<iterator>
advance
· back_insert_iterator
· back_inserter
· bidirectional_iterator_tag
· distance
· forward_iterator_tag
· front_insert_iterator
· front_inserter
· input_iterator_tag
· insert_iterator
· inserter
· istream_iterator
· istreambuf_iterator
· iterator
· iterator_traits
· operator!=
· operator==
· operator<
· operator<=
· operator>
· operator>=
· operator+
· operator-
· ostream_iterator
· ostreambuf_iterator
· output_iterator_tag
· random_access_iterator_tag
· reverse_iterator
namespace std { struct input_iterator_tag; struct output_iterator_tag; struct forward_iterator_tag; struct bidirectional_iterator_tag; struct random_access_iterator_tag; // TEMPLATE CLASSES template<class C, class T, class Dist, class Pt, class Rt> struct iterator; template<class It> struct iterator_traits; template<class T> struct iterator_traits<T *> template<class RanIt> class reverse_iterator; template<class Cont> class back_insert_iterator; template<class Cont> class front_insert_iterator; template<class Cont> class insert_iterator; template<class U, class E, class T, class Dist> class istream_iterator; template<class U, class E, class T> class ostream_iterator; template<class E, class T> class istreambuf_iterator; template<class E, class T> class ostreambuf_iterator; // TEMPLATE FUNCTIONS template<class RanIt> bool operator==( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class U, class E, class T, class Dist> bool operator==( const istream_iterator<U, E, T, Dist>& lhs, const istream_iterator<U, E, T, Dist>& rhs); template<class E, class T> bool operator==( const istreambuf_iterator<E, T>& lhs, const istreambuf_iterator<E, T>& rhs); template<class RanIt> bool operator!=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class U, class E, class T, class Dist> bool operator!=( const istream_iterator<U, E, T, Dist>& lhs, const istream_iterator<U, E, T, Dist>& rhs); template<class E, class T> bool operator!=( const istreambuf_iterator<E, T>& lhs, const istreambuf_iterator<E, T>& rhs); template<class RanIt> bool operator<( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class RanIt> bool operator>( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class RanIt> bool operator<=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class RanIt> bool operator>=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class RanIt> Dist operator-( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class RanIt> reverse_iterator<RanIt> operator+( Dist n, const reverse_iterator<RanIt>& rhs); template<class Cont> back_insert_iterator<Cont> back_inserter(Cont& x); template<class Cont> front_insert_iterator<Cont> front_inserter(Cont& x); template<class Cont, class Iter> insert_iterator<Cont> inserter(Cont& x, Iter it); template<class InIt, class Dist> void advance(InIt& it, Dist n); template<class Init, class Dist> iterator_traits<InIt>::difference_type distance(InIt first, InIt last); };
Include the STL
standard header <iterator>
to define a number of classes, template classes, and template
functions that aid in the declaration and manipulation of iterators.
advance
template<class InIt, class Dist> void advance(InIt& it, Dist n);
The template function effectively advances it
by
incrementing it n
times. If InIt
is
a random-access iterator type, the function evaluates the expression
it += n
. Otherwise, it performs each increment
by evaluating ++it
. If InIt
is an
input or forward iterator type, n
must not be negative.
back_insert_iterator
template<class Cont> class back_insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: typedef Cont container_type; typedef typename Cont::reference reference; typedef typename Cont::value_type value_type; explicit back_insert_iterator(Cont& x); back_insert_iterator& operator=(const reference val); back_insert_iterator& operator*(); back_insert_iterator& operator++(); back_insert_iterator operator++(int); protected: Cont *container; };
The template class describes an output iterator object.
It inserts elements
into a container of type Cont
, which it accesses via
the protected pointer object it stores called
container
.
