< cpp‎ | iterator
Defined in header <iterator>
template< class ForwardIt >

ForwardIt next(
  ForwardIt it,

  typename std::iterator_traits<ForwardIt>::difference_type n = 1 );
(since C++11)
(until C++17)
template< class InputIt >

constexpr InputIt next(
  InputIt it,

  typename std::iterator_traits<InputIt>::difference_type n = 1 );
(since C++17)

Return the nth successor of iterator it.


[edit] Parameters

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

[edit] Return value

The nth successor of iterator it.

[edit] Complexity


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

[edit] Possible implementation

template<class ForwardIt>
ForwardIt next(ForwardIt it,
               typename std::iterator_traits<ForwardIt>::difference_type n = 1)
    std::advance(it, n);
    return it;

[edit] 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 LegacyBidirectionalIterator requirement that specifies that increment of an rvalue is guaranteed to work. In particular, when iterators are implemented as pointers, ++c.begin() does not compile, while std::next(c.begin()) does.

[edit] Example

#include <iostream>
#include <iterator>
#include <vector>
int main() 
    std::vector<int> v{ 3, 1, 4 };
    auto it = v.begin();
    auto nx = std::next(it, 2);
    std::cout << *it << ' ' << *nx << '\n';


3 4

[edit] See also

decrement an iterator
(function template) [edit]
advances an iterator by given distance
(function template) [edit]