Standard library header <iterator>
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C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Standard library headers
<compare> (C++20)
<contracts> (C++26)
<coroutine> (C++20)
<cstdint> (C++11)
<source_location> (C++20)
<stdfloat> (C++23)
<version> (C++20)
<concepts> (C++20)
<debugging> (C++26)
<stacktrace> (C++23)
<system_error> (C++11)
<memory_resource> (C++17)
<scoped_allocator> (C++11)
<type_traits> (C++11)
<ratio> (C++11)
<any> (C++17)
<bit> (C++20)
<charconv> (C++17)
<expected> (C++23)
<format> (C++20)
<optional> (C++17)
<stdbit.h> (C++26)
<tuple> (C++11)
<typeindex> (C++11)
<variant> (C++17)
<array> (C++11)
<flat_map> (C++23)
<flat_set> (C++23)
<forward_list> (C++11)
<hive> (C++26)
<mdspan> (C++23)
<span> (C++20)
<unordered_map> (C++11)
<unordered_set> (C++11)
<iterator>
<generator> (C++23)
<ranges> (C++20)
<cuchar> (C++11)
<string_view> (C++17)
<codecvt> (C++11/17/26*)
<regex> (C++11)
<cfenv> (C++11)
<linalg> (C++26)
<numbers> (C++20)
<random> (C++11)
<simd> (C++26)
<stdckdint.h> (C++26)
<chrono> (C++11)
<ccomplex> (C++11/17/20*)
<ciso646> (until C++20)
<cstdalign> (C++11/17/20*)
<cstdbool> (C++11/17/20*)
<ctgmath> (C++11/17/20*)
<cinttypes> (C++11)
<filesystem> (C++17)
<print> (C++23)
<spanstream> (C++23)
<strstream> (C++98/26*)
<syncstream> (C++20)
<atomic> (C++11)
<barrier> (C++20)
<condition_variable> (C++11)
<future> (C++11)
<hazard_pointer> (C++26)
<latch> (C++20)
<mutex> (C++11)
<rcu> (C++26)
<semaphore> (C++20)
<shared_mutex> (C++14)
<stdatomic.h> (C++23)
<stop_token> (C++20)
<thread> (C++11)
<execution> (C++17)
This header is part of the iterator library.
This header is a partial freestanding header. Everything inside this header is freestanding beside stream iterators.
(since C++23)Contents
- 1 Concepts
- 2 Classes
- 3 Customization point objects
- 4 Constants
- 5 Functions
- 6 Synopsis
- 6.1 Concept indirectly_readable
- 6.2 Concept indirectly_writable
- 6.3 Concept weakly_incrementable
- 6.4 Concept incrementable
- 6.5 Concept input_or_output_iterator
- 6.6 Concept sentinel_for
- 6.7 Concept sized_sentinel_for
- 6.8 Concept input_iterator
- 6.9 Concept output_iterator
- 6.10 Concept forward_iterator
- 6.11 Concept bidirectional_iterator
- 6.12 Concept random_access_iterator
- 6.13 Concept contiguous_iterator
- 6.14 Concept indirectly_unary_invocable
- 6.15 Concept indirectly_regular_unary_invocable
- 6.16 Concept indirect_unary_predicate
- 6.17 Concept indirect_binary_predicate
- 6.18 Concept indirect_equivalence_relation
- 6.19 Concept indirect_strict_weak_order
- 6.20 Concept indirectly_movable
- 6.21 Concept indirectly_movable_storable
- 6.22 Concept indirectly_copyable
- 6.23 Concept indirectly_copyable_storable
- 6.24 Concept indirectly_swappable
- 6.25 Concept indirectly_comparable
- 6.26 Concept permutable
- 6.27 Concept mergeable
- 6.28 Concept sortable
- 6.29 Class template std::incrementable_traits
- 6.30 Class template std::indirectly_readable_traits
- 6.31 Class template std::projected
- 6.32 Class template std::iterator_traits
- 6.33 Iterator tags
- 6.34 Class template std::reverse_iterator
- 6.35 Class template std::back_insert_iterator
- 6.36 Class template std::front_insert_iterator
- 6.37 Class template std::insert_iterator
- 6.38 Class template std::move_iterator
- 6.39 Class template std::move_sentinel
- 6.40 Class template std::common_iterator
- 6.41 Class std::default_sentinel_t
- 6.42 Class template std::counted_iterator
- 6.43 Class std::unreachable_sentinel_t
- 6.44 Class template std::istream_iterator
- 6.45 Class template std::ostream_iterator
- 6.46 Class template std::istreambuf_iterator
- 6.47 Class template std::ostreambuf_iterator
- 6.48 Class template std::iterator
- 7 Defect reports
Concepts
Iterator concepts
(C++20)
*
(concept) [edit]
(C++20)
(concept) [edit]
(C++20)
semiregular
type can be incremented with pre- and post-increment operators (concept) [edit]
(C++20)
weakly_incrementable
type is equality-preserving and that the type is equality_comparable
(concept) [edit]
(C++20)
(concept) [edit]
(C++20)
input_or_output_iterator
type (concept) [edit]
(C++20)
(concept) [edit]
(C++20)
(concept) [edit]
(C++20)
(concept) [edit]
(C++20)
input_iterator
is a forward iterator, supporting equality comparison and multi-pass (concept) [edit]
(C++20)
forward_iterator
is a bidirectional iterator, supporting movement backwards (concept) [edit]
(C++20)
bidirectional_iterator
is a random-access iterator, supporting advancement in constant time and subscripting (concept) [edit]
(C++20)
random_access_iterator
is a contiguous iterator, referring to elements that are contiguous in memory (concept) [edit]
Indirect callable concepts
(C++20)(C++20)
indirectly_readable
type (concept) [edit]
(C++20)
indirectly_readable
type, satisfies predicate
(concept) [edit]
(C++20)
indirectly_readable
types, satisfies predicate
(concept) [edit]
(C++20)
indirectly_readable
types, satisfies equivalence_relation
(concept) [edit]
(C++20)
indirectly_readable
types, satisfies strict_weak_order
(concept) [edit]
Common algorithm requirements
(C++20)
indirectly_readable
type to an indirectly_writable
type (concept) [edit]
(C++20)
indirectly_readable
type to an indirectly_writable
type and that the move may be performed via an intermediate object (concept) [edit]
(C++20)
indirectly_readable
type to an indirectly_writable
type (concept) [edit]
(C++20)
indirectly_readable
type to an indirectly_writable
type and that the copy may be performed via an intermediate object (concept) [edit]
(C++20)
indirectly_readable
types can be swapped (concept) [edit]
(C++20)
indirectly_readable
types can be compared (concept) [edit]
(C++20)
(concept) [edit]
(C++20)
(concept) [edit]
(C++20)
(concept) [edit]
Classes
Algorithm utilities
(C++20)
indirectly_readable
types(alias template)[edit]
(C++20)
(alias template)[edit]
(C++26)
indirectly_readable
type by projection(alias template)[edit]
Associated types
(C++20)
weakly_incrementable
type (class template) [edit]
(C++20)
indirectly_readable
type (class template) [edit]
(C++20)(C++20)(C++23)(C++20)(C++20)(C++20)
(alias template)[edit]
Primitives
(class template) [edit]
(class) [edit]
(deprecated in C++17)
(class template) [edit]
Adaptors
(class template) [edit]
(C++11)
(class template) [edit]
(C++20)
(class template) [edit]
(C++23)
(class template) [edit]
(C++23)
(alias template)[edit]
(C++23)
(alias template)[edit]
