std::ranges::adjacent_view<V,N>::iterator<Const>::operator++,--,+=,-=

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Ranges library

Range access
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
Range conversions
to (C++23)
Range primitives
range_size_trange_difference_trange_value_trange_reference_t	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)	elements_of (C++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Range factories
empty_viewviews::empty single_viewviews::single	iota_viewviews::iota repeat_viewviews::repeat (C++23)(C++23)	basic_istream_viewviews::istream
Range adaptors
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (C++23)(C++23) filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (C++23)(C++23) lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)
Range generators
std::generator (C++23)
Range adaptor objects
Range adaptor closure objects
range_adaptor_closure (C++23)
Helper items
copyable-box movable-box (until C++23)(C++23)	simple-view non-propagating-cache

 

std::ranges::adjacent_view

Member functions

adjacent_view::adjacent_view (C++23)

adjacent_view::begin (C++23)

adjacent_view::end (C++23)

adjacent_view::size (C++23)

Iterator

Member functions

adjacent_view::iterator::iterator (C++23)

adjacent_view::iterator::operator* (C++23)

adjacent_view::iterator::operator[] (C++23)

adjacent_view::iterator::operator++ adjacent_view::iterator::operator++(int) adjacent_view::iterator::operator-- adjacent_view::iterator::operator--(int) adjacent_view::iterator::operator+= adjacent_view::iterator::operator-= (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

Non-member functions

operator==(adjacent_view::iterator) operator<(adjacent_view::iterator) operator>(adjacent_view::iterator) operator<=(adjacent_view::iterator) operator>=(adjacent_view::iterator) operator<=>(adjacent_view::iterator) (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

operator+(adjacent_view::iterator) operator-(adjacent_view::iterator) (C++23)(C++23)

iter_move(adjacent_view::iterator) (C++23)

iter_swap(adjacent_view::iterator) (C++23)

Sentinel

Member functions

adjacent_view::sentinel::sentinel (C++23)

Non-member functions

operator==(adjacent_view::iterator,adjacent_view::sentinel) (C++23)

operator-(adjacent_view::iterator,adjacent_view::sentinel) (C++23)

 

constexpr /*iterator*/& operator++();	(1)	(since C++23)
constexpr /*iterator*/ operator++( int );	(2)	(since C++23)
constexpr /*iterator*/& operator--()   requires ranges::bidirectional_range<Base>;	(3)	(since C++23)
constexpr /*iterator*/ operator--( int )   requires ranges::bidirectional_range<Base>;	(4)	(since C++23)
constexpr /*iterator*/& operator+=( difference_type n )   requires ranges::random_access_range<Base>;	(5)	(since C++23)
constexpr /*iterator*/& operator-=( difference_type n )   requires ranges::random_access_range<Base>;	(6)	(since C++23)

Increments or decrements the iterator.

Let current_ be an underlying array of iterators.

1) Equivalent to:

for (auto& i : current_)
    std::ranges::next(i);
return *this;

The behavior is undefined if before the call the current_.back() is not incrementable.

2) Equivalent to:

auto tmp = *this;
++*this;
return tmp;

3) Equivalent to:

for (auto& i : current_)
    std::ranges::prev(i);
return *this;

The behavior is undefined if before the call the current_.front() is not decrementable.

4) Equivalent to:

auto tmp = *this;
--*this;
return tmp;

5) Equivalent to:

for (auto& i : current_)
    i += n;
return *this;

The behavior is undefined if before the call the current_.back() + n does not have well-defined behavior.

6) Equivalent to:

for (auto& i : current_)
    i -= n;
return *this;

The behavior is undefined if before the call the current_.front() - n does not have well-defined behavior.

Parameters

n

-

position relative to current location

Return value

1,3,5,6) *this

2,4) a copy of *this that was made before the change

Example

A link to test: Compiler Explorer/g++-13

Run this code

#include <cassert>
#include <list>
#include <ranges>
#include <utility>
#include <vector>
 
[[nodiscard]]
bool operator== (std::pair<int&, int&> x, std::pair<int, int> y)
{
    return x.first == y.first and x.second == y.second;
}
 
int main()
{
    {
        auto v = std::vector{0, 1, 2, 3, 4, 5};
        auto i = (v | std::views::pairwise).begin();
        assert((*i == std::pair{0, 1}));
        ++i;                            // overload (1)
        assert((*i == std::pair{1, 2}));
        --i;                            // overload (3)
        assert((*i == std::pair{0, 1}));
        i += 2;                         // overload (5)
        assert((*i == std::pair{2, 3}));
        i -= 2;                         // overload (6)
        assert((*i == std::pair{0, 1}));
    }
    {
        auto v = std::list{0, 1, 2, 3, 4, 5};
        auto i = (v | std::views::pairwise).begin();
        assert((*i == std::pair{0, 1}));
        ++i;                            // overload (1)
        assert((*i == std::pair{1, 2}));
        --i;                            // overload (3)
        assert((*i == std::pair{0, 1}));
//      i += 2; // Error: v is not a random_access_range; overload (5)
//      i -= 2; // Error: v is not a random_access_range; overload (6)
    }
}

See also

operator+operator- (C++23)

performs iterator arithmetic (public member function)