std::ranges::views::join_with,std::ranges::join_with_view

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Ranges library(C++20)
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Ranges library

Range access

begin
cbegin
end
cend

rbegin
crbegin
rend
crend

size
ssize
data
cdata

reserve_hint (C++26)
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
common_range

sized_range
viewable_range
view

input_range
output_range
forward_range

bidirectional_range
random_access_range
contiguous_range

approximately_sized_range (C++26)
constant_range (C++23)

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
as_rvalue_viewviews::as_rvalue (C++23)(C++23)
filter_viewviews::filter
transform_viewviews::transform
take_viewviews::take
take_while_viewviews::take_while
common_viewviews::common
views::counted
to_input_viewviews::to_input (C++26)(C++26)

ref_view
drop_viewviews::drop
drop_while_viewviews::drop_while
lazy_split_viewviews::lazy_split
split_viewviews::split
join_viewviews::join
join_with_viewviews::join_with (C++23)(C++23)
concat_viewviews::concat (C++26)(C++26)
cache_latest_viewviews::cache_latest (C++26)(C++26)

owning_view
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

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std::ranges::join_with_view

Member functions
join_with_view::join_with_view
join_with_view::base
join_with_view::begin
join_with_view::end
Deduction guides
Iterator
Member functions
join_with_view::iterator::iterator
join_with_view::iterator::operator*
join_with_view::iterator::operator++ join_with_view::iterator::operator++(int) join_with_view::iterator::operator-- join_with_view::iterator::operator--(int)
Non-member functions
operator==(join_with_view::iterator) (C++23)
iter_move(join_with_view::iterator) (C++23)
iter_swap(join_with_view::iterator) (C++23)
Sentinel
join_with_view::sentinel::sentinel
operator==(join_with_view::sentinel) (C++23)

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Defined in header`<ranges>`
template<ranges::input_range V,ranges::forward_range Pattern> requiresranges::view<V>&& ranges::input_range<ranges::range_reference_t<V>>&& ranges::view<Pattern>&& /concatable/<ranges::range_reference_t<V>, Pattern> class join_with_view: ranges::view_interface<join_with_view<V, Pattern>>	(1)	(since C++23)
namespace views{ inlineconstexpr/* unspecified / join_with=/ unspecified */; }	(2)	(since C++23)
Call signature
template<ranges::viewable_range R,class Pattern> requires/* see below */ constexprranges::viewauto join_with( R&& r, Pattern&& pattern);		(since C++23)
template<class Pattern> constexpr/* range adaptor closure */ join_with( Pattern&& pattern);		(since C++23)

1) A range adaptor that representsview consisting of the sequence obtained from flattening a view of ranges, with every element of the delimiter inserted in between elements of the view. The delimiter can be a single element or a view of elements.

For the definition of/*concatable*/, seestd::ranges::concat_view.

2)RangeAdaptorObject. The expressionviews::join_with(e, f) isexpression-equivalent tojoin_with_view(e, f) for any suitable subexpressionse andf.

join_with_view modelsinput_range.

join_with_view modelsforward_range when:

ranges::range_reference_t<V> is a reference, and
V andranges::range_reference_t<V> each modelforward_range.

join_with_view modelsbidirectional_range when:

ranges::range_reference_t<V> is a reference,
V,ranges::range_reference_t<V>, andPattern each modelsbidirectional_range, and
ranges::range_reference_t<V> andPattern each modelcommon_range.

join_with_view modelscommon_range when:

ranges::range_reference_t<V> is a reference, and
V andranges::range_reference_t<V> each modelforward_range andcommon_range.

[edit]Nested types

Type	Definition
`InnerRng`	ranges::range_reference_t<V> (exposition-only member type*)

[edit]Data members

Member	Definition
`Vbase_`	the underlying (adapted) view (exposition-only member object*)
`Patternpattern_`	the pattern object (exposition-only member object*)
`non-propagating-cache` <ranges::iterator_t<V>>`outer_it_` (present only if`V` does not model`forward_range`)	the cache of the outer iterator (exposition-only member object*)
`non-propagating-cache` <std::remove_cv_t<`InnerRng` >>`inner_` (present only ifstd::is_reference_v<`InnerRng` > isfalse)	the cache of the inner range (exposition-only member object*)

[edit]Member functions

(constructor)	constructs a`join_with_view` (public member function)[edit]
base	returns a copy of the underlying (adapted) view (public member function)[edit]
begin	returns an iterator to the beginning (public member function)[edit]
end	returns an iterator or a sentinel to the end (public member function)[edit]
Inherited fromstd::ranges::view_interface
empty	returns whether the derived view is empty, provided only if it satisfies`sized_range` or`forward_range` (public member function of`std::ranges::view_interface<D>`)[edit]
cbegin (C++23)	returns a constant iterator to the beginning of the range (public member function of`std::ranges::view_interface<D>`)[edit]
cend (C++23)	returns a sentinel for the constant iterator of the range (public member function of`std::ranges::view_interface<D>`)[edit]
operator bool	returns whether the derived view is not empty, provided only ifranges::empty is applicable to it (public member function of`std::ranges::view_interface<D>`)[edit]
front	returns the first element in the derived view, provided if it satisfies`forward_range` (public member function of`std::ranges::view_interface<D>`)[edit]
back	returns the last element in the derived view, provided only if it satisfies`bidirectional_range` and`common_range` (public member function of`std::ranges::view_interface<D>`)[edit]

[edit]Deduction guides

[edit]Nested classes

iterator	the iterator type (exposition-only member class template*)
sentinel	the sentinel type (exposition-only member class template*)

[edit]Notes

Feature-test macro	Value	Std	Feature
`__cpp_lib_ranges_join_with`	`202202L`	(C++23)	`std::ranges::join_with_view`

[edit]Example

Run this code

#include <iostream>#include <ranges>#include <string_view>#include <vector> int main(){usingnamespace std::literals; std::vector v{"This"sv,"is"sv,"a"sv,"test."sv};auto joined= v| std::views::join_with(' '); for(auto c: joined)std::cout<< c;std::cout<<'\n';}

Output:

This is a test.

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 4074	C++23	`join_with_view` was underconstrained	updated the constraints

[edit]See also

ranges::join_viewviews::join (C++20)	a`view` consisting of the sequence obtained from flattening a`view` of`range`s (class template)(range adaptor object)[edit]
ranges::concat_viewviews::concat (C++26)	a`view` consisting of concatenation of the adapted views (class template)(customization point object)[edit]