(C++20)
(class template) [edit]
(C++20)
(class) [edit]
(C++20)
(class template) [edit]
(C++20)
weakly_incrementable
type (class) [edit]
(class template) [edit]
(class template) [edit]
(class template) [edit]
Stream Iterators
(class template) [edit]
(class template) [edit]
(class template) [edit]
(class template) [edit]
Customization point objects
Defined in namespace
std::ranges
(C++20)
(customization point object)[edit]
(C++20)
(customization point object)[edit]
Constants
(C++20)
unreachable_sentinel_t
that always compares unequal to any weakly_incrementable
type (constant) [edit]
(C++20)
default_sentinel_t
used with iterators that know the bound of their range (constant) [edit]
Functions
Adaptors
(C++14)
(function template) [edit]
(C++11)
(function template) [edit]
(C++23)
(function template) [edit]
(C++23)
(function template) [edit]
(function template) [edit]
(function template) [edit]
(function template) [edit]
Non-member operators
(C++11)(C++11)(removed in C++20)(C++11)(C++11)(C++11)(C++11)(C++20)
(function template) [edit]
(C++11)
(function template) [edit]
(C++11)
(function template) [edit]
(function template) [edit]
(function template) [edit]
(function template) [edit]
(C++20)
(function template) [edit]
(C++20)
(function template) [edit]
(C++20)
(function template) [edit]
(removed in C++20)
istream_iterator
s (function template) [edit]
(removed in C++20)
istreambuf_iterator
s (function template) [edit]
Operations
(function template) [edit]
(function template) [edit]
(C++11)
(function template) [edit]
(C++11)
(function template) [edit]
(C++20)
(algorithm function object)[edit]
(C++20)
(algorithm function object)[edit]
(C++20)
(algorithm function object)[edit]
(C++20)
(algorithm function object)[edit]
Range access
(C++11)(C++14)
(function template) [edit]
(C++11)(C++14)
(function template) [edit]
(C++14)
(function template) [edit]
(C++14)
(function template) [edit]
(C++17)(C++20)
(function template) [edit]
(C++17)
(function template) [edit]
(C++17)
(function template) [edit]
[edit] Synopsis
#include <compare> #include <concepts> namespace std { template<class T> using /* with-reference */ = T&; // exposition only template<class T> concept /* can-reference */ // exposition only = requires { typename /* with-reference */<T>; }; template<class T> concept /* dereferenceable */ // exposition only = requires(T& t) { { *t } -> /* can-reference */; // not required to be equality-preserving }; // associated types // incrementable traits template<class> struct incrementable_traits; template<class T> using iter_difference_t = /* see description */; // indirectly readable traits template<class> struct indirectly_readable_traits; template<class T> using iter_value_t = /* see description */; // iterator traits template<class I> struct iterator_traits; template<class T> requires is_object_v<T> struct iterator_traits<T*>; template</* dereferenceable */ T> using iter_reference_t = decltype(*declval<T&>()); namespace ranges { // customization point objects inline namespace /* unspecified */ { // ranges::iter_move inline constexpr /* unspecified */ iter_move = /* unspecified */; // ranges::iter_swap inline constexpr /* unspecified */ iter_swap = /* unspecified */; } } template</* dereferenceable */ T> requires requires(T& t) { { ranges::iter_move (t) } -> /* can-reference */; } using iter_rvalue_reference_t = decltype(ranges::iter_move (declval<T&>())); // iterator concepts // concept indirectly_readable template<class In> concept indirectly_readable = /* see description */; template<indirectly_readable T> using iter_common_reference_t = common_reference_t<iter_reference_t<T>, iter_value_t<T>&>; // concept indirectly_writable template<class Out, class T> concept indirectly_writable = /* see description */; // concept weakly_incrementable template<class I> concept weakly_incrementable = /* see description */; // concept incrementable template<class I> concept incrementable = /* see description */; // concept input_or_output_iterator template<class I> concept input_or_output_iterator = /* see description */; // concept sentinel_for template<class S, class I> concept sentinel_for = /* see description */; // concept sized_sentinel_for template<class S, class I> inline constexpr bool disable_sized_sentinel_for = false; template<class S, class I> concept sized_sentinel_for = /* see description */; // concept input_iterator template<class I> concept input_iterator = /* see description */; // concept output_iterator template<class I, class T> concept output_iterator = /* see description */; // concept forward_iterator template<class I> concept forward_iterator = /* see description */; // concept bidirectional_iterator template<class I> concept bidirectional_iterator = /* see description */; // concept random_access_iterator template<class I> concept random_access_iterator = /* see description */; // concept contiguous_iterator template<class I> concept contiguous_iterator = /* see description */; // indirect callable requirements // indirect callables template<class F, class I> concept indirectly_unary_invocable = /* see description */; template<class F, class I> concept indirectly_regular_unary_invocable = /* see description */; template<class F, class I> concept indirect_unary_predicate = /* see description */; template<class F, class I1, class I2> concept indirect_binary_predicate = /* see description */; template<class F, class I1, class I2 = I1> concept indirect_equivalence_relation = /* see description */; template<class F, class I1, class I2 = I1> concept indirect_strict_weak_order = /* see description */; template<class F, class... Is> requires (indirectly_readable<Is> && ...) && invocable<F, iter_reference_t<Is>...> using indirect_result_t = invoke_result_t<F, iter_reference_t<Is>...