std::prev - cppreference.com

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Definido no cabeçalho `<iterator>`

`template< class BidirIt > BidirIt prev( BidirIt it, typename std::iterator_traits<BidirIt>::difference_type n = 1 );`		(desde C++11)

Retorne o antecessor nth de it iterador.

Original:

Return the nth predecessor of iterator it.

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Parâmetros

it	-	um iterador Original: an iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
n	-	número de `it` elementos devem ser descendentes Original: number of elements `it` should be descended The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Type requirements
-`BidirIt` must meet the requirements of `BidirectionalIterator`.

Valor de retorno

O antecessor de nth it iterador.

Original:

The nth predecessor of iterator it.

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Possível implementação

template<class BidirIt>
BidirIt prev(BidirIt it, typename std::iterator_traits<BidirIt>::difference_type n = 1)
{
    std::advance(it, -n);
    return it;
}

Exemplo

#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';
}

Saída:

Veja também


	incrementar um iterador Original: increment an iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função) [edit]

	avanços de um iterador por determinada distância Original: advances an iterator by given distance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função) [edit]