remove_copy_if (STL Samples)
Veranschaulicht, wie die Funktion remove_copy_if Standardvorlagenbibliothek (STL) in Visual C++ verwendet.
template<class ForwardIterator, class OutputIterator, class Predicate>
inline OutputIterator remove_copy_if(
ForwardIterator First,
ForwardIterator Last,
OutputIterator Result,
Predicate Pred
)
Hinweise
.gif "Hinweis") Hinweis |
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Die Klasse/Parameternamen im Prototyp stimmen nicht mit der Version in der Headerdatei ab.Einige wurden geändert, um die Lesbarkeit zu verbessern. |
Der Algorithmus remove_copy_if kopiert alle Elemente aus dem Bereich (First, Last) auf den Bereich, der im Ergebnisbeginnt und überspringt jedes Element, das das Prädikat wird, truezurückzugeben.Er gibt einen Iterator zurück, der unmittelbar hinter dem letzten neuen Element positioniert wird.
Beispiel
// 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 ;
}
Output
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 }
Anforderungen
Header: <Algorithmus>