>; // projected template<indirectly_readable I, indirectly_regular_unary_invocable<I> Proj> using projected = /* see description */; template<indirectly_readable I, indirectly_regular_unary_invocable<I> Proj> using projected_value_t = remove_cvref_t<invoke_result_t<Proj&, iter_value_t<I>&>>; // common algorithm requirements // concept indirectly_movable template<class In, class Out> concept indirectly_movable = /* see description */; template<class In, class Out> concept indirectly_movable_storable = /* see description */; // concept indirectly_copyable template<class In, class Out> concept indirectly_copyable = /* see description */; template<class In, class Out> concept indirectly_copyable_storable = /* see description */; // concept indirectly_swappable template<class I1, class I2 = I1> concept indirectly_swappable = /* see description */; // concept indirectly_comparable template<class I1, class I2, class R, class P1 = identity, class P2 = identity> concept indirectly_comparable = /* see description */; // concept permutable template<class I> concept permutable = /* see description */; // concept mergeable template<class I1, class I2, class Out, class R = ranges::less, class P1 = identity, class P2 = identity> concept mergeable = /* see description */; // concept sortable template<class I, class R = ranges::less, class P = identity> concept sortable = /* see description */; // primitives // iterator tags struct input_iterator_tag { }; struct output_iterator_tag { }; struct forward_iterator_tag: public input_iterator_tag { }; struct bidirectional_iterator_tag: public forward_iterator_tag { }; struct random_access_iterator_tag: public bidirectional_iterator_tag { }; struct contiguous_iterator_tag: public random_access_iterator_tag { }; // iterator operations template<class InputIt, class Distance> constexpr void advance(InputIt& i, Distance n); template<class InputIt> constexpr typename iterator_traits<InputIt>::difference_type distance(InputIt first, InputIt last); template<class InputIt> constexpr InputIt next(InputIt x, typename iterator_traits<InputIt>::difference_type n = 1); template<class BidirIt> constexpr BidirIt prev(BidirIt x, typename iterator_traits<BidirIt>::difference_type n = 1); // range iterator operations namespace ranges { // ranges::advance template<input_or_output_iterator I> constexpr void advance(I& i, iter_difference_t<I> n); template<input_or_output_iterator I, sentinel_for<I> S> constexpr void advance(I& i, S bound); template<input_or_output_iterator I, sentinel_for<I> S> constexpr iter_difference_t<I> advance(I& i, iter_difference_t<I> n, S bound); // ranges::distance template<class I, sentinel_for<I> S> requires (!sized_sentinel_for<S, I>) constexpr iter_difference_t<I> distance(I first, S last); template<class I, sized_sentinel_for<decay_t<I>> S> constexpr iter_difference_t<decay_t<I>> distance(I&& first, S last); template<range R> constexpr range_difference_t<R> distance(R&& r); // ranges::next template<input_or_output_iterator I> constexpr I next(I x); template<input_or_output_iterator I> constexpr I next(I x, iter_difference_t<I> n); template<input_or_output_iterator I, sentinel_for<I> S> constexpr I next(I x, S bound); template<input_or_output_iterator I, sentinel_for<I> S> constexpr I next(I x, iter_difference_t<I> n, S bound); // ranges::prev template<bidirectional_iterator I> constexpr I prev(I x); template<bidirectional_iterator I> constexpr I prev(I x, iter_difference_t<I> n); template<bidirectional_iterator I> constexpr I prev(I x, iter_difference_t<I> n, I bound); } // predefined iterators and sentinels // reverse iterators template<class It> class reverse_iterator; template<class It1, class It2> constexpr bool operator==(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr bool operator!=(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr bool operator<(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr bool operator>(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr bool operator<=(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr bool operator>=(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, three_way_comparable_with<It1> It2> constexpr compare_three_way_result_t<It1, It2> operator<=>(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y); template<class It1, class It2> constexpr auto operator-(const reverse_iterator<It1>& x, const reverse_iterator<It2>& y) -> decltype(y.base() - x.base()); template<class It> constexpr reverse_iterator<It> operator+(iter_difference_t<It> n, const reverse_iterator<It>& x); template<class It> constexpr reverse_iterator<It> make_reverse_iterator(It i); template<class It1, class It2> requires (!sized_sentinel_for<It1, It2>) inline constexpr bool disable_sized_sentinel_for<reverse_iterator<It1>, reverse_iterator<It2>> = true; // insert iterators template<class Container> class back_insert_iterator; template<class Container> constexpr back_insert_iterator<Container> back_inserter(Container& x); template<class Container> class front_insert_iterator; template<class Container> constexpr front_insert_iterator<Container> front_inserter(Container& x); template<class Container> class insert_iterator; template<class Container> constexpr insert_iterator<Container> inserter(Container& x, ranges::iterator_t <Container> i); // move iterators and sentinels template<class It> class move_iterator; template<class It1, class It2> constexpr bool operator==(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, class It2> constexpr bool operator<(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, class It2> constexpr bool operator>(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, class It2> constexpr bool operator<=(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, class It2> constexpr bool operator>=(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, three_way_comparable_with<It1> It2> constexpr compare_three_way_result_t<It1, It2> operator<=>(const move_iterator<It1>& x, const move_iterator<It2>& y); template<class It1, class It2> constexpr auto operator-(const move_iterator<It1>& x, const move_iterator<It2>& y) -> decltype(x.base() - y.base()); template<class It> constexpr move_iterator<It> operator+(iter_difference_t<It> n, const move_iterator<It>& x); template<class It> constexpr move_iterator<It> make_move_iterator(It i); template<semiregular S> class move_sentinel; // common iterators template<input_or_output_iterator I, sentinel_for<I> S> requires (!same_as<I, S> && copyable<I>) class common_iterator; template<class I, class S> struct incrementable_traits<common_iterator<I, S>>; template<input_iterator I, class S> struct iterator_traits<common_iterator<I, S>>; // default sentinel struct default_sentinel_t; inline constexpr default_sentinel_t default_sentinel{}; // counted iterators template<input_or_output_iterator I> class counted_iterator; template<input_iterator I> requires /* see description */ struct iterator_traits<counted_iterator<I>>; // unreachable sentinel struct unreachable_sentinel_t; inline constexpr