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which is a valid friend declaration for class template given below. I guess line 2 is valid...any suggestions?
Code:
template<class T> class Y {};
template<class T> class X{
friend class T; //line 1
friend class Y <T>; //line 2
friend T; //line 3
};
int main () {
}
You are aware that, if you obtained a compiler, you could experiment with such questions, and learn more in the doing. Throwing random, undirected, and (mostly) trivial and pointless questions at a forum is an effective way to annoy other people by wasting their time, while minimising your chances of learning anything useful.
You might also try explaining WHY you think line 2 is valid, but that lines 1 and 3 are not. The process of writing that description down will take more effort on your part, but you will learn more in the process, and annoy other people less when they see you applying genuine efforts to understand rather than asking increasingly pointless questions.
Note that, with templates, it is often necessary to write a program which actually instantiates a template class or that calls a template function, since some types of coding errors only arise when instantiating a template, or using the instantiation.
here line 1 already has forward declaration. So I could say friend declaration in line 2 is valid. Any suggestions?Quote:
Originally Posted by grumpy
Line 1 is not a forward declaration, and its presence doesn't affect whether line 2 is valid or not.
Apparently you are selective. I made suggestions in my previous post, you ignored most of them, and asked for more.
since my assumption got wrong here, which one do you think is valid friend declaration? pls help me.Quote:
Originally Posted by grumpy
Re-read post #2.
Elaborate on which ones you think is right/false, and why you think that.
Then you will get answers that tells you if you are right/wrong and why.
Y template delcaration already exists, so line 2 is valid...any inputs?
Yes, line 2 is correct.