remove_copy_if (STL Samples)

Ilustra como usar o remove_copy_if função de biblioteca STL (Standard Template) no Visual C++.

template<class ForwardIterator, class OutputIterator, class Predicate>
   inline OutputIterator remove_copy_if(
      ForwardIterator First,
      ForwardIterator Last,
      OutputIterator Result,
      Predicate Pred
   )

Comentários

Observação
Nomes de classe/parâmetro o protótipo não coincidem com a versão no arquivo de cabeçalho.Alguns foram modificados para melhorar a legibilidade.

O remove_copy_if algoritmo copia todos os elementos do intervalo (First, Last) para o intervalo começando em resultado, ignorando qualquer elemento que faz com que o predicado retornar true.Ele retorna um iterador posicionado imediatamente após o último elemento novo.

Exemplo

// remove_copy_if.cpp
// compile with: /EHsc
// Illustrates how to use the remove_copy_if function.
//
// Functions:
//   remove_copy_if - copy the elements of a sequence to another sequence
//                    eliminating any elements that satisfy a predicate.
//   bind2nd - Returns true for elements for which the condition is true
//   begin - Returns an iterator that points to the first element in a
//           sequence
//   end - Returns an iterator that points one past the end of a sequence
//////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 characters,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>

using namespace std;


int main()
{
    const int MAX_ELEMENTS = 8 ;

    // Define a template class vector of integers
    typedef vector<int > IntVector ;

    //Define an iterator for template class vector of integer
    typedef IntVector::iterator IntVectorIt ;

    //vector containing numbers
    IntVector Numbers(MAX_ELEMENTS), Result(MAX_ELEMENTS) ;

    IntVectorIt start, end, it, last, resultIt ;

    //Initialize vector Numbers
    Numbers[0] = 10 ;
    Numbers[1] = 20 ;
    Numbers[2] = 10 ;
    Numbers[3] = 15 ;
    Numbers[4] = 12 ;
    Numbers[5] = 25 ;
    Numbers[6] = 30 ;
    Numbers[7] = 10 ;

    start = Numbers.begin() ;   // location of first
                                // element of Numbers

    end = Numbers.end() ;       // one past the location
                                // last element of Numbers

    resultIt = Result.begin() ; // location of first
                                // element of Result

    // print content of Numbers
    cout << "Numbers { " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << " }\n" << endl ;

    // copy all elements from Numbers to Result
    // skipping any item that >= 25
    last = remove_copy_if(start, end, resultIt,
                          bind2nd(greater_equal<int>(), 25)) ;

    //print number of elements copied to Result
    cout << "Total number of elements copied to Result = "
        << last - resultIt << endl ;

    start = Result.begin() ;   // location of first
                                // element of Result

    end = Result.end() ;       // one past the location
                               // last element of Result

    // print content of Result
    cout << "Result { " ;
    for(it = start; it != end; it++)
        cout << *it << " " ;
    cout << " }\n" << endl ;
}

Saída

Numbers { 10 20 10 15 12 25 30 10  }

Total number of elements copied to Result = 6
Result { 10 20 10 15 12 10 0 0  }

Requisitos

Cabeçalho: <algorithm>

Consulte também

Conceitos

Exemplos de biblioteca de modelo padrão