Issue #7300 has been updated by knu (Akinori MUSHA). ??????????????®ã?³ã?¼ã????¯ä????§ã?????????????? ?????????å???????nil??ªã????¦å???????¦ã????£ã???????³ã?¼ã????£ã?³ã?°ã????¹ã?ªã?®ã?§ã??è¦å???????ºã????????????ªã??ä¾?å¤??????ºã????¦ç?´ã??????????¹ã???????¨æ???????¾ã????? ?????¯ã?? Hash[enum.map {|x| x > 0 ? [x, x*x] : nil }] ??®ã???????«å???????«ã??????·ã?¥ã??ä½??????¨ã????«æ???³ç?????nilï¼????????????¯é??????????§ã????ªã??ä»»æ???®å?¤ï?????使ã?£ã?¦ã????¢ã?®ç??????????¹ã?ã?????????????´å????§ã?????????????? ????????«ã????¦ã??????????ªä??æ§???¯æ???????????示ã???????¦ã????ªã????®ã?§ã???????????æ©???«ç?´ã????¦ã??????????®ã????????æ°?????????¾ã????????Hash[?????§æ??ç´¢å?½ã???????? Hash[enum.map {|x| x > 0 ? [x, x*x] : nil }.compat] # minimum change Hash[enum.flat_map {|x| x > 0 ? [x, x*x] : [] }] # 1.9+ only {}.tap { |h| enum.each {|x| x > 0 and h[x] = x*x } } ---------------------------------------- Bug #7300: Hash#[] ??®æ???????? 1.9.3 ??¨ç?°ã?ªã?£ã?¦ã????? https://bugs.ruby-lang.org/issues/7300#change-32547 Author: hsbt (Hiroshi SHIBATA) Status: Open Priority: Normal Assignee: Category: core Target version: 2.0.0 ruby -v: ruby 2.0.0dev (2012-11-07) [x86_64-darwin12.2.0] Hash[[nil]] ???å®?è¡?????????? 1.9.3 ??§ã?? {} ??¨ã?ªã???????®ã?? 2.0.0 ??§ã?? ArgumentError ??¨ã?ªã????¾ã????? ??ªã?????????????«ç?¸è???????¦ã?¿ã????????2.0.0 ??®å????????ä¸?æ£ã?ªã????®ã???????§ã????¯ã????¦ã?¦æ£??????????????? ???????????¨ã??????????¦ã??????????¾ã???????????2.0.0 ??§ã?? dupricate ??®è¦???????????«ã????¦ã?? 次ã?®ã?ªã?ªã?¼ã?¹ã?§æ???????¨ã???????¹ã????¯ã??????????«æ???????¾ã????? -- http://bugs.ruby-lang.org/