unreachable_sentinel_t unreachable_sentinel{}; // stream iterators template<class T, class CharT = char, class Traits = char_traits<CharT>, class Distance = ptrdiff_t> class istream_iterator; template<class T, class CharT, class Traits, class Distance> bool operator==(const istream_iterator<T, CharT, Traits, Distance>& x, const istream_iterator<T, CharT, Traits, Distance>& y); template<class T, class CharT = char, class traits = char_traits<CharT>> class ostream_iterator; template<class CharT, class Traits = char_traits<CharT>> class istreambuf_iterator; template<class CharT, class Traits> bool operator==(const istreambuf_iterator<CharT, Traits>& a, const istreambuf_iterator<CharT, Traits>& b); template<class CharT, class Traits = char_traits<CharT>> class ostreambuf_iterator; // range access template<class C> constexpr auto begin(C& c) -> decltype(c.begin()); template<class C> constexpr auto begin(const C& c) -> decltype(c.begin()); template<class C> constexpr auto end(C& c) -> decltype(c.end()); template<class C> constexpr auto end(const C& c) -> decltype(c.end()); template<class T, size_t N> constexpr T* begin(T (&a)[N]) noexcept; template<class T, size_t N> constexpr T* end(T (&a)[N]) noexcept; template<class C> constexpr auto cbegin(const C& c) noexcept(noexcept(std::begin (c))) -> decltype(std::begin (c)); template<class C> constexpr auto cend(const C& c) noexcept(noexcept(std::end (c))) -> decltype(std::end (c)); template<class C> constexpr auto rbegin(C& c) -> decltype(c.rbegin()); template<class C> constexpr auto rbegin(const C& c) -> decltype(c.rbegin()); template<class C> constexpr auto rend(C& c) -> decltype(c.rend()); template<class C> constexpr auto rend(const C& c) -> decltype(c.rend()); template<class T, size_t N> constexpr reverse_iterator<T*> rbegin(T (&a)[N]); template<class T, size_t N> constexpr reverse_iterator<T*> rend(T (&a)[N]); template<class E> constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il); template<class E> constexpr reverse_iterator<const E*> rend(initializer_list<E> il); template<class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin (c)); template<class C> constexpr auto crend(const C& c) -> decltype(std::rend (c)); template<class C> constexpr auto size(const C& c) -> decltype(c.size()); template<class T, size_t N> constexpr size_t size(const T (&a)[N]) noexcept; template<class C> constexpr auto ssize(const C& c) -> common_type_t<ptrdiff_t, make_signed_t<decltype(c.size())>>; template<class T, ptrdiff_t N> constexpr ptrdiff_t ssize(const T (&a)[N]) noexcept; template<class C> constexpr auto empty(const C& c) -> decltype(c.empty()); template<class T, size_t N> constexpr bool empty(const T (&a)[N]) noexcept; template<class E> constexpr bool empty(initializer_list<E> il) noexcept; template<class C> constexpr auto data(C& c) -> decltype(c.data()); template<class C> constexpr auto data(const C& c) -> decltype(c.data()); template<class T, size_t N> constexpr T* data(T (&a)[N]) noexcept; template<class E> constexpr const E* data(initializer_list<E> il) noexcept; }
[edit] Concept indirectly_readable
namespace std { template<class In> concept /*indirectlyReadableImpl*/ = // exposition only requires(const In in) { typename iter_value_t<In>; typename iter_reference_t<In>; typename iter_rvalue_reference_t<In>; { *in } -> same_as<iter_reference_t<In>> { iter_move(in) } -> same_as<iter_rvalue_reference_t<In>> } && common_reference_with<iter_reference_t<In>&&, iter_value_t<In>&> && common_reference_with<iter_reference_t<In>&&, iter_rvalue_reference_t<In>&&> && common_reference_with<iter_rvalue_reference_t<In>&&, const iter_value_t<In>&>; template<class In> concept indirectly_readable = /*indirectlyReadableImpl*/<remove_cvref_t<In>> }
[edit] Concept indirectly_writable
namespace std { template<class Out, class T> concept indirectly_writable = requires(Out&& o, T&& t) { *o = std::forward <T>(t); // not required to be equality-preserving *std::forward <Out>(o) = std::forward <T>(t); // not required to be equality-preserving const_cast<const iter_reference_t<Out>&&>(*o) = std::forward <T>(t); // not required to be equality-preserving const_cast<const iter_reference_t<Out>&&>(*std::forward <Out>(o)) = std::forward <T>(t); // not required to be equality-preserving }; }
[edit] Concept weakly_incrementable
namespace std { template<class T> inline constexpr bool /*is_integer_like*/ = /* see description */; // exposition only template<class T> inline constexpr bool /*is_signed_integer_like*/ = // exposition only /* see description */; template<class I> concept weakly_incrementable = default_initializable<I> && movable<I> && requires(I i) { typename iter_difference_t<I>; requires /*is_signed_integer_like*/<iter_difference_t<I>>; { ++i } -> same_as<I&>; // not required to be equality-preserving i++; // not required to be equality-preserving }; }
[edit] Concept incrementable
namespace std { template<class I> concept incrementable = regular<I> && weakly_incrementable<I> && requires(I i) { { i++ } -> same_as<I>; }; }
[edit] Concept input_or_output_iterator
namespace std { template<class I> concept input_or_output_iterator = requires(I i) { { *i } -> can-reference; } && weakly_incrementable<I>; }
[edit] Concept sentinel_for
namespace std { template<class S, class I> concept sentinel_for = semiregular<S> && input_or_output_iterator<I> && /*WeaklyEqualityComparableWith*/<S, I>; }
[edit] Concept sized_sentinel_for
namespace std { template<class S, class I> concept sized_sentinel_for = sentinel_for<S, I> && !disable_sized_sentinel<remove_cv_t<S>, remove_cv_t<I>> && requires(const I& i, const S& s) { { s - i } -> same_as<iter_difference_t<I>>; { i - s } -> same_as<iter_difference_t<I>>; }; }
[edit] Concept input_iterator
namespace std { template<class I> concept input_iterator = input_or_output_iterator<I> && indirectly_readable<I> && requires { typename /* ITER_CONCEPT */(I); } && derived_from</* ITER_CONCEPT */(I), input_iterator_tag>; }
[edit] Concept output_iterator
namespace std { template<class I, class T> concept output_iterator = input_or_output_iterator<I> && indirectly_writable<I, T> && requires(I i, T&& t) { *i++ = std::forward <T>(t); // not required to be equality-preserving }; }
[edit] Concept forward_iterator
namespace std { template<class I> concept forward_iterator = input_iterator<I> && derived_from</* ITER_CONCEPT */(I), forward_iterator_tag> && incrementable<I> && sentinel_for<I, I>; }
