Issue #13146 has been updated by Robert A. Heiler. This is actually interesting altogether. First that Float::NAN becomes NaN in the display; this is the first surprise to me. But second, that we have seemingly the same key twice (???), at the least in the display. {NaN=>1, NaN=>2} Should not the second key be a negative one? I guess NaN does not specify this as any more accurate but it treats them as two different entries in the hash regardless, or? That is a bit confusing to me. I have no idea if this is a correct behaviouor or not but to me this was a surprise to see. Some docu can be found here: http://ruby-doc.org/core-2.0.0/Float.html "NAN: An expression representing a value which is ¡Ènot a number¡É." To me I guess the surprise is that NAN in itself should be unique? But in hashes you can store different NANs? Then again I probably do not understand anything anyway. :) ---------------------------------------- Bug #13146: Float::NANs in Hashes are confusing (more than usual). https://bugs.ruby-lang.org/issues/13146#change-62637 * Author: Linus Sellberg * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.3.1p112 * Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- `test = {Float::NAN => 1, -Float::NAN => 2} => {NaN=>1, NaN=>2} test.values_at(Float::NAN, -Float::NAN) => [1, nil]` I don't know what the correct behaviour ought to be, but it seems inconsistent to create a hash with two elements but not be able to extract both values. -- https://bugs.ruby-lang.org/ Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=unsubscribe> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>