The container must define:
reference
, which is the type of
a reference to an element of the sequence controlled by the containervalue_type
, which is the type of
an element of the sequence controlled by the containerpush_back(value_type c)
,
which appends a new element with value c
to the end of
the sequenceback_insert_iterator::back_insert_iterator
explicit back_insert_iterator(Cont& x);
The constructor initializes
container
with &x
.
back_insert_iterator::container_type
typedef Cont container_type;
The type is a synonym for the template parameter Cont
.
back_insert_iterator::operator*
back_insert_iterator& operator*();
The member function returns *this
.
back_insert_iterator::operator++
back_insert_iterator& operator++(); back_insert_iterator operator++(int);
The member functions both return *this
.
back_insert_iterator::operator=
back_insert_iterator& operator=(const reference val);
The member function evaluates
container.
push_back(val)
, then returns *this
.
back_insert_iterator::reference
typedef typename Cont::reference reference;
The type describes a reference to an element of the sequence controlled by the associated container.
back_insert_iterator::value_type
typedef typename Cont::value_type value_type;
The type describes the elements of the sequence controlled by the associated container.
back_inserter
template<class Cont> back_insert_iterator<Cont> back_inserter(Cont& x);
The template member function returns
back_insert_iterator<Cont>(x)
.
bidirectional_iterator_tag
struct bidirectional_iterator_tag : public forward_iterator_tag { };
The type is the same as
iterator<It>::iterator_category
when It
describes an object that can serve as a
bidirectional iterator.
distance
template<class Init, class Dist> typename iterator_traits<InIt>::difference_type distance(InIt first, InIt last);
The template function sets a count n
to zero. It then
effectively advances first
and increments n
until first == last
.
If InIt
is
a random-access iterator type, the function evaluates the expression
n += last - first
. Otherwise, it performs each iterator
increment by evaluating ++first
.
forward_iterator_tag
struct forward_iterator_tag : public input_iterator_tag { };
The type is the same as
iterator<It>::iterator_category
when It
describes an object that can serve as a
forward iterator.
front_insert_iterator
template<class Cont> class front_insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: typedef Cont container_type; typedef typename Cont::reference reference; typedef typename Cont::value_type value_type; explicit front_insert_iterator(Cont& x); front_insert_iterator& operator=(const reference val); front_insert_iterator& operator*(); front_insert_iterator& operator++(); front_insert_iterator operator++(int); protected: Cont *container; };
The template class describes an output iterator object.
It inserts elements
into a container of type Cont
, which it accesses via
the protected pointer object it stores called
container
.
The container must define:
reference
, which is the type of
a reference to an element of the sequence controlled by the containervalue_type
, which is the type of
an element of the sequence controlled by the containerpush_front(value_type c)
,
which prepends a new element with value c
to the beginning of
the sequencefront_insert_iterator::container_type
typedef Cont container_type;
The type is a synonym for the template parameter Cont
.
front_insert_iterator::front_insert_iterator
explicit front_insert_iterator(Cont& x);
The constructor initializes
container
with &x
.
front_insert_iterator::operator*
front_insert_iterator& operator*();
The member function returns *this
.
front_insert_iterator::operator++
front_insert_iterator& operator++(); front_insert_iterator operator++(int);
The member functions both return *this
.
front_insert_iterator::operator=
front_insert_iterator& operator=(const reference val);
The member function evaluates
container.
push_front(val)
, then returns *this
.
front_insert_iterator::reference
typedef typename Cont::reference reference;
The type describes a reference to an element of the sequence controlled by the associated container.
front_insert_iterator::value_type
typedef typename Cont::value_type value_type;
The type describes the elements of the sequence controlled by the associated container.
front_inserter
template<class Cont> front_insert_iterator<Cont> front_inserter(Cont& x);
The template member function returns
front_insert_iterator<Cont>(x)
.
input_iterator_tag
struct input_iterator_tag { };
The type is the same as
iterator<It>::iterator_category
when It
describes an object that can serve as an
input iterator.
insert_iterator
template<class Cont> class insert_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: typedef Cont container_type; typedef typename Cont::reference reference; typedef typename Cont::value_type value_type; explicit insert_iterator(Cont& x, typename Cont::iterator it); insert_iterator& operator=(const reference val); insert_iterator& operator*(); insert_iterator& operator++(); insert_iterator& operator++(int); protected: Cont *container; typename Cont::iterator iter; };
The template class describes an output iterator object.
