VC6 compiling problem

[Gernot Frisch]

class Q
{
public:
template<class T>void foo(){}
};

main()
{
Q q;
q.foo<int>(); // error
}

error C2062: unexpected type 'int'

What can I do?

 

[wittempj]

on g++ this compiles and runs fine for me, it is essentially the same
as your code, except for the addition of returntype to main
#include <cstdlib>
#include <iostream>

using namespace std;
class Q
{
public:
template<class T>void foo(T t){ cout << t << endl; }

};

int main()
{
Q q;
q.foo<int>(4); // no error, it prints 4

system("PAUSE");
return 0;
}

 

[Gernot Frisch]

on g++ this compiles and runs fine for me, it is essentially the
same
as your code, except for the addition of returntype to main
#include <cstdlib>
#include <iostream>

using namespace std;
class Q
{
public:
template<class T>void foo(T t){ cout << t << endl; }

};

int main()
{
Q q;
q.foo<int>(4); // no error, it prints 4

system("PAUSE");
return 0;
}

Whatch it! you cnahged my code:

class Q
{
public:
template <class T> good(T*) {}
template <class T> bad () {}
};

main()
{
Q q;
int* i=NULL;
q.good(&i); // ok
q.bad<int>(); // fails
}

 

[Victor Bazarov]

class Q
{
public:
template<class T>void foo(){}
};

main()
{
Q q;
q.foo<int>(); // error
}

error C2062: unexpected type 'int'

What can I do?

Change your compiler. VC++ v6 is notoriously bad with member
templates.

 

[Victor Bazarov]

Whatch it! you cnahged my code:

class Q
{
public:
template <class T> good(T*) {}
template <class T> bad () {}
};

main()
{
Q q;
int* i=NULL;
q.good(&i); // ok
q.bad<int>(); // fails
}

Your code deserved it. In the posted form it's ill-formed.
Both member functions do not have a return value type.
'main' have no return value type.
"NULL" used in the main is undefined.

This is the corrected program (which still fails on VC++ v6):

class Q
{
public:
template <class T> void good(T*) {}
template <class T> void bad () {}
};

int main()
{
Q q;
int* i=0;
q.good(&i); // ok
q.bad<int>(); // fails
}

V

 

[Ron Natalie]

Change your compiler. VC++ v6 is notoriously bad with member
templates.

Actually, the problem is VC++ 6 is notoriously bad with template
function names. It relies on the normal function arg decoration
to disambiguate instances of the same template. When you have a
template that none of the args depends on the template variable it
gets confused. Even more stupid is in the case of non-member
templated functions, it links just fine, but all refer to the same
function (i.e., it uses only one instance of the template).