#!/usr/bin/perl

eval 'undef %x::; sub yak {$x::a}; $x::a = 1';
eval 'print "t1: ",keys %x::,"\n"';
eval 'print "t2: ",keys %x::,"\n"; $x::a = 2';
eval 'print "t3: ",yak,",",$x::a,"\n"';

##</code><code>##

t1: 
t2: a
t3: 1,2