From: Tanaka Akira Date: 2008-05-10T18:56:17+09:00 Subject: [ruby-dev:34631] "abc".tr_s!("x", "y") returns "abc" "abc".tr_s!("x", "y") が "abc" を返します。 % ./ruby -ve 'p "abc".tr_s!("x", "y")' ruby 1.9.0 (2008-05-10 revision 16345) [i686-linux] "abc" 1.8 では nil です。 % ruby-1.8 -ve 'p "abc".tr_s!("x", "y")' ruby 1.8.7 (2008-05-07 patchlevel 5000) [i686-linux] nil -- [田中 哲][たなか あきら][Tanaka Akira]