Re: Template class parameter
George wrote:
Thanks Alex,
My question is answered.
BTW: after learning from you guys, I think I understand the concept of
template class with only parameter. But I still doubt whether it is a very
practical programming technique? It is more like a trick. If you have any
good experiences to share with us, it would be appreciated. :-)
Goerge:
You may see this "template meta-programming" factorial example as a
trick, but Igor's example is more down to earth. One advantage of
template parameters over construct ro parameters is that they can be
used in a typedef. For instance, in Igor's example you can do
typedef FixedArray<4> FixedArray4;
A perhaps more useful example I wrote my own versions of the ATL W2A/A2W
classes to take the 8-bit code page as a parameter. For example
template <int nPage> class CW2N; // wide to narrow
Now I can do
typedef CW2N<CP_UTF8> CW2U;
and have an easy to use converter from UTF-16 to UTF-8.
--
David Wilkinson
Visual C++ MVP
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