-mswin32]