use warnings;
use strict;
eval( rand() < 0.5
	? q{ sub foo { print "Hello!\n" } sub quz { print "Quz!\n" } }
	: q{ sub foo { print "Perl!\n"  } sub baz { print "Baz!\n" } } );
foo(); # will it print "Hello!" or "Perl!" ?
quz(); # will it die or won't it?