std::prev - cppreference.com
Espaços nominais
Variantes
    Ações

      std::prev

      De cppreference.com

      <metanoindex/>

       
      C++
       
      Biblioteca Iterator
      Primitivas iterador
      Original:
      Iterator primitives
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Adaptadores de iterador
      Original:
      Iterator adaptors
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Iteradores fluxo
      Original:
      Stream iterators
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      Operações iterador
      Original:
      Iterator operations
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
      Variar de acesso
      Original:
      Range access
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.
      (C++11)
      (C++11)
       
      <tbody> </tbody>
      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.
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.

      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.
      The text has been machine-translated via Google Translate.
      You can help to correct and verify the translation. Click here for instructions.

      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: 

      1

      Veja também