Re: [boost] [optional] std::tr2::optional

Subject: Re: [boost] [optional] std::tr2::optional
From: Dave Abrahams (dave_at_[hidden])
Date: 2011-11-28 19:05:07

on Fri Nov 18 2011, paul Fultz <pfultz2-AT-yahoo.com> wrote:

>>I provide a list of
>>modifications that I could think of. What is your opinion?
> This is more of an addition to your list, but I think adding 
>
> the | operator for getting the optional value or a default value would be nice.
> For example:
>
> optional<double> safe_sqrt(double x)
> {
> Â Â Â  if (x < 0) return none;
> Â Â Â  else return sqrt(x);
> }
>
> double x = safe_sqrt(4) | 0; //x = 4
> double y = safe_sqrt(-1) | 0; //y = 0 
>
> I dont know if this is possible for tr2, but would be really nice
> addition in the future. Especially, since a lot of times i just 
> want a default value if the optional value doesn't exist.

+1

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com