[edit] Concept bidirectional_iterator
namespace std { template<class I> concept bidirectional_iterator = forward_iterator<I> && derived_from</* ITER_CONCEPT */(I), bidirectional_iterator_tag> && requires(I i) { { --i } -> same_as<I&>; { i-- } -> same_as<I>; }; }
[edit] Concept random_access_iterator
namespace std { template<class I> concept random_access_iterator = bidirectional_iterator<I> && derived_from</* ITER_CONCEPT */(I), random_access_iterator_tag> && totally_ordered<I> && sized_sentinel_for<I, I> && requires(I i, const I j, const iter_difference_t<I> n) { { i += n } -> same_as<I&>; { j + n } -> same_as<I>; { n + j } -> same_as<I>; { i -= n } -> same_as<I&>; { j - n } -> same_as<I>; { j[n] } -> same_as<iter_reference_t<I>>; }; }
[edit] Concept contiguous_iterator
namespace std { template<class I> concept contiguous_iterator = random_access_iterator<I> && derived_from</* ITER_CONCEPT */(I), contiguous_iterator_tag> && is_lvalue_reference_v<iter_reference_t<I>> && same_as<iter_value_t<I>, remove_cvref_t<iter_reference_t<I>>> && requires(const I& i) { { to_address(i) } -> same_as<add_pointer_t<iter_reference_t<I>>>; }; }
[edit] Concept indirectly_unary_invocable
namespace std { template<class F, class I> concept indirectly_unary_invocable = indirectly_readable<I> && copy_constructible<F> && invocable<F&, iter_value_t<I>&> && invocable<F&, iter_reference_t<I>> && common_reference_with< invoke_result_t<F&, iter_value_t<I>&>, invoke_result_t<F&, iter_reference_t<I>>>; }
[edit] Concept indirectly_regular_unary_invocable
namespace std { template<class F, class I> concept indirectly_regular_unary_invocable = indirectly_readable<I> && copy_constructible<F> && regular_invocable<F&, iter_value_t<I>&> && regular_invocable<F&, iter_reference_t<I>> && common_reference_with< invoke_result_t<F&, iter_value_t<I>&>, invoke_result_t<F&, iter_reference_t<I>>>; }
[edit] Concept indirect_unary_predicate
namespace std { template<class F, class I> concept indirect_unary_predicate = indirectly_readable<I> && copy_constructible<F> && predicate<F&, iter_value_t<I>&> && predicate<F&, iter_reference_t<I>>; }
[edit] Concept indirect_binary_predicate
namespace std { template<class F, class I1, class I2 = I1> concept indirect_binary_predicate = indirectly_readable<I1> && indirectly_readable<I2> && copy_constructible<F> && predicate<F&, iter_value_t<I1>&, iter_value_t<I2>&> && predicate<F&, iter_value_t<I1>&, iter_reference_t<I2>> && predicate<F&, iter_reference_t<I1>, iter_value_t<I2>&> && predicate<F&, iter_reference_t<I1>, iter_reference_t<I2>>; }
[edit] Concept indirect_equivalence_relation
namespace std { template<class F, class I1, class I2 = I1> concept indirect_equivalence_relation = indirectly_readable<I1> && indirectly_readable<I2> && copy_constructible<F> && equivalence_relation<F&, iter_value_t<I1>&, iter_value_t<I2>&> && equivalence_relation<F&, iter_value_t<I1>&, iter_reference_t<I2>> && equivalence_relation<F&, iter_reference_t<I1>, iter_value_t<I2>&> && equivalence_relation<F&, iter_reference_t<I1>, iter_reference_t<I2>>; }
[edit] Concept indirect_strict_weak_order
namespace std { template<class F, class I1, class I2 = I1> concept indirect_strict_weak_order = indirectly_readable<I1> && indirectly_readable<I2> && copy_constructible<F> && strict_weak_order<F&, iter_value_t<I1>&, iter_value_t<I2>&> && strict_weak_order<F&, iter_value_t<I1>&, iter_reference_t<I2>> && strict_weak_order<F&, iter_reference_t<I1>, iter_value_t<I2>&> && strict_weak_order<F&, iter_reference_t<I1>, iter_reference_t<I2>>; }
[edit] Concept indirectly_movable
namespace std { template<class In, class Out> concept indirectly_movable = indirectly_readable<In> && indirectly_writable<Out, iter_rvalue_reference_t<In>>; }
[edit] Concept indirectly_movable_storable
namespace std { template<class In, class Out> concept indirectly_movable_storable = indirectly_movable<In, Out> && indirectly_writable<Out, iter_value_t<In>> && movable<iter_value_t<In>> && constructible_from<iter_value_t<In>, iter_rvalue_reference_t<In>> && assignable_from<iter_value_t<In>&, iter_rvalue_reference_t<In>>; }
[edit] Concept indirectly_copyable
namespace std { template<class In, class Out> concept indirectly_copyable = indirectly_readable<In> && indirectly_writable<Out, iter_reference_t<In>>; }
[edit] Concept indirectly_copyable_storable
namespace std { template<class In, class Out> concept indirectly_copyable_storable = indirectly_copyable<In, Out> && indirectly_writable<Out, iter_value_t<In>&> && indirectly_writable<Out, const iter_value_t<In>&> && indirectly_writable<Out, iter_value_t<In>&&> && indirectly_writable<Out, const iter_value_t<In>&&> && copyable<iter_value_t<In>> && constructible_from<iter_value_t<In>, iter_reference_t<In>> && assignable_from<iter_value_t<In>&, iter_reference_t<In>>; }
[edit] Concept indirectly_swappable
namespace std { template<class I1, class I2 = I1> concept indirectly_swappable = indirectly_readable<I1> && indirectly_readable<I2> && requires(const I1 i1, const I2 i2) { ranges::iter_swap (i1, i1); ranges::iter_swap (i2, i2); ranges::iter_swap (i1, i2); ranges::iter_swap (i2, i1); }; }
[edit] Concept indirectly_comparable
[edit] Concept permutable
namespace std { template<class I> concept permutable = forward_iterator<I> && indirectly_movable_storable<I, I> && indirectly_swappable<I, I>; }
[edit] Concept mergeable
namespace std { template<class I1, class I2, class Out, class R = ranges::less, class P1 = identity, class P2 = identity> concept mergeable = input_iterator<I1> && input_iterator<I2> && weakly_incrementable<Out> && indirectly_copyable<I1, Out> && indirectly_copyable<I2, Out> && indirect_strict_weak_order<R, projected <I1, P1>, projected <I2, P2>>; }
[edit] Concept sortable
namespace std { template<class I, class R = ranges::less, class P = identity> concept sortable = permutable<I> && indirect_strict_weak_order<R, projected <I, P>>; }
[edit] Class template std::incrementable_traits
namespace std { template<class> struct incrementable_traits { }; template<class T> requires is_object_v<T> struct incrementable_traits<T*> { using difference_type = ptrdiff_t; }; template<class I> struct incrementable_traits<const I> : incrementable_traits<I> { }; template<class T> requires requires { typename T::difference_type; } struct incrementable_traits<T> { using difference_type = typename T::difference_type; }; template<class T> requires (!requires { typename T::difference_type; } && requires(const T& a, const T& b) { { a - b } -> integral; }) struct incrementable_traits<T> { using difference_type = make_signed_t<decltype(declval<T>() - declval<T>())>; }; template<class T> using iter_difference_t = /* see description */; }
