libstdc++
std::reverse_iterator< _Iterator > Class Template Reference

#include <stl_iterator.h>

Inheritance diagram for std::reverse_iterator< _Iterator >:
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Public Types

using difference_type
 
using iterator_category
 
using iterator_concept
 
typedef _Iterator iterator_type
 
typedef __traits_type::pointer pointer
 
using reference
 
using value_type
 

Public Member Functions

constexpr reverse_iterator () noexcept(/*conditional */)
 
constexpr reverse_iterator (const reverse_iterator &__x) noexcept(/*conditional */)
 
template<typename _Iter >
requires __convertible<_Iter>
constexpr reverse_iterator (const reverse_iterator< _Iter > &__x) noexcept(/*conditional */)
 
constexpr reverse_iterator (iterator_type __x) noexcept(/*conditional */)
 
constexpr iterator_type base () const noexcept(/*conditional */)
 
constexpr reference operator* () const
 
constexpr reverse_iterator operator+ (difference_type __n) const
 
constexpr reverse_iteratoroperator++ ()
 
constexpr reverse_iterator operator++ (int)
 
constexpr reverse_iteratoroperator+= (difference_type __n)
 
constexpr reverse_iterator operator- (difference_type __n) const
 
constexpr reverse_iteratoroperator-- ()
 
constexpr reverse_iterator operator-- (int)
 
constexpr reverse_iteratoroperator-= (difference_type __n)
 
constexpr pointer operator-> () const
 
reverse_iteratoroperator= (const reverse_iterator &)=default
 
template<typename _Iter >
requires __convertible<_Iter> && assignable_from<_Iterator&, const _Iter&>
constexpr reverse_iteratoroperator= (const reverse_iterator< _Iter > &__x) noexcept(/*conditional */)
 
constexpr reference operator[] (difference_type __n) const
 

Protected Types

typedef iterator_traits< _Iterator > __traits_type
 

Protected Attributes

_Iterator current
 

Friends

constexpr iter_rvalue_reference_t< _Iterator > iter_move (const reverse_iterator &__i) noexcept(is_nothrow_copy_constructible_v< _Iterator > &&noexcept(ranges::iter_move(--std::declval< _Iterator & >())))
 
template<indirectly_swappable< _Iterator > _Iter2>
constexpr void iter_swap (const reverse_iterator &__x, const reverse_iterator< _Iter2 > &__y) noexcept(is_nothrow_copy_constructible_v< _Iterator > &&is_nothrow_copy_constructible_v< _Iter2 > &&noexcept(ranges::iter_swap(--std::declval< _Iterator & >(), --std::declval< _Iter2 & >())))
 

Detailed Description

template<typename _Iterator>
class std::reverse_iterator< _Iterator >

Bidirectional and random access iterators have corresponding reverse iterator adaptors that iterate through the data structure in the opposite direction. They have the same signatures as the corresponding iterators. The fundamental relation between a reverse iterator and its corresponding iterator i is established by the identity:

This mapping is dictated by the fact that while there is always a pointer past the end of an array, there might not be a valid pointer before the beginning of an array. [24.4.1]/1,2

Reverse iterators can be tricky and surprising at first. Their semantics make sense, however, and the trickiness is a side effect of the requirement that the iterators must be safe.

Definition at line 136 of file bits/stl_iterator.h.

Member Typedef Documentation

◆ __traits_type

template<typename _Iterator >
typedef iterator_traits<_Iterator> std::reverse_iterator< _Iterator >::__traits_type
protected

Definition at line 157 of file bits/stl_iterator.h.

◆ difference_type

template<typename _Iterator >
using std::reverse_iterator< _Iterator >::difference_type

Definition at line 172 of file bits/stl_iterator.h.

◆ iterator_category

template<typename _Iterator >
using std::reverse_iterator< _Iterator >::iterator_category

Definition at line 169 of file bits/stl_iterator.h.

◆ iterator_concept

template<typename _Iterator >
using std::reverse_iterator< _Iterator >::iterator_concept

Definition at line 166 of file bits/stl_iterator.h.

◆ iterator_type

template<typename _Iterator >
typedef _Iterator std::reverse_iterator< _Iterator >::iterator_type

Definition at line 160 of file bits/stl_iterator.h.

◆ pointer

template<typename _Iterator >
typedef __traits_type::pointer std::reverse_iterator< _Iterator >::pointer

Definition at line 161 of file bits/stl_iterator.h.

◆ reference

template<typename _Iterator >
using std::reverse_iterator< _Iterator >::reference

Definition at line 173 of file bits/stl_iterator.h.

◆ value_type

template<typename _Iterator >
using std::reverse_iterator< _Iterator >::value_type

Definition at line 171 of file bits/stl_iterator.h.

Constructor & Destructor Documentation

◆ reverse_iterator() [1/4]

template<typename _Iterator >
constexpr std::reverse_iterator< _Iterator >::reverse_iterator ( )
inlineconstexprnoexcept

The default constructor value-initializes member current. If it is a pointer, that means it is zero-initialized.

Definition at line 184 of file bits/stl_iterator.h.

◆ reverse_iterator() [2/4]

template<typename _Iterator >
constexpr std::reverse_iterator< _Iterator >::reverse_iterator ( iterator_type __x)
inlineexplicitconstexprnoexcept

This iterator will move in the opposite direction that x does.

Definition at line 193 of file bits/stl_iterator.h.

◆ reverse_iterator() [3/4]

template<typename _Iterator >
constexpr std::reverse_iterator< _Iterator >::reverse_iterator ( const reverse_iterator< _Iterator > & __x)
inlineconstexprnoexcept

The copy constructor is normal.