It inserts elements
into a container of type Cont
, which it accesses via
the protected pointer object it stores called
container
.
It also stores the protected iterator object, of class
Cont::iterator
, called
iter
.
The container must define:
iterator
, which is the type of
an iterator for the containerreference
, which is the type of
a reference to an element of the sequence controlled by the containervalue_type
, which is the type of
an element of the sequence controlled by the containerinsert(iterator it,
value_type c)
,
which inserts a new element with value c
immediately before
the element designated by it
in the controlled sequence,
then returns an iterator that designates the inserted elementinsert_iterator::container_type
typedef Cont container_type;
The type is a synonym for the template parameter Cont
.
insert_iterator::insert_iterator
explicit insert_iterator(Cont& x, typename Cont::iterator it);
The constructor initializes
container
with &x
, and
iter
with it
.
insert_iterator::operator*
insert_iterator& operator*();
The member function returns *this
.
insert_iterator::operator++
insert_iterator& operator++(); insert_iterator& operator++(int);
The member functions both return *this
.
insert_iterator::operator=
insert_iterator& operator=(const reference val);
The member function evaluates
iter =
container.
insert(iter, val)
, then returns *this
.
insert_iterator::reference
typedef typename Cont::reference reference;
The type describes a reference to an element of the sequence controlled by the associated container.
insert_iterator::value_type
typedef typename Cont::value_type value_type;
The type describes the elements of the sequence controlled by the associated container.
inserter
template<class Cont, class Iter> insert_iterator<Cont> inserter(Cont& x, Iter it);
The template member function returns
insert_iterator<Cont>(x, it)
.
istream_iterator
template<class U, class E, class T = char_traits<E>, class Dist = ptrdiff_t> class istream_iterator : public iterator<input_iterator_tag, U, Dist, U *, U&> { public: typedef E char_type; typedef T traits_type; typedef istream<E, T> istream_type; istream_iterator(); istream_iterator(istream_type& is); const U& operator*() const; const U *operator->() const; istream_iterator<U, E, T, Dist>& operator++(); istream_iterator<U, E, T, Dist> operator++(int); };
The template class describes an input iterator object.
It extracts objects of class U
from an input stream, which it accesses via an object it stores,
of type pointer to
istream<E, T>
.
After constructing or incrementing an object of class
istream_iterator
with a non-null stored pointer,
the object attempts to extract and store an object of type
U
from the associated input stream. If the extraction
fails, the object effectively replaces the stored pointer with
a null pointer (thus making an end-of-sequence indicator).
In this
implementation, if the
underlying library is Embedded C++, you should specify only the
first template parameter, as in istream_iterator<U>
.
The input stream has type istream
.
istream_iterator::char_type
typedef E char_type;
The type is a synonym for the template parameter E
.
istream_iterator::istream_iterator
istream_iterator(); istream_iterator(istream_type& is);
The first constructor initializes the input stream pointer
with a null pointer.
The second constructor initializes the input stream pointer
with &is
, then attempts to extract and store
an object of type U
.
istream_iterator::istream_type
typedef istream<E, T> istream_type;
The type is a synonym for
istream<E, T>
.
istream_iterator::operator*
const U& operator*() const;
The operator returns the stored object of type U
.
istream_iterator::operator->
const U *operator->() const;
The operator returns &**this
.
istream_iterator::operator++
istream_iterator<U, E, T, Dist>& operator++(); istream_iterator<U, E, T, Dist> operator++(int);
The first operator attempts to extract and store an object
of type U
from the associated input stream. The second
operator makes a copy of the object, increments the object, then
returns the copy.
istream_iterator::traits_type
typedef T traits_type;
The type is a synonym for the template parameter T
.
