remove_copy_if (STL Samples)
Illustre comment utiliser la fonction de bibliothèque de types (STL) Standard de remove_copy_if dans Visual C++.
template<class ForwardIterator, class OutputIterator, class Predicate>
inline OutputIterator remove_copy_if(
ForwardIterator First,
ForwardIterator Last,
OutputIterator Result,
Predicate Pred
)
Notes
[!REMARQUE]
Les noms de classes/paramètre dans le prototype ne correspondent pas à la version du fichier d'en-tête.certains ont été modifiés pour améliorer la lisibilité.
L'algorithme d' remove_copy_if copie tous les éléments de la plage (First, Last) à la plage démarrant au résultat, ignore tout élément qui fait pour retourner l'attribut true.Elle retourne un itérateur positionné immédiatement après le dernier nouvel élément.
Exemple
// 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 ;
}
Sortie
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 }
Configuration requise
en-tête : <algorithm>