From: Yukihiro Matsumoto <matz@...>
Date: 2009-05-12T15:50:54+09:00
Subject: [ruby-core:23434] Re: [Bug #1363] Wrong value for Hash of NaN

Hi,

In message "Re: [ruby-core:23427] Re: [Bug #1363] Wrong value for Hash of NaN"
    on Mon, 11 May 2009 21:58:42 +0900, Urabe Shyouhei <shyouhei@ruby-lang.org> writes:

|I don't argue about correctness on NaNs being different each other, but I also
|agree with the reporter with Hash being inconvenient when NaNs used as keys.

Using float values as hash keys should be strongly discouraged,
because you may not have expected result anyway.  a 3.14 may be
different in bit-wise representation from another 3.14.  I have no
plan to prohibit using them as keys, right now, but see no need to
change the language to encourage bad habit.  If I have to make a
change related to this issue, I'd rather prohibit NaN as a key (or
float keys in general), as in [ruby-core:23426].

							matz.