remove_copy_if(3C++) - remove_copy_if(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMEremove_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 sta‐
ble, which means that the relative order of the elements in the result‐
ing 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_itera‐
tor<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_itera‐
tor<int,char>(cout," "),
all_true<int>());
return 0;
}
Program Output1 2 3 4 5 6 7 8 9 101 2 3 4 5 6 8 9 101 2 3 41 2 4WARNINGS
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 02 Apr 1998 remove_copy_if(3C++)
