Help for this page
my $x = ( 1 << 54 ) | 1; say $x; # 18014398509481985 ... $x = unpack 'J', pack 'J', $x; say $x; # 18014398509481984
use strict; use warnings; ... $x = svref_2object(\$x)->int_value; say $x; # 18014398509481984