Perl 6 Deep Dive

Bound check operator

The bound check operator returns true if both operands are bound to the same variable, or, more precisely, to the same container.

Binding in Perl 6 means that another variable points to the same container and you may change its value using two names. This is demonstrated in the following example:

my $a = 42;my $b := $a;$b = 30;say $a; # 30

Here, the value that was placed in the $a variable is changed using the $b alias. The =:= operator returns true for such names:

say $a =:= $b; # True