Re: [boost] [optional] memory use for optional refs and ptrs

Subject: Re: [boost] [optional] memory use for optional refs and ptrs
From: Nevin Liber (nevin_at_[hidden])
Date: 2010-10-06 14:21:38

On 6 October 2010 02:56, Rutger ter Borg <rutger_at_[hidden]> wrote:

> Although [references aren't] the most important case for me, it has its own section in
> the documentation, and I will probably be using lots of these.

Why?  What is the advantage over using a raw pointer?

> What also
> doesn't seem right to me is that, e.g.,
>
> struct A {
>    int a;
>    double b;
>    double c;
>    std::string d;
> };
>
> struct B {
>    boost::optional< int > a;
>    boost::optional< double > b;
>    boost::optional< double > c;
>    boost::optional< std::string > d;
> };

What bit pattern can be used for an int which says it hasn't been set?

Optional models "the variable is not set."  You want something
different.  Why not just create a different class to model what you
want?
-- 
 Nevin ":-)" Liber  <mailto:nevin_at_[hidden]>  [phone]