remove_copy_if


function template
<algorithm>
template <class InputIterator, class OutputIterator, class Predicate>
  OutputIterator remove_copy_if ( InputIterator first, InputIterator last,
                                  OutputIterator result, Predicate pred );

Copy range removing values

Copies the values of the elements in the range [first,last) to the range positions beginning at result, except those for which pred is true, which are not copied.

The behavior of this function template is equivalent to:
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template <class InputIterator, class OutputIterator, class Predicate>
  OutputIterator remove_copy_if ( InputIterator first, InputIterator last,
                                  OutputIterator result, Predicate pred )
{
  for ( ; first != last; ++first)
    if (!pred(*first)) *result++ = *first;
  return result;
}


Parameters

first, last
Forward iterators to the initial and final positions in a sequence. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
result
Output iterator to the initial position of the range where the resulting range of values is stored.
pred
Unary predicate taking an element in the range as argument, and returning a value indicating the falsehood (with false, or a zero value) or truth (true, or non-zero) of some condition applied to it. This can either be a pointer to a function or an object whose class overloads operator().


Return value

An output iterator pointing to the end of the copied range, which includes all the elements in [first,last) except for those for which pred was true.

Example

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// remove_copy_if example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

bool IsOdd (int i) { return ((i%2)==1); }

int main () {
  int myints[] = {1,2,3,4,5,6,7,8,9};          
  vector<int> myvector (9);
  vector<int>::iterator it;

  remove_copy_if (myints,myints+9,myvector.begin(),IsOdd);

  cout << "myvector contains:";
  for (it=myvector.begin(); it!=myvector.end(); ++it)
    cout << " " << *it;

  cout << endl;
 
  return 0;
}


Output:
myvector contains: 2 4 6 8 0 0 0 0 0


Complexity

Applies pred as many times as the number of elements in the range [first,last), and at most, that same amount of assignment operations.

See also

remove Remove value from range (function template)
remove_copy Copy range removing value (function template)
replace_copy_if Copy range replacing value (function template)
count Count appearances of value in range (function template)
copy Copy range of elements (function template)