istreambuf_iterator
template<class E, class T = char_traits<E> > class istreambuf_iterator : public iterator<input_iterator_tag, E, typename T::off_type, E *, E&> { public: typedef E char_type; typedef T traits_type; typedef typename T::int_type int_type; typedef streambuf<E, T> streambuf_type; typedef istream<E, T> istream_type; istreambuf_iterator(streambuf_type *sb = 0) throw(); istreambuf_iterator(istream_type& is) throw(); const E& operator*() const; const E *operator->(); istreambuf_iterator& operator++(); istreambuf_iterator operator++(int); bool equal(const istreambuf_iterator& rhs); };
The template class describes an input iterator object.
It extracts elements of class E
from an input stream buffer,
which it accesses via an object it stores,
of type pointer to
streambuf<E,
T>
.
After constructing or incrementing an object of class
istreambuf_iterator
with a non-null stored pointer,
the object effectively attempts to extract and store an object of type
E
from the associated itput stream.
(The extraction may be delayed, however, until the object
is actually dereferenced or copied.) If the extraction
fails, the object effectively replaces the stored pointer with
a null pointer (thus making an end-of-sequence indicator).
In this
implementation, if the
underlying library is Embedded C++, you should specify only the
first template parameter, which must be type char,
as in istreambuf_iterator<char>
.
The input stream buffer has type streambuf
.
istreambuf_iterator::char_type
typedef E char_type;
The type is a synonym for the template parameter E
.
istreambuf_iterator::equal
bool equal(const istreambuf_iterator& rhs);
The member function returns true only if the stored streambbuffer
pointers for the object and rhs
are both null pointers
or are both non-null pointers.
istreambuf_iterator::int_type
typedef typename T:int_type int_type;
The type is a synonym for
T::int_type
.
istreambuf_iterator::istream_type
typedef istream<E, T> istream_type;
The type is a synonym for
istream<E,
T>
.
istreambuf_iterator::istreambuf_iterator
istreambuf_iterator(streambuf_type *sb = 0) throw(); istreambuf_iterator(istream_type& is) throw();
The first constructor initializes the input stream-buffer pointer
with sb
.
The second constructor initializes the input stream-buffer pointer with
is.rdbuf()
,
then (eventually) attempts to extract and store
an object of type E
.
istreambuf_iterator::operator*
const E& operator*() const;
The operator returns the stored object of type E
.
istreambuf_iterator::operator++
istreambuf_iterator& operator++(); istreambuf_iterator operator++(int);
The first operator (eventually) attempts to extract and store an object
of type E
from the associated input stream. The second
operator makes a copy of the object, increments the object, then
returns the copy.
istreambuf_iterator::operator->
const E *operator->() const;
The operator returns &**this
.
istreambuf_iterator::streambuf_type
typedef streambuf<E, T> streambuf_type;
The type is a synonym for
streambuf<E,
T>
.
istreambuf_iterator::traits_type
typedef T traits_type;
The type is a synonym for the template parameter T
.
iterator
template<class C, class T, class Dist = ptrdiff_t class Pt = T *, class Rt = T&> struct iterator { typedef C iterator_category; typedef T value_type; typedef Dist difference_type; typedef Pt pointer; typedef Rt reference; };
The template class serves as a base type for all iterators.
It defines the member types
iterator_category
(a synonym for the template parameter C
),
value_type
(a synonym for the template parameter T
),
difference_type
(a synonym for the template parameter Dist
),
pointer
(a synonym for the template parameter Pt
), and
reference
(a synonym for the template parameter T
).
iterator_traits
template<class It> struct iterator_traits { typedef typename It::iterator_category iterator_category; typedef typename It::value_type value_type; typedef typename It::difference_type difference_type; typedef typename It::pointer pointer; typedef typename It::reference reference; }; template<class T> struct iterator_traits<T *> { typedef random_access_iterator_tag iterator_category; typedef T value_type; typedef ptrdiff_t difference_type; typedef T *pointer; typedef T& reference; };
The template class determines several critical types associated
with the iterator type It
.
