std::ranges::basic_istream_view::iterator

 

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)

Diagnostics library

Memory management library

Metaprogramming library (C++11)

General utilities library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library (C++17)

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) views::counted	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 common_viewviews::common cache_latest_viewviews::cache_latest (C++26)(C++26)	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::basic_istream_view

Member functions

basic_istream_view::basic_istream_view

basic_istream_view::begin

basic_istream_view::end

Iterator

basic_istream_view::iterator::iterator

basic_istream_view::iterator::operator=

basic_istream_view::iterator::operator++

basic_istream_view::iterator::operator*

operator==(basic_istream_view::iterator)

 

struct /*iterator*/;		(exposition only*)

ranges::basic_istream_view<Val, CharT, Traits>::iterator is the type of the iterators returned by begin() of ranges::basic_istream_view<Val, CharT, Traits>.

iterator is an input_iterator, but does not satisfy LegacyInputIterator, and thus does not work with pre-C++20 algorithms.

Nested types

Type	Definition
iterator_concept	std::input_iterator_tag
difference_type	std::ptrdiff_t
value_type	Val

Data members

Member	Definition
ranges::basic_istream_view<Val, CharT, Traits> parent_	a pointer to the parent view (exposition-only member object*)

Member functions

std::ranges::basic_istream_view::iterator::iterator

/*iterator*/( const /*iterator*/& ) = delete;	(1)	(since C++20)
/*iterator*/( /*iterator*/&& ) = default;	(2)	(since C++20)
constexpr explicit /*iterator*/( basic_istream_view& parent );	(3)	(since C++20)

1) The copy constructor is deleted. The iterator is not copyable.

2) The move constructor is defaulted.

3) Initializes parent_ with std::addressof(parent).

std::ranges::basic_istream_view::iterator::operator=

/*iterator*/& operator=( const /*iterator*/& ) = delete;	(1)	(since C++20)
/*iterator*/& operator=( /*iterator*/&& ) = default;	(2)	(since C++20)

1) The copy assignment operator is deleted. The iterator is not copyable.

2) The move assignment operator is defaulted.

std::ranges::basic_istream_view::iterator::operator++

/*iterator*/& operator++();	(1)	(since C++20)
void operator++(int);	(2)	(since C++20)

1) Equivalent to *parent_ ->stream_ >> parent_ ->value_.

2) Equivalent to ++*this.

std::ranges::basic_istream_view::iterator::operator*

Val& operator*() const;		(since C++20)

Returns parent_ ->value_.

Non-member functions

operator==(std::ranges::basic_istream_view::iterator, std::default_sentinel)

friend bool operator==( const /*iterator*/& x, std::default_sentinel_t );		(since C++20)

Returns !*parent_ ->stream_.

This function is not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::ranges::basic_istream_view::iterator is an associated class of the arguments.

Defect reports

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

DR	Applied to	Behavior as published	Correct behavior
P2325R3	C++20	default constructor was provided as C++20 iterators must be default_initializable	removed along with the requirement