our %h;
my $x = do { local %h=(a=>'3'); \%h };
my $y = do { local %h=(b=>'5'); \%h };
dd \%h;  # {}
dd $x;   # { a => 3 }
dd $y;   # { b => 5 }

##</code><code>##

use Symbol qw/gensym/;
my $foo = gensym;
*$foo->{bar} = 'quz';
dd \%Symbol::GEN0;  # { bar => "quz" }

##</code><code>##

sub gensym { \do{ local *ANONGLOB; *ANONGLOB } }