template members in a non-template class

[Nico Massi]

Hi NG!

I have a class A that should store a vector of pointers to objects of class
B.
But class B contains a template argument and each of the stored objects in
class A could have a different template argument. So i need a way to store
an array of template objects in a non-template class. Obviously this wont
work
cause a can`t tell the compiler which template argument to use.
So whats the usual way to solve such a situation?

The first solution that comes to my mind is, create a non-template base
interface to class B and store pointers to that base interface in A.
But i think this is not the best solution for that kind of problem.

[White Wolf]

Re: template members in a non-template class

Nico Massi wrote:[color=blue]
> Hi NG!
>
> I have a class A that should store a vector of pointers to objects of
> class B.
> But class B contains a template argument and each of the stored
> objects in class A could have a different template argument. So i
> need a way to store an array of template objects in a non-template
> class. Obviously this wont work
> cause a can`t tell the compiler which template argument to use.
> So whats the usual way to solve such a situation?
>
> The first solution that comes to my mind is, create a non-template
> base interface to class B and store pointers to that base interface
> in A.
> But i think this is not the best solution for that kind of problem.[/color]

IMHO you are trying to do some very suspicious desing. I suggest that you
give us a higher level view of this problem (like: I want to handle
different complex numbers). Try stay away in that case from C++ terms (if
it is feasible) and just try to define the problem. I guess there should be
an easier solution.

--
WW aka Attila

[Nico Massi]

Re: template members in a non-template class

On Fri, 29 Aug 2003 20:07:01 +0300, White Wolf <wolof@freemail .hu> wrote:
[color=blue]
> Nico Massi wrote:[color=green]
>> Hi NG!
>>
>> I have a class A that should store a vector of pointers to objects of
>> class B.
>> But class B contains a template argument and each of the stored
>> objects in class A could have a different template argument. So i
>> need a way to store an array of template objects in a non-template
>> class. Obviously this wont work
>> cause a can`t tell the compiler which template argument to use.
>> So whats the usual way to solve such a situation?
>>
>> The first solution that comes to my mind is, create a non-template
>> base interface to class B and store pointers to that base interface
>> in A.
>> But i think this is not the best solution for that kind of problem.[/color]
>
> IMHO you are trying to do some very suspicious desing. I suggest that
> you
> give us a higher level view of this problem (like: I want to handle
> different complex numbers). Try stay away in that case from C++ terms
> (if
> it is feasible) and just try to define the problem. I guess there should
> be
> an easier solution.
>[/color]


ok here is what i will do:
i would be able to configure my app with a config file where i could set
some values
mostly there are simple values ( int, float, string would cover around 80% )
but i would also be able to read complex types like a 3D Vector or an RGB
color value
so i thought templates would be the way to go for the config values

for the config values i need a class that known all possible config values
by their name
the values would be saved in a config class where the app can query the
config for a value
by specifying its name

[llewelly]

Re: template members in a non-template class

Nico Massi <desertswat@gmx .de> writes:
[color=blue]
> On Fri, 29 Aug 2003 20:07:01 +0300, White Wolf <wolof@freemail .hu> wrote:
>[color=green]
>> Nico Massi wrote:[color=darkred]
>>> Hi NG!
>>>
>>> I have a class A that should store a vector of pointers to objects of
>>> class B.
>>> But class B contains a template argument and each of the stored
>>> objects in class A could have a different template argument. So i
>>> need a way to store an array of template objects in a non-template
>>> class. Obviously this wont work
>>> cause a can`t tell the compiler which template argument to use.
>>> So whats the usual way to solve such a situation?
>>>
>>> The first solution that comes to my mind is, create a non-template
>>> base interface to class B and store pointers to that base interface
>>> in A.
>>> But i think this is not the best solution for that kind of problem.[/color]
>>
>> IMHO you are trying to do some very suspicious desing. I suggest
>> that you
>> give us a higher level view of this problem (like: I want to handle
>> different complex numbers). Try stay away in that case from C++
>> terms (if
>> it is feasible) and just try to define the problem. I guess there
>> should be
>> an easier solution.
>>[/color]
>
>
> ok here is what i will do:
> i would be able to configure my app with a config file where i could
> set some values
> mostly there are simple values ( int, float, string would cover around 80% )
> but i would also be able to read complex types like a 3D Vector or an
> RGB color value
> so i thought templates would be the way to go for the config values
>
> for the config values i need a class that known all possible config
> values by their name
> the values would be saved in a config class where the app can query
> the config for a value
> by specifying its name[/color]

hm. Maybe boost::any is helpful?

http://boost.org/doc/html/any.html