$a=1;
$b=2;
sub {
    my (0?$a:$b) = 3;
    print "a=$a\nb=$b\n"
}->()

##</code><code>##

my (0?$a:$b) = 3;
# becomes
BEGIN { create_lexicals(0?$a:$b); } # A
(0?$a:$b) = 3; # B

##</code><code>##

a=
b=3

##</code><code>##

$a = 1;
$b = 2;
sub {
    my($b) = 3;
    print "a=$a\nb=$b\n";
}
->();