my @b = uniq @a;

my %seen;
my @b = grep !$seen{$_}++, @a;

[download]

But if you really want to use reduce with just one expression, it's definitely possible. 

my @b = @{( reduce { push @{$a->[1]}, $b if !$a->[0]{$b}++ } [ {}, [] 
+], @a; $a )->[1]};

[download]

In reply to Re: reduce like iterators by ikegami
in thread reduce like iterators by LanX

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