Ruby考古学 
消された機能編ArchaeologyofRuby: 
RemovedFeatures 
Kazuhiro	NISHIYAMA 
RubyKaigi2014 
2014/09/19
Selfintroduction 
oneofRubyCommitters 
Mr.fixtypo(byChikanaga) 
IuseRubysince1.4
Agenda 
リリースに⼊った後、消された 
機能 Somefeaturesremovedafterrelease 
開発版のみに⼊っていた機能 Somefeaturesonlyindevelopmentbranch
SafeLevel 
isobsoletesince 
2.1.0 
不完全なSandBox 
SafeLevel自体の削除の話も何 
度かあった
Safelevel 
Feature#8468Remove 
$SAFE 
MatzagreedatGitHubTokyo 
drinkup(on2013) 
tDiary,whichistheonly 
applicationusing$SAFE==4, 
alsoagreed 
isafail-safefeatureto 
detectbugsofapplications
SafeLevel 
isobsoletesince 
2.1.0 
raiseArgumentError
since1.9.1
isdeprecatedsince 
2.1.0 
itsbehaviorissameastaint
from	
 
securityreason 
sameas
doesnot 
containsince1.9.2 
use
instead
fromtoEncoding 
(m17n) 
#=nil#warning: 
variable$KCODEisno 
longereffective 
#warning:variable 
$KCODEisnolonger 
effective;ignored
Regexpoptions 
Regexpliteraloptions 
(remains):
!
(ignorecase) 

 
ruby1.8.7:warning: 
modifying$=isdeprecated 
ruby1.9.3:warning:variable 
$=isnolongereffective; 
ignored
between1.6.7and1.8.0 
 →
!
→
!
→!#
→$%!#
!
→!#
until1.8 
 
' 
#
 
	 
:をつけられる隠し機能の削除
(

rubykaigi2014-ruby-removed-features ===================================