Custom iterator for STL-style container

[gallows]

The container is:

template <typename T>
class Container {
public:
// container methods..

// iterator:
class const_iterator {
public:
const_iterator(T* i)
: pntr(i) { }

const_iterator& operator=
(const_iterator);
const_iterator& operator++();
const_iterator operator++(const_iterator);
const_iterator& operator--();
const_iterator operator--(const_iterator);
bool operator==(const_iterator);
bool operator!=(const_iterator);

private:
T* pntr;
};

const_iterator begin() const;
const_iterator end() const;

private:
std::vector<Tv;
};

// Well... implementation for Container<T>::begin() :
template <typename T>
Container<T>::const_iterator Container<T>::begin() const
{
const_iterator i(&v[0]);
return i;
}

g++ says: "error: expected constructor, destructor, or type conversion
before 'Container'"
Where is it wrong? Which is the right way to do that?

Thanks in advance,

s.

[Pierre Senellart]

"gallows" ,comp.lang.c++:

template <typename T>
Container<T>::const_iterator Container<T>::begin() const

Container<T>::const_iterator is a qualified (by Container<T>) and
dependent (on T) name; therefore, you have to prefix it by the keyword
"typename" to disambiguate the fact that it is the name of a type
(Container<T>::const_iterator could very well be the name of a data
member for some T).

[mlimber]

On Mar 5, 10:49 am, "gallows" <[e-mail]:

The container is:

template <typename T>
class Container {
public:
// container methods..

// iterator:
class const_iterator {
public:
const_iterator(T* i)
: pntr(i) { }

const_iterator& operator=
(const_iterator);
const_iterator& operator++();
const_iterator operator++(const_iterator);

This should be:

const_iterator operator++(int);

const_iterator& operator--();
const_iterator operator--(const_iterator);

This should be:

const_iterator operator--(int);

bool operator==(const_iterator);
bool operator!=(const_iterator);

private:
T* pntr;
};

const_iterator begin() const;
const_iterator end() const;

private:
std::vector<Tv;

};

// Well... implementation for Container<T>::begin() :
template <typename T>
Container<T>::const_iterator Container<T>::begin() const

Add "typename" (see http://womble.decadentplace.org.uk/c...syntax-error):

typename Container<T>::const_iterator Container<T>::begin() const

{
const_iterator i(&v[0]);
return i;

}

g++ says: "error: expected constructor, destructor, or type conversion
before 'Container'"
Where is it wrong? Which is the right way to do that?

Cheers! --M

[gallows]

Clear, I Understood. Thanks a lot!