std::next

 

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

 

Defined in header <iterator>
template<class InputIt > InputIt next( InputIt it, typenamestd::iterator_traits<InputIt>::difference_type n =1);		(since C++11) (until C++17)
template<class InputIt > constexpr InputIt next( InputIt it, typenamestd::iterator_traits<InputIt>::difference_type n =1);		(since C++17)

Return the n^th successor (or -n^th predecessor if n is negative) of iterator it.

Parameters

it	-	an iterator
n	-	number of elements to advance
Type requirements
- InputIt must meet the requirements of LegacyInputIterator.

Return value

An iterator of type InputIt that holds the n^th successor (or -n^th predecessor if n is negative) of iterator it.

Complexity

Linear.

However, if InputIt additionally meets the requirements of LegacyRandomAccessIterator, complexity is constant.

Possible implementation

template<class InputIt>constexpr// since C++17 InputIt next(InputIt it, typenamestd::iterator_traits<InputIt>::difference_type n =1){std::advance(it, n);return it;}

Notes

Although the expression ++c.begin() often compiles, it is not guaranteed to do so: c.begin() is an rvalue expression, and there is no LegacyInputIterator requirement that specifies that increment of an rvalue is guaranteed to work. In particular, when iterators are implemented as pointers or its operator++ is lvalue-ref-qualified, ++c.begin() does not compile, while std::next(c.begin()) does.

Example

Run this code

#include <iostream>#include <iterator>#include <vector>   int main(){std::vector<int> v{4, 5, 6};   auto it = v.begin();auto nx = std::next(it, 2);std::cout<<*it <<' '<<*nx <<'\n';   it = v.end(); nx = std::next(it, -2);std::cout<<' '<<*nx <<'\n';}

Output:

4 6 5

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 2353	C++11	next required LegacyForwardIterator	LegacyInputIterator allowed

See also

prev (C++11)	decrement an iterator (function template)
advance	advances an iterator by given distance (function template)
distance	returns the distance between two iterators (function template)
ranges::next (C++20)	increment an iterator by a given distance or to a bound (algorithm function object)