[edit] Class template std::indirectly_readable_traits
namespace std { template<class> struct /*cond_value_type*/ { }; // exposition only template<class T> requires is_object_v<T> struct /*cond_value_type*/ { using value_type = remove_cv_t<T>; }; template<class> struct indirectly_readable_traits { }; template<class T> struct indirectly_readable_traits<T*> : /*cond_value_type*/<T> { }; template<class I> requires is_array_v<I> struct indirectly_readable_traits<I> { using value_type = remove_cv_t<remove_extent_t<I>>; }; template<class I> struct indirectly_readable_traits<const I> : indirectly_readable_traits<I> { }; template<class T> requires requires { typename T::value_type; } struct indirectly_readable_traits<T> : /*cond_value_type*/<typename T::value_type> { }; template<class T> requires requires { typename T::element_type; } struct indirectly_readable_traits<T> : /*cond_value_type*/<typename T::element_type> { }; }
[edit] Class template std::projected
namespace std { template<class I, class Proj> struct /*projected-impl*/ { // exposition only struct /*type*/ { // exposition only using value_type = remove_cvref_t<indirect_result_t<Proj&, I>>; using difference_type = iter_difference_t<I>; // present only if I // models weakly_incrementable indirect_result_t<Proj&, I> operator*() const; // not defined }; }; template<indirectly_readable I, indirectly_regular_unary_invocable<I> Proj> using projected = /*projected-impl*/<I, Proj>::/*type*/; }
[edit] Class template std::iterator_traits
namespace std { template<class I> struct iterator_traits { using iterator_category = /* see description */; using value_type = /* see description */; using difference_type = /* see description */; using pointer = /* see description */; using reference = /* see description */; }; template<class T> requires is_object_v<T> struct iterator_traits<T*> { using iterator_concept = contiguous_iterator_tag; using iterator_category = random_access_iterator_tag; using value_type = remove_cv_t<T>; using difference_type = ptrdiff_t; using pointer = T*; using reference = T&; }; }
[edit]
namespace std { struct input_iterator_tag { }; struct output_iterator_tag { }; struct forward_iterator_tag: public input_iterator_tag { }; struct bidirectional_iterator_tag: public forward_iterator_tag { }; struct random_access_iterator_tag: public bidirectional_iterator_tag { }; struct contiguous_iterator_tag: public random_access_iterator_tag { }; }
[edit] Class template std::reverse_iterator
namespace std { template<class Iter> class reverse_iterator { public: using iterator_type = Iter; using iterator_concept = /* see description */; using iterator_category = /* see description */; using value_type = iter_value_t<Iter>; using difference_type = iter_difference_t<Iter>; using pointer = typename iterator_traits<Iter>::pointer; using reference = iter_reference_t<Iter>; constexpr reverse_iterator(); constexpr explicit reverse_iterator(Iter x); template<class U> constexpr reverse_iterator(const reverse_iterator<U>& u); template<class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u); constexpr Iter base() const; constexpr reference operator*() const; constexpr pointer operator->() const requires /* see description */; constexpr reverse_iterator& operator++(); constexpr reverse_iterator operator++(int); constexpr reverse_iterator& operator--(); constexpr reverse_iterator operator--(int); constexpr reverse_iterator operator+ (difference_type n) const; constexpr reverse_iterator& operator+=(difference_type n); constexpr reverse_iterator operator- (difference_type n) const; constexpr reverse_iterator& operator-=(difference_type n); constexpr /* unspecified */ operator[](difference_type n) const; friend constexpr iter_rvalue_reference_t<Iter> iter_move(const reverse_iterator& i) noexcept(/* see description */); template<indirectly_swappable<Iter> Iter2> friend constexpr void iter_swap(const reverse_iterator& x, const reverse_iterator<Iter2>& y) noexcept(/* see description */); protected: Iter current; }; }
[edit] Class template std::back_insert_iterator
namespace std { template<class Container> class back_insert_iterator { protected: Container* container = nullptr; public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using container_type = Container; constexpr back_insert_iterator() noexcept = default; constexpr explicit back_insert_iterator(Container& x); constexpr back_insert_iterator& operator=(const typename Container::value_type& value); constexpr back_insert_iterator& operator=(typename Container::value_type&& value); constexpr back_insert_iterator& operator*(); constexpr back_insert_iterator& operator++(); constexpr back_insert_iterator operator++(int); }; }
[edit] Class template std::front_insert_iterator
namespace std { template<class Container> class front_insert_iterator { protected: Container* container = nullptr; public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using container_type = Container; constexpr front_insert_iterator(Container& x) noexcept = default; constexpr explicit front_insert_iterator(Container& x); constexpr front_insert_iterator& operator=(const typename Container::value_type& value); constexpr front_insert_iterator& operator=(typename Container::value_type&& value); constexpr front_insert_iterator& operator*(); constexpr front_insert_iterator& operator++(); constexpr front_insert_iterator operator++(int); }; }
[edit] Class template std::insert_iterator
namespace std { template<class Container> class insert_iterator { protected: Container* container = nullptr; ranges::iterator_t <Container> iter = ranges::iterator_t <Container>(); public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using container_type = Container; insert_iterator() = default; constexpr insert_iterator(Container& x, ranges::iterator_t <Container> i); constexpr insert_iterator& operator=(const typename Container::value_type& value); constexpr insert_iterator& operator=(typename Container::value_type&& value); constexpr insert_iterator& operator*(); constexpr insert_iterator& operator++(); constexpr insert_iterator& operator++(int); }; }
