## Example 1
our $x = "Hello";
sub f {
  local $x = "Goodbye";
  ...;
}
f();

## Example 2
our $x = "Hello";
sub f {
  my $original = $x;
  $x = "Goodbye";
  ...;
  $x = $original;  # restore
}
f();

##</code><code>##

use v5.14;

{
	my $count = 1;
	sub counter {
		say $count++;
	}
}

counter();
counter();
counter();
counter();