[boost] Re: In-place construction for variant

From: Eric Friedman (ebf_at_[hidden])
Date: 2003-10-26 17:30:31

Hi Jaap,

Jaap Suter wrote:
> Hello,
> 
> I was wondering if it would be possible to provide a method for in-place
> construction into a Boost variant, to avoid copy construction.
> 
> For example:
> 
>     boost::variant<foo, bar> v;
>     bar b;
>     v = b; // copy constructs b into v, first destroying the old foo.
>     v.construct<bar>(); // default constructs a bar into v;
>     v.construct<bar>(3.14f); // constructs a bar into v using the
> constructor that takes one float;

I plan to eventually support something like the following:

   boost::variant< foo,bar > v( inplace<foo>(...) );
   v = inplace<bar>(...);

I believe it will enable you to do what you want. Unfortunately, it will 
not be ready for the upcoming 1.31 release.

  - Eric