For no particular reason other than a lazy desire to type less, I want to design a routine that modifies an array in place. The following code is close, but no cigar!! 
#!/usr/bin/perl -w
# test.pl --
use strict;
use warnings;
use diagnostics;

my @a = (
'one',
'two',
'three'
);

print join("\n",@a),"\n__________\n";
setmode('add_test',@a);
print join("\n",@a);

sub setmode {
    my $val = shift(@_);
    my @a = @_;
    splice(@a,1,0,$val);
    $_[$_] = $a[$_] for (0..@a);
}

[download]
Which produces: 
C:>test
one
two
three
__________
one
add_test
two

[download]
Obviously @_ is an array of aliases and that portion of the direct hands on works as expected. And I've no expectation that there would be anyway to effect what I want short of references. But since TIMTOWTDI, I thought I'd ask if anyone knew a method that would allow me to have my cake and eat it too. Clearly this would work: 
sub setmode {
    my($val,$ref) = @_;
    splice(@$ref,1,0,$val);
}

[download]
but I was looking for a little magic here...

--hsm

"Never try to teach a pig to sing...it wastes your time and it annoys the pig."

In reply to Can @_ be extended? by hsmyers

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