Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

 
remove_copy_if
 
 - Moves desired elements to the front of a container, and returns an iterator that describes where the sequence of desired elements ends.
 
 
 

SYNOPSIS

 
 
#include <algorithm>
template <class InputIterator,

class OutputIterator,
class Predicate>

OutputIterator remove_copy_if (InputIterator first,

InputIterator last,
OutputIterator result,
Predicate pred);
 
 
 

DESCRIPTION

 
 
The remove_copy_if algorithm copies all the elements referred to by the iterator i in the range [first, last) for which the following condition does not hold: pred(∗i)  == true. remove_copy_if returns an iterator that points to the end of the resulting range. remove_copy_if is stable, which means that the relative order of the elements in the resulting range is the same as their relative order in the original range. 
 
 
 

COMPLEXITY

 
 
Exactly last1 - first1 applications of the corresponding predicate are done. 
 
 
 

EXAMPLE

//
// remove.cpp
//

#include <algorithm>
#include <vector>
#include <iterator>
#include <iostream>

using namespace std;
 
template<class Arg>
struct all_true : public unary_function<Arg, bool>

{

bool operator() (const Arg&) { return 1; }

};

 
int main ()

{

int arr[10] = {1,2,3,4,5,6,7,8,9,10};
vector<int> v(arr+0, arr+10);

copy(v.begin(),v.end(),

ostream_iterator<int,char>(cout," "));

cout << endl << endl;

//
// Remove the 7.
//

vector<int>::iterator result = remove(v.begin(),

v.end(), 7);

//
// Delete dangling elements from the vector.
//

v.erase(result, v.end());

copy(v.begin(),v.end(),

ostream_iterator<int,char>(cout," "));

cout << endl << endl;

//
// Remove everything beyond the fourth element.
//

result = remove_if(v.begin()+4, v.begin()+8,

all_true<int>());

//
// Delete dangling elements.
//

v.erase(result, v.end());

copy(v.begin(),v.end(),

ostream_iterator<int,char>(cout," "));

cout << endl << endl;

//
// Now remove all 3s on output.
//

remove_copy(v.begin(), v.end(), <br>               ostream_iterator<int>(cout," "), 3);
cout << endl << endl;

//
// Now remove everything satisfying predicate on output.
// Should yield a NULL vector.
//
remove_copy_if(v.begin(), v.end(), <br>                  ostream_iterator<int,char>(cout," "),

all_true<int>());

return 0;

}
 

Program Output
 
 
 

 
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 8 9 10
1 2 3 4
1 2 4
 
 
 

WARNINGS

 
 
If your compiler does not support default template parameters, then you always need to supply the Allocator template argument. For instance, you need to write:
 
vector<int, allocator<int> >
 
instead of:
 
vector<int>
 
If your compiler does not support namespaces, then you do not need the using declaration for std. 
 
 
 

SEE ALSO

 
 
remove, remove_if, remove_copy
 

Rogue Wave Software  —  Last change: 02 Apr 1998