std::next

Header: <iterator>

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

# Declarations

template< class InputIt >
InputIt next( InputIt it, typename std::iterator_traits<InputIt>::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)

# Parameters

• it: an iterator
• n: number of elements to advance

# Return value

An iterator of type InputIt that holds the nth successor (or -nth predecessor if n is negative) of iterator 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

#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';
}

# Defect reports

# See also

• prev
• advance
• distance
• ranges::next