The hyper operator is more appropriate

@z .^~ @a;        # I believe _ has been replaced by ~ 
                  # as the new replacement for '.'
[download]

but multi-variable loops work, too, though not as fast.

my @new;
for @z;@d -> $z;$d {
    push @new,  $z ~ $d;
}
[download]

--
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