std::prev

 

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Iterator library

Iterator primitives
iterator_traits
input_iterator_tag output_iterator_tag forward_iterator_tag bidirectional_iterator_tag random_access_iterator_tag
iterator
Iterator adaptors
reverse_iterator
move_iterator (C++11) back_insert_iterator front_insert_iterator insert_iterator	make_move_iterator (C++11) back_inserter front_inserter inserter
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istream_iterator
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distance
prev (C++11)
next (C++11)
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begin (C++11)
end (C++11)

 

Defined in header <iterator>
template< class BidirectionalIterator > BidirectionalIterator prev(BidirectionalIterator it,                            typename std::iterator_traits<BidirectionalIterator>::difference_type n = 1);		(since C++11)

Return the nth predecessor of iterator it.

Equivalent to std::advance(it, -n); return it;, that is, advances a copy of the iterator it in the reverse direction.

Parameters

it	-	bidirectional iterator
n	-	number of elements it should be descended

Return value

The nth predecessor of iterator it.

Example

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

Output:

1

See also

next (C++11)	increment an iterator (function)
advance	advances an iterator by given distance (function)