[boost] Re: Singleton

From: Dave Handley (dave_at_[hidden])
Date: 2005-01-10 14:15:55

Scott Woods wrote:

<long snip>
>
> Sometimes the type-equals-only-instance is a royal pain?
>
> Cheers,
> Scott
>

My view is that you should keep the singleton as a singleton, but write some 
code in the singleton to manage N instances.  This way your access to PBX 
number 1 would be something like:

PBX::GetInstance().GetPBX( 1 );

and so on.  It keeps the design of the singleton clean, but allows the 
flexibility of "exactly N" instances of a class.

I have to say that I do like Jason's solution using an int template 
parameter on the singleton itself - although that has the weakness that 
every single function that uses the PBX would probably need to be 
templatised by type - where as a solution like I discuss above means that 
you PBX (or Important) class would always have the same type.

Dave