Re: [boost] [review] Fast track review of Boost.Utility/Singleton begins today

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2008-01-17 13:28:29

Anthony Williams wrote:
> Tobias Schwinger <tschwinger <at> isonews2.com> writes:
>> Anthony Williams wrote:
>>>>> I've written code that used singletons (and regretted it later), and used
>>>>> code that other people have written containing singletons.
>>>> So you should like this library: The design chosen allows you to easily
>>>> substitute Singletons with Smart Pointers.
>>> I disagree. If people know something is a singleton, then they don't bother
>>> keep the reference around, as they can get it again later. Changing code 
>>> that
>>> does that to code that can use a passed in instance requires adding 
>>> parameters
>>> and/or storing references. You can't just change uses of a singleton to use a
>>> smart pointer instead without thought to *how* it's being used.
>> I won't argue on this one. I can imagine that having to refactor a mess 
>> like this is a most unpleasant experience.
>>
>> Still it's not the fault of the Singletons but of developer's laziness: 
>> At least the developers in the project you mention had a choice whether 
>> to write flexible code or not. With globals and static functions, they
>> wouldn't have had a choice but to make a mess.
> 
> Singletons *are* globals.
> 

OK, that was a bit unclear. Let's put it this way:

It's not globals that are evil but accessing them all over the place
(or "coupling" to use the technical term that describes the problem).

Regards,
Tobias