Bug #492: defined? a && defined? b
http://redmine.ruby-lang.org/issues/show/492
e$B5/I<<Te(B: Shyouhei U.
e$B%9%F!<%?%9e(B: Open, e$BM%@hEYe(B: Normal
e$BC4Ev<Te(B: Yukihiro M., e$B%+%F%4%je(B: core
defined? a && defined? b
e$B$,e(Bnile$B$K$J$j$^$9!#N>J}Dj5A$5$l$F$k$s$@$+$ie(Bnile$B$O$*$+$7$$$O$:$G$9!#e(B
irb(main):001:0> [RUBY_VERSION, RUBY_REVISION]
=> [“1.9.0”, 17576]
irb(main):002:0> a = b = nil
=> nil
irb(main):003:0> defined? a && defined? b
=> nil
1.8e$B$G$Oe(Bdefined?(a && defined?
b)e$B$H2r<a$5$l$Fe(B"expression"e$B$K$J$j$^$9e(B
irb(main):001:0> [RUBY_VERSION, RUBY_REVISION]
=> [“1.8.7”, 17572]
irb(main):002:0> a = b = nil
=> nil
irb(main):003:0> defined? a && defined? b
=> “expression”
irb(main):004:0>