It defines the member types
iterator_category
(a synonym for It::iterator_category
),
value_type
(a synonym for It::value_type
),
difference_type
(a synonym for It::difference_type
),
pointer
(a synonym for It::pointer
), and
reference
(a synonym for It::reference
).
The partial specialization determines the critical types associated
with an object pointer type T *
. In this
implementation,
you can also use several template functions that do not make use of
partial specialization:
template<class C, class T, class Dist> C _Iter_cat(const iterator<C, T, Dist>&); template<class T> random_access_iterator_tag _Iter_cat(const T *); template<class C, class T, class Dist> T *_Val_type(const iterator<C, T, Dist>&); template<class T> T *_Val_type(const T *); template<class C, class T, class Dist> Dist *_Dist_type(const iterator<C, T, Dist>&); template<class T> ptrdiff_t *_Dist_type(const T *);
which determine several of the same types a bit more indirectly. You use these functions as arguments on a function call. Their sole purpose is to supply a useful template class parameter to the called function.
operator!=
template<class RanIt> bool operator!=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class U, class E, class T, class Dist> bool operator!=( const istream_iterator<U, E, T, Dist>& lhs, const istream_iterator<U, E, T, Dist>& rhs); template<class E, class T> bool operator!=( const istreambuf_iterator<E, T>& lhs, const istreambuf_iterator<E, T>& rhs);
The template operator returns !(lhs == rhs)
.
operator==
template<class RanIt> bool operator==( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs); template<class U, class E, class T, class Dist> bool operator==( const istream_iterator<U, E, T, Dist>& lhs, const istream_iterator<U, E, T, Dist>& rhs); template<class E, class T> bool operator==( const istreambuf_iterator<E, T>& lhs, const istreambuf_iterator<E, T>& rhs);
The first template operator returns true only if
lhs.current ==
rhs.current
. The second template operator returns true only
if both lhs
and rhs
store the same
stream pointer. The third template operator returns
lhs.equal(rhs)
.
operator<
template<class RanIt> bool operator<( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs);
The template operator returns
rhs.current <
lhs.current
[sic].
operator<=
template<class RanIt> bool operator<=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs);
The template operator returns !(rhs < lhs)
.
operator>
template<class RanIt> bool operator>( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs);
The template operator returns rhs < lhs
.
operator>=
template<class RanIt> bool operator>=( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs);
The template operator returns !(lhs < rhs)
.
operator+
template<class RanIt> reverse_iterator<RanIt> operator+(Dist n, const reverse_iterator<RanIt>& rhs);
The template operator returns rhs + n
.
operator-
template<class RanIt> Dist operator-( const reverse_iterator<RanIt>& lhs, const reverse_iterator<RanIt>& rhs);
The template operator returns
rhs.current -
lhs.current
[sic].
ostream_iterator
template<class U, class E, class T = char_traits<E> > class ostream_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: typedef U value_type; typedef E char_type; typedef T traits_type; typedef ostream<E, T> ostream_type; ostream_iterator(ostream_type& os); ostream_iterator(ostream_type& os, const E *delim); ostream_iterator<U, E, T>& operator=(const U& val); ostream_iterator<U, E, T>& operator*(); ostream_iterator<U, E, T>& operator++(); ostream_iterator<U, E, T> operator++(int); };
The template class describes an output iterator object.
It inserts objects of class U
into an output stream, which it accesses via an object it stores,
of type pointer to
ostream<E, T>
.
It also stores a pointer to a delimiter string, a
null-terminated string
of elements of type E
, which is appended after
each insertion. (Note that the string itself is not copied
by the constructor.
In this
implementation, if the
underlying library is Embedded C++, you should specify only the
first template parameter, as in ostream_iterator<U>
.
