my $x = 'foo';
my $y = 'The answer is $x';
my $z = eval enquote($y);

sub enquote {
    return 'qq{' . shift() . '}';
}

##</code><code>##

my $z = eval 'qq{' . $y . '}';

##</code><code>##

my $z = eval "qq{$y}";