Select Code to Download

my %seen;
@$ref = grep { ! $seen{$_->{id}}++ } @$ref;

#!/usr/bin/env perl

...
my %seen;
@$ref = grep { ! $seen{$_->{id}}++ } @$ref;
dd $ref;

[{ id => "a" }, { id => "b" }, { id => "c" }, { id => "b" }]
[{ id => "a" }, { id => "b" }, { id => "c" }]