[edit] Class template std::move_iterator
namespace std { template<class Iter> class move_iterator { public: using iterator_type = Iter; using iterator_concept = /* see description */; using iterator_category = /* see description */; using value_type = iter_value_t<Iter>; using difference_type = iter_difference_t<Iter>; using pointer = Iter; using reference = iter_rvalue_reference_t<Iter>; constexpr move_iterator(); constexpr explicit move_iterator(Iter i); template<class U> constexpr move_iterator(const move_iterator<U>& u); template<class U> constexpr move_iterator& operator=(const move_iterator<U>& u); constexpr iterator_type base() const &; constexpr iterator_type base() &&; constexpr reference operator*() const; constexpr pointer operator->() const; constexpr move_iterator& operator++(); constexpr auto operator++(int); constexpr move_iterator& operator--(); constexpr move_iterator operator--(int); constexpr move_iterator operator+(difference_type n) const; constexpr move_iterator& operator+=(difference_type n); constexpr move_iterator operator-(difference_type n) const; constexpr move_iterator& operator-=(difference_type n); constexpr reference operator[](difference_type n) const; template<sentinel_for<Iter> S> friend constexpr bool operator==(const move_iterator& x, const move_sentinel<S>& y); template<sized_sentinel_for<Iter> S> friend constexpr iter_difference_t<Iter> operator-(const move_sentinel<S>& x, const move_iterator& y); template<sized_sentinel_for<Iter> S> friend constexpr iter_difference_t<Iter> operator-(const move_iterator& x, const move_sentinel<S>& y); friend constexpr iter_rvalue_reference_t<Iter> iter_move(const move_iterator& i) noexcept(noexcept(ranges::iter_move (i.current))); template<indirectly_swappable<Iter> Iter2> friend constexpr void iter_swap(const move_iterator& x, const move_iterator<Iter2>& y) noexcept(noexcept(ranges::iter_swap (x.current, y.current))); private: Iter current; // exposition only }; }
[edit] Class template std::move_sentinel
namespace std { template<semiregular S> class move_sentinel { public: constexpr move_sentinel(); constexpr explicit move_sentinel(S s); template<class S2> requires convertible_to<const S2&, S> constexpr move_sentinel(const move_sentinel<S2>& s); template<class S2> requires assignable_from<S&, const S2&> constexpr move_sentinel& operator=(const move_sentinel<S2>& s); constexpr S base() const; private: S last; // exposition only }; }
[edit] Class template std::common_iterator
namespace std { template<input_or_output_iterator I, sentinel_for<I> S> requires (!same_as<I, S> && copyable<I>) class common_iterator { public: constexpr common_iterator() = default; constexpr common_iterator(I i); constexpr common_iterator(S s); template<class I2, class S2> requires convertible_to<const I2&, I> && convertible_to<const S2&, S> constexpr common_iterator(const common_iterator<I2, S2>& x); template<class I2, class S2> requires convertible_to<const I2&, I> && convertible_to<const S2&, S> && assignable_from<I&, const I2&> && assignable_from<S&, const S2&> common_iterator& operator=(const common_iterator<I2, S2>& x); decltype(auto) operator*(); decltype(auto) operator*() const requires dereferenceable<const I>; decltype(auto) operator->() const requires /* see description */; common_iterator& operator++(); decltype(auto) operator++(int); template<class I2, sentinel_for<I> S2> requires sentinel_for<S, I2> friend bool operator==( const common_iterator& x, const common_iterator<I2, S2>& y); template<class I2, sentinel_for<I> S2> requires sentinel_for<S, I2> && equality_comparable_with<I, I2> friend bool operator==( const common_iterator& x, const common_iterator<I2, S2>& y); template<sized_sentinel_for<I> I2, sized_sentinel_for<I> S2> requires sized_sentinel_for<S, I2> friend iter_difference_t<I2> operator-( const common_iterator& x, const common_iterator<I2, S2>& y); friend constexpr decltype(auto) iter_move(const common_iterator& i) noexcept(noexcept(ranges::iter_move (declval<const I&>()))) requires input_iterator<I>; template<indirectly_swappable<I> I2, class S2> friend void iter_swap(const common_iterator& x, const common_iterator<I2, S2>& y) noexcept(noexcept(ranges::iter_swap (declval<const I&>(), declval<const I2&>()))); private: variant<I, S> v_; // exposition only }; template<class I, class S> struct incrementable_traits<common_iterator<I, S>> { using difference_type = iter_difference_t<I>; }; template<input_iterator I, class S> struct iterator_traits<common_iterator<I, S>> { using iterator_concept = /* see description */; using iterator_category = /* see description */; using value_type = iter_value_t<I>; using difference_type = iter_difference_t<I>; using pointer = /* see description */; using reference = iter_reference_t<I>; }; }
[edit] Class std::default_sentinel_t
namespace std { struct default_sentinel_t { }; }
[edit] Class template std::counted_iterator
namespace std { template<input_or_output_iterator I> class counted_iterator { public: using iterator_type = I; constexpr counted_iterator() = default; constexpr counted_iterator(I x, iter_difference_t<I> n); template<class I2> requires convertible_to<const I2&, I> constexpr counted_iterator(const counted_iterator<I2>& x); template<class I2> requires assignable_from<I&, const I2&> constexpr counted_iterator& operator=(const counted_iterator<I2>& x); constexpr I base() const & requires copy_constructible<I>; constexpr I base() &&; constexpr iter_difference_t<I> count() const noexcept; constexpr decltype(auto) operator*(); constexpr decltype(auto) operator*() const requires dereferenceable<const I>; constexpr auto operator->() const noexcept requires contiguous_iterator<I>; constexpr counted_iterator& operator++(); decltype(auto) operator++(int); constexpr counted_iterator operator++(int) requires forward_iterator<I>; constexpr counted_iterator& operator--() requires bidirectional_iterator<I>; constexpr counted_iterator operator--(int) requires bidirectional_iterator<I>; constexpr counted_iterator operator+(iter_difference_t<I> n) const requires random_access_iterator<I>; friend constexpr counted_iterator operator+( iter_difference_t<I> n, const counted_iterator& x) requires random_access_iterator<I>; constexpr counted_iterator& operator+=(iter_difference_t<I> n) requires random_access_iterator<I>; constexpr counted_iterator operator-(iter_difference_t<I> n) const requires