template class

[Qian Xin]

template<typename T>
class TestCase: public MyClass
{
public:

int stringLength;
vector<T> String;
vector<T>::iterator i;
}

why the above cannot be compiled, gcc reporting the error:
xx.h:53: error: type ‘std::vector<T, std::allocator<_CharT> >’ is not
derived from type ‘TestCase<T>’
xx.h:53: error: expected ‘;’ before ‘i’

But the following can be compiled, any one can give a reason or
reference?

class TestCase: public MyClass
{
public:

int stringLength;
vector<T> String;
typename vector<T>::iterator i;
}

 

[Qian Xin]

template<typename T>
class TestCase: public MyClass
{
public:

    int stringLength;
    vector<T> String;
    vector<T>::iterator i;

}

why the above cannot be compiled, gcc reporting the error:
xx.h:53: error: type ‘std::vector<T, std::allocator<_CharT> >’ is not
derived from type ‘TestCase<T>’
xx.h:53: error: expected ‘;’ before ‘i’

But the following can be compiled, any one can give a reason or
reference?

class TestCase: public MyClass
{
public:

    int stringLength;
    vector<T> String;
    typename vector<T>::iterator i;







}

sorry, I have found the answer:
http://blogs.msdn.com/b/slippman/archive/2004/08/11/212768.aspx

 

[Johannes Schaub]

template<typename T>
class TestCase: public MyClass
{
public:

int stringLength;
vector<T> String;
vector<T>::iterator i;
}

why the above cannot be compiled, gcc reporting the error:
xx.h:53: error: type ‘std::vector<T, std::allocator<_CharT> >’ is not
derived from type ‘TestCase<T>’
xx.h:53: error: expected ‘;’ before ‘i’

But the following can be compiled, any one can give a reason or
reference?

class TestCase: public MyClass
{
public:

int stringLength;
vector<T> String;
typename vector<T>::iterator i;
}

See http://stackoverflow.com/questions/5577950/keyword-typename-in-
templates/5581807#5581807

 

[Juha Nieminen]

any one can give a reason

The standard says so.