in reply to array add/sub/mult/div

Sorry, but your wheel has already been invented. 

$_ += 123 for @foo;
$_ -= 123 for @foo;
$_ *= 123 for @foo;
$_ /= 123 for @foo;

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Isn't that great? Perl has loops and simple math built in!

And if that isn't simple enough, Perl 6 will provide these: 
@foo ^+= 123;
@foo ^-= 123;
@foo ^*= 123;
@foo ^/= 123;

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Oops, I didn't read the original post well enough. Anyway, Perl 6 will provide: 
@foo ^+= @bar;
etcetera

[download]

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In Section Cool Uses for Perl