The output stream has type ostream
.
ostream_iterator::char_type
typedef E char_type;
The type is a synonym for the template parameter E
.
ostream_iterator::operator*
ostream_iterator<U, E, T>& operator*();
The operator returns *this
.
ostream_iterator::operator++
ostream_iterator<U, E, T>& operator++(); ostream_iterator<U, E, T> operator++(int);
The operators both return *this
.
ostream_iterator::operator=
ostream_iterator<U, E, T>& operator=(const U& val);
The operator inserts val
into the
output stream associated with the object,
then returns *this
.
ostream_iterator::ostream_iterator
ostream_iterator(ostream_type& os); ostream_iterator(ostream_type& os, const E *delim);
The first constructor initializes the output stream pointer
with &os
. The delimiter string pointer designates an
empty string. The second constructor initializes the output stream
pointer with &os
and the delimiter string pointer
with delim
.
ostream_iterator::ostream_type
typedef ostream<E, T> ostream_type;
The type is a synonym for
ostream<E, T>
.
ostream_iterator::traits_type
typedef T traits_type;
The type is a synonym for the template parameter T
.
ostream_iterator::value_type
typedef U value_type;
The type is a synonym for the template parameter U
.
ostreambuf_iterator
template<class E, class T = char_traits<E> > class ostreambuf_iterator : public iterator<output_iterator_tag, void, void, void, void> { public: typedef E char_type; typedef T traits_type; typedef streambuf<E, T> streambuf_type; typedef ostream<E, T> ostream_type; ostreambuf_iterator(streambuf_type *sb) throw(); ostreambuf_iterator(ostream_type& os) throw(); ostreambuf_iterator& operator=(E x); ostreambuf_iterator& operator*(); ostreambuf_iterator& operator++(); T1 operator++(int); bool failed() const throw(); };
The template class describes an output iterator object.
It inserts elements of class E
into an output stream buffer,
which it accesses via an object it stores,
of type pointer to
streambuf<E, T>
.
In this
implementation, if the
underlying library is Embedded C++, you should specify only the
first template parameter, which must be type char,
as in ostreambuf_iterator<char>
.
The output stream buffer has type streambuf
.
ostreambuf_iterator::char_type
typedef E char_type;
The type is a synonym for the template parameter E
.
ostreambuf_iterator::failed
bool failed() const throw();
The member function returns true only if no insertion into the output stream buffer has earlier failed.
ostreambuf_iterator::operator*
ostreambuf_iterator& operator*();
The operator returns *this
.
ostreambuf_iterator::operator++
ostreambuf_iterator& operator++(); T1 operator++(int);
The first operator returns *this
. The second operator
returns an object of some type T1
that can be converted to
ostreambuf_iterator<E, T>
.
ostreambuf_iterator::operator=
ostreambuf_iterator& operator=(E x);
The operator inserts x
into the associated stream buffer,
then returns *this
.
ostreambuf_iterator::ostream_type
typedef ostream<E, T> ostream_type;
The type is a synonym for
ostream<E,
T>
.
ostreambuf_iterator::ostreambuf_iterator
ostreambuf_iterator(streambuf_type *sb) throw(); ostreambuf_iterator(ostream_type& is) throw();
The first conttructor initializes the output stream-buffer pointer
with sb
.
The second constructor initializes the output stream-buffer pointer with
is.rdbuf()
.
(The stored pointer must not be a null pointer.)
ostreambuf_iterator::streambuf_type
typedef streambuf<E, T> streambuf_type;
The type is a synonym for streambuf<E, T>
.
ostreambuf_iterator::traits_type
typedef T traits_type;
The type is a synonym for the template parameter T
.
output_iterator_tag
struct output_iterator_tag { };
The type is the same as
iterator<It>::iterator_category
when It
describes an object that can serve as a
output iterator.
random_access_iterator_tag
struct random_access_iterator_tag : public bidirectional_iterator_tag { };
The type is the same as
iterator<It>::iterator_category
when It
describes an object that can serve as a
random-access iterator.