random_access_iterator<I>; template<common_with<I> I2> friend constexpr iter_difference_t<I2> operator-( const counted_iterator& x, const counted_iterator<I2>& y); friend constexpr iter_difference_t<I> operator-( const counted_iterator& x, default_sentinel_t); friend constexpr iter_difference_t<I> operator-( default_sentinel_t, const counted_iterator& y); constexpr counted_iterator& operator-=(iter_difference_t<I> n) requires random_access_iterator<I>; constexpr decltype(auto) operator[](iter_difference_t<I> n) const requires random_access_iterator<I>; template<common_with<I> I2> friend constexpr bool operator==( const counted_iterator& x, const counted_iterator<I2>& y); friend constexpr bool operator==( const counted_iterator& x, default_sentinel_t); template<common_with<I> I2> friend constexpr strong_ordering operator<=>( const counted_iterator& x, const counted_iterator<I2>& y); friend constexpr decltype(auto) iter_move(const counted_iterator& i) noexcept(noexcept(ranges::iter_move (i.current))) requires input_iterator<I>; template<indirectly_swappable<I> I2> friend constexpr void iter_swap(const counted_iterator& x, const counted_iterator<I2>& y) noexcept(noexcept(ranges::iter_swap (x.current, y.current))); private: I current = I(); // exposition only iter_difference_t<I> length = 0; // exposition only }; template<input_iterator I> struct iterator_traits<counted_iterator<I>> : iterator_traits<I> { using pointer = void; }; }
[edit] Class std::unreachable_sentinel_t
namespace std { struct unreachable_sentinel_t { template<weakly_incrementable I> friend constexpr bool operator==(unreachable_sentinel_t, const I&) noexcept { return false; } }; }
[edit] Class template std::istream_iterator
namespace std { template<class T, class CharT = char, class Traits = char_traits<CharT>, class Distance = ptrdiff_t> class istream_iterator { public: using iterator_category = input_iterator_tag; using value_type = T; using difference_type = Distance; using pointer = const T*; using reference = const T&; using char_type = CharT; using traits_type = Traits; using istream_type = basic_istream<CharT, Traits>; constexpr istream_iterator(); constexpr istream_iterator(default_sentinel_t); istream_iterator(istream_type& s); istream_iterator(const istream_iterator& x) = default; ~istream_iterator() = default; istream_iterator& operator=(const istream_iterator&) = default; const T& operator*() const; const T* operator->() const; istream_iterator& operator++(); istream_iterator operator++(int); friend bool operator==(const istream_iterator& i, default_sentinel_t); private: basic_istream<CharT, Traits>* in_stream; // exposition only T value; // exposition only }; }
[edit] Class template std::ostream_iterator
namespace std { template<class T, class CharT = char, classTraits = char_traits<CharT>> class ostream_iterator { public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using char_type = CharT; using traits_type = Traits; using ostream_type = basic_ostream<CharT, Traits>; constexpr ostreambuf_iterator() noexcept = default; ostream_iterator(ostream_type& s); ostream_iterator(ostream_type& s, const CharT* delimiter); ostream_iterator(const ostream_iterator& x); ~ostream_iterator(); ostream_iterator& operator=(const ostream_iterator&) = default; ostream_iterator& operator=(const T& value); ostream_iterator& operator*(); ostream_iterator& operator++(); ostream_iterator& operator++(int); private: basic_ostream<CharT, Traits>* out_stream = nullptr; // exposition only const CharT* delim = nullptr; // exposition only }; }
[edit] Class template std::istreambuf_iterator
namespace std { template<class CharT, class Traits = char_traits<CharT>> class istreambuf_iterator { public: using iterator_category = input_iterator_tag; using value_type = CharT; using difference_type = typename Traits::off_type; using pointer = /* unspecified */; using reference = CharT; using char_type = CharT; using traits_type = Traits; using int_type = typename Traits::int_type; using streambuf_type = basic_streambuf<CharT, Traits>; using istream_type = basic_istream<CharT, Traits>; class proxy; // exposition only constexpr istreambuf_iterator() noexcept; constexpr istreambuf_iterator(default_sentinel_t) noexcept; istreambuf_iterator(const istreambuf_iterator&) noexcept = default; ~istreambuf_iterator() = default; istreambuf_iterator(istream_type& s) noexcept; istreambuf_iterator(streambuf_type* s) noexcept; istreambuf_iterator(const proxy& p) noexcept; istreambuf_iterator& operator=(const istreambuf_iterator&) noexcept = default; CharT operator*() const; istreambuf_iterator& operator++(); proxy operator++(int); bool equal(const istreambuf_iterator& b) const; friend bool operator==(const istreambuf_iterator& i, default_sentinel_t s); private: streambuf_type* sbuf_; // exposition only }; template<class CharT, class Traits> class istreambuf_iterator<CharT, Traits>::proxy { // exposition only CharT keep_; basic_streambuf<CharT, Traits>* sbuf_; proxy(CharT c, basic_streambuf<CharT, Traits>* sbuf) : keep_(c), sbuf_(sbuf) { } public: CharT operator*() { return keep_; } }; }
[edit] Class template std::ostreambuf_iterator
namespace std { template<class CharT, class Traits = char_traits<CharT>> class ostreambuf_iterator { public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = ptrdiff_t; using pointer = void; using reference = void; using char_type = CharT; using traits_type = Traits; using streambuf_type = basic_streambuf<CharT, Traits>; using ostream_type = basic_ostream<CharT, Traits>; constexpr ostreambuf_iterator() noexcept = default; ostreambuf_iterator(ostream_type& s) noexcept; ostreambuf_iterator(streambuf_type* s) noexcept; ostreambuf_iterator& operator=(CharT c); ostreambuf_iterator& operator*(); ostreambuf_iterator& operator++(); ostreambuf_iterator& operator++(int); bool failed() const noexcept; private: streambuf_type* sbuf_ = nullptr; // exposition only }; }
[edit] Class template std::iterator
namespace std { template<class Category, class T, class Distance = ptrdiff_t, class Pointer = T*, class Reference = T&> struct iterator { typedef Category iterator_category; typedef T value_type; typedef Distance difference_type; typedef Pointer pointer; typedef Reference reference; }; }
[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 349 | C++98 | the exposition-only member delim ofstd::ostream_iterator had type const char* |
corrected to const CharT* |