I'm aware of Singleton Pattern, my original code is a very simplistic
implementation to show my problem.
The point here is not about the quality of the pattern but the number of
instances when using these flags: -fvisibility=hidden
-fvisibility-inlines-hidden and __attribute__ ((visibility("default")))
Of course if I don't use these flags I only have one instance.
On Friday 03 June 2005 15:52, Martin York wrote:
> There are many ways to implement the Singleton Pattern. Each has their
> own positives and negatives. I would advice looking at "Scott Meyers"
> book "More Effective C++"
> http://www.amazon.co.uk/exec/obidos/ASIN/020163371X/ref=pd_bxgy_text_2_c
> p/026-5023597-8506032
>
>
> Personally I prefer being as simple as possible (Like your original
> code).
>
>
>
> The only problem with your original code is that
>
> singleton* singleton::instance()
>
> is defined in the header file. Therefore the implementation of instance
> is not in the resulting shared library.
>
> If you move the definition into the file singleton.cc then I believe
> (though not tested) that your problem will be resolved.
Can I move templated code to the implementation file? I thought that templated
code should be written in the declaration file.
>
> As a secondary question/comment. Why return a pointer. To me this
> implies it can fail and return a NULL (and thus needs to be checked). I
> (personally) would return a reference.
[...]
--
Filipe Sousa
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