Re: [boost] singleton: zombie_call

From: Jason Hise (chaos_at_[hidden])
Date: 2005-07-27 17:32:34

Fernando Cacciola wrote:

>Jason Hise wrote:
>  
>
>>I am trying to come up with a mechanism which allows member functions of
>>the singleton to be called if the instance exists, and which do nothing
>>if the instance does not exist (no creation is attempted, the operation
>>is simply skipped).
>>
>>[...]
>>    
>>
>
>Use Boost.Optional:
>
>http://www.boost.org/libs/optional/doc/optional.html
>  
>
I don't see how this helps... optional does not appear to allow member 
functions to be called when the object does not exist.  Instead, it 
simply asserts that the object does exist before the -> operator 
returns.  For my hypothetical zombie_ptr, I want to make usage when the 
instance does not exist a no-op, not an error.

-Jason