From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-02-14 11:50:37
At 02:02 AM 2/14/2002, Matthias Troyer wrote:
>
>On Wednesday, February 13, 2002, at 06:19 PM, quendezus wrote:
>>>
>>> No, I need at least three different types of streams at runtime.
>>> That's why I think I need some type of polymorphism (templates or
>>> virtual functions) on the stream.
>>>
>>> Matthias
>>
>> Ok, I think you are right: the person who calls the serialization
>> function should be able to transmit some info to the serialization
>> code (in your case, the stream to format the output). I realize this
>> is necessary.
>>
>> Therefore the type of the stream (or the type of a context class)
>> should be a template parameter :
>>
>> template < class T, class Context >
>> void serialize( std::streambuf& dest, const T& t, Context& t )
>>
>> or:
>>
>> template < class T, class Stream >
>> void serialize( Stream& dest, const T& t )
>>
>> I have already tried a solution like that and it seems to work but it
>> is complicated. I will think about how to simplify it.
>
>Jen's library already does this in a very elegant way using
>templates.
Yes, and because we've now seen Jen's approach, we are unlikely to be happy
with something less elegant.
>... My concern was that it seems in some cases I need
>runtime-polymorphism using virtual functions.
Do you have a way to do that as an addition, rather than a replacement, for
compile-time polymorphism?
--Beman