I thought it looked like a nice job for List::Util, but it requires too much fiddling to make it come up with an array, so it's not really elegant. (The reason I wanted to try it is that it pre-loads $prev.)

use List::Util 'reduce';

sub uniq {
    return @{;reduce {ref $a or $a=[$a]; push @$a, $b if $b ne $a->[-1
+]; $a} @_};
};
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So it looks like grep is the right tool.

Update: This is a little shorter version with grep:

sub uniq {
    return @_ ? @_[0, grep {$_[$_] ne $_[$_-1]} 1..$#_] : ();
};
[download]