View source for cpp/iterator/reverse iterator/operator+

{{title|1=operator+{{petty|(std::reverse_iterator)}}}}
{{cpp/iterator/reverse_iterator/navbar}}
{{dcl begin}}
{{dcl header|iterator}}
{{dcl rev begin}}
{{dcla|constexpr=c++17|until=c++23|
template< class Iter > 
reverse_iterator<Iter> operator+
    ( typename reverse_iterator<Iter>::difference_type n,
      const reverse_iterator<Iter>& it );
}}
{{dcl|since=c++23|
template< class Iter > 
constexpr reverse_iterator<Iter> operator+
    ( std::iter_difference_t<Iter> n, const reverse_iterator<Iter>& it );
}}
{{dcl end}}

Returns the iterator {{c|it}} incremented by {{c|n}}. In fact, the underlying iterator is decremented by {{c|n}}.

===Parameters===
{{par begin}}
{{par|n|the number of positions to increment the iterator}}
{{par|it|the iterator adaptor to increment}}
{{par end}}

===Return value===
{{c|reverse_iterator<Iter>(it.base() - n)}}

===Example===
{{example
|code=
#include <iostream>
#include <iterator>
#include <list>
#include <vector>

int main()
{
    {
        std::vector v{0, 1, 2, 3};
        std::reverse_iterator<std::vector<int>::iterator>
            ri1{std::reverse_iterator{v.rbegin()}<!---->};
        std::cout << *ri1 << ' '; // 3
        std::reverse_iterator<std::vector<int>::iterator> ri2{2 + ri1};
        std::cout << *ri2 << ' '; // 1
    }
    
    {
        std::list l{5, 6, 7, 8};
        std::reverse_iterator<std::list<int>::iterator>
            ri1{std::reverse_iterator{l.rbegin()}<!---->};
        std::cout << *ri1 << '\n'; // 8
    //  auto ri2{2 + ri1}; // Error: the underlying iterator does not
                           //        model random access iterator
    }
}
|output=
3 1 8
}}

===See also===
{{dsc begin}}
{{dsc inc|cpp/iterator/adaptor/dsc operator arith|reverse_iterator}}
{{dsc inc|cpp/iterator/adaptor/dsc operator-|reverse_iterator}}
{{dsc end}}

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