Definition at line 202 of file bits/stl_iterator.h.

◆ reverse_iterator() [4/4]

template<typename _Iterator >
template<typename _Iter >
requires __convertible<_Iter>
constexpr std::reverse_iterator< _Iterator >::reverse_iterator ( const reverse_iterator< _Iter > & __x)
inlineconstexprnoexcept

A reverse_iterator across other types can be copied if the underlying iterator can be converted to the type of current.

Definition at line 220 of file bits/stl_iterator.h.

Member Function Documentation

◆ base()

template<typename _Iterator >
constexpr iterator_type std::reverse_iterator< _Iterator >::base ( ) const
inlineconstexprnoexcept
Returns
current, the iterator used for underlying work.

Definition at line 246 of file bits/stl_iterator.h.

◆ operator*()

template<typename _Iterator >
constexpr reference std::reverse_iterator< _Iterator >::operator* ( ) const
inlineconstexpr
Returns
A reference to the value at --current

This requires that --current is dereferenceable.

Warning
This implementation requires that for an iterator of the underlying iterator type, x, a reference obtained by *x remains valid after x has been modified or destroyed. This is a bug: http://gcc.gnu.org/PR51823

Definition at line 262 of file bits/stl_iterator.h.

◆ operator+()

template<typename _Iterator >
constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator+ ( difference_type __n) const
inlineconstexpr
Returns
A reverse_iterator that refers to current - __n

The underlying iterator must be a Random Access Iterator.

Definition at line 345 of file bits/stl_iterator.h.

◆ operator++() [1/2]

template<typename _Iterator >
constexpr reverse_iterator & std::reverse_iterator< _Iterator >::operator++ ( )
inlineconstexpr
Returns
*this

Decrements the underlying iterator.

Definition at line 294 of file bits/stl_iterator.h.

◆ operator++() [2/2]

template<typename _Iterator >
constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator++ ( int )
inlineconstexpr
Returns
The original value of *this

Decrements the underlying iterator.

Definition at line 306 of file bits/stl_iterator.h.

◆ operator+=()

template<typename _Iterator >
constexpr reverse_iterator & std::reverse_iterator< _Iterator >::operator+= ( difference_type __n)
inlineconstexpr
Returns
*this

Moves the underlying iterator backwards __n steps. The underlying iterator must be a Random Access Iterator.

Definition at line 355 of file bits/stl_iterator.h.

◆ operator-()

template<typename _Iterator >
constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator- ( difference_type __n) const
inlineconstexpr
Returns
A reverse_iterator that refers to current - __n

The underlying iterator must be a Random Access Iterator.

Definition at line 368 of file bits/stl_iterator.h.

◆ operator--() [1/2]

template<typename _Iterator >
constexpr reverse_iterator & std::reverse_iterator< _Iterator >::operator-- ( )
inlineconstexpr
Returns
*this

Increments the underlying iterator.

Definition at line 319 of file bits/stl_iterator.h.

◆ operator--() [2/2]

template<typename _Iterator >
constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator-- ( int )
inlineconstexpr
Returns
A reverse_iterator with the previous value of *this

Increments the underlying iterator.

Definition at line 331 of file bits/stl_iterator.h.

◆ operator-=()

template<typename _Iterator >
constexpr reverse_iterator & std::reverse_iterator< _Iterator >::operator-= ( difference_type __n)
inlineconstexpr
Returns
*this

Moves the underlying iterator forwards __n steps. The underlying iterator must be a Random Access Iterator.

Definition at line 378 of file bits/stl_iterator.h.

◆ operator->()

template<typename _Iterator >
constexpr pointer std::reverse_iterator< _Iterator >::operator-> ( ) const
inlineconstexpr
Returns
A pointer to the value at --current

This requires that --current is dereferenceable.

Definition at line 275 of file bits/stl_iterator.h.

◆ operator=()

template<typename _Iterator >
template<typename _Iter >
requires __convertible<_Iter> && assignable_from<_Iterator&, const _Iter&>
constexpr reverse_iterator & std::reverse_iterator< _Iterator >::operator= ( const reverse_iterator< _Iter > & __x)
inlineconstexprnoexcept

Definition at line 233 of file bits/stl_iterator.h.

◆ operator[]()

template<typename _Iterator >
constexpr reference std::reverse_iterator< _Iterator >::operator[] ( difference_type __n) const
inlineconstexpr
Returns
The value at current - __n - 1

The underlying iterator must be a Random Access Iterator.

Definition at line 391 of file bits/stl_iterator.h.

Friends And Related Symbol Documentation

◆ reverse_iterator

template<typename _Iterator >
template<typename _Iter >
friend class reverse_iterator
friend

Definition at line 144 of file bits/stl_iterator.h.

◆ iter_move

template<typename _Iterator >
constexpr iter_rvalue_reference_t< _Iterator > iter_move ( const reverse_iterator< _Iterator > & __i)
friend

Definition at line 397 of file bits/stl_iterator.h.

◆ iter_swap

template<typename _Iterator >
template<indirectly_swappable< _Iterator > _Iter2>
constexpr void iter_swap ( const reverse_iterator< _Iterator > & __x,
const reverse_iterator< _Iter2 > & __y )
friend

Definition at line 407 of file bits/stl_iterator.h.

Member Data Documentation

◆ current

template<typename _Iterator >
_Iterator std::reverse_iterator< _Iterator >::current
protected

Definition at line 155 of file bits/stl_iterator.h.


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