Possible way to achieve lazy loading with const objects

[Steven Schveighoffer]

On Wed, 28 Sep 2011 16:03:51 -0400, Jonathan M Davis <jmdavisProg at gmx.com>  
wrote:

> On Wednesday, September 28, 2011 11:31:31 Christophe wrote:
>> "Jonathan M Davis" , dans le message (digitalmars.D:145479), a écrit :
>> > But since lazy initializion will _never_ work with immutable
>>
>> Never say never. One could build a clean and thread-safe way to lazily
>> initialize fields. Like someone said, even without mutex, if the
>> function to compute the variable is pure and based on immutable data,
>> the worst case would be to run the intializing function twice. And the
>> langage could include mutexes to do prevent that to happen. The fact
>> that immutable data could, one day, be put in ROM doesn't mean that it
>> has to. The close issue is like another-one said the issue of
>> memoization of pure methods.
>
> The very fact that an immutable variable _could_ be put into ROM negates  
> the
> possibility of the semantics being such that you don't have to fully
> initialize an immutable variable up front.

No it doesn't.  If it's in ROM, initialize eagerly (which should cost  
nothing, done at compile-time).  If it's not, initialize lazily.

-Steve