PreIterator< I, T > Class Template Reference

#include <elm/iter.h>

Public Types
typedef T	t
typedef T	return_t

Public Member Functions
bool	operator() () const
bool	operator! () const
T	operator* () const
T	operator-> () const
I &	operator++ ()
void	operator++ (int)
bool	operator== (const I &i) const
bool	operator!= (const I &i) const

Detailed Description

template<class I, class T>
class elm::PreIterator< I, T >

This class is an helper in the writing of iterators. It avoids to redefine all iterator operators each time an operator is defined. The user of this class has just to define four methods:

• bool ended() const – that returns true when the iteration ends,
• bool equals(const Iterator& i) const – to test if two iterators are equal,
• void next() – to move to the next item,
• T item() const – to get the current item (if any).

Using these 4 functions, PreIterator is able to support the operators (), !, ++ (prefix), ++ (suffix), *, ->, == and !=.

For example, the iterator on an array can be written as:

template <class T>
class ArrayIter: public PreIterator<ArrayIter, T> {
public:
    inline ArrayIter(int number, T *array)
        : n(number), i(0), a(array) { }
    inline bool ended() const { return i >= n; }
    inline bool equals(const ArrayIter& it)
        { return a == it.a && n == it.n && i == it.i; }
    inline void next() { i++; }
    inline T item() const { return a[i]; }
private:
    int n, i;
    T *a;
};

Parameters

I	Type of the defined iterator.
T	Type of the items.

Member Typedef Documentation

return_t

typedef T return_t

t

t

Type of the element held by the iterator.

Member Function Documentation

operator!()

bool operator! ( ) const

inline

Test if the iteration is not ended.

Returns

True if the iteration is not ended, false else.

operator!=()

bool operator!= ( const I &  i ) const

inline

Test if the current iterator and the argument iterator are different.

Returns

True if both operators are different, false else.

operator()()

bool operator() ( ) const

inline

Test if the iteration is ended.

Returns

True if the iteration is ended, false else.

operator*()

T operator* ( ) const

inline

Get the current item of the iterator. It is forbidden to call this function if the iteration is ended.

Returns

Current iterator item.

operator++() [1/2]

I & operator++ ( )

inline

Move the iterator to the next item. It is forbidden to call this function if the iteration is ended.

Returns

This iterator.

operator++() [2/2]

void operator++ ( int  )

inline

Move the iterator to the next item. It is forbidden to call this function if the iteration is ended.

operator->()

T operator-> ( ) const

inline

Get the current item of the iterator as a deferenced pointer. It is forbidden to call ths function if the iteration is ended.

Returns

Current iterator item.

operator==()

bool operator== ( const I &  i ) const

inline

Test if the current iterator and the argument iterator are equal.

Returns

True if both operators are equal, false else.

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The documentation for this class was generated from the following files:

• include/elm/iter.h
• src/doc.h