raku-rosettacode/programming_tasks/A/Address_of_a_variable.md

Address of a variable

my $x;
say $x.WHERE;
 
my $y := $x;   # alias
say $y.WHERE;  # same address as $x
 
say "Same variable" if $y =:= $x;
$x = 42;
say $y;  # 42
 

Output:

7857931379550584425

How you set the address of a variable (or any other object) is outside the purview of the Perl 6 language, but Perl 6 supports pluggable object representations, and any given representation scheme could conceivably allow an existing address to be treated as an object candidate where that makes sense. Memory-mapped structs are not unreasonable and are likely to be supported on VMs that allow it.