Hallo all!
I have done some Google research, but i have not found something on this:

let us assume that,
in NsDeque.h i have:
in PsConstraint.h i have:

the compiler (g++) points an error at
why is this so???
Is not nested call of templates supported?
Thanks in advance

I didn't have the time to test it, perhaps you could provide us with the error message.

For sure the compiler will have problems with this line

The compiler will confuse the consecutive closing angular braces (">>") with the streaming operator.

Best regards,
Lucian

Your code does not describe calls. Your code describes nested class declarations. The language standard allows the declaration of non-template classes to be nested, but the standard does not allow the declaration of template classes to be nested. All template classes have to be declared at file scope.

The question you need to ask yourself is what does nesting provide that can't also be more easily achieved through judicious use of namespace's.

When posting questions such as this, please provide either minimal code which when compiled will generate the same error, or at least post the error observed. Given what you posted, it is anyone's guess as to what you are really doing. The art of getting good answers lies in the ability to adequately communicate the problem observed.

As LuciWiz said it is the gap that caused the error.
I thank you both of you.

You have not did anything useful.

What do you mean by that?

You're better off not to ask...there are a lot of wannabes around here and shrugging them off is a good skill to have.


Mexican Bob

Hi ocicat.

I am not sure I understand this statement:



I am not aware of the Standard disallowing nested template classes. Can you please clarify what you mean by this?

Thanks,
Lucian

My bad. The following code indicates where I was wrong:
Being able to nest template class declaration has not always been part of the language definition. In the early '90's, all template classes had to be defined at file scope. For anyone that has been programming in C++ for a long time, templates is a topic which has seen significant refinements since ~1999 in the language standard. Perhaps I have seen that template classes can now be nested, but when I responded earlier, I was remembering what was the norm of ~1992. Obviously, I was mistaken.

Irregardless of my memory lapse nesting has never been a common practice, & I stand by my earlier comment that using namespaces to accomplish the same scope limitation is perhaps a preferable practice.

I was 10 back then, sorry


I feel the same way. Nested classes are useful if you draw some value from using the PIMPL idiom, but I can't think of any other useful feature on the spot.

Best regards,
Lucian