reverse_iterator
template<class RanIt> class reverse_iterator : public iterator< typename iterator_traits<RanIt>::iterator_category, typename iterator_traits<RanIt>::value_type, typename iterator_traits<RanIt>::difference_type, typename iterator_traits<RanIt>::pointer, typename iterator_traits<RanIt>::reference> { typedef typename iterator_traits<RanIt>::difference_type Dist; typedef typename iterator_traits<RanIt>::pointer Ptr; typedef typename iterator_traits<RanIt>::reference Ref; public: typedef RanIt iter_type; reverse_iterator(); explicit reverse_iterator(RanIt x); RanIt base() const; Ref operator*() const; Ptr operator->() const; reverse_iterator& operator++(); reverse_iterator operator++(int); reverse_iterator& operator--(); reverse_iterator operator--(); reverse_iterator& operator+=(Dist n); reverse_iterator operator+(Dist n) const; reverse_iterator& operator-=(Dist n); reverse_iterator operator-(Dist n) const; Ref operator[](Dist n) const; protected: RanIt current; };
The template class describes an object that behaves like a
random-access iterator, only in reverse. It stores a random-access iterator
of type RanIt
in the protected object
current
.
Incrementing the object x
of type
reverse_iterator
decrements x.current
, and decrementing x
increments x.current
.
Moreover, the expression *x
evaluates to
*(current - 1)
,
of type Ref
. Typically, Ref
is
type T&
.
Thus, you can use an object of class
reverse_iterator
to access in reverse
order a sequence that is traversed in order by a random-access
iterator.
Several STL containers specialize
reverse_iterator
for RanIt
a bidirectional iterator.
In these cases, you must not call any of the member functions operator+=
,
operator+
, operator-=
, operator-
, or
operator[]
.
reverse_iterator::base
RanIt base() const;
The member function returns
current
.
reverse_iterator::iter_type
typedef RanIt iter_type;
The type is a synonym for the template parameter RanIt
.
reverse_iterator::operator*
Ref operator*() const;
The operator returns
*(current - 1)
.
reverse_iterator::operator+
reverse_iterator operator+(Dist n) const;
The operator returns reverse_iterator(*this) += n
.
reverse_iterator::operator++
reverse_iterator& operator++(); reverse_iterator operator++(int);
The first (preincrement) operator evaluates
--current
.
then returns *this
.
The second (postincrement) operator makes a copy of *this
,
evaluates --current
, then returns the copy.
reverse_iterator::operator+=
reverse_iterator& operator+=(Dist n);
The operator evaluates
current - n
.
then returns *this
.
reverse_iterator::operator-
reverse_iterator operator-(Dist n) const;
The operator returns reverse_iterator(*this) -= n
.
reverse_iterator::operator--
reverse_iterator& operator--(); reverse_iterator operator--();
The first (predecrement) operator evaluates
++current
.
then returns *this
.
The second (postdecrement) operator makes a copy of *this
,
evaluates ++current
, then returns the copy.
reverse_iterator::operator-=
reverse_iterator& operator-=(Dist n);
The operator evaluates
current + n
.
then returns *this
.
reverse_iterator::operator->
Ptr operator->() const;
The operator returns &**this
.
reverse_iterator::operator[]
Ref operator[](Dist n) const;
The operator returns *(*this + n)
.
reverse_iterator::pointer_type
typedef Ptr pointer_type;
The type is a synonym for the template parameter Ref
.
reverse_iterator::reference_type
typedef Ref reference_type;
The type is a synonym for the template parameter Ref
.
reverse_iterator::reverse_iterator
reverse_iterator(); explicit reverse_iterator(RanIt x);
The first constructor initializes
current
with its default constructor. The second constructor initializes
current
with current(x)
.
See also the Table of Contents and the Index.
Copyright © 1992-1996 by P.J. Plauger. Portions derived from work copyright © 1994 by Hewlett-Packard Company. All rights reserved.