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Subject: Re: [boost] optional<optional<T>>
From: Edward Diener (eldiener_at_[hidden])
Date: 2009-09-03 00:01:14

Andrei Alexandrescu wrote:
> Hello,
> I'm defining an "optional" type for D's standard library modeled
> similarly to Boost.optional. An interesting question came up - should
> optional<optional<T>> fold itself into optional<T>, or is "double
> optional" an interesting concept of its own?
> I thought I'd ask here because by now there's a significant body of
> experience with optional<T>. I perused the online documentation and the
> forum and couldn't find information about that specific detail.

Why make optional<optional<T> > an exception to the normal case ? Even
if you imagined no practical use for it, that's no reason to create a
one-off situation.

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