std::ranges::concat_view<Views...>::iterator<Const>::satisfy, prev, advance-fwd, advance-bwd

 

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)

Execution support library (C++26)

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 std::from_range_t std::from_range (C++23)(C++23)     to (C++23)

Dangling iterator handling dangling borrowed_iterator_t borrowed_subrange_t

Range primitives
range_size_trange_difference_trange_value_t elements_of (C++23)	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_reference_trange_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)

Range concepts
range borrowed_range    sized_range	common_range view viewable_range	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	constant_range (C++23)

Views
view_interface	subrange

Range factories
empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota	repeat_viewviews::repeat (C++23)(C++23)

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 concat_viewviews::concat (C++26)(C++26)	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 closure objects range_adaptor_closure (C++23)

Range adaptor objects

Helper items
copyable-box movable-box (until C++23)  (C++23)	simple-view non-propagating-cache

 

std::ranges::concat_view

Member functions

concat_view::concat_view

concat_view::begin

concat_view::end

concat_view::size

Deduction guides

Iterator

Member functions

concat_view::iterator::iterator

concat_view::iterator::operator*

concat_view::iterator::operator[]

concat_view::iterator::operator++ concat_view::iterator::operator++(int) concat_view::iterator::operator-- concat_view::iterator::operator--(int) concat_view::iterator::operator+= concat_view::iterator::operator-=

concat_view::iterator::satisfy concat_view::iterator::prev concat_view::iterator::advance-fwd concat_view::iterator::advance-bwd

Non-member functions

operator==(concat_view::iterator) operator<(concat_view::iterator) operator>(concat_view::iterator) operator<=(concat_view::iterator) operator>=(concat_view::iterator) operator<=>(concat_view::iterator)

operator+(concat_view::iterator) operator-(concat_view::iterator)

iter_move(concat_view::iterator)

iter_swap(concat_view::iterator)

 

The following exposition-only member function templates simplify the description.

Each helper function template has a non-type template parameter of type std::size_t.

• If the name of the template parameter is N, the template argument is always it_ .index().
• If the name of the template parameter is I, the template argument can be any std::size_t value in [​0​, sizeof...(Views)).

However, the template argument might not be a compile-time constant, therefore the actual effect of helper <non_const>(/* arguments */) is similar to if (non_const == 0)
    helper <0>(/* arguments */);
else if (non_const == 1)
    helper <1>(/* arguments */);
/* other indices */
else if (non_const == (sizeof...(Views) - 1))
    helper <sizeof...(Views) - 1>(/* arguments */);
.

Helper templates

Mini helper templates

template< std::size_t N > constexpr auto /*get-iter*/();	(1)	(exposition only*)
template< std::size_t I > constexpr auto /*get-view*/();	(2)	(exposition only*)
template< std::size_t I > constexpr auto /*get-begin*/();	(3)	(exposition only*)
template< std::size_t I > constexpr auto /*get-end*/();	(4)	(exposition only*)
template< std::size_t N > constexpr auto /*to-underlying-diff-type*/( difference_type value );	(5)	(exposition only*)

The mini helper templates simplify the description of the main helper templates and member functions. They are not included in the C++ standard documents.

1) Obtains the underlying iterator contained in it_ .

Returns std::get<N>(it_ ).

2) Obtains the Ith view in the parent concat_view.

Returns std::get<I>(parent_ ->views_ ).

3) Obtains an iterator to the beginning of the Ith view in the parent concat_view.

Returns ranges::begin(get-view <I>()).

4) Obtains a past-the-end iterator or a sentinel of the Ith view in the parent concat_view.

Returns ranges::end(get-view <I>()).

5) Converts value to the underlying difference type of the underlying iterator contained in it_ .

Returns static_cast<std::iter_difference_t<std::variant_alternative_t<N, base-iter >>>(value).

std::ranges::concat_view::iterator::satisfy<N>

template< std::size_t N > constexpr void /*satisfy*/();		(exposition only*)

Adjusts the current (global) position of it_ .

• If N is sizeof...(Views) - 1, does nothing.
• Otherwise, equivalent to if (get-iter <N>() == get-end <N>())
  {
      it_ .template emplace<N + 1>(get-begin <N + 1>());
      satisfy <N + 1>();
  }.

std::ranges::concat_view::iterator::prev<N>

template< size_t N > constexpr void /*prev*/();		(exposition only*)

Moves it_ to the previous (global) position.

• If N is ​0​, equivalent to --get-iter <0>();.
• Otherwise, equivalent to if (get-iter <N>() == get-begin <N>())
  {
      it_ .template emplace<N - 1>(get-end <N - 1>());
      prev <N - 1>();
  }
  else
      --get-iter <0>();.

std::ranges::concat_view::iterator::advance-fwd<N>

template< size_t N > constexpr void /*advance-fwd*/( difference_type offset,                                 difference_type steps );		(exposition only*)

Advances the current (global) position step steps forward.

• If N is sizeof...(Views) - 1, equivalent to get-iter <N>() += to-underlying-diff-type (steps);.
• Otherwise, equivalent to auto n_size = ranges::distance(get-view <N>()));
  if (offset + steps < n_size)
      get-iter <N>() += to-underlying-diff-type (steps);
  else
  {
      it_ .template emplace<N + 1>(get-begin <N + 1>());
      advance-fwd <N + 1>(0, offset + steps - n_size);
  }.

Parameters

offset	-	the offset of the current (global) position from the beginning of range it_ currently refers into
steps	-	the number of steps to advance forward

std::ranges::concat_view::iterator::advance-bwd<N>

template< size_t N > constexpr void /*advance-bwd*/( difference_type offset,                                 difference_type steps );		(exposition only*)

Advances the current (global) position steps steps backward.

• If N is ​0​, equivalent to get-iter <N>() -= to-underlying-diff-type (steps);.
• Otherwise, equivalent to if (offset >= steps)
      get-iter <N>() -= to-underlying-diff-type (steps);
  else
  {
      auto prev_size = ranges::distance(get-view <N - 1>());
      it_ .template emplace<N - 1>(get-end <N - 1>());
      advance-bwd <N - 1>(prev_size, steps - offset);
  }.

Parameters

offset	-	the offset of the current (global) position from the beginning of range it_ currently refers into
steps	-	the number of steps to advance backward