std::reverse_iterator - Man Page

std::reverse_iterator< _Iterator >

Synopsis

Inherits std::iterator< iterator_traits< _Iterator >::iterator_category, iterator_traits< _Iterator >::value_type, iterator_traits< _Iterator >::difference_type, iterator_traits< _Iterator >::pointer, iterator_traits< _Iterator >::reference >.

Public Types

using difference_type = iter_difference_t< _Iterator >
using iterator_category = __detail::__clamp_iter_cat< typename __traits_type::iterator_category, random_access_iterator_tag >
using iterator_concept = __conditional_t< random_access_iterator< _Iterator >, random_access_iterator_tag, bidirectional_iterator_tag >
typedef _Iterator iterator_type
typedef __traits_type::pointer pointer
using reference = iter_reference_t< _Iterator >
using value_type = iter_value_t< _Iterator >

Public Member Functions

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

Public Attributes

__tmp

Protected Types

typedef iterator_traits< _Iterator > __traits_type

Protected Attributes

_Iterator current

Friends

constexpr friend 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 friend 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:

&*(reverse_iterator(i)) == &*(i - 1)

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 132 of file bits/stl_iterator.h.

Constructor & Destructor Documentation

template<typename _Iterator > constexpr std::reverse_iterator< _Iterator >::reverse_iterator () [inline], [constexpr], [noexcept]

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

Definition at line 182 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr std::reverse_iterator< _Iterator >::reverse_iterator (iterator_type __x) [inline], [explicit], [constexpr], [noexcept]

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

Definition at line 191 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr std::reverse_iterator< _Iterator >::reverse_iterator (const reverse_iterator< _Iterator > & __x) [inline], [constexpr], [noexcept]

The copy constructor is normal.

Definition at line 200 of file bits/stl_iterator.h.

template<typename _Iterator > template<typename _Iter > requires constexpr __convertible<_Iter> std::reverse_iterator< _Iterator >::reverse_iterator (const reverse_iterator< _Iter > & __x) [inline], [constexpr], [noexcept]

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

Definition at line 218 of file bits/stl_iterator.h.

Member Function Documentation

template<typename _Iterator > constexpr iterator_type std::reverse_iterator< _Iterator >::base () const [inline], [constexpr], [noexcept]

Returns

current, the iterator used for underlying work.

Definition at line 244 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reference std::reverse_iterator< _Iterator >::operator* () const [inline], [constexpr]

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 260 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator+ (difference_type __n) const [inline], [constexpr]

Returns

A reverse_iterator that refers to current - __n

The underlying iterator must be a Random Access Iterator.

Definition at line 343 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator& std::reverse_iterator< _Iterator >::operator++ () [inline], [constexpr]

Returns

*this

Decrements the underlying iterator.

Definition at line 292 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator++ (int) [inline], [constexpr]

Returns

The original value of *this

Decrements the underlying iterator.

Definition at line 304 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator& std::reverse_iterator< _Iterator >::operator+= (difference_type __n) [inline], [constexpr]

Returns

*this

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

Definition at line 353 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator- (difference_type __n) const [inline], [constexpr]

Returns

A reverse_iterator that refers to current - __n

The underlying iterator must be a Random Access Iterator.

Definition at line 366 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator& std::reverse_iterator< _Iterator >::operator-- () [inline], [constexpr]

Returns

*this

Increments the underlying iterator.

Definition at line 317 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator std::reverse_iterator< _Iterator >::operator-- (int) [inline], [constexpr]

Returns

A reverse_iterator with the previous value of *this

Increments the underlying iterator.

Definition at line 329 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reverse_iterator& std::reverse_iterator< _Iterator >::operator-= (difference_type __n) [inline], [constexpr]

Returns

*this

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

Definition at line 376 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr pointer std::reverse_iterator< _Iterator >::operator-> () const [inline], [constexpr]

Returns

A pointer to the value at --current

This requires that --current is dereferenceable.

Definition at line 273 of file bits/stl_iterator.h.

template<typename _Iterator > constexpr reference std::reverse_iterator< _Iterator >::operator[] (difference_type __n) const [inline], [constexpr]

Returns

The value at current - __n - 1

The underlying iterator must be a Random Access Iterator.

Definition at line 389 of file bits/stl_iterator.h.

Author

Generated automatically by Doxygen for libstdc++ from the source code.

Info

Tue Jan 18 2022 libstdc++