hash.c: [DOC] improve Hash#{select!,keep_if} docs
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65529 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
hash.c: [DOC] improve Hash#{select!,keep_if} docs
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65529 b2dd03c8-39d4-4d8f-98ff-823fe69b080e