my $str = out1();
my $ref = out2();
my $str = fun1($str);
my $ref = fun2(\$str);

##</code><code>##

my $str = out1();
my $str = ${ out2() };
my $str = fun1($str);
my $str = ${ fun2(\$str) };

##</code><code>##

my $ref = \out1();
my $ref = out2();
my $ref = \fun1($str);
my $ref = fun2(\$str);