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From: Olaf van der Spek <olafvdspek@gmail.com>
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Subject: Re: optional<T>, one more value or two states
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On Sun, Jan 27, 2013 at 9:27 PM, Daniel James <dnljms@gmail.com> wrote:
> But it could easily be changed to meet them. 'Optional' is a container
> (in the wider sense) with a maximum of 1 element. It is not in any
> sense a pointer. In fact, std::optional probably should meet the basic
> container requirements, as it would allow it to be used with generic
> functions.

It's a bit like static_vector with max_size 1, true. Though I'm not
sure what supporting a container interface really buys you.

>>  I think using operator* is natural.
>
> But it does currently imply certain semantics. The current situation
> is that if you write:
>
>     auto x = y;
>     *x = 2;
>
> Then for any standard type this is equivalent to assigning '2' to
> whatever y points to. By using 'operator*' in std::optional, the
> semantics of 'operator*' will be changed. That shouldn't be done
> lightly, especially since with templates and 'auto' a type is defined
> by the functions and operators that it supports..

Isn't that more of a problem with the constructor than with operator*?

-- 
Olaf

-- 

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