Explicit template instanciation

Well, Martin, you seem to know how templates work.

But what exactly is your question then? :rolleyes:

As I fail to understand what is the problem.

Either you want to have a template (or function template) that is totally generic whatever the type or you specialize some of the types to do specific stuff depending on the type. It's simple.

But what are you trying to do?!

Yes I begin to well understand templates. Compiling templates with Micro$oft is the better thing to learn.

So, my question was : How can I explicitly instantiate a template function member of a class (that class not being itself a template)?

I know (from Bjarne's book) that I can explicitly instantiate a class template :

Code:

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template class vector<int>;

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or I can explicitly instantiate a member of a class template :

Code:

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template int& vector<int>::operator[](int);

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or I can explicitly instantiate a function template :

Code:

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template int convert<int,double>(double);

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But I never saw an example of my problem.

What I'm trying to do? Having a function member that works for char and wchar_t without duplicating code (no function overload) nor defining my template function member in my class definition. With templates, too many other header files are required. That leads to software that always recompile everything. The solution is explicit instanciation.

Here is how I solve my problem. I use function overloading in my class definition (declaring 2 method ValueTokenGet one for char and the other for wchar_t). But the implementation of both function just call a function template. So the code is reused for both char types and everything is implemented in my .cpp file. No more header files in my .h file.

Martin

Ahhh....
I now "feel" your problem...

Let me think ;)

why don't you put the code for both char and wchar in the generic method?

Code:

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template <typename T>
T*
 CVar::ValueGetToken( T* yo, int ya ) const
{
        T* toto;

        return toto;
}

---

This way, any type coming through this method is using the same code, avoiding code duplication.

I see, this will lead to recompiling every time you make a change :rolleyes:

Well, sorry Martin, I tried, but I can't find a better solution than the one you already found :(

Good luck!

OK. I get the picture now (it's section C.13.10 of Saint Bjarne's book).

I suspect that this is one of those VC++ things - it just can't handle it.

Quote:

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Originally posted by Graham
According to Saint Bjarne, it looks like the simplest explicit specialisation would be:

Code:

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template <> char * CVar::ValueGetToken(char* pc, int i) const

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My memory must be going........

what was I saying?

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Get down to Earth folks ;) YOu forgot we are dealing with the "mighty" M$soft compiler here.... it wont do any of the "template <>" tricks, regardless if Bjarne comes appears the thin air before them and writes it down with golden paint on the wall ;) *hint* *hint* *give us ANSI c++*