Just use grep 
if (grep {$opt{$_}} qw(a b c)}) {

[download]
And you can even capture the keys for which true is returned 
if (my @keys = grep {$opt{$_}} qw(a b c)}) {
    print "@keys match\n";

[download]

In reply to Re^3: nonempty false list by wind
in thread nonempty false list by Anonymous Monk

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