From: "matz (Yukihiro Matsumoto)" Date: 2012-03-31T10:07:51+09:00 Subject: [ruby-core:43969] [ruby-trunk - Feature #6219] Return value of Hash#store Issue #6219 has been updated by matz (Yukihiro Matsumoto). by spec, all assignment should return the assigning value (to enable assignment chain), so that I have to reject the original proposal to change the value from "a[k] = v". but there's still room to change the return value of Hash#store. Matz. ---------------------------------------- Feature #6219: Return value of Hash#store https://bugs.ruby-lang.org/issues/6219#change-25489 Author: MartinBosslet (Martin Bosslet) Status: Assigned Priority: Low Assignee: matz (Yukihiro Matsumoto) Category: core Target version: 3.0 Hash#store returns the value that was just assigned, for example: h[:a] = b # => b Does anyone rely on this behavior, are there cases when this becomes handy? If however the return value is discarded most of the time, I was thinking it might be beneficial if we would return the previous value of a given key (nil if none was assigned yet) instead. That way we could assign and check for a collision in one pass, something that right now can only be done in two separate steps. -- http://bugs.ruby-lang.org/