From: Florian Frank <flori@...>
Date: 2003-08-27T02:30:15+09:00
Subject: Re: Array#uniq!

On 2003-08-27 01:48:14 +0900, mgarriss wrote:
> Anyone know why Array#uniq returns an array in every case and
> Array#uniq! returns nil if nothing is removed?

Array#uniq! modifies the receiver, you should not rely on the objects
that are returned. However, if the receiver was really changed, uniq!
returns a true (not false and not nil) value. You can code something
like that:

if ary.uniq!
	puts "Made it unique: " + ary.inspect
else
	puts "Was already unique: " + ary.inspect
end

I wonder if it would be better to return an instance of TrueClass
because I think a lot of people will code mistakes like that:

new_ary = ary.uniq!
new_ary.each do |x|
	# ...
end

Perhaps this works most of the time, but it's just waiting for a
disaster to happen.

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