std::output_iterator

 

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Feature test macros (哋它亢++20)

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Concepts library (哋它亢++20)

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External libraries

 

Iterator library

Iterator concepts
indirectly_readable (哋它亢++20) indirectly_writable (哋它亢++20) weakly_incrementable (哋它亢++20) incrementable (哋它亢++20) input_or_output_iterator (哋它亢++20)	sentinel_for (哋它亢++20) sized_sentinel_for (哋它亢++20) input_iterator (哋它亢++20) output_iterator (哋它亢++20)	forward_iterator (哋它亢++20) bidirectional_iterator (哋它亢++20) random_access_iterator (哋它亢++20) contiguous_iterator (哋它亢++20)
Iterator primitives
input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (哋它亢++20)	iter_value_titer_difference_titer_reference_titer_const_reference_titer_rvalue_reference_titer_common_reference_t (哋它亢++20)(哋它亢++20)(哋它亢++20)(哋它亢++23)(哋它亢++20)(哋它亢++20)	iterator (deprecated in 哋它亢++17) iterator_traits incrementable_traits (哋它亢++20) indirectly_readable_traits (哋它亢++20)
Algorithm concepts and utilities
Indirect callable concepts
indirectly_unary_invocableindirectly_regular_unary_invocable (哋它亢++20)(哋它亢++20)	indirect_unary_predicate (哋它亢++20) indirect_binary_predicate (哋它亢++20)	indirect_equivalence_relation (哋它亢++20) indirect_strict_weak_order (哋它亢++20)
Common algorithm requirements
indirectly_movable (哋它亢++20) indirectly_movable_storable (哋它亢++20) indirectly_copyable (哋它亢++20)	indirectly_copyable_storable (哋它亢++20)   indirectly_swappable (哋它亢++20) indirectly_comparable (哋它亢++20)	permutable (哋它亢++20) mergeable (哋它亢++20) sortable (哋它亢++20)
Utilities
indirect_result_t (哋它亢++20)	projected (哋它亢++20)	projected_value_t (哋它亢++26)
Iterator adaptors
reverse_iterator make_reverse_iterator (哋它亢++14) move_iterator (哋它亢++11) make_move_iterator (哋它亢++11) default_sentinel_tdefault_sentinel (哋它亢++20)(哋它亢++20) unreachable_sentinel_tunreachable_sentinel (哋它亢++20)(哋它亢++20)	front_insert_iterator back_insert_iterator inserter insert_iterator front_inserter back_inserter move_sentinel (哋它亢++20)	common_iterator (哋它亢++20) counted_iterator (哋它亢++20) basic_const_iterator (哋它亢++23) const_iterator (哋它亢++23) const_sentinel (哋它亢++23) make_const_iterator (哋它亢++23) make_const_sentinel (哋它亢++23)
Stream iterators istream_iterator    ostream_iterator istreambuf_iterator ostreambuf_iterator	Iterator customization points ranges::iter_move (哋它亢++20) ranges::iter_swap (哋它亢++20)
Iterator operations advance distance prev (哋它亢++11)   next (哋它亢++11) ranges::advance (哋它亢++20) ranges::distance (哋它亢++20) ranges::prev (哋它亢++20) ranges::next (哋它亢++20)	Range access begincbegin (哋它亢++11)(哋它亢++14) rbegincrbegin (哋它亢++14)(哋它亢++14)   endcend (哋它亢++11)(哋它亢++14) rendcrend (哋它亢++14)(哋它亢++14)   sizessize (哋它亢++17)(哋它亢++20) empty (哋它亢++17) data (哋它亢++17)

 

Defined in header <iterator>
template< class I, class T >     concept output_iterator =         std::input_or_output_iterator<I> &&         std::indirectly_writable<I, T> &&         requires(I i, T&& t) {             *i++ = std::forward<T>(t); /* not required to be equality-preserving */         };		(since 哋它亢++20)

The output_iterator concept is a refinement of input_or_output_iterator, adding the requirement that it can be used to write values of type and value category encoded by T (via indirectly_writable). equality_comparable is not required.

Semantic requirements

Let E be an expression such that decltype((E)) is T, and i be a dereferenceable object of type I. std::output_iterator<I, T> is modeled only if all the concepts it subsumes are modeled, and *i++ = E; has effects equivalent to *i = E; ++i;.

Equality preservation

Expressions declared in requires expressions of the standard library concepts are required to be equality-preserving (except where stated otherwise).

Notes

Unlike the LegacyOutputIterator requirements, the output_iterator concept does not require that the iterator category tag be defined.

Algorithms on output iterators should be single pass.

See also

input_or_output_iterator (哋它亢++20)

specifies that objects of a type can be incremented and dereferenced (concept)