use strict;
use warnings;

{   no strict "refs";
    my $site = "foo";
    my @{"platforms_$site"} = qw( foo bar );
    my %{"platforms_$site"} = map { $_ => 1 } @{"platforms_$site"};
    }

=>

Can't declare array dereference in "my" at xx.pl line 8, near "} ="
Execution of xx.pl aborted due to compilation errors.

##</code><code>##

use strict;
use warnings;

{   no strict "refs";
    my $site = "foo";
    @{"platforms_$site"} = qw( foo bar );
    %{"platforms_$site"} = map { $_ => 1 } @{"platforms_$site"};
    }