| 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 >
InputIt next( InputIt it,
typename std::iterator_traits<InputIt>::difference_type n = 1 ); | (since C++17) |
Return the nth successor of iterator it.
Parameters
| it | - | an iterator |
| n | - | number of elements to advance |
| Type requirements | ||
- ForwardIt must meet the requirements of ForwardIterator. | ||
- InputIt must meet the requirements of InputIterator. | ||
Return value
The nth successor of iterator it.
Possible implementation
template<class ForwardIt>
ForwardIt next(ForwardIt it, typename std::iterator_traits<ForwardIt>::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 BidirectionalIterator 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.
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';
}Output:
3 4
See also
| (C++11) | decrement an iterator (function) |
| advances an iterator by given distance (function) |
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