#!/usr/bin/perl

use warnings;
use strict;

use Data::Dumper;

sub f { while ( <> ) {} }

my $a = 1;

for ( $a )
{
    f();
    print Dumper( $_, $a );
}

##</code><code>##

map { f(); g( $_ ) } @a;

##</code><code>##

{ map { my $x = $_; f(); g( $x ) } ( my @tmp = @a ) }