template member function

[Alexander Stippler]

Hey all,

what exactly is forbidden/wrong with the following call of a template
member function;

template <typename T>
struct Base
{
template <int N>
void
cio();
};

template <typename T>
struct Derived
: public Base<T>
{
template <int N>
void
cio()
{
Base<T>::cio<N>(); // !!!!!! <--- what's the
problem here?
}
};

int
main()
{
}

Best regards,
Alex

 

[Sam]

Hey all,

what exactly is forbidden/wrong with the following call of a template
member function;

template <typename T>
struct Base
{
template <int N>
void
cio();
};

template <typename T>
struct Derived
: public Base<T>
{
template <int N>
void
cio()
{
Base<T>::cio<N>(); // !!!!!! <--- what's the
problem here?
}
};

int
main()
{
}

Sometimes the parsing rules, when templates are involved, get a bit hairy
and what might seem obvious to a meatbag, is not so obvious to a mechanical
parser, to you have to give the compiler a bit of help. Rewriting the
offending statement as:

Base<T> *b=static_cast<Base<T> *>(this);

b->cio<N>();

This should do what you want.


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[witmer]

Hey all,

what exactly is forbidden/wrong with the following call of a template
member function;

template <typename T>
struct Base
{
    template <int N>
        void
        cio();

};

template <typename T>
struct Derived
    : public Base<T>
{
    template <int N>
        void
        cio()
        {
            Base<T>::cio<N>();           // !!!!!!  <---   what's the
problem here?
        }

};

int
main()
{

}

The parser doesn't know that cio is a template.
Try:

Base<T>::template cio<N>();

 

[Alexander Stippler]

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Sometimes the parsing rules, when templates are involved, get a bit hairy
and what might seem obvious to a meatbag, is not so obvious to a mechanical
parser, to you have to give the compiler a bit of help. Rewriting the
offending statement as:

Base<T> *b=static_cast<Base<T> *>(this);

b->cio<N>();

This should do what you want.


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Content-Transfer-Encoding: 7bit

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Thanks a lot. It should have been obvious to me. I even knew your
solution long time ago :-(