inheritance and typedef - compilation error

[subramanian100in]

Suppose the following program is named x.cpp

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>
{
public:
vector<T>::iterator begin()
{
cout << "non-const begin() is called" << endl;
return vector<T>->begin();
}

vector<T>::const_iterator begin() const
{
cout << "const begin() is called" << endl;
return vector<T>->begin();
}
};

int main()
{
return 0;
}

When I compile this program with g++ as
g++ -std=c++98 -pedantic -Wall -Wextra x.cpp

I am getting the following compilation errors:

x.cpp:10: error: expected `;' before "begin"
x.cpp:16: error: expected `;' before "vector"
x.cpp:16: error: expected `;' before "begin"
x.cpp:21: error: expected `;' before '}' token

Please help me fix the compilation errors.

Can't we use the base-class iterator and const_iterator types in the
derived class Vec ?

Kindly explain.

Thanks
V.Subramanian

[=?UTF-8?B?RXJpayBXaWtzdHLDtm0=?=]

On 2007-10-25 10:20, su**************@yahoo.com, India wrote:

Suppose the following program is named x.cpp

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>

std::vetor<Tdoes not have a virtual destructor and is not designed to
be used as a base class. The usual recommendation is to either use
private inheritance or have a vector as a member instead.

{
public:
vector<T>::iterator begin()

typename vector<T>::iterator begin()

iterator is a dependent type and you need to tell the compiler that it
is a type and nothing else.

{
cout << "non-const begin() is called" << endl;
return vector<T>->begin();

return vector<T>::begin();

The -operator is used when you have a pointer, you have no such thing
in this case.

--
Erik Wikström

[anon]

su**************@yahoo.com, India wrote:

Suppose the following program is named x.cpp

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>
{
public:
vector<T>::iterator begin()
{
cout << "non-const begin() is called" << endl;
return vector<T>->begin();
}

vector<T>::const_iterator begin() const
{
cout << "const begin() is called" << endl;
return vector<T>->begin();
}
};

int main()
{
return 0;
}

When I compile this program with g++ as
g++ -std=c++98 -pedantic -Wall -Wextra x.cpp

I am getting the following compilation errors:

x.cpp:10: error: expected `;' before "begin"
x.cpp:16: error: expected `;' before "vector"
x.cpp:16: error: expected `;' before "begin"
x.cpp:21: error: expected `;' before '}' token

Please help me fix the compilation errors.

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>
{
public:
typename vector<T>::iterator begin()
{
cout << "non-const begin() is called" << endl;
return vec.begin();
}

typename vector<T>::const_iterator begin() const
{
cout << "const begin() is called" << endl;
return vec.begin();
}
private:
vector<Tvec;
};

int main()
{
return 0;
}

[=?UTF-8?B?RXJpayBXaWtzdHLDtm0=?=]

On 2007-10-25 10:54, anon wrote:

su**************@yahoo.com, India wrote:

>Suppose the following program is named x.cpp

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>
{
public:
vector<T>::iterator begin()
{
cout << "non-const begin() is called" << endl;
return vector<T>->begin();
}

vector<T>::const_iterator begin() const
{
cout << "const begin() is called" << endl;
return vector<T>->begin();
}
};

int main()
{
return 0;
}

When I compile this program with g++ as
g++ -std=c++98 -pedantic -Wall -Wextra x.cpp

I am getting the following compilation errors:

x.cpp:10: error: expected `;' before "begin"
x.cpp:16: error: expected `;' before "vector"
x.cpp:16: error: expected `;' before "begin"
x.cpp:21: error: expected `;' before '}' token

Please help me fix the compilation errors.

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>

class Vec // No need to inherit from vector

{
public:
typename vector<T>::iterator begin()
{
cout << "non-const begin() is called" << endl;
return vec.begin();
}

typename vector<T>::const_iterator begin() const
{
cout << "const begin() is called" << endl;
return vec.begin();
}
private:
vector<Tvec;
};

int main()
{
return 0;
}

--
Erik Wikström

[anon]

Erik Wikström wrote:

On 2007-10-25 10:54, anon wrote:

>su**************@yahoo.com, India wrote:

>>Please help me fix the compilation errors.

#include <iostream>
#include <vector>

using namespace std;

template <class T>
class Vec : public vector<T>

class Vec // No need to inherit from vector

I must admit that I missed that tiny detail. I realized it only after
your reply.
My focused was more on making it compile, because after all that was
what he asked for ;)